Amleh A, Taketo T
Department of Biology, McGill University, Royal Victoria Hospital, Montreal, Quebec, Canada.
Biol Reprod. 1998 Feb;58(2):574-82. doi: 10.1095/biolreprod58.2.574.
When the Y chromosome of some Mus musculus domesticus subspecies is placed onto a C57BL/6J mouse background, the XY (B6.Y(TIR)) progeny develop only ovaries or ovotestes during fetal life. The XY sex-reversed female is infertile mainly because of death of embryos during preimplantation development. In the present study, we constructed female mouse chimera composed of B6.Y(TIR) and XX BALB/c cells to determine whether developmental incompetence of XY oocytes can be attributed to defects in the oocytes themselves or in the surrounding XY somatic cells. Distribution of XY cells in chimeric ovaries was examined by in situ hybridization. Of nine XX <--> XY chimeric females born, eight were composed of B6.Y(TIR) and XX BALB/c cells with a wide range of XY contribution (16-95%), whereas one had 12% XY components of the BALB/c strain. All these females produced progeny exclusively derived from XX oocytes. By comparison, most XX <--> XX chimeric females produced progeny derived from oocytes of either strain. Two XY <--> XY males also produced progeny of both strains. In conclusion, the XY chromosomal composition in the oocyte appears to be responsible for programming its incompetence for postfertilization development. On the other hand, the presence of XY somatic cells in the chimeric ovary allows development of fertile XX oocytes.
当将一些小家鼠亚种的Y染色体置于C57BL/6J小鼠背景上时，XY（B6.Y(TIR)）后代在胎儿期仅发育卵巢或卵睾。XY性反转雌性不育主要是因为植入前发育期间胚胎死亡。在本研究中，我们构建了由B6.Y(TIR)和XX BALB/c细胞组成的雌性小鼠嵌合体，以确定XY卵母细胞的发育无能是否可归因于卵母细胞本身或周围XY体细胞的缺陷。通过原位杂交检查嵌合卵巢中XY细胞的分布。在出生的9只XX <--> XY嵌合雌性小鼠中，8只由B6.Y(TIR)和XX BALB/c细胞组成，XY细胞的贡献范围广泛（16 - 95%），而1只具有12%的BALB/c品系XY成分。所有这些雌性小鼠仅产生源自XX卵母细胞的后代。相比之下，大多数XX <--> XX嵌合雌性小鼠产生源自任一品系卵母细胞的后代。两只XY <--> XY雄性小鼠也产生了两个品系的后代。总之，卵母细胞中的XY染色体组成似乎是其受精后发育无能的原因。另一方面，嵌合卵巢中XY体细胞的存在使可育的XX卵母细胞得以发育。
