背景:Djallonke绵羊很好地适应了恶劣的环境条件,并且对血细胞病具有相对抵抗力,对动物锥虫病具有抵抗力。更大的萨赫勒羊,同居同一地区,不太适应这些疾病的挑战。血细胞病和锥虫病每年共同使全球畜牧业损失数十亿美元的生产损失。
结果:这里,我们分别对Djallonke和Sahelian绵羊品种(来自加纳)的五个无关个体的基因组进行了测序,然后根据品种进行汇总,每个品种的综合覆盖率超过22倍。来自Djallonke和Sahelian品种的总共约4.04亿(97%)和3.43亿(97%)的序列读数,已成功映射到绵羊参考基因组Oarv3.1。我们在Djallonke和Sahelian品种中发现了大约11100万个和1090万个单核苷酸多态性(SNP),分别有大约15%和16%的这些以前没有在绵羊中报道过。还发现了多个杂合性降低的区域;70个共定位在基因组区域内,这些基因具有介导疾病抗性的基因,绵羊或牛的免疫反应和适应。杂合性降低的区域中的33个与先前报道的对血红蛋白和锥虫病具有抗性的基因共定位。
结论:我们的分析表明,这些杂合性降低的区域可能是这些经济上重要的疾病的选择特征。
BACKGROUND: The Djallonke sheep is well adapted to harsh environmental conditions, and is relatively resistant to Haemonchosis and resilient to animal trypanosomiasis. The larger
Sahelian sheep, which cohabit the same region, is less well adapted to these disease challenges. Haemonchosis and Trypanosomiasis collectively cost the worldwide animal industry billions of dollars in production losses annually.
RESULTS: Here, we separately sequenced and then pooled according to breed the genomes from five unrelated individuals from each of the Djallonke and
Sahelian sheep breeds (sourced from Ghana), at greater than 22-fold combined coverage for each breed. A total of approximately 404 million (97%) and 343 million (97%) sequence reads from the Djallonke and
Sahelian breeds respectively, were successfully mapped to the sheep reference genome Oar v3.1. We identified approximately 11.1 million and 10.9 million single nucleotide polymorphisms (SNPs) in the Djallonke and
Sahelian breeds, with approximately 15 and 16% respectively of these not previously reported in sheep. Multiple regions of reduced heterozygosity were also found; 70 co-localised within genomic regions harbouring genes that mediate disease resistance, immune response and adaptation in sheep or cattle. Thirty- three of the regions of reduced heterozygosity co-localised with previously reported genes for resistance to haemonchosis and trypanosomiasis.
CONCLUSIONS: Our analyses suggest that these regions of reduced heterozygosity may be signatures of selection for these economically important diseases.