Sreenivasulu G, Sridevi P, Sahoo P K, Swapna I, Ge W, Kirubagaran R, Dutta-Gupta A, Senthilkumaran B
Department of Animal Sciences, School of Life Sciences, University of Hyderabad, P. O. Central University, Gachibowli, Hyderabad 500 046, Andhra Pradesh, India.
Comp Biochem Physiol B Biochem Mol Biol. 2009 Sep;154(1):6-11. doi: 10.1016/j.cbpb.2009.04.010. Epub 2009 May 3.
Complementary DNAs encoding steroidogenic acute regulatory protein (StAR) have been isolated from different fish species, yet the relevance of StAR during gonadal cycle and more importantly in final oocyte maturation has not been assessed so far. A cDNA encoding StAR was isolated from the ovarian follicles of air-breathing catfish, Clarias gariepinus. Catfish StAR exhibited 55 to 72% identity at nucleotide level with other vertebrate orthologs. RT-PCR analysis of tissue distribution pattern demonstrated the presence of StAR mRNA in various tissues including gonads, kidney, liver, brain and intestine of catfish. Real-time RT-PCR analysis revealed high expression of StAR mRNA in the pre-spawning phase of ovary while it was low in preparatory, spawning and regressed phases. In testis, maximum expression was noticed during the preparatory phase. During human chorionic gonadotropin (hCG)-induced oocyte maturation, both in vitro and in vivo, StAR mRNA levels were augmented by 2 h and then declined gradually to reach basal levels by 12 h as that of saline-treated controls. Taken together, high level of expression during hCG-induced oocyte maturation vis-à-vis in spawning suggests a role for StAR, in addition to the steroidogenic enzyme genes in final oocyte maturation.
已经从不同鱼类中分离出编码类固醇生成急性调节蛋白（StAR）的互补DNA，但到目前为止，尚未评估StAR在性腺周期中的相关性，更重要的是在最终卵母细胞成熟过程中的相关性。从呼吸空气的鲶鱼（Clarias gariepinus）的卵巢卵泡中分离出编码StAR的cDNA。鲶鱼StAR在核苷酸水平上与其他脊椎动物直系同源物的同一性为55%至72%。组织分布模式的RT-PCR分析表明，鲶鱼的性腺、肾脏、肝脏、大脑和肠道等各种组织中存在StAR mRNA。实时RT-PCR分析显示，StAR mRNA在卵巢产卵前期高表达，而在准备期、产卵期和退化期低表达。在睾丸中，在准备期观察到最大表达。在人绒毛膜促性腺激素（hCG）诱导的卵母细胞成熟过程中，无论是体外还是体内，StAR mRNA水平在2小时时升高，然后逐渐下降，到12小时时降至与生理盐水处理对照组相同的基础水平。综上所述，与产卵期相比，hCG诱导的卵母细胞成熟过程中StAR的高表达水平表明，除了类固醇生成酶基因外，StAR在最终卵母细胞成熟中也发挥作用。
