Characterization, expression profile, polymorphism and association of porcine NAT9 gene

Effect of SNPs on Litter Size in Swine

Although sows do not directly enter the market, they play an important role in piglet breeding on farms. They consume large amounts of feed, resulting in a significant environmental burden. Pig farms can increase their income and reduce environmental pollution by increasing the litter size (LS) of swine. PCR-RFLP/SSCP and GWAS are common methods to evaluate single-nucleotide polymorphisms (SNPs) in candidate genes. We conducted a systematic meta-analysis of the effect of SNPs on pig LS. We collected and analysed data published over the past 30 years using traditional and network meta-analyses. Trial sequential analysis (TSA) was used to analyse population data. Gene set enrichment analysis and protein-protein interaction network analysis were used to analyse the GWAS dataset. The results showed that the candidate genes were positively correlated with LS, and defects in PCR-RFLP/SSCP affected the reliability of candidate gene results. However, the genotypes with high and low LSs did not have a significant advantage. Current breeding and management practices for sows should consider increasing the LS while reducing lactation length and minimizing the sows' non-pregnancy period as much as possible.

Novel function of N-acetyltransferase for microtubule stability and JNK signaling in Drosophila organ development

Regulation of microtubule stability is crucial for the maintenance of cell structure and function. While the acetylation of α-tubulin lysine 40 by acetylase has been implicated in the regulation of microtubule stability, the in vivo functions of N-terminal acetyltransferases (NATs) involved in the acetylation of N-terminal amino acids are not well known. Here, we identify an N-terminal acetyltransferase, Mnat9, that regulates cell signaling and microtubule stability in Drosophila Loss of Mnat9 causes severe developmental defects in multiple tissues. In the wing imaginal disc, Mnat9 RNAi leads to the ectopic activation of c-Jun N-terminal kinase (JNK) signaling and apoptotic cell death. These defects are suppressed by reducing the level of JNK signaling. Overexpression of Mnat9 can also inhibit JNK signaling. Mnat9 colocalizes with mitotic spindles, and its loss results in various spindle defects during mitosis in the syncytial embryo. Furthermore, overexpression of Mnat9 enhances microtubule stability. Mnat9 is physically associated with microtubules and shows a catalytic activity in acetylating N-terminal peptides of α- and β-tubulin in vitro. Cell death and tissue loss in Mnat9-depleted wing discs are restored by reducing the severing protein Spastin, suggesting that Mnat9 protects microtubules from its severing activity. Remarkably, Mnat9 mutated in the acetyl-CoA binding site is as functional as its wild-type form. We also find that human NAT9 can rescue Mnat9 RNAi phenotypes in flies, indicating their functional conservation. Taken together, we propose that Mnat9 is required for microtubule stability and regulation of JNK signaling to promote cell survival in developing Drosophila organs.

Association of single-nucleotide polymorphisms in NAT9 and MAP3K3 genes with litter size traits in Berkshire pigs

Litter size is an economically important trait in the pig industry. We aimed to identify genetic markers associated with litter size, which can be used in breeding programs for improving reproductive traits. Single-nucleotide polymorphisms (SNPs) of Berkshire pigs in the N-acetyltransferase 9 (NAT9) and Mitogen-activated protein kinase kinase kinase 3 (MAP3K3) genes were from RNA sequencing results, and already exist in the databank (NCBI), and were confirmed by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). A total of 272 Berkshire sows were used to examine the genotype, and their association with litter size traits was analyzed. The NAT9 SNP was located in chromosome 12 exon 640 mRNA (A > G) and the MAP3K3 SNP was located in chromosome 12 intron 11 (80, C > T). Association analysis indicated that the GG genotype of NAT9 and the CT genotype of MAP3K3 had the highest values for litter size traits. The GG genotype expressed higher levels of NAT9 mRNA in the endometrium than the other genotypes did, and a positive correlation was found between litter size traits and NAT9, but not MAP3K3 expression level. These results indicate that the NAT9 and MAP3K3 can be used as candidate genes applicable in breeding program for the improvement of litter size traits in Berkshire pigs.

[Expression of MIER3 in colorectal cancer and bioinformatic analysis of MIER3- interacting proteins]

OBJECTIVE

To explore role of MIER3 gene in the development and progression of human colorectal carcinoma (CRC) and analyze the proteins that interact with MIER3 using bioinformatic techniques.

METHODS

MIER3 mRNA and protein expressions were detected in 8 CRC biopsy samples and paired adjacent tissues using real-time PCR and Western blotting. A recombinant eukaryotic expression vector pcDNA3-MIER3 was constructed and its effect on the proliferation and invasion of CRC cells were tested using CCK8 assay and Transwell migration assay. Bioinformatic methods were used to predict and analyze MIER3-interacting proteins.

RESULTS

MIER3 was obviously down-regulated in the 8 CRC tissues as compared with the paired adjacent tissues. In human CRC cell line DLD1, MIER3 overexpression induced by transfection of the cells with pcDNA3-MIER3 significantly inhibited the cell proliferation and suppressed cell invasiveness in vitro. Bioinformatics analyses indicated that NAT9 was a potential MIER3-interacting protein and MIER3 was probably associated with tumor susceptibility.

CONCLUSION

MIER3, which is obviously down-regulated in CRC tissues, is closely associated with the proliferation and invasion of CRC, and NAT9 protein is a probable MIER3-interacting protein.

Molecular characterization, tissue expression, polymorphism and association of porcine LCK gene

Lymphocyte-specific protein tyrosine kinase (LCK) is an important reproduction related gene. In this study, the full-length cDNA sequence of porcine LCK gene was cloned through the rapid amplification of cDNA ends (RACE) method. The porcine LCK gene encodes a protein of 509 amino acids which shares high homology with the LCK of nine species: giant panda (97%), dog (97%), cattle (96%), sheep (95%), rabbit (95%), human (96%), rat (94%), mouse (94%) and horse (94%). This novel porcine gene was assigned to GeneID: 100233188. The phylogenetic analysis revealed that the porcine LCK gene has a closer genetic relationship with the LCK gene of dog. This gene is structured in twelve exons and eleven introns as revealed by computer-assisted analysis. The tissue transcription profile analysis indicated that the porcine LCK gene is generally but differentially expressed in the detected tissues including large intestine, spleen, lung, muscle, fat, liver, heart, kidney and ovary. PCR-Alu I-RFLP was established to detect an A/G substitution at the position of 1127-bp of mRNA and eight pig breeds displayed obvious genotype and allele frequency differences at this mutation locus. Association of this single-nucleotide polymorphism with litter size traits was assessed in Large White (n = 100) and Landrace (n = 100) pig populations, and results demonstrated that this polymorphic locus was significantly associated with the litter size of all parities in Large White sows and Landrace sows (P < 0.01). Therefore, LCK gene could be an useful candidate gene in selection for increasing litter size in pigs. These data serve as a foundation for further insight into this novel porcine gene.