Animal Breeding and Genomics Centre, Wageningen University and Research Centre, Wageningen, the Netherlands.
BMC Genet. 2010 Feb 8;11:11. doi: 10.1186/1471-2156-11-11.
Although several genetic linkage maps of the chicken genome have been published, the resolution of these maps is limited and does not allow the precise identification of recombination hotspots. The availability of more than 3.2 million SNPs in the chicken genome and the recent advances in high throughput genotyping techniques enabled us to increase marker density for the construction of a high-resolution linkage map of the chicken genome. This high-resolution linkage map allowed us to study recombination hotspots across the genome between two chicken populations: a purebred broiler line and a broiler x broiler cross. In total, 1,619 animals from the two different broiler populations were genotyped with 17,790 SNPs.
The resulting linkage map comprises 13,340 SNPs. Although 360 polymorphic SNPs that had not been assigned to a known chromosome on chicken genome build WASHUC2 were included in this study, no new linkage groups were found. The resulting linkage map is composed of 31 linkage groups, with a total length of 3,054 cM for the sex-average map of the combined population. The sex-average linkage map of the purebred broiler line is 686 cM smaller than the linkage map of the broiler x broiler cross.
In this study, we present a linkage map of the chicken genome at a substantially higher resolution than previously published linkage maps. Regional differences in recombination hotspots between the two mapping populations were observed in several chromosomes near the telomere of the p arm; the sex-specific analysis revealed that these regional differences were mainly caused by female-specific recombination hotspots in the broiler x broiler cross.
尽管已经发表了几个鸡基因组的遗传连锁图谱，但这些图谱的分辨率有限，无法精确定位重组热点。鸡基因组中存在超过 320 万个 SNP，以及高通量基因分型技术的最新进展，使我们能够增加标记密度，构建鸡基因组的高分辨率连锁图谱。该高分辨率连锁图谱使我们能够研究两个鸡群体（纯系肉鸡品系和肉鸡 x 肉鸡杂交群体）之间整个基因组中的重组热点。总共对来自两个不同肉鸡群体的 1619 只动物进行了 17790 个 SNP 的基因分型。
所得到的连锁图谱包含 13340 个 SNP。尽管本研究包括了 360 个未分配到鸡基因组 WASHUC2 构建版已知染色体上的多态 SNP，但未发现新的连锁群。所得到的连锁图谱由 31 个连锁群组成，在合并群体的性别平均图谱中，总长度为 3054cM。纯系肉鸡品系的性别平均连锁图谱比肉鸡 x 肉鸡杂交的连锁图谱小 686cM。
在这项研究中，我们提出了一个鸡基因组的连锁图谱，其分辨率高于先前发表的连锁图谱。在两个作图群体的几个靠近 p 臂端粒的染色体上观察到重组热点的区域差异；性别特异性分析表明，这些区域差异主要是由肉鸡 x 肉鸡杂交中的雌性特异性重组热点引起的。
