Whole-Genome Selective Scans Detect Genes Associated with Cashmere Traits and Climatic Adaptation in Cashmere Goats (Capra hircus) in China

Background: Cashmere, valued for its exceptional softness and warmth, is a major focus in goat breeding due to its high economic importance. However, the molecular mechanisms underlying cashmere production remain largely unknown, hindering efforts to optimize yield and quality. Additionally, domestic goats exhibit remarkable adaptability to diverse climates, ranging from arid northern regions to humid southern areas, yet the genetic basis for these adaptations is poorly understood. Exploring the genetic factors driving cashmere production and climatic adaptation could provide crucial insights into trait evolution and support the development of breeding strategies for improved productivity and resilience. Methods: We utilized whole-genome resequencing data from 157 samples representing 14 goat populations to analyze the genetic diversity between cashmere and non-cashmere breeds. Additionally, we conducted the tests of selective sweeps (i.e., pairwise FST, theta pi and XP-EHH) for cashmere traits and genome-environment association analysis (i.e., XtX statistic), respectively. Results: We identified strong selective signatures in previous reports (e.g., AKT3, FOXP1, FGF5, TGFBR3) and novel genes (e.g., ZEB1, ZNRF3, MAPK8IP3, MAPK8IP2, AXIN1) associated with cashmere traits. Further gene annotation and KEGG analyses showed that these genes were identified to be the most probable genes accounting for the cashmere traits. Also, we detected some genes such as PDGFRB, PRDM8, SLC26A2, SCAMP1, EPHX1, CDC25A, and POLK that played critical roles in the adaptation of goats to local climate variation. Conclusions: Collectively, our results provide novel insights into the genetic mechanisms underlying the cashmere traits and climatic adaptation, and also identified new genetic markers for genetic improvement in goats.