Genomewide Mapping of Selection Signatures and Genes for Extreme Feather Pecking in Two Divergently Selected Laying Hen Lines
Genomewide Mapping of Selection Signatures and Genes for Extreme Feather Pecking in Two Divergently Selected Laying Hen Lines
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DOI：
10.3390/ani10020262
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发表时间：
2020-02-01
期刊：
影响因子：
3
通讯作者：
Bennewitz, Joern
中科院分区：
文献类型：
--
作者：
Iffland, Hanna;Wellmann, Robin;Bennewitz, Joern
简单概述啄羽是商业蛋鸡群中经常发生的一种行为。它经常会导致皮肤损伤和吃人。除了经济损失，严重的动物福利问题也不容忽视。此前的研究表明，这一特征是可遗传的。因此，进行抗啄羽的育种是可能的，但目前在商业环境中进行表型鉴定在经济上是不可行的，因为缺乏适当的技术。因此，了解该性状的遗传背景是建立基因组育种计划的必要条件。这将需要母鸡的基因类型信息，这在实际条件下是可行的。在目前的研究中，我们使用了不同的方法来识别基因组中影响啄羽和极端啄羽的区域。我们发现了一个与基因组区域相关的特征。在针对不受欢迎的行为进行选择方面，利用该区域的基因分型信息可能有助于改善蛋鸡群的动物福利。啄羽(FP)是商品蛋鸡群长期存在的严重问题。这是一种高度多基因的性状，其遗传背景尚不完全清楚。为了寻找影响FP的基因组区域，利用群体内IHS和群体间F-ST方法对不同选择的高羽和低羽蛋鸡品系之间的选择特征进行了定位。此外，通过对数据进行负二项分布的混合拟合和计算每只母鸡属于极端亚群(PEFP)的后验概率，证明了在两个选定的品系中都存在FP母鸡的极端亚群(EFP)。对pEFP和FP传递(FPD)的性状进行了全基因组关联研究(GWAS)，随后进行了GWAS后的分析。选择标记的作图显示没有明确的选择区域。Gwas在1号染色体上发现了一个区域，在该区域中可能存在影响FP的QTL。在该区域发现的候选基因是GABA能系统的一部分，在之前的研究中已经发现该系统与FP有关。尽管FP具有多基因性质，但对这些候选基因的选择可能会降低FP。
Simple Summary Feather pecking is a behavior frequently occurring in commercial layer flocks. It often leads to skin injuries and cannibalism. Besides economic losses, severe animal welfare problems cannot be ignored. Previous research has shown that the trait is heritable. Thus breeding against feather pecking is possible, but phenotyping in a commercial environment is economically unfeasible at the moment because of the lack of proper techniques. Therefore, understanding the genetic background of the trait is mandatory to establish a genomic breeding program. This would require genotypic information of the hens, which is feasible under practical conditions. In the present study, we used different methods to identify regions in the genome that influence feather pecking and extreme feather pecking. We found one trait associated with the genomic region. The use of genotypic information from this region in terms of selection against the undesired behavior may help to improve animal welfare in layer flocks. Feather pecking (FP) is a longstanding serious problem in commercial flocks of laying hens. It is a highly polygenic trait and the genetic background is still not completely understood. In order to find genomic regions influencing FP, selection signatures between laying hen lines divergently selected for high and low feather pecking were mapped using the intra-population iHS and the inter-population F-ST approach. In addition, the existence of an extreme subgroup of FP hens (EFP) across both selected lines has been demonstrated by fitting a mixture of negative binomial distributions to the data and calculating the posterior probability of belonging to the extreme subgroup (pEFP) for each hen. A genomewide association study (GWAS) was performed for the traits pEFP and FP delivered (FPD) with a subsequent post GWAS analysis. Mapping of selection signatures revealed no clear regions under selection. GWAS revealed a region on Chromosome 1, where the existence of a QTL influencing FP is likely. The candidate genes found in this region are a part of the GABAergic system, which has already been linked to FP in previous studies. Despite the polygenic nature of FP, selection on these candidate genes may reduce FP.