Copy-number variation in goat genome sequence: A comparative analysis of the different litter size trait groups.

Copy number variation (CNV), as an important component of genomic structural variation (SV), plays essential roles in phenotypic variability, disease susceptibility and species evolution. To investigate whether critical CNVs exist in dairy goats with differing fecundity, we performed genome-wide sequencing of two populations of Laoshan dairy goats with large differences in litter size. After reference genome aligning, CNV calling, and annotation, we screened identified CNVs in the high-fecundity (HF) and low-fecundity (LF) groups to identify discrepant CNVs and their distribution within the genome. Prolactin-related protein 1 and 6 (PRP1 and PRP6), important factors regulating reproductive processes, were demonstrated to be duplicated in the HF group. In summary, based on the differences in CNVs between goats with differing litter sizes, it suggests CNVs may contribute to litter size in Laoshan dairy goats.