Oztürk Arzu, Fresnoza Agnes, Savoie Amanda, Duckworth Harry W, Duckworth Mary Lynn
Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada R3E 3J7.
Endocrinology. 2003 Nov;144(11):4742-54. doi: 10.1210/en.2003-0591. Epub 2003 Jul 31.
Members of the large rat prolactin gene family located on chromosome 17 are expressed in one or more placental trophoblast cell types and maternal decidua at specific times during pregnancy. Studies to identify the factors involved in these highly specific developmental expression patterns, using limited amounts of 5'-flanking DNA, have met with only partial success. Here we report the isolation and characterization of an 80-kb rat genomic clone, P1 12830, containing linked rat placental lactogen II, rat prolactin-like protein-I, and rat prolactin-like protein-B genes with substantial amounts of 5'- and 3'-flanking DNA as well as a rat placental lactogen II-related pseudogene, the first to be described in this gene family. This clone was used to create F0 transgenic mice, and the levels of expression of the three rat genes were compared with those of the endogenous mouse genes, using RT-PCR. Each rat gene was expressed differently in the same placenta, confirming the importance of sufficient flanking sequences in the expression of the individual genes. These studies emphasize the need for large genomic clones in defining the complete complement of factors that regulate the developmental expression of the rat prolactin gene locus.
位于大鼠17号染色体上的大鼠催乳素大基因家族成员，在孕期特定时间于一种或多种胎盘滋养层细胞类型以及母体蜕膜中表达。利用有限量的5'侧翼DNA来鉴定参与这些高度特异性发育表达模式的因子的研究，仅取得了部分成功。在此，我们报告一个80kb大鼠基因组克隆P1 12830的分离与鉴定，该克隆包含相连的大鼠胎盘催乳素II、大鼠催乳素样蛋白-I和大鼠催乳素样蛋白-B基因，以及大量的5'和3'侧翼DNA，还有一个大鼠胎盘催乳素II相关假基因，这是该基因家族中首个被描述的此类假基因。该克隆用于创建F0转基因小鼠，并使用逆转录聚合酶链反应（RT-PCR）将三个大鼠基因的表达水平与内源性小鼠基因的表达水平进行比较。每个大鼠基因在同一胎盘中的表达各异，证实了足够的侧翼序列在单个基因表达中的重要性。这些研究强调了在确定调节大鼠催乳素基因位点发育表达的完整因子补充时，需要大型基因组克隆。
