College of Agriculture, Family Sciences, and Technology, Fort Valley State University, Fort Valley, GA 31030, USA; Department of Animal Sciences, University of Florida, Gainesville, FL, USA.
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
Int J Parasitol. 2021 Jun;51(7):535-543. doi: 10.1016/j.ijpara.2020.11.003. Epub 2021 Feb 5.
Florida Native sheep is among the sheep breeds best adapted to humid and hot climatic conditions such as those of Florida, USA, and have shown a superior ability to regulate nematode burdens. This is one of the oldest sheep breeds in North America and is an endangered species. To ensure genetic diversity and long-term survival of the breed, protection of the current genetic stock is critical and conservation efforts are required to promote its breeding and production. The objective of the present study was to investigate the importance of additive and non-additive genetic effects on resistance to natural Haemonchus contortus infections in Florida Native sheep using a whole genome scan. A total of 200 sheep were evaluated in the present study. Phenotypic records included faecal egg count (FEC, eggs/gram), FAMACHA® score, packed cell volume (PCV, %), body condition score and average daily gain (ADG, kg). Sheep were genotyped using the GGP Ovine 50K SNP chip and 45.2 k single nucleotide polymorphism (SNP) markers spanning the entire genome were available for quality control procedures. Mixed models were used to analyse the response variables and included the identity by state matrix to control for population structure. Bonferroni correction was used to control for multiple testing and a second arbitrary threshold (0.1 × 10) was used. Fifteen SNPs with additive and non-additive genetic effects and located in Ovis aries chromosome OAR1, 2, 3, 6, 8, 10, 11, 12, 13 and 21 were associated with FEC, FAMACHA® score, PCV and ADG. These SNPs could be potential genetic markers for resistance to natural H. contortus exposure in Florida Native sheep.
佛罗里达原生绵羊是最适应美国佛罗里达州潮湿和炎热气候条件的绵羊品种之一，具有出色的调节线虫负担的能力。这是北美的最古老的绵羊品种之一，也是濒危物种。为了确保品种的遗传多样性和长期生存，保护当前的遗传资源至关重要，需要保护努力来促进其繁殖和生产。本研究的目的是使用全基因组扫描研究加性和非加性遗传效应对佛罗里达原生绵羊对自然感染捻转血矛线虫的抗性的重要性。本研究共评估了 200 只绵羊。表型记录包括粪便虫卵计数（FEC，每克卵）、FAMACHA®评分、红细胞压积（PCV，%）、体况评分和平均日增重（ADG，kg）。绵羊使用 GGP 绵羊 50K SNP 芯片进行基因分型，共有 45.2k 个单核苷酸多态性（SNP）标记覆盖整个基因组，可用于质量控制程序。混合模型用于分析响应变量，并包括状态矩阵以控制群体结构。使用 Bonferroni 校正控制多重检验，并使用第二个任意阈值（0.1×10）。15 个具有加性和非加性遗传效应的 SNP 与 FEC、FAMACHA®评分、PCV 和 ADG 相关，位于 Ovis aries 染色体 OAR1、2、3、6、8、10、11、12、13 和 21 上。这些 SNP 可能是佛罗里达原生绵羊对自然 H. contortus 暴露抗性的潜在遗传标记。
