Low-Coverage Whole-Genome Sequencing Identifies Loci Associated with Birth Weight in East Friesian × Hu Crossbred Sheep
Abstract
Birth weight is a key early-life trait in sheep that influences neonatal survival and subsequent growth, but its genetic basis remains incompletely understood. Here, we used low-coverage whole-genome sequencing (lcWGS)-based genotyping and genome-wide association analysis (GWAS) to investigate birth weight in 671 East Friesian × Hu crossbred lambs, achieving high imputation accuracy (98.5% allelic concordance). A total of 148 SNPs reached the suggestive significance threshold, of which 20 reached genome-wide significance. Among these signals, the chromosome 7 locus contained 69 suggestive variants spanning an approximately 6 kb interval within the SPATA7 region, including 14 genome-wide significant SNPs. Notably, 13 of these suggestive variants overlapped annotated enhancer intervals, of which 3 reached genome-wide significance. Portions of the associated interval also coincided with pituitary ATAC-seq and liver H3K4me1 ChIP-seq signals. Chr7:98,178,889 A > G, the most strongly associated SNP in this region, showed birth-weight differences among genotypes. Lambs carrying the AG genotype had significantly higher adjusted least-squares mean birth weight than AA lambs (3.81 vs. 3.56 kg; Δ = 0.25 kg, +7.0%). These findings prioritize the SPATA7 region as a candidate regulatory locus for birth-weight variation and provide a basis for future fine-mapping and functional validation.
Publication Title
Animals
Recommended Citation
Bai, Y., Jiao, S., Yang, J., Liu, J., Sun, B., Cao, C., Gao, H., Wang, R., Wang, M., Qin, J., Li, Y., Wang, H., Jiang, Y., & Li, R. (2026). Low-Coverage Whole-Genome Sequencing Identifies Loci Associated with Birth Weight in East Friesian × Hu Crossbred Sheep. Animals, 16 (13) https://doi.org/10.3390/ani16132013
