202108Kina

研究発表を行った学会；52nd JSDB meeting
2019年 5月15日　（大阪国際交流センター）
タイトル； Drosophila Tpp ensures the germ plasm assembly by facilitating the posterior localization of Aubergine in the oocyte.
発表者；喜納　寛野氏
（熊本大学　大学院薬学教育部・発生医学研究所　生殖発生分野）
要旨；Germ cells are the only cell type that transmits genetic information to the next generation, and essential for species preservation. In many animals, including Drosophila, germ cell formation relies on the germ plasm, which contains maternal RNAs and proteins essential for germline development. The Drosophila germ plasm is assembled during oogenesis at the posterior pole of the oocyte. However, the mechanism by which the germ plasm is assembled remains poorly understood. To identify new factors involved in germ cell formation, we conducted CRISPR-Cas9-mediated gene knockout screening for uncharacterized genes. We found that embryos lacking tiny pole plasm (tpp) gene failed to form pole cells. In tpp^-/- ovaries, although the posterior localization of a germ plasm protein, Vasa, was intact, that of Aubergine (Aub) was significantly reduced. Furthermore, Aub was co-immunoprecipitated with Tpp from ovarian lysates, and Tpp::GFP^KI was colocalized with Vas and Aub in the perinuclear region of nurse cells, known as nuage. However, Tpp::GFP^KI did not accumulate to the germ plasm at the posterior pole of the oocyte and embryo. Since Aub is known to facilitate the accumulation of germ plasm mRNAs to the posterior pole of the oocyte, these results suggest that Tpp mediates the posterior localization of Aub in the oocyte, thereby facilitating the germ plasm assembly in oogenesis. We are currently seeking to understand the mechanism by which Tpp promotes the posterior localization Aub in the oocyte.