The Transcriptome Analysis And The LncRNA Identification In Lung Of Piglets At Prenatal And Postnatal

The lungs are the main organs for breath of many animals,including humans.From prenatal to postnatal,the lungs transition from a relatively stable uterine environment to external environment in short time.Meanwhile,lungs were transition from "dormancy" state at prenatal to the "working" state at postnatal state and to be the main place for animals to breath.Previous study in investigation the lung from prenatal and postnatal were ofthen focused on apparent level such as physiological phenotype and cellular morphology.In this study,swine were used as the animal model,the RNA-seq were used to investigate the change of lung between two states at 24 hours before brith and 48 houres after brith,the main results were shown below:(1)At two stages of prenatal and postnatal,the morphology of swine lung tissue were obviously changed,for example,the saccules of lung tissue which were the future pulmonary alveoli at postnatal were more smooth and more dense than prenatal lung tissue.(2)In current study,6 samples from prenatal and postnatal group of lung tissues were sequenced by RNA-seq and then produced in total 92.58GB of Raw data,the 86.46GB of Raw data were passed the quality filter and deemed as clean data,and there where at average 76.21%of clean reads from those clean data can be mapped on swine reference genome.(3)There were 16,509 of mRNA transcripts and 18,416 of lncRNA transcripts identified from 6 libraries.The identified lncRNA have less exon numbers and shorter transcript length,and it also has lower expression level and lower protein coding potential than identified mRNA in current study.(4)There were 3,276 of mRNA differential expressed,and 1,762 of them were high expressed at prenatal lung,1,514 of them were high expressed at postnatal lung.And 441 of lncRNA were also differential expressed,137 of them were high expressed at prenatal lung,441 of them were high expressed at postnatal lung.(5)From the functional analysis of these differential expressed genes(DEGs),the DEGs were mainly enriched in four domains of biological process,such as cell proliferation、immune、hypoxia response and energy metabolism.From the expression level analysis of these DEGs,we found the cell proliferation related DEGs such as CCNA2、CCNB1、CCNB2、CCND1、CCNE2、CDK1、CDK2、FOXM1 and MK167 have an significantly enhanced expression in postnatal piglet lungs,and the immune related DEGs such as TLR2、TLR4、TLR8、IL18、IL33、TNF and SEMA7A were also have an significantly enhanced expression in postnatal piglet lungs,the hypoxia response related DEGs such as EGLN3、HBB and XRCC1 were found to have a significantly decreased expression level in postnatal piglet lungs,and the energy metabolism related DEGs such as GPD2、MDH2 and PKC2 were found to have significantly enhanced expression level in postnatal piglet lungs.(6)To predict the function of differential expressed IncRNA,we made the expression correction analysis with identified lncRNA and identified mRNA,then we found mRNA corrected with some of these differential expressed lncRNA were mainly enriched in cell proliferation and immune biological process,which might imply these differential expressed lncRNA might have functional in cell proliferation and immune biological process,and these lncRNA could be an important candidate regulatory element in future study.