Comparative Analysis Of The Whole Transcriptome Of Chenghua Pig Dorsal Skin Tissue At Different Developmental Stages

The skin is the largest organ of the human body,consisting of epidermis and dermis,and has various biological functions such as barrier protection.Porcine skin is often used as an ideal model material for human skin research because it is more similar to human skin in terms of histology,anatomy and physiology.Chenghua pig is a famous local pig breed in China,and its unique skin thickness trait has become an important characteristic of this breed,however,there are few studies on Chenghua pig skin,especially few studies on gene expression change characteristics during the development process.In order to reveal the dynamic changes of the whole transcriptome expression level in the developing skin of Chenghua pigs,we collected dorsal skin samples from four developmental time points of Chenghua pigs,E56,E76,E105 and D3,and used whole transcriptome sequencing technology(RNA-seq)to obtain the expression data of messengerRNA(mRNA),long-stranded non-codingRNA(lncRNA),circularRNA(circRNA)and microRNA(miRNA)in the dorsal skin of Chenghua pigs.The main results of the study are as follows:(1)Histological analysis showed that with the increase of development time,the dorsal skin thickness of Chenghua pigs gradually thickened,the number of hair follicles in the dermis gradually increased,the collagen fibers in the skin gradually deposited,and the skin development gradually improved.(2)During the four developmental stages,the skin tissue mRNA expression level of Chenghua pigs showed dynamic changes,and a total of 5686 differentially expressed mRNAs were screened.These differentially expressed mRNAs were mainly enriched in human diseases,tissue and organ development and other related biological processes,and 217 mRNAs related to skin development were screened.(3)During the four developmental stages,Chenghua pig skin tissue lncRNA expression levels showed dynamic changes,and a total of 807 differentially expressed lncRNAs were screened.These differentially expressed lncRNAs were mainly enriched in organism metabolism,tissue and organ development and other related biological processes,and 9 lncRNAs were screened that were related to skin development.(4)During the four developmental stages,the expression levels of circRNAs in Chenghua pig skin tissues showed dynamic changes,and a total of 260 differentially expressed circRNAs were screened.These differentially expressed circRNAs were mainly enriched in bioregulation,tissue organ development and other related biological processes,and 8 circRNAs related to skin development were screened.(5)During the four developmental stages,miRNA expression levels of Chenghua pig skin tissues showed dynamic changes,and a total of 833 differentially expressed miRNAs were screened.These differentially expressed miRNAs were mainly enriched in tissue and organ development,organism metabolism and other related biological processes,and 72 miRNAs related to skin development were screened.(6)A ceRNA expression network map was constructed during dorsal skin development in adult Chinese pigs,which included 55 circRNA-miRNA-mRNA relationship pairs formed by the co-expression of 2 circRNAs,3 miRNAs,and 44 mRNAs,and 2 circRNAs(novel＿circ＿015556,novel＿circ＿009800)and three miRNAs(novel-ssc-mi R1129-3p,novel-ssc-mi R681-3p,and ssc-mi R-296-3p)were screened as potential candidate genes affecting dorsal skin development in adult Chinese pigs.In summary,the results reveal the dynamic changes of the whole transcriptome expression level during the development of skin tissue on the back of Chenghua pigs,unearth potential candidate genes and regulatory elements related to skin development,and provide reference data for the study of the molecular mechanism of skin development and the conservation of genetic resources in Chenghua pigs.