Developmental Biotechnology
Developmental Biotechnology
Staff
 | Prof. Dr. FUNAHASHI Hiroaki E-mail： hirofun＠（@okayama-u.ac.jp） Specialty： Animal Gamete Biotechnology Basic and applied research on mammalian gametes (maturation, fertilization and early development) |
 | Assoc. Prof. Dr. WAKAI Takuya E-mail： t2wakai＠（@okayama-u.ac.jp） Specialty： Reproductive & Developmental Biology Basic and applied research on organelles in mammalian oocytes and embryos |
Research Topics
We are developing new more effective IVF systems and micromanipulation techniques for gametes in mammals including humans. Through these technological developments, we are also undertaking basic studies to make clear the systems of gamete (oocytes and spermatozoa) formation, fertilization and early development, as well as applied studies to improve the efficiency in the production of more value-added useful animals. The details are as follows.
Development of new systems to produce embryos in vitro from oocytes collected from small diameter follicles
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For in vitro embryo production in mammals, especially domestic animals, usually oocyte-cumulus complexes derived from middle follicles with a diameter of 3-6 mm have been used. However, a large number of small follicles with less than 3 mm in diameter, rather than middle follicles, exist on the surface of ovaries. But the developmental competence of the complexes from small follicles (in meiosis and early development following fertilization) has been known to be much lower than those from middle follicles. We're trying to make clear why the developmental competence is lower in the oocytes from small follicle as compared with middle ones and whether those abilities are improved when what kind of processing are applied. |  |
New assessment of sperm quality and the function associated with penetration
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In mammals, although a quite large number of spermatozoa are ejaculated into the female reproductive tract before ovulation, consequently only one spermatozoon will be able to penetrate into an ovulated oocyte. So far, sperm function and the quality has been assessed as the motility and membrane intactness of spermatozoa under a microscope. However, this assessment may not be ideal in objectivity and may require quite expensive equipment such as a flow-cytometer. So, we are focusing on the work of the mitochondria and RNA in spermatozoa to make clear the mechanisms regulating the function and maintaining the quality of spermatozoa. We are also applying the knowledge to sperm assessment. |  |
Roles of organelles in mammalian oocytes
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Gametes (oocytes and spermatozoa) are highly specialized cells for the transmission of genes to the progeny. Our laboratory is interested in understanding the mechanisms of oocyte development, maturation and fertilization in mammals. Problems in oocyte quality cause the infertility, and the development of organelles, such as mitochondria and endoplasmic reticulum, is a key determinant for the successful fertilization and subsequent embryonic development. We are using several techniques to address the roles of organelles in oocytes including in vitro maturation, fertilization, genetic manipulation and live cell imaging. |  |
Publication List
- Okuyama, M., Funahashi, H.: Glycosaminoglycans improves early development of zona-free 8-cell rat embryos to the blastocyst stage in a chemically defined medium, but not the pregnancy rate following transfer of the blastocysts. Journal of Reproduction and Development, 58(3)295-301. June 2012
- Endo, Y., Fujii, Y., Kurotsuchi, S., Motoyama, H., Funahashi, H.: Successful delivery derived from vitrified-warmed spermatozoa from a patient with non-obstructive azoospermia. Fertility and Sterility 98(6) 1423-1427. December 2012
- Kohata, C., Izquierdo-Rico, M.J., Romar, R., Funahashi, H., Development competence and relative transcript abundance of oocytes derived from small and medium follicles of prepubertal gilts. Theriogenology 80(9) 970-978, December 2013
- Wakai T, Zhang N, Vangheluwe P, Fissore RA.: Regulation of endoplasmic reticulum Ca2+ oscillations in mammalian eggs. Journal of Cell Science,126, 5714-5724, (2013).
- Wakai, T., Harada, Y., Miyado, K., and Kono, T.: Mitochondrial dynamics controlled by mitofusins define organelle positioning and movement during mouse oocyte maturation. Mol Hum Reprod, 20, 1090-1100, (2014).