Researcher Information


Assistant Professor

Understanidng of avian spesific polyspermic fertilization system

Department of Biological Sciences, Reproductive and Developmental Biology


Molecular Mechanisms of fertilization and early development and establishment of novel gene modification methods in birds

FieldAvian Reproductive Biology
KeywordBird, Polyspermic fertilization, Egg activation, Germ cell, Cleavage, In vitro fertilization, Genome editing

Introduction of Research

Birds exhibit physiologically polyspermic fertilization, in which the entry of several sperm into one egg is permitted. We have previously established avian intracytoplasmic sperm injection (ICSI) method and this technique have revealed that a single sperm is insufficient for triggering fertilization and subsequent early embryo development. In order to understand more comprehensive avian polyspermic fertilization, we try to elucidate the molecular mechanism which regulates sperm selection for zygotic formation, now (Figure 1 Movement and degradation of sperm nuclei in germinal disc of avian egg).

We also try to establish a new method of avian transgenesis and gene editing by in vitro fertilization technique (Figure 2 Avian specific in vitro fertilization system), because a progress in gene modification in birds has been hampered due to the lack of traditional strategies such as pronuclear injection of DNA, sperm vector and somatic nuclear transfer. Establishment of this new avian technologies will aid our understanding the mechanism of avian fertilization and sex differentiation of germ cell and so on, as well as assisting in the production low allergenic egg via the disruption of allergen-related genes.

Figure 2 Avian specific in vitro fertilization system
Figure 2 Avian specific in vitro fertilization system

Representative Achievements

Fertilization 2: Polyspermic fertilization II, S. Mizushima, Adv. Exp. Med. Biol., 2017, 1001, 105-123.
Handling of gamates for in vitro insemination in birds. S. Mizushima, M. Matsuzaki, T. Sasanami, Method. Mol. Biol., 2017, 1650, 243-257.
Lactic acid is a sperm motility inactivation factor in the sperm storage tubules of the domestic bird, M. Matsuzaki, S. Mizushima, G. Hiyama, N. Hirohashi, K. Shiba, K. Inaba, T. Suzuki, H. Dohra, T. Ohnishi, Y. Sato, T. Kohsaka, Y. Ichikawa, Y. Atsumi, T. Yoshimura, T. Sasanami, Sci. Rep., 2015, 5, 17643.
The birth of quail chicks after intracytoplasmic sperm injection, S. Mizushima, G. Hiyama, K. Shiba, K. Inaba, H. Dohra, T. Ono, K. Shimada, T. Sasanami, Development, 2014, 141, 3799-3806.
Novel method of gene transfer in birds: intracytoplasmic sperm injection for green fluorescent protein expression in quail blastoderms, S. Mizushima, T. Ono, Y. Atsumi, A. Tsukada, N. Saito, T. Sasanami, M. Okabe, K. Shimada, Biol. Reprod., 2010, 83, 965-969.
Academic background2002 Bachelor of Animal Science and Technology, School of Veterinary Medicine, Azabu University
2005 Master of Bioagricultural Science, Graduate School of Bioagricultural Sciences, Nagoya University
2008 Doctor of Bioagricultural Science (Ph.D.), Graduate School of Bioagricultural Sciences, Nagoya University
2008-2011 Research Associate, Faculty of Human Sciences, Waseda University
2011-2014 Research Fellowship for Young Scientists (PD), Departement of Agriculture, Shizuoka University
2015-2016 Assistant Professor, Graduate School of Science and Engineering for Research, University of Toyama
2017- Assistant Professor, Faculty of Science, Hokkaido University
2015- Visiting Associate Professor, Departement of Agriculture, Shizuoka University
Affiliated academic societyJapan Poultry Science Association, World Poultry Science Association, Japanese Society of Animal Sciences, Zoological Science of Japan
Room addressScience Buiding 5 11-03