Analysis Of Gene Transcription And Differential Expression In Mesenchymal Tissue Between Male And Female Reindeer (Rangifer Tarandus) Antler

Reindeer(Rangifer Tarandus)is widely distributed around the Arctic Circle.In China,Reindeer is only distributed in the northwest of the Great Xingan Mountains and domesticated by Ewenki hunters.Antler is the only organ that can regenerate completely and circularly among mammals,and can proliferate and and grow rapidly without signs of canceration.It can be said that antler is a unique animal model for the research on wound repair,organ regeneration and tumor in the field of human medicine.Antler is usually a male characteristic of the deer family,while reindeer are both female and male antlers.There are many apparent differences among antlers of the female reindeer,male reindeer and other male deer in the deer family such as branch size,number,thickness,complexity and regeneration and shedding time.Therefore,to explore and elucidate the underlying molecular mechanisms of these apparent differences from the perspective of molecular regulatory mechanisms has become a challenging focus of the scientific community.It is also a more novel and unique field of study that is different from that of males of other deer.The purpose of this study is to select a scientific topic concerning the lack of understanding of the internal molecular mechanism of both male and female reindeer velvet.The mesenchymal tissues of adult healthy male and female reindeer were used as materials,which was sequenced transcriptome by RNA-Seq sequencing using Illumina high-throughput sequencing platform.Meanwhile,the reindeer antler Unigene library was obtained by De novo assembly.Unigenes sequence was aligned with NR,Swissprot,GO,COG,KOG,Pfam,KEGG and other databases for gene functional and structural annotation.It was used to reveal the molecular mechanism of gene transcription and differential expression in the mesenchymal tissues of the antler of male and female reindeer.The results showed that:1.Transcriptome sequencing was performed on the cDNA library of mesenchymal tissues of tip from female and male reindeer antler to obtain the original transcriptome data,which were stored in NCBI SRY database,Accesion Numbers:SRR9051566 and SRR9051567.After filtering the Data,a large amount of high-quality Clean Data of 18.86GB was obtained,and the percentage of Q30 base of each sample was not less than 88.73%.Trinity software was used for sequence De novo assembly to obtain transcripts and Unigenes of male and female reindeer antler,and there are 124,139 and 94,575,respectively.The length of N50 is 1,768 and 1,193,respectively;the average length was 911.36 and 704.68,respectively.2.By aligned with biological database,a total of 30,980 genes were annotated.Nr database annotation results showed that the reindeer and bovine had the highest homology ingene sequence.The results of GO functional classification show that transcriptional regulation plays an important role in the growth and development of reindeer mesenchymal tissue.The results of COG and KOG functional classification show that a large number of genes are involved in cellular activities,such as protein synthesis,signal transmission,transcription during the growth and development of reindeer antler,indicating that functional proteins such as growth factors and transcription factors are closely related to the growth and development of antler.A total of 15,167 genes were annotated in 292 KEGG pathways,among which 2 cancer pathways,4 signal transduction pathways and 3 protein synthesis activity-related pathways were annotated to more genes,indicating oncogenic growth and active protein synthesis in reindeer antler mesenchymal tissues.3.Through annotating the database,we screened 22 growth factor and 22 receptor of growth factor,and 77 transcription factor member including 7 transcription factor families closely related to growth and development.A large number of findings of growth factors and receptors indicate that growth factors are involved in the growth and development of reindeer antler mesenchymal tissues by transmitting cell growth signals through their interaction with receptors.The discovery of a large number of members of the transcription factor family indicates that transcription factors have a broad regulatory effect on the growth of mesenchymal of reindeer antler's tip.The structural analysis among members of the Fox,SOX and E2F transcription factor families revealed the common ancestor origin of the members within the family,and the regulation effect of each transcription factor family on the growth and development of the mesenchymal tissue of reindeer antler's tip was related to the structure.There are a large number of SSRs(7,480)and SNPs(84,435 and 82,226 for male and female,respectively)in reindeer antler.4.By calculating the expression levels of genes,30 genes which were highly expressed in reindeer antler mesenchymal tissues were selected.There were 8 genes encoding signal transduction proteins CDKN1B,CDKN1C,PTN,GJA1,TGFB1,IHH,MDK,ENG and,which contained 4 tumor suppressor factors.There were 5 transcription factor genes,including ATF4,AP-1,RUNX2,DLX5 and SOx-9.There are 17 extracellular matrix protein genes,including TNN,COL5A1,LGALS1,COL2A1,COL6A1,COL5A2,IBSP,OPN,COL9A2,COL18A1,COL15A1,WISP1,COL27A1,COL3A1,COL13A1,COL4A1,which are related to the proliferation,differentiation,cell cycle control and other activities of the mesenchymal tissue cells of reindeer antler's tip.The results of protein interaction analysis of 30 highly expressed genes showed the co-expression of signal transduction proteins and transcription factors,which indicated that transcription factors in response to cell growth signals transmitted by signal transduction proteins to regulate the expression of related genes and participate in the growth and development of reindeer antler mesenchymal tissues.5.A total of 649 differentially expressed genes were screened out by differential expression gene analysis.GO functional enrichment analysis showed that the differential genes were enriched in the extracellular space,structural constituent of ribosome,translation and other functions.Among the 32 genes differentially expressed,the genes related to cartilage formation were significantly down-regulated and the genes related to cell adhesion were up-regulated,indicating that there were differences in the cartilage formation process and cell adhesion state in mesenchymal tissues of the female and male reindeer antler's tip.Protein interaction network analysis and screening showed that BMP4 and other 9 genes played an important role in the process of cerviciosis of male and female reindeer antler.The quantitative validation results of RT-qPCR gene expression level were consistent with the results of transcriptome analysis results.In this study,gene transcription and differential expression of mesenchymal tissues of tip between female and male reindeer were analyzed,which has positive scientific significance for understanding the gene structure,function,signal transmission,and regulation differences of the growth process of female and male reindeer velvet at the molecular level.