The goat PRLR gene: mRNA expression, association analysis of InDel variants with body weight and growth traits

•The 16 bp InDel of PRLR gene had a significant impact on various traits such as body height and chest width in both yearling and adult goats (P < 0.05).•The growth traits influenced by the 16 bp InDel of PRLR gene showed a significant correlation with body weight (P < 0.01).•The 16 bp InDel variant locus II genotype of the PRLR gene could potentially influence goat growth traits through interactions with transcription factors AP-2α and Sp1. Prolactin is a single-chain peptide hormone produced by the anterior pituitary gland and plays an important role in the reproductive development of mammals. Therefore, we investigated the expression of the PRLR gene in various goat tissues during distinct developmental stages, as well as the correlation between the 16 bp InDel and growth traits in goats. The study findings demonstrated a consistent expression and distribution of PRLR in both yearling and adult goat tissues, with the highest levels observed in the testis. Association analysis showed that in the yearling IMWC goat population (n = 463), this 16 bp InDel variation was associated with body weight (P = 0.026), body height (P = 0.005), body length (P = 0.008), heart girth (P = 0.001), chest depth (P = 0.000075), and chest width (P = 0.005); In the adult IMWC goat population (n = 211), the 16 bp InDel variation was associated with body height (P = 0.011), height across the hip (P = 0.0003), chest depth (P = 0.001), and cashmere fineness (P = 0.022); In all IMWC goat populations (n = 674), this 16 bp InDel was related to body weight (P = 0.042), body height (P = 0.001), body length (P = 0.013), heart girth (P = 0.012), height across the hip (P = 0.038), chest depth (P = 0.001), and chest width (P = 0.006). The bioinformatics analysis has revealed that the significant impact of a 16 bp InDel on growth traits in goats may be attributed to its specific binding to the transcription factors AP-2α and Sp1. These findings suggest that this genetic variant plays a crucial role in the growth and development of goats, making it a valuable DNA marker for selecting goats with superior growth traits.