黄鳝性逆转过程中Gsdf基因cDNA片段的克隆和表达分析

Cloning and Expression Analysis of Gsdf cDNA During Sex Reversal in Rice-Field Eel,Monopterus albus

通过RT-PCR法从黄鳝性腺中首次克隆获得黄鳝Gsdf(gonadal soma-derived factor)基因的片段序列,该片段序列长218 bp,编码72个氨基酸。氨基酸序列分析表明黄鳝Gsdf基因片段与其他物种的相似性在61%~76%之间,其中与舌齿鲈(Dicentrarchus labrax)GsdfⅠ型、舌齿鲈GsdfⅡ型同源性最高,均为76%;系统进化树显示,黄鳝Gsdf与尼罗罗非鱼(Oreochromis niloticus)Gsdf基因聚成一支,与鲈形目鱼类亲缘关系较近。此外,不同性腺组织的基因检测结果显示,黄鳝Gsdf在卵巢和间期性腺的表达量很低,两者没有显著性差异(P>0.05);在精巢组织中的表达量显著高于卵巢、间期性腺组织的表达量(P<0.05)。上述结果表明Gsdf基因可能在黄鳝的性腺尤其是精巢的分化和发育过程中起着重要的作用。

The gonadal soma-derived factor （GsdJ） gene fragment sequence was cloned from the gonad of the rice-field eel （Monopterus albus） by RT-PCR. The obtained cDNA fragment sequence is 218 bp, encoding 72 amino acids. The amino acid sequence comparison showed that the amino acids encoded by Gsdf of the rice-field eel share 61%-76% identities with other species, and is most similar to GsdfI and GsdflI of Di- centrarchus labrax （both 76%）. Phylogenetic analysis showed that M. albus Gsdf is clustered closely with that of Oreochromis niloticus, and has a close relationship with the Perciformes. The expression results showed that the expression levels of the Gsdf gene in the ovary and ovotestis of M. albus were both very low, and there was no significant difference between them （P〉0.05）, while in the testis tissue, the expression level was significantly higher than those in the ovary and ovotestis （P〈0.05）. The results suggest that Gsdf might be involved in the development of gonad （especially in testis differentiation and development） in rice-field eel.