Kyushu University Academic Staff Educational and Research Activities Database
List of Presentations
Yoshitaka Kobayakawa Last modified date:2019.05.29

Professor / Division for Experimental Natural Science / Division for Experimental Natural Science / Faculty of Arts and Science

1. 恵崎晃太, 山下貴志, 渡邊英博, 山脇 兆史, Thomas Carle, Kobayakawa Y., 横張文男, Classification of olfactory sensory neurons in antennal basiconic sensilla of the praying mantis Tenodera aridifolia based on response spectra, The Joint meeting of the 22n International Congress of Zoology & the 87th meeting of the Zoological Society of Japan, 2016.11.
2. Junya Yamaguchi, Yoshitaka Kobayakawa, VERTICAL TRANSMISSION OF SYMBIOTIC CHLORELLAEIN GREEN HYDRA, International Workshop “Unravelling the Developmental Regulatory Network in Early Animals", 2013.09, Although physiological investigations of green hydra (viridissima group) have been reported, few have closely examined the origin and evolution of symbiosis (Huss et al., 1993; Pröschold et al., 2011; Kawaida et al., 2013). For understanding of the evolution of symbiosis in green hydra, it is important to know whether or not symbionts are inherited certainly by the offspring of the hosts for stable symbiosis. In the symbiosis between green hydra and chlorella, it is clear that chlorellae, which are in the endodermal epitheliomuscular cells, are inherited by new polyps through the asexual reproduction by budding (Habetha et al., 2003). Are the symbiotic chlorellae inherited by offspring vertically in the case of sexual reproduction? Thorington et al. (1979) reported that symbiotic chlorellae were released in large numbers from a sexually mature green hydra and were deposited onto an embryonic theca, after which the hatching polyp engulfed these chlorellae. They did not suggest the incorporation of the symbiotic chlorellae into oocytes or matured ova. On the other hand, Campbell (1990), Habetha et al. (2003), and Kawaida et al. (2013) showed that the vertical inheritance of symbiotic chlorellae occurs through the ooplasm of the egg by the transmission electron microscope and fluorescence microscope observation.
In this study, we aimed to investigate the maintenance process of symbiotic relation during the sexual reproduction in green hydra. In results, the migration of chlorellae into oocytes was recognized by the observation with the fluorescence microscope and LSM. Therefore, we are convinced that symbiotic chlorellae are transmitted certainly vertically through both the asexual and the sexual reproduction of the green hydra. Moreover, it turned out that the number of migrated chlorellae and the timing of migration are different between strains of green hydra. We also recognized that newly introduced symbiotic chlorellae from a strain of green hydra (K10) into a different strain of aposymbitotic green hydra (N11; M9 strain which had been removed symbiotic chlorellae artificially) could make stable symbiotic relation between the new host (we have been keeping the newly established symbiotic green hydra for more than a year), and that the newly established symbiotic green hydra also transmit the symbiotic chlorellae vertically through the ooplasm of the egg in the sexual reproduction.
3. Sexual reproduction in genus Hydra .
4. Molecular Phylogenetic Research on Symbiosis of Green Hydra.
5. Molecular Phylogenetic Research in Hydra.
6. Sexual reproduction in green hydra, Hydra viridissima.