Research Center for Advanced Science and Technology, Tokyo University of Marine Science and Technology, Tateyama, Chiba 294-0308, Japan.
Marine Fishery Institute of Zhejiang Province, Key Laboratory of Mariculture and Enhancement of Zhejiang Province, 316100 Zhoushan, Zhejiang Province, PR China.
Genetics. 2018 Jun;209(2):507-521. doi: 10.1534/genetics.118.300777. Epub 2018 Apr 2.
Sterility in hybrid animals is widely known to be due to a cytological mechanism of aberrant homologous chromosome pairing during meiosis in hybrid germ cells. In this study, the gametes of four marine fish species belonging to the Sciaenid family were artificially fertilized, and germ cell development was examined at the cellular and molecular levels. One of the intergeneric hybrids had gonads that were testis-like in structure, small in size, and lacked germ cells. Specification of primordial germ cells (PGCs) and their migration toward genital ridges occurred normally in hybrid embryos, but these PGCs did not proliferate in the hybrid gonads. By germ cell transplantation assay, we showed that the gonadal microenvironment in hybrid recipients produced functional donor-derived gametes, suggesting that the germ cell-less phenotype was caused by cell autonomous proliferative defects of hybrid PGCs. This is the first evidence of mitotic arrest of germ cells causing hybrid sterility in animals.
杂种动物的不育性是众所周知的，这是由于杂种生殖细胞减数分裂过程中同源染色体配对异常的细胞学机制所致。在这项研究中，人工授精了四种属于石首鱼科的海洋鱼类的配子，并在细胞和分子水平上检查了生殖细胞的发育。一个属间杂种的性腺结构类似于睾丸，体积小，缺乏生殖细胞。杂种胚胎中原始生殖细胞（PGC）的特化和向生殖脊的迁移正常发生，但这些 PGC 在杂种性腺中不增殖。通过生殖细胞移植试验，我们表明杂种受者的性腺微环境产生了功能性的供体衍生配子，这表明无生殖细胞表型是由杂种 PGC 自主增殖缺陷引起的。这是首例有丝分裂期生殖细胞停滞导致动物杂种不育的证据。
