Department of Veterinary Biosciences, University of Helsinki, PO Box 66, FI-00014 University of Helsinki, Finland.
Dev Comp Immunol. 2012 Jul;37(3-4):457-61. doi: 10.1016/j.dci.2012.02.006. Epub 2012 Feb 25.
A comprehensive analysis of cattle shotgun sequencing data reveals 36 immunoglobulin heavy chain variable genes. The previously described bovine subgroup IGHV1 contains 10 functional genes with a conserved promoter including the consensus octamer and several other transcription factor binding sites, intact exons and matching cDNA sequences. Subgroups IGHV2 and IGHV3 consist entirely of pseudogenes. Thus, the bovine germline IGHV repertoire is very limited. The IGHV genes are distributed in mammalian clans I and II, while no clan III genes were detected. Clan-specific PCR of genomic DNA from cattle, sheep, Eurasian elk, white-tailed deer, pig and dolphin indicates highly dynamic evolution of IGHV gene usage within Cetartiodactyla. The bovine germline IGHV repertoire was probably generated by recent duplications of an IGHV1-IGHV2 homology unit. Immunoglobulin heavy chain genes are largely incorrectly assembled in the current cattle genome versions Btau_4.2 and UMD_3.1. FISH experiments confirm an IGHV locus close to terminus of BTA21.
对牛 shotgun 测序数据的综合分析揭示了 36 个免疫球蛋白重链可变基因。先前描述的牛亚群 IGHV1 包含 10 个具有保守启动子的功能基因，包括共识八聚体和其他几个转录因子结合位点、完整的外显子和匹配的 cDNA 序列。亚群 IGHV2 和 IGHV3 完全由假基因组成。因此，牛种系 IGHV 库非常有限。IGHV 基因分布在哺乳动物的 I 族和 II 族，而没有检测到 III 族基因。来自牛、绵羊、欧亚驼鹿、白尾鹿、猪和海豚的基因组 DNA 的族特异性 PCR 表明，在鲸偶蹄目动物中，IGHV 基因的使用发生了高度动态的进化。牛种系 IGHV 库可能是由 IGHV1-IGHV2 同源单元的近期重复产生的。当前的牛基因组版本 Btau_4.2 和 UMD_3.1 中，免疫球蛋白重链基因在很大程度上是错误组装的。荧光原位杂交 (FISH) 实验证实 IGHV 基因座靠近 BTA21 的末端。
