Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom.
The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom.
PLoS Genet. 2022 Apr 21;18(4):e1010099. doi: 10.1371/journal.pgen.1010099. eCollection 2022 Apr.
East Coast fever, a tick-borne cattle disease caused by the Theileria parva parasite, is among the biggest natural killers of cattle in East Africa, leading to over 1 million deaths annually. Here we report on the genetic analysis of a cohort of Bos indicus (Boran) cattle demonstrating heritable tolerance to infection with T. parva (h2 = 0.65, s.e. 0.57). Through a linkage analysis we identify a 6 Mb genomic region on bovine chromosome 15 that is significantly associated with survival outcome following T. parva exposure. Testing this locus in an independent cohort of animals replicates this association with survival following T. parva infection. A stop gained variant in a paralogue of the FAF1 gene in this region was found to be highly associated with survival across both related and unrelated animals, with only one of the 20 homozygote carriers (T/T) of this change succumbing to the disease in contrast to 44 out of 97 animals homozygote for the reference allele (C/C). Consequently, we present a genetic locus linked to tolerance of one of Africa's most important cattle diseases, raising the promise of marker-assisted selection for cattle that are less susceptible to infection by T. parva.
东非裂谷热，一种由泰勒氏梨形虫寄生虫引起的蜱传牛病，是东非地区导致牛死亡的主要自然杀手之一，每年导致超过 100 万头牛死亡。在这里，我们报告了对一批印度野牛（Boran）牛的遗传分析，这些牛表现出对感染泰勒氏梨形虫（T. parva）的遗传耐受性（h2 = 0.65，s.e. 0.57）。通过连锁分析，我们在牛 15 号染色体上确定了一个与 T. parva 暴露后的存活结果显著相关的 6 Mb 基因组区域。在另一批动物中测试这个基因座，复制了与 T. parva 感染后存活的关联。在这个区域中，一个 FAF1 基因的同源基因的获得性终止变异与存活高度相关，在这两个相关和不相关的动物中，只有 20 个这种变化的纯合子携带者（T/T）患病，而 97 个参考等位基因（C/C）的纯合子动物中有 44 个患病。因此，我们提出了一个与非洲最重要的牛病之一的耐受性相关的遗传基因座，为对 T. parva 感染敏感性较低的牛提供了标记辅助选择的希望。
