TYR Gene in Llamas: Polymorphisms and Expression Study in Different Color Phenotypes.

Area of Science:

• Genetics
• Animal Science
• Molecular Biology

Background:

• The tyrosinase (TYR) gene is crucial for mammalian pigmentation, controlling melanin production.
• Mutations in TYR can lead to albinism or diluted coat colors in various species.
• Llamas exhibit diverse coat colors, suggesting genetic factors influencing TYR function.

Purpose of the Study:

• To investigate the role of the TYR gene in llama coat color variation.
• To identify genetic variations and analyze TYR expression in llamas with different coat colors.

Main Methods:

• Sequencing of TYR exons and flanking regions in llamas with varying coat colors.
• Genotyping of identified single nucleotide polymorphisms (SNPs) and other variations.
• Quantitative PCR (qPCR) analysis of TYR mRNA expression in skin biopsies.

Main Results:

• Nine SNPs were identified in the TYR coding region, including three non-synonymous variants.
• A promoter SNP (c.1-26C > T) showed partial association with diluted coat colors.
• Lower TYR expression levels were significantly observed in white llamas compared to others.

Conclusions:

• TYR gene variations contribute to coat color diversity in llamas.
• Reduced TYR expression is a significant factor in white coat phenotypes.
• While regulatory region screening did not fully explain expression differences, TYR expression is key to llama pigmentation.