Abstract: The test was to through the molecular level and histological level shed light the different mechanism of coat color in yak. The experiment adopted the Real-time fluorescent quantitive PCR technique to detect the skin tissue determines the main effect of pigment formation pathway genes:gray mouse gene (agouti signaling protein gene (ASIP),Agouti),small eye malformation associated transcription factor (microphthalmia-associated transcription factor, MITF),melanin cortisol receptor 1 gene (melanocortin receptor 1, MC1R) and tyrosine enzyme gene (tyrosinase gene, TYR) expression.The results showed that the MC1R expression quantity in black the color was higher than the white color;MITF expression quantity in the black coat with white color difference was obvious; ASIP expression quantity in white color and black color was not different; TYR expression quantity in Tianzhu white coat was Datong pure black coat 2.87 times,this result was opposite the colored coat with high expression result,the TYR expression quantity of yak melanin synthesis effect remained to be further research.Test made by paraffin section method,using HE and toluidine blue staining.Mammalian hair by hair follicle growth and development of derivatives,the melanothore mainly distributed in the epidermis and hair follicles.Through microscope found the yak hair follicle was made up of wool sheath,hair papilla and connective tissue around the group formed outside the bulb.A lot of melanothores were found in skin and around hair follicels in Tianzhu white yak,and found that there was a small amount of melanin granules.Melanin granules were found in hair follicle and epidermis melanothore in Datong yak.The melanin content near the hair dermal papilla was higher than other parts around the hair follicle in black coat hair follicle.Datong yak hair follicle group was more serried than Tianzhu yak hair follicle group,and the diameter of the hair follicle was longer than Tianzhu yak,with thicker hair.The melanin cell around the hair follicle of Datong yak was denser than Tianzhu yak,and the nucleus was larger,and more obvious.

Key words: Yak, Genes about colour, RT-PCR, Paraffin section, Melanin

CLC Number: 

• Q78

• S823