Long non-coding RNAs in Sus scrofa ileum under starvation stress.

OBJECTIVE: In this study, we aimed to identify long non-coding RNAs (lncRNAs) that play important roles in starvation stress, analyze their functions, and discover potential molecular targets to alleviate starvation stress to provide a theoretical reference for subsequent in-depth research. METHODS: We generated a piglet starvation stress animal model. Nine Yorkshire weaned piglets were randomly divided into a long-term starvation stress group (starved for 72 h), short-term starvation stress group (starved for 48 h), and the control group. LncRNA libraries were constructed using high-throughput sequencing of piglet ileums. RESULTS: We obtained 11,792 lncRNAs, among which, 2,500 lncRNAs were novel. In total, 509 differentially expressed (DE)lncRNAs were identified in this study. Target genes of DElncRNAs were predicted via cis and trans interactions, and functional and pathway analyses were performed. Gene ontology functions and Kyoto encyclopedia of genes and genomes analysis revealed that lncRNA-targeted genes mainly participated in metabolic pathways, cellular processes, immune system processes, digestive systems, and transport activities. To reveal the mechanism underlying starvation stress, the interaction network between lncRNAs and their targets was constructed based on 26 DElncRNAs and 72 DEmRNAs. We performed an interaction network analysis of 121 DElncRNA-DEmRNA pairs with a Pearson correlation coefficient greater than 0.99. CONCLUSION: We found that MSTRG.19894.13, MSTRG.16726.3, and MSTRG.12176.1 might play important roles in starvation stress. This study not only generated a library of enriched lncRNAs in piglets, but its outcomes also provide a strong foundation to screen key lncRNAs involved in starvation stress and a reference for subsequent in-depth research.

Novel alternatively spliced isoforms of MEF2A and their mRNA expression patterns in pigs.

The present study aimed to identify the alternatively spliced isoforms of pig MEF2A gene and to determine theirmRNA expression patterns. Four alternatively spliced isoforms of pig MEF2A gene (i.e. MEF2A1, MEF2A2, MEF2A3 and MEF2A4) were cloned according to the results of transcriptome sequencing. The fifth to eighth exons of MEF2A1 were normally spliced. In MEF2A2, the fifth exon was missing; the sixth exon had an extra 138 bp at its 5' end, and the seventh exon had an extra 102 bp at its 3' end. In MEF2A3, the fifth exon was missing, and the sixth exon had an additional 138 bp at its 5' end. In MEF2A4, the seventh exon had an extra 102 bp at its 3' end. Quantitative real-time polymerase chain reaction (qPCR) analysis indicated that the expression profiles of the four alternatively spliced transcripts in the longissimus dorsi differed between the Mashen and Large White pigs. MEF2A1 and MEF2A2 expression levels were the highest at 90 days of age and lowest at 180 days of age. MEF2A3 and MEF2A4 expression levels increased with age (in days). The four alternatively spliced isoforms of MEF2A were also expressed in the small intestine, cerebellum, pancreas, heart and lung. The discovery of new alternatively spliced transcripts of the MEF2A gene may be utilized in understanding its biological functions.

[Research on the polymorphism of heart fatty acid-binding protein gene in Shanxi pig breeds and their crossbred populations using PCR-RFLP].

The genetic variation in 5' - upstream (Hinf I -RFLP)and the second intron (Hinf I *-RFLP, Hae III-RFLP)of heart fatty acid-binding protein(H-FABP)gene were detected with PCR-RFLP in 286 pigs including Mashen, Shanxi white pig and their crossbred populations. The results showed as follows: (1)Mashen presented only DD genotype while other populations varied,and Mashen crossbred populations had only 2 genotypes(DD, Dd) at the Hae III-RFLP site; (2)At the Hinf I -RFLP site of the 5' -upstream region, the crossbred population of Shanxi white pig and Duroc presented only HH genotype while other populations varied. Frequency of h allele in Mashen was 0.9727. (3)At the Hinf I *-RFLP site of the second intron, only Mashen presented 2 genotypes (BB, Bb), and frequency of B allele was 0.9667. (4)At the Hae III-RFLP and Hinf I *-RFLP sites, all populations were in Hardy-weinberg equilibrium.