Associate Professor
Department of Biological Sciences, MMBS, The Misaki Marine Biological Station (MMBS), Department of Biological Sciences (UG), Department of Biological Sciences (GR), Graduate School of Science
TEL +81-46-827-6543 | (ext.)
Room MMBS (Misaki Marine Biological Station)

Research Field

Reproductive Biology, Cell Biology

Research Subject

Main subject is '''Molecular mechanisms of fertilization'''. '''1. Mechanisms of Sperm Activation and Chemotaxis'''Activation of the sperm motility and chemotactic behavior of sperm toward eggs are the first communication between spermatozoa and eggs at fertilization. We have determined the molecular structure of SAAF, the sperm-activating and attracting factor of the ascidian Ciona intestinalis, and now we are analyzing the molecular mechanisms of sperm activation and chemotaxis. '''2. Capacitation of Mammalian Sperm'''Mammalian sperm are infertile just after ejaculation, and capacitated in the female genital tract. On the other hand, some factors in seminal plasma is involved in the sperm capacitation. We are studying on the effect of a seminal vesicle, and we found that the protein released from the seminal vesicle acts as the decapacitation factor. Now we are analyzing the mechanisms of decapacitation.

Current Research

Shiba, K., Baba, S., Inoue, T., and Yoshida, M. Ca<sup>2+</sup> bursts occur around a local minimal concentration of attractant and trigger sperm chemotactic response. '''Proc Natl Acad Sci USA 105,''' 19311-19316 (2008). Kawano, N., Yoshida, K., Iwamoto, T. and Yoshida, M. Ganglioside GM1 mediates decapacitation effects of SVS2 on murine spermatozoa. '''Biol Reprod 79,''' 1153-1159 (2008). Yoshida, M., Yoshida, K., Shiba, K., Tsuchikawa, H., Ootou, O., Oishi, T. and Murata, M. Ascidian sperm activating and attracting factor: importance of sulfate groups for the activities and implication of its putative receptor. Kawano, N. and Yoshida, M. Seminal vesicle protein, secretion 2 (SVS2) controls mouse sperm fertility. Biology of Reproduction, 76, 353-361 (2007). Matsu-ura, T., Michikawa, T., Inoue, T., Miyawaki, A., Yoshida, M., and Mikoshiba, K. Cytosolic inositol 1,4,5-trisphosphate dynamics during intracellular calcium oscillations in living cells. '''J Cell Biol 173,''' 755-765 (2006) Oishi, T., Tuchikawa, H., Murata, M., Yoshida, M., and Morisawa, M. Oishi, T., Tuchikawa, H., Murata, M., Yoshida, M., and Morisawa, M. '''Tetrahedron 60,''' 6971-6980 (2004). Fukami, K., Yoshida, M., Inoue, T., Kurokawa, M., Fissore, R., Yoshida, N., Mikoshiba, K., and Takenawa, T. Phospholipase Cdelta4 is required for Ca<sup>2+</sup>-mobilization essential for acrosome reaction in sperm. '''J Cell Biol 161,''' 79-88 (2003). Yoshida, M., Ishikawa, M., Izumi, H., DeSantis, R., and Morisawa, M. Store operated calcium channel regulates chemotactic behavior of ascidian sperm. '''Proc Natl Acad Sci USA 100,''' 149-154 (2003). Yoshida, M., Murata, M., Inaba, K, and Morisawa, M. A chemoattractant for ascidian spermatozoa is a sulfated steroid. '''Proc Natl Acad Sci USA, 99,''' 14831-14836 (2002). Yoshida, M., Sensui, N., Inoue, T., Morisawa, M., and Mikoshiba, K. Role of two series of Ca<sup>2+</sup> oscillations on activation of ascidian eggs. '''Dev Biol 203,''' 122-133 (1998).


fertilization, sperm, oocyte, chemotaxis, capacitation, seminal plasma, acrosome reaction, calcium