作　　者： ; ;

机构地区： 中山大学生命科学学院

出　　处： 《动物学报》 2000年第2期175-182,共8页

摘　　要： 建立核糖核酸酶保护法 ,检测性类固醇激素对鲤鱼脑垂体生长激素基因表达水平的影响。根据已知的鲤鱼生长激素cDNA设计PCR引物 ,亚克隆构建新的含鲤鱼生长激素cDNA片段的质粒 ,并以此作为模板 ,体外转录合成鲤鱼生长激素的反义RNA探针 ,用以检测鲤鱼脑垂体中的生长激素mRNA水平。处于性腺成熟早期的雌性鲤鱼埋植雌二醇 5天或 10天后 ,血液中生长激素水平均显著高于对照组 ,但其脑垂体的生长激素mRNA水平均没有显著变化 ;埋植睾酮 5天或 10天 ,血液中生长激素水平与对照组之间无显著性差异 ,生长激素mRNA水平也没有显著性变化。但埋植雌二醇 5天后显著增强了促性腺激素释放激素类似物对血液生长激素水平升高和促进生长激素mRNA合成的刺激作用。这表明 :性类固醇激素不能在转录水平上对生长激素基因表达进行调控 。 To examine the regulation of growth hormone (GH) gene expression, a sequence specific solution hybridization/ribonuclease protection assay (RPA) for Common carp GH mRNA was developed. A subclone of Common carp GH cDNA sequence, which was prepared using polymerase chain reaction, was used as a template in in vitro transcription to synthesize a RNA probe for RPA. Using this assay, the effects of sex steroid on the growth hormone mRNA expression were examined in vivo . It was found that implantation of solid silastic pellets containing estradiol (E 2 100μg/g body weight for 5 or 10 days) increased serum GH levels significantly ( P <0.05) in female Common carp in early stage of sexual mature compared to the controls with implantation of blank pellets; however, implantation of testosterone (T) did not affect the GH level. Nevertheless, neither E 2 nor T was found to play a role in pituitary GH mRNA levels. On the other hand, E 2 treatment increased both the serum GH levels and the pituitary GH mRNA levels stimulated by LHRH A. The results indicate that sex steroid may associate with the change of GH production in the posttranscriptional or translational level but not the transcriptional mRNA level; and for the first time, E\-2 enhance the LHRH A effect on GH mRNA level. The sequence specific assay established in the present study can be used for accurate quantitation of GH mRNA in cyprinid species, and contribute to a better understanding of the regulation of GH mRNA expression in teleosts.

关 键 词： 鲤鱼 性类固醇激素 生长激素 脑垂体 基因表达

领　　域： [生物学] [生物学]