猪LPL基因多态性及其部分DNA片段的测序

STUDY ON THE POLYMORPHISM OF PORCINE LIPOPROTEIN LIPASE GENE AND SEQUENCING THE PARTIAL DNA FRAGMENTS

脂蛋白脂肪酶（Ｌｉｐｏｐｒｏｔｅｉｎｌｉｐａｓｅ，ＬＰＬ） 是影响动物脂肪沉积的关键酶之一。本文利用ＰＣＲＳＳＣＰ法，对猪的ＬＰＬ基因进行了多态性分析，发现其５’端区域存在ＤＮＡ 多态性。脂肪型猪种梅山猪和通城猪表现出３种等位基因型（ＡＡ、ＡＢ、ＢＢ） ，其等位基因Ａ和Ｂ的频率分别为０．７６、０ ．２４ 和０．７７、０ ．２３ ；而瘦肉型猪种长白猪和大白猪表现出另外不同的３ 种等位基因型（ ＣＣ、ＣＤ、ＤＤ），其等位基因Ｃ和Ｄ 的频率分别为０．７６ 、０ ．２４ 和０．７２、０．２８ 。测序结果表明具四种等位基因纯合子的ＤＮＡ 片段之间存在５ 处碱基突变，分别表示为等位基因ＡＡＴＣＣＴ，ＢＡＴＴＣＴ，ＣＧＣＣＣＴ和ＤＧＣＣＧＣ，其中等位基因Ｄ 第＋ ３２ 处发生Ｔ／Ｃ 的突变导致亮氨酸到脯氨酸的改变（Ｌｅｕ→Ｐｒｏ） 。

Lipoprotein lipase (LPL) is a key enzyme for the hydrolysis of circulating triacylglycerols. In this paper, the polymorphisms in 5'untranslate part of the LPL gene was revealed with seven pairs of PCR primers. The fat type pig breeds Meishan and Tongcheng had three genotypes ( AA, AB and BB ), with allele frequencies of 0.76 A , 0.24 B and 0.77 A , 0.23 B , respectively;however, the lean type pig breeds Landrace and the Large white were showed to have three different genotypes ( CC, CD and DD ), with allele frequencies of 0.76 C , 0.24 D and 0.72 C , 0.28 D , respectively. The fragments representing the different LPL genotypes AA、BB、CC and DD were sequenced. Five polymorphic allele were detected, given the haplotypes A : ATCCT, B : ATTCT, C : GCCCT, and D : GCCGC. The T/C polymorphism at the last one resulted in a Leu→Pro shift at amino acid 11 in the LPL protein.\;