The Research On The Expression Of Coat Color-related MiRNAs And Their Target Genes In The Goats Of Different Breeds And Ages

Coat color is an important economic trait for goats,and it is also an important symbol for identifying animal breeds.If the genetic laws of various coat colors can be found,it will be beneficial to obtain the type of coat color determined by breeding goals or required by the market.miRNAs are a class of endogenous,single-stranded small-molecule RNAs,through complementary pairing with target genes,lead to the degradation of target gene mRNA,inhibit protein synthesis,and ultimately participate in many life activities of the body.However,there are few studies between the two at present.The purpose of this test is to study the expression of coat color-related miRNAs and their target genes in the skin of goats of different breeds and different ages.The role of related miRNAs in the formation of goat coat color can provide reference materials.First,Dazu black goats,Inner Mongolia cashmere goats,and F₁ hybrid generation of Dazu black goats and Inner Mongolia cashmere goats of different ages?0-month-old,2-month-old,6-month-old,and 12-month-old?were selected in this study.The skin and wool were collected surgically from 6 animals each.The melanin content in the skin and wool of goats of different breeds and different ages,and the expression site of melanin in the skin were measured,and the expression of miRNA and its target genes in the skin were measured by fluorescent quantitative PCR.Later,Western blot and immunohistochemistry were used to study the expression of target genes at the protein level and their protein expression sites in the skin.The main findings are as follows:1.The melanin content in the skin and hair of Dazu black goat is significantly higher than that in Inner Mongolia cashmere goat?P<0.05?.The melanin content in the skin and hair of hybrid F₁ goats decreases with age.Melanin is mainly distributed in the hair follicle and skin epidermis.2.Coat color-related miRNAs are expressed differently in the skin of different breeds of goats.Among them,the expression of miR-129-5p in the skin of Dazu black goat is significantly lower than that of Inner Mongolia cashmere goats?P<0.05?,while the expression of miR-544-5p in the skin of Dazu black goat is significantly higher than that of Inner Mongolia cashmere goats?P<0.05?,the expression of miR-148a,miR-381-3p,mi R-543-3p in the two skins was not significantly different.3.The expression of miR-129-5p in the skin of hybrid F₁ goats of different ages showed an increasing trend and then displayed a decreasing trend,and its expression at 0 months was significantly lower than the other three time points?P<0.05?.The expression of miR-148a have no differences at different ages.The expression of miR-381-3p and miR-543-3p had no obvious rules with age.The expression of miR-544-5p gradually decreased with age,and its expression was significantly higher at 0 month old?P<0.05?.4.The expression of target genes TYR,FZD6,GSK3?,PLCB4,EDN1,CAMK2A and CAMK2G in the skin of Dazu black goat was significantly higher than that of Inner Mongolia cashmere goat?P<0.05?,there was no significant difference in the expression of MITF and EP00 between the two.5.The expression of target genes TYR,EDN1,EP300,and CAMK2G showed a decreasing trend with the age of F₁ goats,the expressions of MITF,PLCB4,and CAMK2A showed a trend of first increase and then decrease with the age of F₁ goats,the expression of FZD6 and GSK3?had no obvious rules.6.The expression of TYR protein is basically consistent with its mRNA level expression.It is also higher in the skin of Dazu black goat than in Inner Mongolia cashmere goat,and its expression gradually decreases with the increase of F₁ age?P<0.05?.The expression of MITF protein in the skin of Inner Mongolian cashmere goats is significantly higher than that of Dazu black goats?P<0.05?,but its protein expression also shows a decreasing trend with age.7.TYR protein mainly exists in the skin hair follicle and epidermal layer,which is highly consistent with the melanin expression site.Conclusion:1.F1 hybrid generation of Dazu black goats and Inner Mongolia cashmere goats coat color gradually becomes lighter with age,and its skin and hair melanin content also gradually decreases.TYR expression activity will gradually decrease with the increase of the age of F1 goats.It reflects that TYR plays an important role in regulating the formation of goat coat color.2.miR-129-5p plays an important role in the regulation of goat hair color,and it mainly exerts its regulatory effect by targeting TYR.