Cloning, Sequence Analysis, and Prokaryotic Expression of the Porcine DECR1 Gene

2,4-dienoyl-CoA reductase 1 （ DECR1 ） is the key rate-limiting enzyme in the metabolism of polyunsaturated fatty acids. Although this protein has been studied in a variety of mammals, its role in por- cine is yet to be fully elucidated. However, it is a candidate determinant/indicator of meat quality, growth traits, and carcass quality. Here, we employed RT-PCR and rapid amplification of cDNA ends （RACE） analysis to amplify the full-length cDNA of DECR1 from Mashen pig liver, and cloned it into the expression vector pET-32a＋. After confirmation by sequencing and restriction analysis, the recombinant plasmid was transformed into E. coli BL21 cells. The cDNA of pig DECR1 contained 2,352 nucleotides, including a 987 bp open reading frame flanked by a 53 bp 5＇-untranslated region （UTR） and a 1,312 bp 3＇-UTR. The pig DECR1 coding sequence encoded 328 amino acid residues, which shared 99%, 88%, 87%, 87%, 87%, 87%, and 83% identity with those of Sus scrofa （predicted）, Bos taurus, Homo sapiens, Macaca mulatta, Pan troglodytes, Equus caballus, Canis, and Mus musculus, respectively. SDS-PAGE analysis revealed that the recombinant protein was expressed and that the expression level reached its highest level after 4 h induction. Western blot analysis indicated that the molecular weight of the expressed protein was the same as that predicted, ap- proximately 35 kDa. Collectively these data provide the basis for further studies into the physiological functions and molecular mechanisms of the pig DE- CR1 gene.

Mining Unknown Porcine Protein Isoforms by Tissue-based Map of Proteome Enhances Pig Genome Annotation

A lack of the complete pig proteome has left a gap in our knowledge of the pig genome and has restricted the feasibility of using pigs as a biomedical model.In this study,we developed a tissue-based proteome map using 34 major normal pig tissues.A total of 5841 unknown protein isoforms were identified and systematically characterized,including 2225 novel protein isoforms,669 protein isoforms from 460 genes symbolized beginning with LOC,and 2947 protein isoforms without clear NCBI annotation in the current pig reference genome.These newly identified protein isoforms were functionally annotated through profiling the pig transcriptome with high-throughput RNA sequencing of the same pig tissues,further improving the genome annotation of the corresponding protein-coding genes.Combining the well-annotated genes that have parallel expression pattern and subcellular witness,we predicted the tissue-related subcellular locations and potential functions for these unknown proteins.Finally,we mined 3081 orthologous genes for 52.7% of unknown protein isoforms across multiple species,referring to 68 KEGG pathways as well as 23 disease signaling pathways.These findings provide valuable insights and a rich resource for enhancing studies of pig genomics and biology,as well as biomedical model application to human medicine.