Bos taurus genome sequence reveals the assortment of immunoglobulin and surrogate light chain genes in domestic cattle
Bos taurus genome sequence reveals the assortment of immunoglobulin and surrogate light chain genes in domestic cattle
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DOI：
10.1186/1471-2172-10-22
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发表时间：
2009-04-30
期刊：
影响因子：
3
通讯作者：
Iivanainen, Antti
中科院分区：
文献类型：
--
作者：
Ekman, Anna;Niku, Mikael;Iivanainen, Antti
背景资料：牛免疫球蛋白和替代轻链基因的分类已从3.1版本的牛基因组序列中提取，作为国际努力的一部分，以测序和注释牛genome.Results：63可变λ链和22可变κ链基因被鉴定，并在遗传学上分别分配到8和4个亚组。指定的系统发育关系与已建立的反刍动物轻链可变基因家族或亚组相容。由于组装的基因组序列中的缺口和不确定性，基因的数量可能会在未来版本的基因组序列中发生变化。此外，还鉴定了3个牛替代轻链基因。结论：牛Kappa基因位点结构紧凑，结构简单，可能反映了λ链在牛中的优先使用。在这两个基因座的可变和连接基因的相对取向是一致的VJ连接的缺失机制。根据现有数据无法确定某些可变基因的方向。与人或小鼠相比，功能可变基因的数量是中等的。因此，后重组机制可能有助于牛免疫前抗体库的产生。重链可能比轻链对重组免疫球蛋白库多样性的贡献更大，但重链基因座不能从牛基因组3.1版本中注释。
Background: The assortment of cattle immunoglobulin and surrogate light chain genes has been extracted from the version 3.1 of Bos taurus genome sequence as a part of an international effort to sequence and annotate the bovine genome.Results: 63 variable lambda chain and 22 variable kappa chain genes were identified and phylogenetically assigned to 8 and 4 subgroups, respectively. The specified phylogenetic relationships are compatible with the established ruminant light chain variable gene families or subgroups. Because of gaps and uncertainties in the assembled genome sequence, the number of genes might change in the future versions of the genome sequence. In addition, three bovine surrogate light chain genes were identified. The corresponding cDNAs were cloned and the expression of the surrogate light chain genes was demonstrated from fetal material.Conclusion: The bovine kappa gene locus is compact and simple which may reflect the preferential use of the lambda chain in cattle. The relative orientation of variable and joining genes in both loci are consistent with a deletion mechanism in VJ joining. The orientation of some variable genes cannot be determined from the data available. The number of functional variable genes is moderate when compared to man or mouse. Thus, post-recombinatorial mechanisms might contribute to the generation of the bovine pre-immune antibody repertoire. The heavy chains probably contribute more to recombinational immunoglobulin repertoire diversity than the light chains but the heavy chain locus could not be annotated from the version 3.1 of Bos taurus genome.