Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada.
Department of Pathobiology, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada.
Genes (Basel). 2024 Jan 30;15(2):187. doi: 10.3390/genes15020187.
Gastrointestinal nematodes (GINs) can be a major constraint and global challenge to the sheep industry. These nematodes infect the small intestine and abomasum of grazing sheep, causing symptoms such as weight loss, diarrhea, hypoproteinemia, and anemia, which can lead to death. The use of anthelmintics to treat infected animals has led to GIN resistance, and excessive use of these drugs has resulted in residue traced in food and the environment. Resistance to GINs can be measured using multiple traits, including fecal egg count (FEC), Faffa Malan Chart scores, hematocrit, packed cell volume, eosinophilia, immunoglobulin (Ig), and dagginess scores. Genetic variation among animals exists, and understanding these differences can help identify genomic regions associated with resistance to GINs in sheep. Genes playing important roles in the immune system were identified in several studies in this review, such as the and genes. Results from several studies showed overlapping quantitative trait loci (QTLs) associated with multiple traits measuring resistance to GINs, mainly FEC. The discovery of genomic regions, positional candidate genes, and QTLs associated with resistance to GINs can help increase and accelerate genetic gains in sheep breeding programs and reveal the genetic basis and biological mechanisms underlying this trait.
胃肠道线虫（GINs）可能是绵羊产业的主要制约因素和全球性挑战。这些线虫感染放牧绵羊的小肠和皱胃，导致体重减轻、腹泻、低蛋白血症和贫血等症状，严重时可导致死亡。使用驱虫药治疗感染动物会导致 GIN 耐药性，这些药物的过度使用会导致食品和环境中的残留。可以使用多种特征来衡量对 GIN 的耐药性，包括粪便虫卵计数（FEC）、Faffa Malan 图表评分、红细胞压积、红细胞比容、嗜酸性粒细胞、免疫球蛋白（Ig）和暗淡评分。动物之间存在遗传变异，了解这些差异有助于确定与绵羊对 GIN 耐药性相关的基因组区域。在本综述的几项研究中，确定了免疫系统中发挥重要作用的基因，如 和 基因。几项研究的结果表明，与多个衡量对 GIN 耐药性的特征相关的重叠数量性状位点（QTL）主要是 FEC。发现与 GIN 耐药性相关的基因组区域、候选基因和 QTL 有助于增加和加速绵羊育种计划中的遗传进展，并揭示该性状的遗传基础和生物学机制。
