Retrotransposon Insertion Polymorphisms (RIPs) in Pig Coat Color Candidate Genes

Area of Science:

• Genetics
• Animal Science
• Genomics

Background:

• Livestock coat color diversity is shaped by human selection and is crucial for breed identity.
• Pig coat color is a key phenotypic trait linked to adaptation and energy metabolism, making its genetic basis of significant interest.
• The melanocortin system plays a role in both pigmentation and energy balance, with implications for domestic animal evolution.

Purpose of the Study:

• To identify structural variations (SVs) in pig coat color genes.
• To investigate the role of retrotransposon insertions in these variations.
• To analyze the distribution of these variations across different pig breeds.

Main Methods:

• Sequence alignment of 17 assembled pig genomes to identify SVs in 20 coat color-related genes.
• Identification of large structural variations overlapping with retrotransposon insertions (>50 bp), termed putative RIPs.
• PCR detection to confirm RIPs and genotypic distribution analysis in 11 domesticated pig breeds.

Main Results:

• A total of 167 large structural variations overlapping with retrotransposon insertions (putative RIPs) were identified in coat color genes.
• 42 putative RIPs were confirmed through PCR detection.
• Differential genotypic distributions of 11 confirmed RIPs were observed across various pig breeds, suggesting a link to breed-specific coat colors.

Conclusions:

• Structural variations, particularly those involving retrotransposon insertions, are present in pig coat color genes.
• These variations (RIPs) show differential distribution across pig breeds, indicating their potential role in coat color diversity and breed differentiation.
• Further research into these RIPs can enhance our understanding of the genetic architecture of pig coat color and breed characteristics.