Abstract:

SNPs of the intron 12 and exon 13 of LAP3 were analyzed by PCR-SSCP, CRS-PCR, PCR-RFLP and sequencing in Chinese Holstein cattles(CH), Luxi Yellow cattles(LY) and Bohai Black cattles(BB). Five SNPs were detected, 24 794（T/G), 24 803(T/C), 24 846（T/C）, 24 564（G/A）and 25 415（T/C）, among them SNP 24 564（G/A） was new. Three SNPs of 24 794（T/G）, 24 803(T/C), 24 846（T/C）were linked completely and detected by PCR-SSCP, but they were not found in Luxi Yellow cattles. The alleles T, T, T, G and T were the dominant alleles in 3 breeds, and the allelic frequencies are T（CH0.579/LY 1/BB 0.722）, T（CH 0.579/LY 1/BB 0.722）, T（CH 0.579/LY 1/BB 0722）, G(CH 0.584/ LY 0.775/BB 0.500) and T (CH 0.596/LY 0.796/BB 0.750). The PIC of the 5 SNPs in these 3 breeds all belong to the midrange polymorphism (0.25<PIC<0.5).

Key words: Bos Taurus, LAP3 gene, single nucleotide polymorphisms (SNPs), dominant allele

摘要：

采用单链构象多态性(single-strand conformation polymorphism,SSCP)、创造酶切位点PCR(created restriction site-PCR, CRS-PCR)、限制性片段长度多态性(restriction fragment length polymorphism, RFLP)以及直接测序方法,研究中国荷斯坦牛、鲁西黄牛和渤海黑牛LAP3基因第12内含子和第13外显子的单核苷酸多态性(SNP)。共检测到5个SNP,分别为24 794（T/G）、24 803(T/C)、24 846（T/C）、24 564（G/A）和25 415（T/C）,其中24 564（G/A）为首次报道的位点。经PCR-SSCP结合测序图谱发现24 794（T/G）、24 803(T/C)、24 846（T/C）位点完全连锁,但该连锁位点在鲁西黄牛群体中未检测到。5个SNP位点在中国荷斯坦牛、鲁西黄牛和渤海黑牛群体的优势等位基因相同,分别是T、T、T、G、T,其等位基因频率分别是T（CH 0.579/LY 1/BB 0.722）、T（CH 0.579/LY 1/BB 0.722）、T（CH 0.579/LY 1/BB 0.722）、G(CH 0.584/ LY 0.775/BB 0.500)和T(CH 0.596/LY 0.796/BB 0.750),多态信息含量均在0.25至0.5之间,属于中度多态。

关键词: 牛;LAP3基因;单核苷酸多态性;单链构象多态性;优势等位基因