Pegoraro L, Yang Z, Samaké S, Meirelles F V, Bordingnon V, Moquin L C, Smith L C
Centre de recherche en reproduction animale (CRRA), Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada.
Anim Genet. 1996 Apr;27(2):91-4. doi: 10.1111/j.1365-2052.1996.tb00473.x.
Although the complete bovine mitochondrial DNA molecule has been previously sequenced and sequence comparisons of the mitochondrial displacement loop have been performed, detailed sequence information is limited on coding regions of mitochondrial DNA within and among breeds of Bos taurus and Bos indicus. This study analysed polymorphism of the mitochondrial DNA transfer RNA genes for tryptophan, alanine, asparagine, cysteine, tyrosine and the origin of light strand replication among Ayrshire, Canadian, Belgium Blue, Brown Swiss, Hereford, Jersey, Limousine, Piedmontaise, Red Angus, Simmental (Bos taurus) and a Nellore (Bos indicus). Nucleotide sequence analysis of a 420-bp fragment of mitochondrial DNA comprising the five transfer RNA genes showed 100% homology among single individuals of the Bos taurus breeds. The Nellore breed showed guanine to adenine substitutions in the DHU arm of asparagine tRNA and in the origin of light-strand replication. This equates to a 0.5% sequence difference between the Nellore and Bos taurus breeds and may reflect an independent evolutionary origin of the species.
尽管完整的牛线粒体DNA分子此前已被测序，并且已对线粒体置换环进行了序列比较，但关于瘤牛和印度瘤牛品种内及品种间线粒体DNA编码区的详细序列信息仍然有限。本研究分析了艾尔斯牛、加拿大牛、比利时蓝牛、瑞士褐牛、赫里福德牛、泽西牛、利木赞牛、皮埃蒙特牛、红安格斯牛、西门塔尔牛（瘤牛）和内洛尔牛（印度瘤牛）的线粒体DNA中色氨酸、丙氨酸、天冬酰胺、半胱氨酸、酪氨酸的转运RNA基因的多态性以及轻链复制起点。对包含五个转运RNA基因的线粒体DNA的一个420碱基对片段进行核苷酸序列分析，结果显示瘤牛品种的单个个体之间具有100%的同源性。内洛尔牛品种在天冬酰胺tRNA的DHU臂和轻链复制起点出现了鸟嘌呤到腺嘌呤的替换。这相当于内洛尔牛和瘤牛品种之间存在0.5%的序列差异，可能反映了该物种独立的进化起源。
