黔北麻羊CTSK、FN1基因生物信息学分析及其在性腺轴中的表达

Bioinformatics analysis of CTSK and FN1 genes and their expression in gonadal axis of Qianbei Ma goat

【目的】研究组织蛋白酶K(Cathepsin K,CTSK)和纤维连接蛋白1(Fibronectin 1,FN1)基因与黔北麻羊繁殖率之间的相互关系,为研究CTSK、FN1基因调控山羊卵泡发育的分子机制提供参考。【方法】通过生物信息学方法分析黔北麻羊CTSK、FN1蛋白理化性质、亚细胞定位、信号肽位点和蛋白高级结构,并进行氨基酸同源性分析,构建系统发育进化树;采用荧光定量PCR法检测CTSK、FN1基因在单羔、多羔黔北麻羊性腺轴(下丘脑、垂体、子宫、输卵管、卵巢)中的表达量。【结果】CTSK、FN1基因分别编码330和2478个氨基酸,理论PI值分别为8.82和5.37,CTSK是一种具有信号肽的稳定亲水性蛋白,而FN1是一种具有信号肽的不稳定亲水性蛋白;亚细胞定位结果说明:CTSK蛋白可能主要在细胞外和内质网中发挥生物学作用,而FN1蛋白可能主要在细胞核中发挥生物学作用;高级结构预测结果显示,CTSK和FN1蛋白均主要由无规则卷曲构成;与其他动物相比,黔北麻羊CTSK、FN1基因均与反刍动物绵羊及牛的亲缘关系最近。qPCR分析表明:CTSK和FN1基因在单羔、多羔黔北麻羊下丘脑、垂体、子宫、输卵管和卵巢组织中均有表达,与单羔组相比,多羔组CTSK基因在卵巢、下丘脑、子宫中的表达量均极显著下调(P<0.01),而FN1基因在下丘脑和子宫中的表达均极显著上调(P<0.01),在卵巢中显著上调(P<0.05)。【结论】CTSK基因表达量与黔北麻羊的繁殖性状呈负相关,FN1基因则呈正相关,CTSK和FN1基因均是影响黔北麻羊繁殖性能的重要候选基因。

【Objective】The correlation between cathepsin K(CTSK)and fibronectin 1(FN1)genes and reproductive rate of Qianbei Ma goat were studied,which provides reference for molecular mechanism of regulating follicular development of goat by CTSK and FN1 genes.【Method】The physical and chemical properties,subcellular localization,signal peptide sites and high-level structure of protein of CTSK and FN1 proteins of Qianbei Ma goat were analyzed by bioinformatics method.The amino acid homology was analyzed and the phylogenetic tree was constructed.The expression levels of CTSK and FN1 in the gonadal axis(hypothalamus,pituitary gland,uterus,oviduct and ovary)of montocous and polytocous lambs of Qianbei Ma goat were detected by fluorescence quantitative PCR.【Result】CTSK and FN1 genes had 330 and 2478 encoding amino acids,respectively,with the theoretical PI values of 8.82 and 5.37.CTSK was a stable hydrophilic protein with signal peptide,while FN1 was an unstable hydrophilic protein with signal peptide.The results of subcellular localization indicated that CTSK protein may play a biological role mainly in extracellular and endoplasmic reticulum,while FN1 protein may play a biological role mainly in nucleus.Advanced structural prediction results showed that both CTSK and FN1 proteins were mainly composed of random coils.Compared with other animals,the CTSK and FN1 genes of Qianbei Ma goat were closely related to ruminant sheep and cattle.THe qPCR showed that CTSK and FN1 genes were expressed in hypothalamus,pituitary gland,uterus,oviduct and ovarian tissues of montocous and polytocous lambs of Qianbei Ma goat.Compared with montocous lamb,the expression of CTSK gene in ovary,hypothalamus and uterus of polytocous lamb group was significantly down-regulated(P0.01),while the expression of FN1 gene was significantly up-regulated in hypothalamus and uterus(P0.01),and significantly up-regulated in ovary(P0.05).【Conclusion】The CTSK gene expression was negatively related to reproductive characteristics of Qianbei Ma goat,while FN1 gene was positively related to that of Qianbei Ma goat.CTSK and FN1 genes both were the important candidate genes to influence the reproductive performance of Qianbei Ma goat.