The Screening Of LncRNAs And MRNAs In The Hypothalamus Of Pubertal Rat

Early puberty,an important economic traits in livestock production,is controlled by many factors,including epigenetic.Long non-conding RNA,as one of the epigenetic modified patterns,which regulate the onset of puberty,has not been reported.Therefore,the aim of this research was to screen differential expression lncRNAs and mRNAs,and predict their functions in the hypothalamuses of rats during prepuberty and puberty by RNA-seq.The study consists of the following components:(1)Four of prepubertal(postnatal day 25)and pubertal(the day of vaginal opening)female SD rats hypothalamuses were collected and mixed together,respectively,and were extracted total RNA for library construction.The raw data was obtained through the RNA-seq after testing to ensure library quality.This study revealed that 110868128 and 98901278 reads were obtained in RNA library of hypothalamus in rat at prepuberty and puberty,respectively.The hypothalamus of rat at prepuberty and puberty,99129182(89.41%)and 89032171(90.02%)reads were matched to genome of rat;known type analysis of reads showed that there were73.51% reads of the protein encoded gene and 25% reads of other functional gene.(2)Differential expression lncRNAs and mRNAs were selected through data evaluation.The target genes of lncRNAs were predicted and GO and KEGG analysis were performed.In addition,the comparision of total expression,structure and conservative of lncRNAs and mRNAs were made.This study revealed that lncRNAs generally showed a lower expression level compared to mRNAs that was observed;the conserved of lncRNAs were significantly higher than coding gene.(P <0.00001);most of the lncRNAs contained a relatively shorter ORF than that of mRNAs;a distinct divergence in the distribution of transcript length was found between mRNAs and lncRNAs.Most of lncRNAs contained two to four exons,which differed from those of mRNAs.1444 differential expression transcripts from the 1283 genes were obtained.868 up-regulated transcripts and 576 down-regulated transcripts were observed at puberty compared to prepuberty,contained 364 lncRNA transcripts(146known lncRNAs and 128 novel lncRNAs)and 1080 differential mRNAs transcripts.The target genes of differential lncRNAs were predicted by cis,633 and 8425 target genes were found from up and downstream of the differentia lncRNAs genes,within the range of 10 K and 100 K,respectively.The target gene of differential expressionlncRNAs did not show significantly enriched GO term;only ribosomal pathway significantly enriched by KEGG pathway analysis(P <0.05);Ribosomal and Vasopressin-regulation water re-absorption pathways were different at prepuberty and puberty by pathway hierarchical clustering analysis.Many significant GO terms were enriched in differential mRNAs.GO hierarchical clustering analysis showed that the development of nervous system and synaptic were different between prepuberty and puberty;six significant enriched pathways(P <0.05)were foune by the KEGG pathway analysis.The KEGG hierarchical clustering analysis showed that the pathway of insulin secretion and oxytocin signal had a difference between perpuberty and puberty.(3)RT-PCR was used to detect the differential lncRNAs,which was chosen randomly.The results of RT-PCR showed that the expression patterns of 8 differential lncRNAs were consistent with the sequencing data,but the specific multiples were difference with sequencing data.In conclusion,the expressions of many specifical and different lncRNAs and mRNAs in the hypothalamus of rat at puberty are found firstly in this study.The enrichment of these lncRNAs and mRNAs show significantly difference in the development of nervous system,synaptic,the ribosomal pathway,the vasopressin-regulation water re-absorption pathways,the insulin secretion and the oxytocin signal pathway,which indicates the onset of puberty is affected by these signaling pathways or biological processes.