Study On Melanin Deposition In Fur And Skin Of White And Wild-type Raccoon Dog

Mammalian skin and hair follicle melanin content directly affect the color of its hair.We selected 5-year-old Wusuli raccoon dog,white raccoon dog.Ussuri raccoon as the control group,white raccoon as the experimental group.The amount of melanin in the hair was determined,the total amount of melanin in the guard hair was higher than that in the fluff,and the content of the melanin in the white raccoon was only a small amount.The sections of the two raccoon skin tissues were stained with HE staining and ferrous sulfate solution(melanin-specific staining).After microscopic observation,the distribution of melanin in the skin was mainly concentrated in the primary hair follicles and hairy(Used in the formation of needle hair),the skin base and other tissues of the skin did not detect the distribution of melanin,white raccoon hair follicles almost do not contain melanin,but there are still a few hair follicles can be specific staining,and distribution in the hair melanin particles should be more in the hair root.After analyzing the results of the transcriptome,it was found that there was a significant difference in the melanin synthesis pathway between the Wusuli raccoon dog and the white raccoon dog.Melanosomes are the only organelles in mammals that are used to synthesize and deposit melanin.Most of the genes associated with melanin synthesis are located on melanosomes.The expression or absence of these genes will directly affect the final synthesis and deposition of melanin The ?-melanocyte estrogen(?-MSH)binds to melanocytic protein melanocortin receptor 1(MC1R),which activates the synthesis pathway of true melanin,tyrosinase(TYR),tyrosine Acidase 1(TYPR1)can catalyze the conversion of tyrosine to quinone in melanin synthesis,and the quinone is further oxidized to melanin in melanogenesis.Proteins SLC24A5 and SLC45A2 are melanoma on the membrane of the proton pump,play a stable melanin in vivo environment role.The expression of TYR,TYRP1,MC1 R,SCL24a5 and SLC45a2 were lower than those of Wusuli raccoon,and the results were also validated in qRT-PCR.It is suggested that the expression of TYR,TYRP1,MC1 R,SCL24a5 and SLC45a2 is reduced by white hair,which may lead to the serious inhibition of the synthesis of melanin synthesis,but it can still synthesize melanin less but not deficiency,because in the hair can still detect the presence of a small amount of melanin,and the white raccoon skin melanin specific staining can also be observed after a small part of hair follicles in the presence of melanin particles...