Chan W Y, Tease L A, Bates J M, Borjigin J, Shupert W L
Laboratory of Protein Studies, Oklahoma Medical Research Foundation, Oklahoma City 73104.
Hum Reprod. 1988 Jul;3(5):687-92. doi: 10.1093/oxfordjournals.humrep.a136767.
A partial cDNA of pregnancy-specific beta 1 glycoprotein isolated from human term placenta was used as probe for slot-blot analysis of total RNA extracted from placental and non-placental tissues in the rat. RNA hybridization with the probe was observed in rat placenta, indicating the presence of mRNA highly homologous to human SP1. The quantity of hybridizing RNA increased with increasing gestational age. In non-pregnant rats, SP1-hybridizing mRNAs were found in uterus, intestine and testis, while no hybridizing material was detected in liver or muscle. The amount of rat SP1 mRNA, based on percentage of total tissue RNA, was greatest in the testis followed by intestine, uterus and placenta. Using the same probe, six clones were obtained by screening a rat testis cDNA library. These clones carried cDNA inserts ranging in size from 1530 to 1983 bp. An internal EcoRI site was present in all cDNA clones. Southern blot analysis confirmed that the cDNA insert of all the clones was homologous to human placental SP1 cDNA. These results suggest a possible origin for the trace quantities of SP1 detected in non-pregnant individuals. It also confirms that the rat is an appropriate model for studying the physiological functions of SP1.
从人足月胎盘分离得到的妊娠特异性β1糖蛋白的部分cDNA被用作探针，对从大鼠胎盘组织和非胎盘组织中提取的总RNA进行狭缝印迹分析。在大鼠胎盘中观察到RNA与该探针发生杂交，表明存在与人SP1高度同源的mRNA。杂交RNA的量随着胎龄增加而增加。在未孕大鼠中，在子宫、肠道和睾丸中发现了与SP1杂交的mRNA，而在肝脏或肌肉中未检测到杂交物质。基于总组织RNA的百分比，大鼠SP1 mRNA的量在睾丸中最高，其次是肠道、子宫和胎盘。使用相同的探针，通过筛选大鼠睾丸cDNA文库获得了六个克隆。这些克隆携带的cDNA插入片段大小在1530至1983 bp之间。所有cDNA克隆中都存在一个内部EcoRI位点。Southern印迹分析证实，所有克隆的cDNA插入片段都与人胎盘SP1 cDNA同源。这些结果提示了在未孕个体中检测到的微量SP1的可能来源。这也证实了大鼠是研究SP1生理功能的合适模型。
