202108Tanno

研究発表を行った学会；日本発生生物学会
2020年 9月 11日　（オンライン）
タイトル； Phosphorylation of the Anaphase Promoting Complex activator FZR1/CDH1 is required for Meiosis II entry in mouse male germ cell.
発表者；丹野　修宏氏
（熊本大学　発生医学研究所　染色体制御分野）
要旨；FZR1 is an activator of Anaphase promoting complex/Cyclosome(APC/C). APC/CFZR1 activity is negatively regulated by CDK-mediated phosphorylation of FZR1 during mitotic phase.  So far, the critical role of FZR1 phosphorylation has been shown mainly yeast and in vitro cell culture studies. The physiological significance of FZR1 phosphorylation is yet to be examined in vertebrate mitotic tissues in vivo. Here, we examined the in vivo role of FZR1 phosphorylation using a mouse model, in which non-phosphorylatable substitutions were introduced in the putative CDK- phosphorylation sites of FZR1. Ablation of FZR1 phosphorylation led to severe testicular defects resulting in male infertility. In the absence of FZR1 phosphorylation, male germ cells entered meiosis normally but failed to enter meiosis II or form differentiated spermatids.  This study revealed that phosphorylation of FZR1 is required for temporal regulation of APC/C activity at meiosis II entry.