Whole genome and transcriptome analyses in dairy goats identify genetic markers associated with high milk yield

Milk production is the most important economic trait of dairy goats and a key indicator for genetic improvement and breeding. However, milk yield is a complex phenotypic trait, and its genetic mechanisms are still not fully understood. This study focuses on dairy goats and non-dairy goats. By analyzing the population structure of these two groups, we found that there is a significant genetic distance between the populations of dairy goats and non-dairy goats. Using SNP and Indel analyses to identify selection signals, we identified several genes associated with milk production traits, including MPP7, PRPF6, DNAJC5, TPD52L2, HNF4G, LAMA3, FAM13A, and EPHA5. Through longitudinal GWAS of the milk production traits of 298 dairy goats, we discovered additional genes such as TRNAS-GGA-102, TTC39C, LAMA3, ANKRD29, NPC1, C24H18orf8, LOC108633789, RIOK3, TMEM241, CABLES1, LOC108633781, and RBBP8. Transcriptome sequencing of breast tissues at different lactation stages reveals dynamic LAMA3 expression changes. Three non-synonymous mutations in LAMA3 are identified, with the TT genotype at one site correlating significantly with average milk production in dairy goats. Our study discovered new genetic markers for improving dairy goat genetics and provided valuable insights into the genetic mechanisms underlying complex traits.