Kobayashi Momoko, Suzuki Maiko, Saito Toru R, Tanaka Minoru
Department of Animal Science, Faculty of Applied Life Science, Nippon Veterinary and Life Science University, Tokyo, Japan.
Endocr Res. 2007;32(3):143-51. doi: 10.1080/07435800701764022.
One of the alternative first exons, E1(4), of the rat prolactin receptor (PRLR) gene was identified 5.4 kb downstream of exon 2 by sequence analysis of a rat genomic clone. In female and male rat brains, expression levels of E1(4)-containing PRLR mRNA increased remarkably between 2 and 4 weeks of age during postnatal development, whereas the levels of PRLR mRNAs containing other first exons, E1(3) and E1(5), did not change throughout the development. The levels of E1(4)-containing PRLR mRNA in the female rats at 8 weeks of age decreased by ovariectomy, and recovered by the administration of 17beta-estradiol, whereas castration and following testosterone treatment showed no effect on the levels of E1(4)-containing PRLR mRNA in the male rats. The levels of E1(3)- and E1(5)-containing PRLR mRNAs were not affected by gonadectomy and following sex steroid hormone treatments in both sexes. These results indicate that expression of PRLR gene in the female and male rat brains increases during postnatal development due to the transcriptional activation of the E1(4) first exon.
通过对大鼠基因组克隆进行序列分析，在大鼠催乳素受体（PRLR）基因外显子2下游5.4 kb处鉴定出一个替代性的首个外显子E1(4)。在雌性和雄性大鼠大脑中，含E1(4)的PRLR mRNA的表达水平在出生后发育的2至4周龄之间显著增加，而含其他首个外显子E1(3)和E1(5)的PRLR mRNA水平在整个发育过程中没有变化。8周龄雌性大鼠中含E1(4)的PRLR mRNA水平通过卵巢切除术降低，并通过给予17β-雌二醇恢复，而阉割和随后的睾酮处理对雄性大鼠中含E1(4)的PRLR mRNA水平没有影响。含E1(3)和E1(5)的PRLR mRNA水平在两性中均不受性腺切除术和随后的性甾体激素处理的影响。这些结果表明，由于E1(4)首个外显子的转录激活，雌性和雄性大鼠大脑中PRLR基因的表达在出生后发育过程中增加。
