Russian Research Institute of Farm Animal Genetics and Breeding Branch of the L. K. Ernst Federal Science Centre for Animal Husbandry, Pushkin, St Petersburg, 196601, Russia.
University of Helsinki, FI-00014, Helsinki, Finland.
BMC Genomics. 2019 Apr 4;20(1):270. doi: 10.1186/s12864-019-5605-5.
The Russian White is a gene pool breed, registered in 1953 after crossing White Leghorns with local populations and, for 50 years, selected for cold tolerance and high egg production (EL). The breed has great potential in meeting demands of local food producers, commercial farmers and biotechnology sector of specific pathogen-free (SPF) eggs, the former valuing the breed for its egg weight (EW), EL, age at first egg (AFE), body weight (BW), and the latter for its yield of extraembryonic fluid (YEF) in 12.5-day embryos, ratio of extraembryonic fluid to egg weight, and embryo mass. Moreover, its cold tolerance has been presumably associated with day-old chick down colour (DOCDC) - white rather than yellow, the genetic basis of these traits being however poorly understood.
We undertook genome-wide association studies (GWASs) for eight performance traits using single nucleotide polymorphism (SNP) genotyping of 146 birds and an Illumina 60KBeadChip. Several suggestive associations (p < 5.16*10) were found for YEF, AFE, BW and EW. Moreover, on chromosome 2, an association with the white DOCDC was found where there is an linkage disequilibrium block of SNPs including genes that are responsible not for colour, but for immune resistance.
The obtained GWAS data can be used to explore the genetics of immunity and carry out selection for increasing YEF for SPF eggs production.
俄罗斯白鸡是一个基因库品种，于 1953 年通过将白来航鸡与当地种群杂交后注册，50 年来一直被用于耐寒性和高蛋产量（EL）的选育。该品种在满足当地食品生产商、商业农民和特定无病原体（SPF）鸡蛋生物技术部门的需求方面具有巨大潜力，前者重视该品种的蛋重（EW）、EL、开产日龄（AFE）、体重（BW），后者重视其 12.5 日龄胚胎的胚胎外液产量（YEF）、胚胎外液与蛋重的比例和胚胎质量。此外，其耐寒性可能与雏鸡绒羽颜色（DOCDC）有关——白色而非黄色，但其遗传基础却知之甚少。
我们使用 146 只鸟的单核苷酸多态性（SNP）基因分型和 Illumina 60KBeadChip 对 8 个性能性状进行了全基因组关联研究（GWASs）。发现 YEF、AFE、BW 和 EW 存在几个提示关联（p<5.16*10）。此外，在 2 号染色体上发现了与白色 DOCDC 的关联，其中存在一个包括负责免疫抵抗而非颜色的基因的 SNP 连锁不平衡块。
获得的 GWAS 数据可用于探索免疫遗传学，并开展针对增加 SPF 鸡蛋生产中 YEF 的选择。
