鳜不同亚型瘦素受体基因克隆与表达分析

Molecular cloning and expression analysis of leptin receptor gene in Chinese perch(Siniperca chuatsi)

以鳜(Siniperca chuatsi)为研究对象,使用cDNA 3′末端快速克隆法扩增瘦素受体基因(lepr)cDNA序列,获得了由mRNA 3′端可变剪切产生的鳜lepr的4个不同亚型,包括编码序列(coding sequence,CDS)长度为3474 bp、编码1157个氨基酸的长型受体亚型lepr-L,以及3个短型受体亚型lepr-S1、lepr-S2和lepr-S3,CDS长度分别为1512、945和915 bp,分别编码503、314、304个氨基酸。对氨基酸序列进行结构域分析和多重比对发现,鳜lepr长型受体亚型包含完整的功能域,短型受体亚型无跨膜区及胞内结构,鳜lepr及其leptin结合域(leptin binding domain,LBD)序列保守程度高。鳜lepr在鳃中表达最高,其次是肾和垂体,腹腔注射鳜leptin B而非leptin A的同源重组蛋白2 h后引起脑lepr表达量的升高(P<0.05)。以上结果表明,鳜leptins能引起组织中lepr表达的不同变化而发挥独特的生理功能。

The coding sequence of the leptin receptor(lepr)gene in Chinese perch was obtained by RACE cloning method,and four different subtypes of lepr from alternative splicing of the 3′end of mRNA were obtained.The long-form receptor lepr-L was 3474 bp in length encoding 1157 amino acids,and three short subtypes of leptin receptor were lepr-S1,lepr-S2 and lepr-S3,with coding sequence of 1512 bp,945 bp,and 915 bp in length,encoding 503,314 and 304 amino acids,respectively.Sequence analysis and multiple amino acid sequences alignment revealed that the lepr-L contains complete functional domains exclusively,none of the short receptor subtype contains the transmembrane region and intracellular structure,and lepr and its leptin binding domain(LBD)sequence are highly conserved.The lepr gene is highly expressed in the gill,followed by the kidney and pituitary.The lepr mRNA abundance significantly increased at 2 h after intraperitoneal injection of the homologous recombination leptins protein B not A(P<0.05).These results indicated that different leptins may lead to different expression changes of lepr mRNA,and lead to various physiological functions.