Adaptation to high-altitude hypoxia is essential for domestic animals, such as yak, Tibetan chicken, and Tibetan sheep, living on high plateaus, as it ensures efficient oxygen absorption and utilization. Red blood cells are the primary medium for transporting oxygen in the blood. However, little is known about the genetic mechanism of erythrocyte traits. Genome-wide association studies (GWASs) based on single markers or haplotypes have identified potential mechanisms for genetic variation and quantitative traits. To identify loci associated with erythrocyte traits, we performed a GWAS based on the method of the single marker and haplotype in 498 Alpine Merino sheep for six erythrocyte traits: red blood cell count (RBC), hemoglobin (HGB), hematocrit (HCT), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and RBC volume distribution width coefficient of variation (RWD_CV). Forty-two significant single-nucleotide polymorphisms (SNPs) associated with the six erythrocyte traits were detected by means of a single-marker GWAS, and 34 significant haplotypes associated with five erythrocyte traits were detected by means of haplotype analysis. We identified six genes (DHCR24, SPATA9, FLI1, PLCB1, EFNB2, and SH2B3) as potential genes of interest via gene function annotations, location, and expression variation. In particular, FLI1 and PLCB1 were associated with hematopoiesis and erythropoiesis, respectively. These results provide a theoretical basis for analyzing erythrocyte traits and high-altitude hypoxia adaptation in Alpine Merino sheep and will be a useful reference for future studies of plateau-dwelling livestock.

适应高海拔缺氧对于生活在高原上的domestic牛，藏鸡和藏绵羊等家畜至关重要，因为它可以确保有效地吸收和利用氧气。红细胞是在血液中运输氧气的主要介质。但是，关于红细胞性状的遗传机制知之甚少。基于单个标记或单倍型的全基因组关联研究（GWAS）已确定了遗传变异和数量性状的潜在机制。为了确定与红细胞性状相关的基因座，我们基于单一标记和单倍型方法对498例美利奴绵羊的六种红细胞性状进行了GWAS：红细胞计数（RBC），血红蛋白（HGB），血细胞比容（HCT），平均血红蛋白（MCH），平均血红蛋白浓度（MCHC），和RBC体积分布宽度变异系数（RWD_CV）。通过单标记GWAS检测到与六个红细胞性状相关的42个重要的单核苷酸多态性（SNP），并通过单倍型分析检测与34个与五个红细胞性状相关的重要单倍型。我们鉴定了六个基因（DHCR24，SPATA9，FLI1，PLCB1，EFNB2和 SH2B3）作为潜在的感兴趣基因，通过基因功能注释，位置和表达变异来实现。尤其是，FLI1 和 PLCB1分别与造血和红细胞生成有关。这些结果为分析高山美利奴绵羊的红细胞特性和高原低氧适应提供了理论基础，并将为今后对高原家畜的研究提供有用的参考。