Cattle Genomics Lab, National Bureau of Animal Genetics Resources, P.O. Box 129, Karnal, 132 001, Haryana, India.
Mol Biol Rep. 2013 Jul;40(7):4473-81. doi: 10.1007/s11033-013-2539-x. Epub 2013 May 9.
Regulatory region of milk protein alpha S2-casein (αS2-CN) gene sequence was characterized and analyzed for nucleotide variations in animals representing 13 Indian zebu cattle (Bos indicus) breeds. A total of 15 variations; 11 in promoter region (1.56 Kb): -1481 (C>T), -1412 (C>T), -1342 (C>T), -1084 (G>A), -979 (A>G), -657 (A>T), -508 (A>G), -186 (T>C), -184 (T>C), -151 (T>C) and -135 (C>T); 1 in 5'-UTR (44 bp): 7 (C>T) while, 3 in intron-I region (73 bp): 186 (C>T), 194 (A>C) and 301 (A>T) were identified. Additionally, single deletion was observed at -975 (A>-) but not involve any known potential transcription factor binding sites (TFBS). Comparison with Bos taurus sequence revealed two additional variations -1085 (T>C) and -739 (A>G). Out of the total 18 variations observed between indicine and taurine αS2-CN regulatory region sequence, 15 were novel to B. indicus and are reported for the first time. Among these, four variations were located within the potential TFBSs; -1342 (C>T) within HNF-3beta, -739 (A>G) within C/EBP-alpha while -657 (A>T) and -508 (A>G) were found within glucocorticoid receptor TFBSs. Variations located within or in proximity to putative TFBSs could possibly influence the binding affinity of nuclear factors towards DNA binding domains, thus affecting transcriptional rate of αS2-CN gene. Phylogenetically, as expected, Indian zebu cattle were grouped close to B. taurus and were most distantly placed in comparison to human. The study indicated possible genetic variations in the regulatory regions of αS2-CN gene within Indian native cattle (B. indicus) and also its comparison with evolutionary different B. taurus breeds.
对代表 13 个印度瘤牛（Bos indicus）品种的动物的乳蛋白α S2-酪蛋白（αS2-CN）基因序列的调控区进行了特征描述和核苷酸变异分析。共发现 15 种变异；11 种位于启动子区域（1.56 Kb）：-1481（C>T）、-1412（C>T）、-1342（C>T）、-1084（G>A）、-979（A>G）、-657（A>T）、-508（A>G）、-186（T>C）、-184（T>C）、-151（T>C）和-135（C>T）；1 种位于 5'-UTR（44 bp）：7（C>T），而 3 种位于内含子-I 区域（73 bp）：186（C>T）、194（A>C）和 301（A>T）。此外，在-975（A> -）处观察到单个缺失，但不涉及任何已知的潜在转录因子结合位点（TFBS）。与 Bos taurus 序列的比较显示出另外两个额外的变异-1085（T>C）和-739（A>G）。在 indicine 和 taurine αS2-CN 调控区序列之间观察到的总共 18 个变异中，有 15 个是 B. indicus 所特有的，这是首次报道。其中，四个变异位于潜在的 TFBS 内；-1342（C>T）位于 HNF-3beta 内，-739（A>G）位于 C/EBP-alpha 内，而-657（A>T）和-508（A>G）位于糖皮质激素受体 TFBS 内。位于潜在 TFBS 内或附近的变异可能会影响核因子与 DNA 结合域的结合亲和力，从而影响αS2-CN 基因的转录速率。从进化的角度来看，与预期的一样，印度瘤牛与 B. taurus 关系密切，与人类的关系最远。该研究表明，在印度本土牛（B. indicus）的αS2-CN 基因调控区可能存在遗传变异，同时也与进化上不同的 B. taurus 品种进行了比较。
