Analysis of mRNA and Long Non-Coding RNA Expression Profiles in Developing Yorkshire Pig Spleens

SIMPLE SUMMARY: Epidemic disease is a prominent problem in intensive pig production. The spleen is a blood bank and the largest immune organ, and most of the diseases in pig farms will be reflected as spleen abnormality. The results showed how the mRNA–lncRNA expression profiles in Yorkshire spleens varied with age (seven, 90, and 180 days after birth). Our study shows that 90 days after birth the gene-expression profile of pig spleen no longer changes significantly. The results are helpful for a better understanding of the transcriptome and functional genomics of spleen tissue in farm animals and could provide reference for precision pig disease research and prevention and control in pig farms. ABSTRACT: Epidemic diseases cause great economic loss in pig farms each year; some of these diseases are characterized mainly in the spleen, but mRNA and lncRNA (long non-coding RNA) expression networks in developing Yorkshire pig spleens remain obscure. Here, we profiled the systematic characters of mRNA and lncRNA repertoires in three groups of spleens from nine Yorkshire pigs, each three aged at seven days, 90 days, and 180 days. By using a precise mRNA and lncRNA identification pipeline, we identified 19,647 genes and 219 known and 3219 putative lncRNA transcripts; 1729 genes and 64 lncRNAs therein were found to express differentially. The gene expression characteristics of genes and lncRNAs were found to be basically fixed before 90 days after birth. Three large gene expression modules were detected. The enrichment analyses of differentially expressed genes and the potential target genes of differentially expressed lncRNAs both displayed the crucial roles of up-regulation in immune activation and hematopoiesis, and down-regulation in cell replication and division in 90 days and 180 days compared to seven days. ENSSSCT00000001325 was the only lncRNA transcript that existed in the three groups. CDK1, PCNA, and PLK were detected to be node genes that varied with age. This study contributes to a further understanding of mRNA and lncRNA expression in different developmental pig spleens.