中文摘要：

【目的】克隆兰州大尾羊过氧化物酶体增殖物激活受体（peroxisome proliferator-activated receptor gamma,PPARG）基因,分析其序列及编码蛋白的生物学特性,阐明PPARG基因在绵羊中的生物学作用,为生产应用提供理论依据。【方法】根据绵羊PPARG基因CDS序列设计特异性引物,利用RACE和RT-PCR技术克隆获得兰州大尾羊PPARG基因序列,结合生物信息学方法分析其生物学特性。【结果】克隆获得兰州大尾羊PPARG cDNA序列全长1 774 bp（GenBank序列号：KF727439）,其CDS区片段长1 428 bp,编码475个氨基酸,编码区两侧翼分别具有5’-UTR 131 bp（1-131 nt）和3’-UTR 214 bp（1 560-1 774 nt）。预测兰州大尾羊PPARG蛋白分子量为54.40 kD,理论等电点为4.94。预测PPARG编码蛋白疏水性最大值为3.600,最小值为-2.744,为非跨膜的疏水性蛋白。亚细胞定位主要在细胞质（65.2%）和细胞核（21.7%）中,少量作用于细胞支架（4.3%）和过氧化物酶体（4.3%）,无信号肽,不属于分泌蛋白。预测其氨基酸序列有26个磷酸化位点,无糖基化位点,含有1个ZnF_C4结构域、1个HOLI结构域和1个LCR结构域,二级结构以随机卷曲为主。同源性分析显示兰州大尾羊PPARG核苷酸序列与山羊、野牛、水牛、绵羊、虎鲸、野猪和人类核苷酸序列间的同源性分别为99%、98%、97%、99%、94%、92%和90%,兰州大尾羊PPARG氨基酸序列与山羊、野牛、水牛、绵羊、虎鲸、野猪和人类核苷酸序列间的同源性分别为100%、99.8%、100%、100%、98.7%、98.5%和97.5%。系统发育树表明,兰州大尾羊与山羊、绵羊和水牛的进化水平更为接近,与鱼类、人类和鼠类较远。其基因第486位发生碱基转换（C←→T）,第828位发生碱基转换（C←→A）,但其所编码氨基酸不变。【结论】兰州大尾羊与其他物种PPARG在结构上相似性较高,说明该基因具有高度的保守性。推测PPARG蛋白大部分在游离核糖体上合

英文摘要：

【Objective】The objective of this study is to reveal the biological function of peroxisome proliferator-activated receptor gamma（PPARG） gene in sheep and provide theoretical data for application by cloning PPARG and analyzing its sequence as well as genetic features.【Method】The specific primers on the CDS template of PPARG gene were designed and then the PPARG gene sequence of Lanzhou fat-tail sheep was cloned using RACE and RT-PCR technology. After that, its genetic characteristics were analyzed by bioinformatics methods. 【Results】 The 1 774 bp full-length cDNA of PPARG of Lanzhou fat-tailed sheep（Genbank No.： KF727439） was obtained, in which the length of CDS is 1 428 bp. It encodes 475 amino acids in total. The coding regions on both sides of the wing are respectively provided with 5 ＇-UTR 131 bp（1-131 nt） and 3＇-UTR 214 bp（1560-1774 nt）. It was predicted that the molecular weight of PPARG protein of Lanzhou fat-tail sheep is 54.40 kD and its theoretical isoelectric point is 4.94. In addition, its maximum hydrophobic value is 3.600 and minimum hydrophobic value is-2.744. It is a non-transmembrane hydrophobin with no signal peptide, which locates mostly in cytoplasm（65.2%）, seldom in nucleus（21.7%）, scaffold（4.3%） and peroxisome（4.3%） by the result of subcellular level prediction and does not belong to the secretory protein. Its amino acid sequence contains 26 phosphorylation sites, 0 glycosylation site, 1 ZnF_C4 domain, 1 HOLI domain and 1 LCR domain. Also, its secondary structure is mainly randomly curly. Nucleotide sequence analysis revealed that the gene nucleotide sequence of Lanzhou fat-tail sheep is similar with those of the capra（99%）, bos（98%）, bubalus（97%）, ovis（99%）, orcinus（94%）, sus（92%） and homo（90%）. The similarity of amino acid sequence of PPARG between Lanzhou fat-tailed sheep and capra, bos, bubalus, ovis, orcinus, sus and homo are 100%, 99.8%, 100%, 100%, 98.7%, 98.5% and 97.5%. The phylogenetic tree indicates that L