Takasaki N, Rankin T, Dean J
Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
Mol Cell Biol. 2001 Dec;21(23):8197-202. doi: 10.1128/MCB.21.23.8197-8202.2001.
Gpbox is a paired-like homeobox gene that colocalizes with two other members of the family, PsxI and Pem, on the proximal portion of the mouse X chromosome. Gpbox is expressed in the extraembryonic placenta and within the germ cells of the embryonic gonad. Beginning with the onset of sexual dimorphism (embryonic day [E]11.5 to 12.5), GPBOX transcripts accumulate faster in female than in male germ cells but disappear later in embryogenesis (E16) and have not been reported in adult tissues. To investigate the function of Gpbox, mouse cell lines lacking GPBOX were established using targeted mutagenesis in embryonic stem cells. Both homozygous Gpbox null female and hemizygous Gpbox null male mice were fertile and reproduced normally. Additionally, the development of male and female gonads in the null background was indistinguishable from that observed in normal littermates. The lack of an obvious phenotype raises the possibility that another member of this homeobox gene family provides the absent Gpbox function.
Gpbox是一个类配对同源框基因，它与该家族的另外两个成员PsxI和Pem在小鼠X染色体的近端共定位。Gpbox在胚外胎盘和胚胎性腺的生殖细胞中表达。从性二态性开始（胚胎第[E]11.5至12.5天），GPBOX转录本在雌性生殖细胞中比在雄性生殖细胞中积累得更快，但在胚胎发育后期（E16）消失，并且在成年组织中未被报道。为了研究Gpbox的功能，利用胚胎干细胞中的靶向诱变建立了缺乏GPBOX的小鼠细胞系。纯合Gpbox缺失的雌性小鼠和半合子Gpbox缺失的雄性小鼠均能生育且繁殖正常。此外，在缺失背景下雄性和雌性性腺的发育与正常同窝仔鼠中观察到的情况没有区别。缺乏明显的表型增加了该同源框基因家族的另一个成员提供缺失的Gpbox功能的可能性。
