Single nucleotide polymorphisms in the growth hormone-insulin-like growth factor axis in straightbred and crossbred Angus, Brahman, and Romosinuano heifers: Population genetic analyses and association of genotypes with reproductive phenotypes
Single nucleotide polymorphisms in the growth hormone-insulin-like growth factor axis in straightbred and crossbred Angus, Brahman, and Romosinuano heifers: Population genetic analyses and association of genotypes with reproductive phenotypes
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DOI：
10.2527/jas.2010-3483
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发表时间：
2011-04-01
影响因子：
3.3
通讯作者：
Thomas, M. G.
中科院分区：
文献类型：
--
作者：
Luna-Nevarez, P.;Rincon, G.;Thomas, M. G.
生长内分泌轴影响生殖。本研究的目的是评估GH-IGF轴基因内GH-IGF轴基因的SNP基因型在安格斯、婆罗曼和Romosinuano纯种小母牛(n=650)中的群体遗传特征，并测试这些基因型与繁殖指标的相关性。这些目标是通过使用5号染色体上7个基因中的73个SNP以及分别定位到第16和20号染色体的妊娠相关血浆蛋白A2(PAPP-A2)和生长激素受体基因来实现的。通过使用多品种发现群体中与家族无关的牛的DNA对每个基因的保守区进行重新测序，从而阐明了SNP。多重SNP分析产生59个双等位SNP，可用于评估遗传同一性和距离。具体地说，在5个受牛群影响的品种群中，直系婆罗门牛的差异约为15.5%。在作为验证群体的直系群体中，只有3个SNP具有微小的等位基因频率>；10%。这些SNP分别位于PAPP-A2基因(内含子10内的ss115492449-A/C和ss115492450-G/T)和转录信号转导和激活因子2(STAT2；5‘非翻译区的ss252841035-A/G)中，符合Hardy-Weinberg平衡条件(P&gT；0.31)。另外56个SNP用于将每个动物归入祖先群(n=3个比例)，以解释基因与表型关联分析中的群体分层。PAPP-A2基因中的2个SNP影响(P<；0.05)指示第一胎小母牛繁殖的性状(即产犊间隔、产犊天数和妊娠率)。STAT2 SNP基因型(即GG)x初级祖先聚类互作(P<；0.05)表明，与主要作为公牛祖先的小母牛相比，主要是金牛血统的小母牛在产犊间隔和产犊天数上减少了约16.4+/-0.1%。尽管还需要进一步研究GH-IGF轴基因的等位基因变异，但本研究结果支持STAT2和PAPP-A2作为与第一胎小母牛繁殖性状相关的潜在候选基因。
The growth endocrine axis influences reproduction. The objectives of this study were to evaluate population genetic characteristics of SNP genotypes within genes of the GH-IGF axis in straightbred and crossbred Angus, Brahman, and Romosinuano heifers (n = 650) and to test the association of these genotypes with measures of reproduction. These objectives were achieved using 73 SNP within 7 genes on chromosome 5 and the pregnancy-associated plasma protein A2 (PAPP-A2) and GH-receptor genes, which map to chromosomes 16 and 20, respectively. The SNP were elucidated by resequencing conserved regions of each gene by using DNA from familial-unrelated cattle of a multibreed discovery population. A multiplex SNP assay yielded 59 biallelic SNP useful for evaluating genetic identity and distance. Specifically, the divergence of straightbred Brahman cattle was approximately 15.5% from 5 Bos taurus-influenced breed groups. In the straightbred groups used as a validation population, only 3 SNP had minor allele frequencies > 10%. These SNP were in the genes PAPP-A2 (ss115492449-A/C and ss115492450-G/T within intron 10) and signal transducers and activators of transcription 2 (STAT2; ss252841035-A/G within the 5' untranslated region), and they met the conditions of Hardy-Weinberg equilibrium (P > 0.31). The other 56 SNP were useful for assigning each animal into ancestral clusters (n = 3 proportions) to account for population stratification in genotype to phenotype association analyses. The 2 SNP in the PAPP-A2 gene influenced (P < 0.05) traits indicative of first-calf heifer rebreeding (i.e., calving interval, days to calving, and pregnancy rate). A STAT2 SNP genotype (i.e., GG) x primary ancestral cluster interaction (P < 0.05) suggested heifers primarily of B. taurus ancestry had a reduction of approximately 16.4 +/- 0.1% in calving interval and days to calving relative to heifers clustering primarily as Bos indicus ancestry. Even though additional research is needed to delineate the allelic variation attributed to genes of the GH-IGF axis, results of this study provide support for STAT2 and PAPP-A2 as potential candidate genes associated with first-calf heifer rebreeding traits.