Hemicastration Induced DNA Methylation And Gene Expression Changes In Mice Testis

Testicle is the most important reproductive organ for mammalian multiplication,which is responsible for generation of male gametes and the production and release of sex steroids.External force,biochemistry or illness may injure unilateral testis and influence testicular function,even cause male infertility.Hemicastration is a unilateral orchiectomy to remove an injured testis,which can induce hormonal changes and compensatory hypertrophy of the remaining testis,and may influence spermatogenesis.However,the underlying molecular mechanisms need further research.In present study,we explored the effect of hemicastration on remaining testicular function.Mice(age 24 days)were performed hemicastration on prepuberty(age 24 days),and monitored growth and development indexes until they reached physical maturity(age 72 days).Subsequently,testicular DNA methylation patterns of normal and hemicastrated mice were determined through reduced representation bisulfite sequencing.Moreover,we profiled the testicular gene expression patterns by RNA sequencing(RNA-seq)to explore the relationship between gene expression and DNA methylation in hemicastrated mice,and discussed the mechanism of lncRNA regulated spermatogenesis-related gene expression through DNA methylation.The main results are described as follows:(1)Compared with control,hemicastration did not significantly affect growth or testosterone(P > 0.05).Meanwhile,there is no significant aberrant histological morphological structure of remaining testis(2)The genome-wide DNA methylation pattern of remaining testis suggested that substantial genes harbored differentially methylated regions(1,139)in gene bodies,which were enriched in process of protein binding and cell adhesion.(3)The results of mRNA analysis indicated that 46 differentially expressed genes(DEGs)involved in meiotic cell cycle,synaptonemal complex assembly and spermatogenesis were upregulated in the hemicastration group,while 197 DEGs were downregulated,which were related to arachidonic acid metabolism.(4)19 lncRNA differentially expressed in hemicastrated mice testis.The cis and trans results indicated that the function of lncRNA-9230019H11 Rik,lncRNA-Gm13652 and lncRNA-Gm30934 may related to peptidase inhibitor activity.The trans target mRNAs of lncRNA-1700095K22 Rik and lncRNA-Gm36525 were enriched in animo acid transmembrane transporter activity.Meanwhile,the potential fuction of lncRNA-1700061I17 Rik,lncRNA-4930432O09 Rik and lncrRNA-4930401O12 Rik may relate to arachidonic acid metabolism.(5)Integrative analysis revealed that proteasome 26 S subunit ATPase 3 interacting protein(PSMC3IP)gene,which encodes a protein crucial for homologous recombination in spermatocytes,exhibited promoter hypo-methylation and higher expression level in hemicastrated mice,and significantly negative correlated with three lncRNAs(lncrRNA-4930401O12 Rik,lncRNA-9230019H11 Rik and lncRNA-Gm13652).DNA methylation changes induced by hemicastration may relate to testicular function,which regulated relevant genes expression to participate in spermatogenesis.