Expression of the Tyrosinase Gene in Different Dromedary Camels of Saudi Arabia

Tyrosinase (TYR) gene has a role in regulating the pigmentation process and acts as a precursor for eumelanin or pheomelanin. There have been many studies that reported variations in this gene associate with the coat color of the animal. This is the first study of TYR gene expression analysis from various dromedary or Arabian camel (Camelus dromedarius) phenotypes from Saudi Arabia. The four camel groups included were white, diluted (light brown, creamy and fawn), black and dark brown representing eumelanin and pheomelanin coat colors. Generally, the TYR gene expresses less in non-pigmented than the pigmented species. The results of our study showed that the mRNA from skin biopsies has low expression in white dromedary camels while higher expression in dark brown phenotypes followed by black and diluted ones through real time quantitative PCR. MicroRNAs (miRNAs) miR-129-5p and miR145 were evaluated for their depigmentary role and observed reciprocal expression against the TYR gene expression. Hence the miR-129 and miR-145 expressed higher in non-pigmented camels compared to the pigmented ones and correlated with TYR expression. Our data provides useful information to understand the camel TYR role in coat color variation which is supportive in genotyping, genetic selection, breeding and classification.