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In vertebrates, estrogen receptors are essential for estrogen-associated early gonadal sex development. Our previous studies revealed sexual dimorphic expression of estrogen receptor β2 (ERβ2) during embryogenesis of medaka, and here we investigated the functional importance of ERβ2 in female gonad development and maintenance using a transgenerational ERβ2-knockdown (ERβ2-KD) line and ERβ2-null mutants. We found that ERβ2 reduction favored male-biased gene transcription, suppressed female-responsive gene expression, and affected SDF1a and CXCR4b co-assisted chemotactic primordial germ cell (PGC) migration. Co-overexpression of SDF1a and CXXR4b restored the ERβ2-KD/KO associated PGC mismigration. Further analysis confirmed that curtailment of ERβ2 increased intracellular Ca²⁺ concentration, disrupted intra- and extracellular calcium homeostasis, and instigated autophagic germ cell degradation and germ cell loss, which in some cases ultimately affected the XX female sexual development. This study is expected improve our understanding of germ cell maintenance and sex spectrum, and hence open new avenues for reproductive disorder management. In this article, Chakraborty et al. find that estrogen receptor β2 (ERβ2) plays multifaceted crucial roles in medaka gonadal development and sexuality. ERβ2 predominantly expresses in germ cells, influences the SDF1/CXCR4 chemotaxis, PGC migration, and death, and regulates germ cell proliferation and various sex-biased gene transcriptions that are essential for gonadal sex assignment and maintenance.

DOI： 10.1016/j.stemcr.2019.07.013

Language：English   Publishing type：Research paper (scientific journal)  

Environmental stressors, gonadal degenerative diseases and tumour development can significantly alter the oocyte physiology, and species fertility and fitness. To expand the molecular understanding about oocyte degradation, we isolated several spliced variants of Japanese anchovy hatching enzymes (AcHEs; ovastacin homologue) 1 and 2, and analysed their potential in oocyte sustenance. Particularly, AcHE1b, an ovary-specific, steroid-regulated, methylation-dependent, stress-responsive isoform, was neofunctionalized to regulate autophagic oocyte degeneration. AcHE1a and 2 triggered apoptotic degeneration in vitellogenic and mature oocytes, respectively. Progesterone, starvation, and high temperature elevated the total degenerating oocyte population and AcHE1b transcription by hyper-demethylation. Overexpression, knockdown and intracellular zinc ion chelation study confirmed the functional significance of AcHE1b in autophagy induction, possibly to mitigate the stress effects in fish, via ion-homeostasis. Our finding chronicles the importance of AcHEs in stress-influenced apoptosis/autophagy cell fate decision and may prove significant in reproductive failure assessments, gonadal health maintenance and ovarian degenerative disease therapy.

DOI： 10.1038/s41598-017-03314-7

Language：English   Publishing type：Research paper (scientific journal)  

Despite identification of several sex-determining genes in non-mammalian vertebrates, their detailed molecular cascades of sex determination/differentiation are not known. Here, we used a novel RNAi to characterise the molecular mechanism of Dmy (the sex-determining gene of medaka)-mediated masculinity in XY fish. Dmy knockdown (Dmy-KD) suppressed male pathway (Gsdf, Sox9a2, etc.) and favoured female cascade (Rspo1, etc.) in embryonic XY gonads, resulting in a fertile male-to-female sex-reversal. Gsdf, Sox9a2, and Rspo1 directly interacted with Dmy, and co-injection of Gsdf and Sox9a2 re-established masculinity in XY-Dmy-KD transgenics, insinuating that Dmy initiates masculinity by stimulating and suppressing Gsdf/Sox9a2 and Rspo1 expression, respectively. Gonadal expression of Wt1a starts prior to Dmy and didn't change upon Dmy-KD. Furthermore, Wt1a stimulated the promoter activity of Dmy, suggesting Wt1a as a regulator of Dmy. These findings provide new insights into the role of vertebrate sex-determining genes associated with the molecular interplay between the male and female pathways.

DOI： 10.1038/srep19480

Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Environmental Pollution  

Benzalkonium chloride (BAC), a commonly used quaternary ammonium compound in various products like antiseptics, cosmetics, and disinfectants, has raised concerns due to its potential to contaminate aquatic environments and subsequently affect the reproductive performance of the organisms within those ecosystems. The article underscores a critical concern regarding the impact of BAC on aquatic ecosystems, particularly its effect on fish reproductive quality, using medaka (Oryzias latipes) as a model organism. Firstly, while measuring lethal dose of BAC in adult medaka, we observed a dose dependent mortality in BAC treated fish (100 and 200 ppm: 100%; 60 ppm: 51.7%; 30 ppm or less: no mortality at 24 h post treatment (hpt)) and calculated the LD50 at 96 hpt as 39.291 ppm (95% confidence interval: 28.817-53.570 ppm). Further, we assessed the molecular, cellular and histological changes through long-term exposure. Enlarged sperm pockets and reduced spermatocyte were seen in BAC exposed testis while no significant structural changes were observed in the ovaries. Following BAC exposure, drastic alterations in the gene expression and cellular localization related to sex, estrogen signaling, and autophagy were also noted from gonads and liver. Subsequently, using a short-term exposure analysis, we confirmed the sex and time responsive transcriptional kinetics and found that BAC sequentially affected the gonadal somatic cells followed by germ cell differentiation. Finally, using reproductively competent male and female medaka, we conducted progeny production and performance analysis and depicted a drastic reduction in fecundity, and fertilization and hatching rate, indicating adverse effects of BAC on reproductive success. Cumulatively, these findings emphasize the consequences of widespread use of BAC on reproductive security of aquatic animals and highlights the need for further research to comprehend the potential harm posed by such compounds to aquatic animal health and ecosystem integrity.

DOI： 10.1016/j.envpol.2024.124778

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Language：English   Publisher：Comparative Biochemistry and Physiology Part - B: Biochemistry and Molecular Biology  

Steroidogenic acute regulatory protein (Star) plays an essential role in the biosynthesis of corticosteroids and sex steroids by mediating the transport of cholesterol from the outer to the inner membrane of mitochondria. Two duplicated Star genes, namely star1 and star2, have been identified in non-mammalian vertebrates. To investigate the roles of star genes in fish steriodogenesis, we generated two mutation lines of star1−/− and star1−/−/star2−/− in Nile tilapia (Oreochromis niloticus). Previous studies revealed that deficiency of star2 gene caused delayed spermatogenesis, sperm apoptosis and sterility in male tilapia. Our present data revealed that mutation of star genes impaired male fertility. Disordered seminiferous lobules and spermatic duct obstruction were found in the testis of both types of mutants. Moreover, significant decline in semen volume, sperm abnormality and impaired fertility were also detected in star1−/− and star1−/−/star2−/− males. In star1−/− male fish, lipid accumulation, up-regulation of steroidogenic enzymes, and significant decline of androgens were found. Additionally, hyperplasic interrenal cells, elevated steroidogenic gene expression level and decline of serum glucocorticoids were detected in star1 mutants. Intriguingly, either 11-KT or cortisol supplementation successfully rescued the impaired fertility of the star1−/− mutants. Taken together, these results further indicate that Star1 might play critical roles in the production of both 11-KT and glucocorticoids, which are indispensable for the maintenance of male fertility in fish.

DOI： 10.1016/j.cbpb.2024.110985

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Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Frontiers Media SA  

Sexual development and reproduction are largely linked to epigenetic changes in many fish species. However, understanding of epigenetic regulation in scombrid species, such as tunas and mackerels, is limited. This study investigates DNA methylation’s impact on cyp19a expression, crucial for estrogen synthesis, focusing on chub mackerel. Given the commercial significance of scombrids and susceptibility of marine fish to environmental changes, elucidating epigenetic mechanisms, particularly in the context of global warming, becomes imperative. We aimed to generalize observations from chub mackerel to other scombrids. Additionally, we studied DNA methylation patterns across fish with different sexual systems to understand aromatase regulation’s phenotypic plasticity. Our in silico analysis revealed highly conserved promoter sequences within scombrids, sharing TFBS like Foxl2, FOS::JUN, ESRR, and Sox3, while CpG content varies. This indicates a conserved regulatory network controlling gene expression. We found sexual dimorphism in DNA methylation, with males hypermethylated and aromatase expression downregulated. Despite similar dnmt1 expression, tet1, tet2, and tet3 were higher expressed in females, suggesting that the observed DNA methylation patterns are maintained through active demethylation rather than differential methylation. Gonochoristic Japanese anchovy and protogynous bamboo leaf wrasse displayed similar trends, but species-specific methylation patterns highlight DNA methylation’s complex role in gonadal changes. In vitro assays confirmed methylation’s regulatory role and identified an SF-1 binding site relevant for promoter activation in chub mackerel. Another studied SF-1 site, present in both chub mackerel and bamboo leaf wrasse, showed regulatory effects, indicating potential similar regulatory mechanisms for cyp19a expression. Overall, our findings suggest that while global methylation affects cyp19a transcription, the variation in CpG density and location could be introducing nuances in its epigenetic regulation. This study contributes to our understanding of the cyp19a regulation in fish gonad maturation.

DOI： 10.3389/fmars.2024.1408561

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

Primordial germ cells (PGCs) are pivotal for gonadal development and reproductive success. Though artificial induction of sterility by targeting PGCs are gaining popularity due to its advantages in fish surrogacy and biodiversity management, it is often skill and time intensive. In this study, we have focused on understanding the role of PGCs and the chemotactic SDF-1/CXCR4 signaling on gonad development of Japanese anchovy (JA, Engraulis japonicus), an upcoming marine model organism with eco-commercial values, with an aim to develop a novel, easy, and versatile gonad sterilization method. Our data showed that PGC migration related genes, i.e., sdf-1a, sdf-1b, cxcr4a, cxcr4b and vasa, are phylogenetically closer relatives of respective herring (Clupea harengus) and zebrafish (Danio rerio) homolog. Subsequently, PGC marking and live tracing experiments confirmed that PGC migration in JA initiates from 16 hours post fertilization (hpf) followed by PGC settlement in the gonadal ridge at 44 hpf. We found that overexpression of zebrafish sdf-1a mRNA in the germ cell suppresses cxcr4a and increases cxcr4b transcription at 8 hpf, dose dependently disrupts PGC migration at 24–48 hpf, induces PGC death and upregulates sdf-1b at 5 days post hatching. 48 h of immersion treatment with CXCR4 antagonist (AMD3100, Abcam) also accelerated PGC mismigration and pushed the PGC away from gonadal ridge in a dose responsive manner, and further when grown to adulthood caused germ cell less gonad formation in some individuals. Cumulatively, our data, for the first time, suggests that JA PGC migration is largely regulated by SDF1/CXCR4 signaling, and modulation of this signaling has strong potential for sterile, germ cell less gonad preparation at a mass scale. However, further in-depth analysis is pertinent to apply this methodology in marine fish species to successfully catapult Japanese anchovy into a true marine fish model.

DOI： 10.1016/j.ygcen.2024.114476

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Frontiers in Marine Science  

The gonadal sexual fate of vertebrates is either defined by genetics or environment, or a combination of both factors. Interestingly, in sequential hermaphroditism, the animal can undergo natural sex changes from female-to-male, male-to-female, and bidirectional way throughout their lives. This change exhibits the process which shifts between oogenesis and spermatogenesis and is regarded as an ideal instance of sexual plasticity. To develop the experimental model for studying the sexual plasticity of protogynous fish, the social conditions that induce sex changes were defined in wrasse, Pseudolabrus sieboldi. When six females were kept together in a tank, the largest female became a male, whereas a similar conversion did not occur when only two females were present in a tank. A semi-gonadectomy analysis developed in the present study verified the direct relationship between gonadal sex and body coloration. In P. sieboldi, the sex change is controlled by the relative body size of an individual within a group, rather than by absolute body size. When six females were kept in smaller sized tanks, delayed sex change or unchanged individuals was observed. Overall, more than 90% of the largest females demonstrated sex change after being housed with five smaller females in different sizes of tanks ranging from 80 to 500 L. Furthermore, the experiment using a transparent barrier suggested that visual stimuli are one of the major cues to initiate sex change. Our findings on the laboratory conditions leading to the initiation of sex change in wrasse suggest the usefulness of this species as a model organism for comparative studies in molecular, cellular, and physiological mechanisms of sexual plasticity, as well as on social and reproductive behaviors.

DOI： 10.3389/fmars.2022.1048506

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：International Journal of Molecular Sciences  

Germ cells are pivotal for gonadal sexuality maintenance and reproduction. Sex lethal (sxl), the somatic sex determining gene of Drosophila, is the known regulator and initiator of germ cell femininity in invertebrates. However, the role of the Sxl homologue has rarely been investigated in vertebrates. So, we used medaka to clarify the role of sxl in vertebrate gonadogenesis and sexuality and identified two Sxl homologues, i.e., Sxl1a and Sxl1b. We found that sxl1a specifically expresses in the primordial germ cells (PGC), ovary, (early gonia and oocytes), while sxl1b distributions are ubiquitous. An mRNA overexpression of sxl1a accelerated germ cell numbers in 10 DAH XY fish, and sxl1a knockdown (KD), on the other hand, induced PGC mis-migration, aberrant PGC structuring and ultimately caused significant germ cell reduction in XX fish. Using an in vitro promoter analysis and in vivo steroid treatment, we found a strong link between sxl1a and estrogenic germ cell-population maintenance. Further, using sxl1a-KD and erβ2-knockout fish, we determined that sxl1 acts through erβ2 and controls PGC sexuality. Cumulatively, our study highlights the novel role of sxl1a in germ cell maintenance and sexual identity assignment and thus might become a steppingstone to understanding the commonalities of animal sexual development.

DOI： 10.3390/ijms232415496

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Language：English   Publisher：Frontiers in Endocrinology  

Background: Steroid hormones play an essential role in many reproductive processes of vertebrates. Previous studies revealed that teleost-specific Cyp17a2 (cytochrome P450 family 17 subfamily a 2) might be required for the production of cortisol in the head-kidney and 17α,20β-dihydroxy-4-pregnen-3-one (DHP) in ovary during oocyte maturation. However, the role of Cyp17a2 in male reproduction remains to be largely unknown. The aim of this study was to explore the essentiality of cyp17a2 gene in male steroidogenesis, spermatogenesis, and male fertility. Methods: A homozygous mutation line of cyp17a2 gene was constructed in tilapia by CRISPR/Cas9 gene editing technology. The expression level of germ cell and meiosis-related genes and steroidogenic enzymes were detected by qRT-PCR, IHC, and Western blotting. EIA and LC-MS/MS assays were used to measure the steroid production levels. And sperm quality was examined by Sperm Quality Analyzer software. Results: In this study, cyp17a2 gene mutation resulted in the significant decline of serum DHP and cortisol levels. On the contrary, significant increases in intermediate products of cortisol and DHP were found in cyp17a2-/- male fish. The deficiency of cyp17a2 led to the arrest of meiotic initiation in male fish revealing as the reduction of the expression of germ cell-related genes (vasa, piwil, oct4) and meiosis-related genes (spo11 and sycp3) by 90 dah. Afterwards, spermatogenesis was gradually recovered with the development of testis in cyp17a2-/- males, but it showed a lower sperm motility and reduced fertility compared to cyp17a2+/+ XY fish. Deletion of cyp17a2 led to the abnormal upregulation of steroidogenic enzymes for cortisol production in the head-kidney. Moreover, unaltered serum androgens and estrogens, as well as unchanged related steroidogenic enzymes were found in the testis of cyp17a2-/- male fish. Conclusion: This study proved that, for the fist time, Cyp17a2 is indispensable for cortisol and DHP production, and cyp17a2 deficiency associated curtailed meiotic initiation and subfertility suggesting the essentiality of DHP and cortisol in the male fertility of fish.

DOI： 10.3389/fendo.2022.1074921

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Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Frontiers Media SA  

Fisheries and aquaculture are the fastest-growing food-producing sector and rapidly becoming an important element for the global food security since they are the primary source of seafood and high animal protein in the human diet. Genome editing offers new possibilities such as the clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein (Cas9) technology, which has the potential to accelerate the sustainable genetic improvement in fisheries and aquaculture. The CRISPR/Cas9 system has four key components, namely, target DNA, Cas9, the protospacer adjacent motif sequence, and the guide RNA or single-guide RNA. CRISPR/Cas is cheaper, easier, and more precise than the other genome editing technologies and can be used as a new breeding technology in fisheries and aquaculture to solve the far-reaching challenges. The attributes like high fecundity, external fertilization, short generation interval, the established method of breeding, and the larval rearing of most aquaculture species have advantages for CRISPR/Cas9 genome editing applications. CRISPR/Cas9 has recently been applied to the traits valued in some aquaculture species (almost >20 species), targeting the main traits of traditional genetic improvement initiatives like growth, disease resistance, reproduction, sterility, and pigmentation. Genome editing can fast forward the breeding process with precision where changes occur in the targeted genes. The probability of desired changes occurring and passing the trait in the next generation is high, so it takes 1-3 generations to establish a breed. Moreover, CRISPR/Cas genome editing rapidly introduces favorable changes by disrupting genes with targeted minor changes, in contrast to transgenesis, which introduces foreign genes into the host genome and thereby alleviates major public concerns on safety. Although the CRISPR/Cas technology has a tremendous potential, there are several technical challenges and regulatory and public issues concerning the applications in fisheries and the aquaculture breeding sector. Nonetheless, the exciting point in the CRISPR/Cas9 genome editing is that two CRISPR-edited fish, namely, red sea bream and tiger puffer developed by the Kyoto-based startup got approval and are now on the market for sale, and another fish, FLT-01 Nile tilapia developed by the AquaBounty, is not classified under genetically modified organism regulatory. However, there is still a way to go before it revolutionizes and becomes viable in commercial aquaculture as the new breeding technology for aquaculture-important traits and species.

DOI： 10.3389/fmars.2022.924475

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.1016/j.jsbmb.2021.105974

Language：English   Publishing type：Research paper (scientific journal)  

Mifepristone (RU486), a clinical abortion agent and potential endocrine disruptor, binds to progestin and glucocorticoid receptors and has multiple functional importance in reproductive physiology. A long-term exposure of RU486 resulted in masculinization of female fish, however, the epigenetic landscape remains elusive. Recent studies demonstrated that long non-coding RNAs (lncRNAs) might play potential roles in epigenetic modulation of sex differentiation, ovarian cancer and germline stem cell survival. To further understand the influence of RU486 exposure on epigenetic regulation, we performed a comparative investigation on sex-biased gonadal lncRNAs profiles using control XX/XY and RU486-induced sex reversed XX Nile tilapia (Oreochromis niloticus) by RNA-seq. In total, 962 sexually differentially expressed lncRNAs and their target genes were screened from the gonads of control and sex reversed fish. In comparison with the control XX group, sex reversal induced by RU486 treatment led to significant up-regulation of 757 lncRNAs and down-regulation of 221 lncRNAs. Hierarchical clustering analysis revealed that global lncRNA expression profiles in RU486-treated XX group clustered into the same branch with the control XY, whereas XX control group formed a separate branch. The KEGG pathway enrichment analysis showed that the cis-target genes between RU486-XX and control-XX were concentrated in NOD − like receptor signaling pathway, Cell adhesion molecules (CAMs) and Biosynthesis of amino acids. Real-time PCR and in situ hybridization experiments demonstrate that lncRNAs showing intense fluctuation during RU486 treatment are also sexually dimorphic during early sex differentiation, which further proves the intimate relationship between lncRNAs and sex differentiation and sexual transdifferentiation. Taken together, our data strongly indicates that a long-term exposure of RU486 resulted in sex reversal of XX female fish and the altered expression of sexually dimorphic lncRNAs might partially account for the sex reversal via epigenetic modification.

DOI： 10.1016/j.aquatox.2019.105289

Language：English   Publishing type：Research paper (scientific journal)  

The complement system plays an important role in immune regulation and acts as the first line of defense against any pathogenic attack. To comprehend the red sea bream (Pagrus major) immune response, three complement genes, namely, pmC1r, pmMASP and pmC3, belonging to the classical, lectin and alternative complement cascade, respectively, were identified and characterized. pmC1r, pmMASP, and pmC3 were comprised of 2535, 3352, and 5735 base mRNA which encodes 732, 1029 and 1677 aa putative proteins, respectively. Phylogenetically, all the three studied genes clustered with their corresponding homologous clade. Tissue distribution and cellular localization data demonstrated a very high prevalence of all the three genes in the liver. Both bacterial and viral infection resulted in significant transcriptional alterations in all three genes in the liver with respect to their vehicle control counterparts. Specifically, bacterial challenge affected the pmMASP and pmC3 expression, while the viral infection resulted in pmC1r and pmC3 mRNA activation. Altogether, our data demonstrate the ability of pmC1r, pmMASP and pmC3 in bringing about an immune response against any pathogenic encroachment, and thus activating, not only one, but all the three complement pathways, in red sea bream.

DOI： 10.1016/j.fsi.2018.08.027

Language：English   Publishing type：Research paper (scientific journal)  

17α, 20β-dihydroxypregn-4-en-3-one (17α, 20β-DP, DHP), a teleost specific biologically active progestin, has been proved to play a critical role in oocytes maturation, ovulation and spermiation. RU486 (Mifepristone, an antagonist of progestin receptor) has been applied in contraceptives, abortion and hormone therapy in clinical medicine. To get further insights into the molecular mechanisms of nuclear progestin receptor (Pgr) activated ovarian differentiation and maintenance, we conducted comparative gonadal transcriptome analysis, and investigated histological and transcriptional differences using 4 months after hatching (mah) RU486-treated XX and control XX/XY Nile tilapia (Oreochromis niloticus). DESeq analysis identified 7148 DEGs (differentially expressed genes) between RU486-treated and control XX gonads, while merely 442 DEGs were screened between the gonads of RU486-treated XX and control XY fish highlighting that RU486 treatment set forwards masculinity in XX fish. Comprehensive analysis of gene hierarchical clustering revealed that RU486 treatment in XX fish resulted in robust changes of gene expression profiles. In comparison with XX group, female-dominant genes were significantly repressed in RU486 treated XX fish gonads. Moreover, most parts of down-regulated genes in wild type female were evidently up-regulated genes in RU486-treated XX fish gonads. Comparing with control XY group, the majority of male-dominant genes represent a high level of expression. However, RU486-treatment led to an up-regulation of a cluster genes specifically which showed relative lower expression in both control XX and XY group. RU486-treatment mediated global changes of gene expression profiles in steroidogenesis, germ cell differentiation and follicular cell trans-differentiation were verified by quantitative PCR. Both morphological and immunohistochemistry results further proved that RU486 treatment initiates testicular-like gonads development in XX fish via simultaneously enhancing the male responsive genes and suppressing the female-dominant genes. Moreover, RU486 treatment caused significant decline of fshr, lhr and increase of ars. Taken together, our data confirms blocking of DHP physiology by RU486 treatment induces masculinization in XX gonad preferably via repressing of gonadotropin physiology, germ cell differentiation and promoting follicular trans-differentiation in teleosts.

DOI： 10.1016/j.ygcen.2018.03.005

Language：English   Publishing type：Research paper (scientific journal)  

Dietary regime modifications have been an integral part of health and healing practices throughout the animal kingdom. Thus, to assess the effects of periodic starvation and refeeding schedule on the physiological and immunological perturbations in Edwardsiella tarda infected red sea bream, we conducted a 20 day experiment using 4 treatment groups, namely, pre-fed placebo (PFP); pre-starved placebo (PSP); pre-fed infected (PFI); and pre-starved infected (PSI), wherein a 5 h E. tarda infection was done on the 11th day. In the present investigation, the pre-starved groups showed significant (P < 0.05) alterations in the liver Hexokinase and Glucose-6-phosphatase activity. The pre-starved fish also exhibited significant (P < 0.05) increment in the hepatosomatic index, along with increased hepatic glycogen content, in a time dependent fashion. The PPAR (peroxisome proliferator activated receptors)α transcription in the pre-starved group decreased significantly (P < 0.05) by 10dai, while the PPARγ showcased a reverse pattern. The transcription of Hepcidin1 and Transferrin (iron homeostasis related genes), and Cathepsin D and Ubiquitin (programmed cell death related genes) portrayed a time responsive decrease and increase in PSI and PFI groups, respectively. Additionally, in comparison to the PFI group, the PSI fish demonstrated substantially reduced oxidative stress level. Fluorescent Immunohistochemistry showed significant (P < 0.05) increase in p63 positive cells in the 10dai PFI fish in relation to the PSI group. Therefore, these findings provide new insight into the beneficial role of alternating starvation and refeeding schedule, preferably short-term starvation prior to an infection, in order to obtain better capability to battle against E. tarda infection in red sea bream.

DOI： 10.1016/j.cbpb.2017.01.009

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Previous studies indicated that maturation inducing hormone, 17α, 20β-Dihydroxy-4-pregnen-3-one (DHP), probably through nuclear progestin receptor (Pgr), might be involved in spermatogenesis and oogenesis in fish. To further elucidate DHP actions in teleostean ovarian differentiation, we analyzed the expression of pgr in the ovary of Nile tilapia (Oreochromis niloticus), and performed RU486 (a synthetic Pgr antagonist) treatment in XX fish from 5 days after hatching (dah) to 120dah. Tilapia Pgr was abundantly expressed in the follicular cells surrounding oocytes at 30 and 90dah. Continuous RU486 treatment led to the blockage of oogenesis and masculinization of somatic cells in XX fish. Termination of RU486 treatment and maintenance in normal condition resulted in testicular differentiation, and estrogen compensation in RU486-treated XX fish successfully restored oogenesis. In RU486-treated XX fish, transcript levels of female dominant genes were significantly reduced, while male-biased genes were evidently augmented. Meanwhile, both germ cell mitotic and meiotic markers were substantially reduced. Consistently, estrogen production levels were significantly declined in RU486-treated XX fish. Taken together, our data further proved that DHP, possibly through Pgr, might be essential in the ovarian differentiation and estrogen production in fish.

DOI： 10.1016/j.bbrc.2016.03.045

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In contrast to our understanding of testicular differentiation, ovarian differentiation is less well understood in vertebrates. In mammals, R-spondin1 (Rspo1), an activator of Wnt/β-catenin signaling pathway, is located upstream of the female sex determination pathway. However, the functions of Rspo1 in ovarian differentiation remain unclear in non-mammalian species. In order to elucidate the detailed functions of Rspo/Wnt signaling pathway in fish sex determination/differentiation, the ectopic expression of the Rspo1 gene was performed in XY medaka (Oryzias latipes). The results obtained demonstrated that the gain of Rspo1 function induced femininity in XY fish. The overexpression of Rspo1 enhanced Wnt4b and β-catenin transcription, and completely suppressed the expression of male-biased genes (Dmy, Gsdf, Sox9a2 and Dmrt1) as well as testicular differentiation. Gonadal reprograming of Rspo1-over-expressed-XY (Rspo1-OV-XY) fish, induced the production of female-biased genes (Cyp19a1a and Foxl2), estradiol-17β production and further female type secondary sexuality. Moreover, Rspo1-OV-XY females were fertile and produced successive generations. Promoter analyses showed that Rspo1 transcription was directly regulated by DM domain genes (Dmy, the sex-determining gene, and Dmrt1) and remained unresponsive to Foxl2. Taken together, our results strongly suggest that Rspo1 is sufficient to activate ovarian development and plays a decisive role in the ovarian differentiation in medaka.

DOI： 10.1038/srep19543

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Dietary compromises, especially food restrictions, possess species-specific effects on the health status and infection control in several organisms, including fish. To understand the starvation-mediated physiological responses in Edwardsiella tarda infected red sea bream, especially in the liver, we performed a 20-day starvation experiment using 4 treatment (2 fed and 2 starved) groups, namely, fed-placebo, starved-placebo, fed-infected, and starved-infected, wherein bacterial exposure was done on the 11th day. In the present study, the starved groups showed reduced hepatosomatic index and drastic depletion in glycogen storage and vacuole formation. The fed-infected fish showed significant (P < 0.05) increase in catalase and superoxide dismutase activity in relation to its starved equivalent. Significant (P < 0.05) alteration in glucose and energy metabolism, as evident from hexokinase and glucose-6-phosphate dehydrogenase activity, was recorded in the starved groups. Interestingly, coinciding with the liver histology, PPAR (peroxisome proliferator activated receptors) α transcription followed a time-dependent activation in starved groups while PPARγ exhibited an opposite pattern. The transcription of hepcidin 1 and transferrin, initially increased in 0dai (days after infection) starved fish but reduced significantly (P < 0.05) at later stages. Two-color immunohistochemistry and subsequent cell counting showed significant increase in P63-positive cells at 0dai and 5dai but later reduced slightly at 10dai. Similar results were also obtained in the lysosomal (cathepsin D) and non-lysosomal (ubiquitin) gene transcription level. All together, our data suggest that starvation exerts multidirectional responses, which allows for better physiological adaptations during any infectious period, in red sea bream.

DOI： 10.1016/j.cbpa.2015.07.003

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Figla (factor in the germ line, alpha), a female germ cell-specific transcription factor, had been shown to activate genetic hierarchies in oocytes. The ectopic expression of Figla was known to repress spermatogenesis-associated genes in male mice. However, the potential role of Figla in other vertebrates remains elusive. The present work was aimed to identify and characterize the functional relevance of Figla in the ovarian development of Nile tilapia (Oreochromis niloticus). Tissue distribution and ontogeny analysis revealed that tilapia Figla gene was dominantly expressed in the ovary from 30 days after hatching. Immunohistochemistry analysis also demonstrated that Figla was expressed in the cytoplasm of early primary oocytes. Intriguingly, over-expression of Figla in XY fish resulted in the disruption of spermatogenesis along with the depletion of meiotic spermatocytes and spermatids in testis. Dramatic decline of sycp3 (synaptonemal complex protein 3) and prm (protamine) expression indicates that meiotic spermatocytes and mature sperm production are impaired. Even though Sertoli cell (dmrt1) and Leydig cell (star and cyp17a1) marker genes remained unaffected, hsd3b1 expression and 11-KT production were enhanced in Figla-transgene testis. Taken together, our data suggest that fish Figla might play an essential role in the ovarian development by antagonizing spermatogenesis.

DOI： 10.1371/journal.pone.0123900

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Interferon gamma (. IFNγ) is an active player in estrogen dependent immuno-regulation of fish. The present work was aimed to characterize the alternatively spliced isoforms of IFNγ2 in the gonadal sex development in medaka. Phylogenetic analysis demonstrated that IFNγ2a and 2b were clustered with fish specific interferon gamma. Our in vitro promoter and mini-genome analysis data confirmed that alternative splicing of IFNγ2 is regulated by estrogens and androgens. Tissue distribution, quantitative PCR and ISH data demonstrated ubiquitous expression of IFNγ2a, while IFNγ2b was only expressed predominantly in female germ cells than males. This was further confirmed by germ cell specific GFP signals in the IFNγ2b-GFP over-expressed embryos and specific induction of IFNγ2b expression in the BrdU positive cells. All together our data suggest that steroid responsive alternatively spliced IFNγ2b isoforms might have some indirect roles in germ cell proliferation and thus can be an important candidate for immuno-reproductive interaction studies.

DOI： 10.1016/j.mce.2014.10.012

Language：English   Publishing type：Research paper (scientific journal)  

A study was conducted to determine the immunomodulatory effect of probiotic mixture on the nonspecific immune response and disease resistance of Labeo rohita. Fish were fed with six different test diets with or without probiotics, namely, T1 (basal feed [BF] without probiotics), T2 (BF+Bacillus subtilis [BS]+Lactococcus lactis [LL]), T3 (BF+LL+Saccharomyces cerevisiae [SC]), T4 (BF+BS+SC), T5 (BF+BS+LL+SC), and T6 (BF+heat-killed bacteria of BS+LL+SC). During the prechallenge period, significantly higher (P<0.01) nitroblue tetrazolium assay (NBT), red blood cells (RBC), hemoglobin (Hb), globulin, and albumin content were recorded in the probiotic-supplemented diet group. Feeding all the three probiotics significantly decreased (P<0.01) the serum aspartate aminotransferases (AST), alanine aminotransferases (ALT), acid phosphatase (ACP), and alkaline phosphatase (ALP) activity and increased the myeloperoxidase (MPO) and immunoglobulin M (IgM) value. Significant difference in the NBT, Hb, serum albumin, and MPO was noticed in both prechallenged and postchallenged fish. Lowest survivability was recorded in the nonprobiotic fed group, followed by the group fed with heat-killed probiotics, whereas the highest survivability was noticed in the group fed with all the three probiotics in live form. Thus, a probiotic mixture diet constituting of three probiotics in viable form is found to be optimum to enhance the immunity and postinfection survivability in L. rohita fingerlings.

DOI： 10.1111/jwas.12144

Language：English   Publishing type：Research paper (scientific journal)  

Probiotics play an important role in growth increment, immune enhancement and stress mitigation in fish. Increasing temperature is a major concern in present aquaculture practices as it markedly deteriorates the health condition and reduces the growth in fish. In order to explore the possibilities of using probiotics as a counter measure for temperature associated problems, a 30 days feeding trial was conducted to study the hemato-immunological and apoptosis response of Labeo rohita (8.3±0.4 g) reared at different water temperatures, fed with or without dietary supplementation of a probiotic mixture (PM) consisting of Bacillus subtilis, Lactococcus lactis and Saccharomyces cerevisiae) (10¹¹ cfu kg^-1). Three hundred and sixty fish were randomly distributed into eight treatment groups in triplicates, namely, T1(28°C+BF(Basal feed)+PM), T2(31°C+BF+PM), T3(34°C+BF+PM), T4(37°C+BF+PM), T5(28°C+BF), T6(31°C+BF), T7(34°C+BF) and T8(37uC+BF). A significant increase (P<0.01) in weight gain percentage was observed in the probiotic fed fish even when reared at higher water temperature (34-37°C). Respiratory burst assay, blood glucose, erythrocyte count, total serum protein, albumin, alkaline phosphatase and acid phosphatase were significantly higher (P<0.01) in the probiotic fed groups compared to the nonprobiotic fed groups. A significant (P<0.01) effect of rearing temperature and dietary probiotic mixture on serum myeloperoxidase activity, HSP70 level and immunoglobulin production was observed. Degree of apoptosis in different tissues was also significantly reduced in probiotic-supplemented groups. Hence, the present results show that a dietary PM could be beneficial in enhancing the immune status of the fish and also help in combating the stress caused to the organism by higher rearing water temperature.

DOI： 10.1371/journal.pone.0100929

Language：English   Publishing type：Research paper (scientific journal)  

Steroidogenic acute regulatory protein (StAR) transports cholesterol, the substrate for steroid synthesis, to the inner membranes of mitochondria. It is well known that estrogen is essential for female sex determination/differentiation in fish. However, no reports showed that the conventional StAR, which was supposed to be essential for estrogen production, was expressed in female gonads during the critical timing of sex determination/differentiation. In this study, two different StAR isoforms, named as StAR1 and StAR2, were characterized from the gonads of Nile tilapia (Oreochromis niloticus). Phylogenetic and synteny analysis revealed that two StAR genes existed in teleosts, Xenopus and chicken indicating that the duplication event occurred before the divergence of teleosts and tetrapods. Real-time PCR revealed that StAR1 was dominantly expressed in the testis, head kidney and kidney; while StAR2 was expressed exclusively in the gonads. In situ hybridization and immunohistochemistry demonstrated that StAR1 was expressed in the interrenal cells of the head kidney and Leydig cells of the testis; while StAR2 was expressed in the Leydig cells of the testis and the interstitial cells of the ovary. Ontogenic analysis demonstrated that StAR2 was expressed abundantly from 5. days after hatching (dah) in the somatic cells in XX gonads, whereas in XY gonads, both StARs could be detected from 30. dah until adulthood. Intraperitoneal injection of human chorionic gonadotropin experiments showed that expression of StAR1 and 2 was significantly elevated at 8. h and persisted until 24. h after injection in the testis. Taken together, our data suggested that StAR1 is likely to be required for cortisol production in the head kidney, and StAR2 is probably involved in estrogen production during early sex differentiation in XX gonads. In contrast, both StARs might be required for androgen production in testes. For the first time, our data demonstrated that two fish StARs might be involved in steroidogenesis in a tissue and developmental stage dependent manner.

DOI： 10.1016/j.mce.2014.05.013

Language：English   Publishing type：Research paper (scientific journal)  

To meet the ever-increasing demand for animal protein, aquaculture continuously requires new techniques to increase the production yield. However, with every step towards intensification of aquaculture practices, there is an increase in stress level on the animal as well as on the environment. Feeding practices in aqua farming usually plays an important role, and the addition of various additives to a balanced feed formula to achieve better growth is a common practice among the fish and shrimp culturists. Probiotics, also known as 'bio-friendly agents', such as LAB (Lactobacillus), yeasts and Bacillus sp., can be introduced into the culture environment to control and compete with pathogenic bacteria as well as to promote the growth of the cultured organisms. In addition, probiotics are non-pathogenic and non-toxic micro-organisms, having no undesirable side effects when administered to aquatic organisms. Probiotics are also known to play an important role in developing innate immunity among the fishes, and hence help them to fight against any pathogenic bacterias as well as against environmental stressors. The present review is a brief but informative compilation of the different essential and desirable traits of probiotics, their mode of action and their useful effects on fishes. The review also highlights the role of probiotics in helping the fishes to combat against the different physical, chemical and biological stress.

DOI： 10.1111/j.1439-0396.2012.01301.x

Language：English   Publishing type：Research paper (scientific journal)  

Background: In mammals, R-spondin (Rspo), an activator of the Wnt/β-catenin signaling pathway, has been shown to be involved in ovarian differentiation. However, the role of the Rspo/Wnt/β-catenin signaling pathway in fish gonads is still unknown. Results: In the present study, full-length cDNAs of Rspo1, 2 and 3 were cloned from the gonads of medaka (Oryzias latipes). The deduced amino acid sequences of mRspo1-3 were shown to have a similar structural organization. Phylogenetic analysis showed that Rspo1, 2 and 3 were specifically clustered into three distinct clads. Tissue distribution revealed that three Rspo genes were abundantly expressed in the brain and ovary. Real-time PCR analysis around hatching (S33-5dah) demonstrated that three Rspo genes were specifically enhanced in female gonads from S38. In situ hybridization (ISH) analysis demonstrated that three Rspo genes were expressed in the germ cell in ovary, but not in testis. Fluorescence multi-color ISH showed that Rspo1 was expressed in both somatic cells and germ cells at 10dah. Exposure to ethinylestradiol (EE2) in XY individuals for one week dramatically enhanced the expression of three Rspo genes both at 0dah and in adulthood. Conclusions: These results suggest that the Rspo-activating signaling pathway is involved in the ovarian differentiation and maintenance in medaka.

DOI： 10.1186/1471-213X-12-36

Language：English   Publishing type：Research paper (scientific journal)  

Five experimental diets with various combinations of probiotics, namely T1 & T6 (basal feed (BF) without probiotics), T2 & T7 (BF+Bacillus subtilis+Lactococcus lactis), T3 & T8 (BF+L. lactis+Saccharomyces cerevisiae), T4 & T9(BF+B. subtilis+S. cerevisiae) and T5 & T10 (BF+B. subtilis+L. lactis+S. cerevisiae) were fed to Labeo rohita fingerlings for 30days. Treatment groups T1, T2, T3, T4 and T5 were exposed to Fenvalerate, at a concentration of 1.79μgL ^-1. The SOD and CAT activity was significantly affected (P<0.01) in fenvalerate treated groups. However, the supplementation of the three-probiotic mixture at equal concentration showed markedly reduced activity. Similarly, RBC, Hb, NBT, total protein and albumin values were reduced significantly (P<0.01) in the fenvalerate exposed fish as compared to the probiotic supplemented fish. Fenvalerate exposure also showed increased serum ALP, ACP and Bilirubin values (P<0.01) in comparison to the non-exposed fish. Histological observations of the gills, kidney and liver showed tissue degeneration after fenvalerate exposure, which however showed marked recovery on the three-probiotic mixture supplementation. Therefore, these results indicate that a mixture of multi-species probiotic supplementation in equal concentration acts beneficially in mitigating the stressful effects of fenvalerate.

DOI： 10.1016/j.pestbp.2012.06.006

Language：English   Publishing type：Research paper (scientific journal)  

Six iso-nitrogenous (350g proteinkg ^-1) and iso-caloric (4100kcalkg ^-1) diets with or without probiotics supplementation namely T ₁ (Basal feed (BF) without probiotics; control), T ₂ (BF+Bacillus subtilis and Lactococcus lactis), T ₃ (BF+L. lactis and Saccharomyces cerevisiae), T ₄ (BF+B. subtilis and S. cerevisiae), T ₅ (BF+B. subtilis, L. lactis and S. cerevisiae) and T ₆ (BF+heat-killed bacteria of B. subtilis, L. lactis and S. cerevisiae) were fed to Labeo rohita fingerlings (6.0±0.06g) for 60days in triplicate tanks (30 fish per tank). In all probiotic-supplemented diets, the probiotic concentration was maintained at 10 ¹¹cfukg ^-1 feed. After 60days of culture, the fish fed combination of three probiotics at equal proportion (T ₅) had higher (P<0.05) growth, protein efficiency ratio, nutrient retention and digestibility and lower (P>0.05) feed conversion ratio over other treatment groups. Total heterotrophic bacterial population in intestine was drastically reduced on 15th and 30th days of sampling than the initial value (0day of sampling) for T ₃, T ₄ and T ₅ groups. Except T ₆, the gut colonization of respective probiotics, which were supplemented through the diets, was also increased up to 30days of culture of fish and thereafter remained constant.

DOI： 10.1111/j.1365-2095.2011.00866.x

Language：English   Publishing type：Research paper (scientific journal)  

In many vertebrates, estrogens are necessary to promote the growth and differentiation of the female reproductive system during development, and have important reproductive roles in both males and females. Medaka (Oryzias latipes) has three estrogen receptor (ER) subtypes, ERα, ERβ1 and ERβ2. To evaluate the three medaka ER (mER)-ligand interactions, we applied the ERE-luciferase reporter assay system to characterize each ER subtype. In this transient transfection assay system using mammalian cells, the mER proteins displayed estrogen-dependent activation. 17β-Estradiol (E ₂) and op'-DDT showed high activation irrespective of ERs. Endosulfan also exhibited activation; with less/no transactivity measured using other pesticides, i.e., heptachlor, carbendazim, deltamethrin, acephate, dimethoate and amitraz. It was generally observed that ERβ2 had higher activation potential than ERα and ERβ1. To understand the molecular mechanism of estrogen action via ER, we also conducted E ₂ treatment where we observed a trigger in ERβ2 expression upon E ₂ exposure. The present data suggest that ERβ2 is essential for female gonad maintenance. The data were supported by induction of vitellogenin (VTG) mRNA in the liver and reduced VTG receptor mRNA expression in the gonad of both sexes. The present work will provide a basic tool allowing future studies to examine the receptor-ligand interactions and endocrine disrupting mechanisms, and also expands our knowledge of estrogen action on reproductive development in medaka.

DOI： 10.1016/j.jsbmb.2010.11.015

Language：English   Publishing type：Research paper (scientific journal)  

In fish, estradiol-17β (E2) regulates various reproductive processes by acting through estrogen receptors (ERs). Here, we cloned three ER subtypes from medaka and examined their developmental expression in the gonads and liver of genetically females and males from embryos to adults. During embryogenesis, marked increases in the expression of ERβ2, but not either ERα or ERβ1, were found in genetically female embryos during sex differentiation. E2 treatment induced marked up-regulation of ERβ2 expression in genetically male embryos. In adult ovaries, ERα levels were high in follicles (granulosa cells) during oocyte growth. In the testis, ERβ1 expression exhibited a distinct peak at 10 days post hatching (dph). In the liver, very high levels of ERβ2 were found in both females and males throughout the sampling period with significantly higher levels in females during 30-50 dph. These findings suggest each action of E2 to be mediated by different types of ERs.

DOI： 10.1016/j.mce.2010.12.002

Language：English   Publishing type：Research paper (scientific journal)  

A bacterial biosensor is reported that responds to Pb²⁺ in the range of 50-400 μM by expressing green fluorescence protein (GFP). The genetic element that senses Pb²⁺ includes the regulatory protein gene (PbrR) along with operator/promoter (PbrO/P) of the lead resistance operon from plasmid pMOL30. PbrO/P also controls the gfp reporter gene expression. Escherichia coli DH5α is the host organism. GFP response to induction by Pb²⁺ peaked at 250 μM. Decline in fluorescence beyond 250 μM was related to drop in copy number of the biosensor plasmid in the cells. A formula that estimates available Pb²⁺ concentration in test samples with 95% accuracy was derived by multiple regression of fluorescence and cell density values at various Pb²⁺ concentrations at 12 h growth. The biosensor was tested for co-inducibility by Cd²⁺, Zn²⁺ and Hg²⁺. Only Zn²⁺ showed mild induction at high concentrations and the highest fluorescence obtained was 8.5 times lower than that obtained with Pb²⁺. The induction method used here allows water collected from natural resources to be directly tested by using it to prepare the growth medium for the biosensor. This biosensor offers a simple and quick method for detection of available lead in the aquatic environment.

Event date： 2023.5

Language：English  

Venue：Greece   Country：Greece  

Event date： 2023.5

Language：English  

Venue：Greece   Country：Greece  

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Event date： 2024.3

Language：Japanese  

Venue：Tokyo Univiersity of marine sciences   Country：Japan  

Event date： 2023.6

Language：English  

Country：Japan  

Event date： 2023.6

Language：English  

Country：India  

Event date： 2023.6

Language：English  

Country：Japan  

Event date： 2023.6

Language：Japanese  

Country：Japan  

Event date： 2023.6

Language：Japanese  

Country：Japan  

Event date： 2023.6

Language：Japanese  

Country：Japan  

Event date： 2023.6

Language：Japanese  

Country：Japan  

Event date： 2023.6

Language：Japanese  

Country：Japan  

Event date： 2023.6

Language：Japanese  

Country：Japan  

Event date： 2023.6

Language：Japanese  

Country：Japan  

Event date： 2023.6

Language：English  

Country：India  

Event date： 2023.6

Language：English  

Country：Japan  

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Event date： 2023.6

Language：Japanese  

Country：Japan  

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Event date： 2023.6

Language：Japanese  

Country：Japan  

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Event date： 2023.6

Language：Japanese  

Country：Japan  

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Event date： 2023.6

Language：Japanese  

Country：Japan  

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Event date： 2023.6

Language：Japanese  

Country：Japan  

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Event date： 2023.6

Language：Japanese  

Country：Japan  

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Event date： 2023.6

Language：English  

Country：India  

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Event date： 2023.6

Language：English  

Country：Japan  

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Event date： 2023.6

Language：Japanese  

Country：Japan  

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Event date： 2023.5

Language：English  

Venue：Greece   Country：Greece  

Event date： 2023.5

Language：English  

Venue：Greece   Country：Greece  

Event date： 2023.5

Language：English  

Venue：Greece   Country：Greece  

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Event date： 2023.5

Language：English  

Venue：Greece   Country：Greece  

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Event date： 2022.3

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2022.3

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2022.1

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2022.1

Language：English  

Country：Japan  

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Event date： 2022.1

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2022.1

Language：English  

Country：Japan  

Event date： 2022.1

Language：Japanese  

Country：Japan  

Event date： 2022.1

Language：English  

Country：Japan  

Event date： 2022.1

Language：Japanese  

Country：Japan  

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Event date： 2022.1

Language：English  

Country：Japan  

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Event date： 2021.6

Language：English   Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2020.8

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2020.8

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Portugal  

Event date： 2020.8

Language：English   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：Ehime University Graduate School of Medicine   Country：Japan  

Event date： 2020.8

Language：English   Presentation type：Oral presentation (general)  

Country：Canada  

Event date： 2020.8

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2020.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Chongqing   Country：China  

Event date： 2020.8

Language：English  

Country：Japan  

Event date： 2020.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Chennai   Country：India  

Event date： 2020.8

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2020.8

Language：English  

Venue：Manaus, Brazil   Country：Brazil  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Presentation type：Oral presentation (general)  

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Language：English   Presentation type：Oral presentation (general)  

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Language：English   Presentation type：Oral presentation (general)  

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Language：English   Presentation type：Oral presentation (invited, special)  

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J-GLOBAL

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J-GLOBAL

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Language：English  

DOI： https://doi.org/10.1007/978-981-16-3215-0_7

Language：English  

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.

DOI： https://doi.org/10.1080/15548627.2020.1797280

Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Type：Competition, symposium, etc. 

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Type：Academic society, research group, etc. 

Type：Peer review 

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Type：Peer review 

Number of peer-reviewed articles in foreign language journals：15

Type：Academic society, research group, etc. 

Type：Peer review 

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Type：Academic society, research group, etc. 

Type：Peer review 

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Type：Peer review 

Number of peer-reviewed articles in foreign language journals：25

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：10

Number of peer-reviewed articles in Japanese journals：0

Proceedings of International Conference Number of peer-reviewed papers：0

Proceedings of domestic conference Number of peer-reviewed papers：0

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：15

Number of peer-reviewed articles in Japanese journals：0

Proceedings of International Conference Number of peer-reviewed papers：0

Proceedings of domestic conference Number of peer-reviewed papers：0

Type：Academic research 

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Type：Academic research 

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Type：Peer review 

Number of peer-reviewed articles in foreign language journals：5

Number of peer-reviewed articles in Japanese journals：0

Proceedings of International Conference Number of peer-reviewed papers：0

Proceedings of domestic conference Number of peer-reviewed papers：0

Type：Other

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Foreign co-ordinator of COFLAA, India.

Type：Other

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Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Seminar, workshop

Type：Seminar, workshop

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Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Other

Type：Other

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organized training (volunteer) for Primary and high school teachers

Type：Other

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Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Seminar, workshop

Type：Seminar, workshop

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Type：Research consultation

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