| In this study,the extreme phenotypic shedding group and the unshedding group of the ewes of athwart cross progeny of Dorper sheep and Tan sheep were used as the test subjects.After collected the skin tissues in anagen,catagen,telogen,and late-telogen,the strategy of combining high-throughput sequencing and bioinformatics analysis was used to analyze the differentially expressed miRNAs.Bioinformatics methods such as GO analysis and KEGG signal pathway analysis were used to screen the miRNAs related to shedding,then the target gene prediction and verification test were carried out,the results were as follows:1.This study conducted morphological analysis on the wool fibers of four groups of shedding(group S),unshedding(group U),Dorper sheep(group D),and Tan sheep(group T).The results showed that in three different stages(catagen,telogen,late-teligen),the basic trend of straight length,natural length and diameter of the four varieties of wool is S<D<U<T;from the perspective of the pile length,the basic trend of the three periods is the same as that of wool,S<D<U<T;in trems of villi diameter,the difference between the D group and the other three groups was highly significant at different periods(p≤0.01).2.According to the results of miRNA sequencing,the differentially expressed miRNAs that affect the growth and development of hair follicles and the differentially expressed miRNAs that affect shedding were analyzed.The results showed that the number of related differential miRNAs in process of "telogen-late-telogen" in group U and S was less;the number of differential miRNAs in group U was much smaller than that in group S in the process of "anagen-catagen",and the number of differential miRNAs in group U was much more than that of group S in the process of "catagen-telogen".In the group U vs S,a total of 153 miRNAs were detected to be differentially expressed in different periods.Taking the group U as a reference,there were 66 significantly up-regulated miRNAs in the group S compared with the group U at anagen,10 down-regulated miRNAs;14 significantly up-regulated miRNAs at catagen,and 53 down-regulated miRNAs;12 significantly up-regulated miRNAs at telogen,and 8 down-regulated miRNAs;16 significantly up-regulated miRNAs at telogen,28 down-regulated miRNAs;among them,24 miRNAs were differentially expressed at anagen and catagen.3.On the basis of the above results,and combined with mRNA-miRNAjoint analysis,it was found that miR-802-5p,miR-4492-3p,miR-376-3p,miR-1264-3p,miR-545-3p,miR-122-5p were negatively correlated with the corresponding target genes,which might be micro effective miRNAs that caused differences in hair follicle development.Among them,miR-802-5p does play a certain role in the process of hair follicles.It played a significant role in Wnt signaling pathway and was related to hair follicle development and hair loss traits.It may be realized by influencing the related genes and proteins in Wnt signaling pathway,such as APC,Smad4,GSK3 β,which can be used as a candidate miRNA to affect hair follicle growth and development and cause shedding.Through miRNA transcriptomics analysis,several candidate genes related to sheep shedding have been studied and screened,and miRNAs that regulate sheep’s complex economic traits have been combed from a new perspective,which will help to analyze the molecular regulation mechanism of depilation traits and provide a new model for subsequent shedding of sheep and provide theoretical support for the molecular breeding of new breeds of mutton sheep. |
