Identification of Candidate Genes for Pigmentation in Camels Using Genotyping-by-Sequencing

Area of Science:

• Animal Genetics
• Genomics
• Coat Color Genetics

Background:

• Dromedary camel coat color typically ranges from black to white, with brown being most common.
• Understanding the genetic basis of coat color can reveal insights into camel pigmentation.

Purpose of the Study:

• To identify novel color-related genetic variants in dromedary camels.
• To associate single nucleotide polymorphisms (SNPs) with specific coat colors using genome-wide association studies (GWAS).

Main Methods:

• Genotyping-by-sequencing (GBS) was employed to discover genetic variants.
• Mixed linear models (MLM) with a kinship matrix were used to test SNP-coat color associations.
• Three GWAS models were performed: white vs. non-white, black vs. non-black, and light-brown vs. dark-brown.

Main Results:

• No distinct genetic clusters were found based on coat color, indicating admixture.
• Nine significant SNPs associated with white color were identified near several genes, including ANKRD26 and CIITA.
• Thirteen significant SNPs associated with black color were identified near genes such as SNAI1 and CAPN7.
• The SNAI1 gene showed interaction with MC1R, ASIP, and KIT, which are involved in melanin synthesis.

Conclusions:

• This study successfully identified significant SNPs and candidate genes associated with dromedary camel coat color.
• The findings provide a foundation for further research into the genetic mechanisms of pigmentation in camels.
• Larger sample sizes and pedigree data are recommended for confirming these genetic associations.