Generation and Analysis of Expressed Sequence Tags (ESTs) from Muscle Full-Length cDNA Library of Wujin Pig

Abstract

Porcine skeletal muscle genes play a major role in determining muscle growth and meat quality. Construction of a full-length cDNA library is an effective way to understand the expression of functional genes in muscle tissues. In addition, novel genes for further research could be identified in the library. In this study, we constructed a full-length cDNA library from porcine muscle tissue. The estimated average size of the cDNA inserts was 1 076 bp, and the cDNA fullness ratio was 86.2%. A total of 1058 unique sequences with 342 contigs (32.3%) and 716 singleton (67.7%) ESTs were obtained by clustering and assembling. Meanwhile, 826 (78.1%) ESTs were categorized as known genes, and 232 (21.9%) ESTs were categorized as unknown genes. Sixty-five novel porcine genes that exhibit no identity in the TIGR gene index of Sus scrofa and 124 full-length sequences with unknown functions were deposited in the dbEST division of GenBank (accession numbers: EU650784-EU650788; GE843306, GH228978-GH229100). The abundantly expressed genes in porcine muscle tissue were related to muscle fiber development, energy metabolism and protein synthesis. Gene ontology analysis showed that sequences expressed in porcine muscle tissue contained a high percentage of binding activity, catalytic activity, structural molecule activity and motor activity, which involved mainly in metabolic, cellular and developmental process, distributed mainly in intracellular region. The sequence data generated in this study would provide valuable information for identifying porcine genes expressed in muscle tissue and help to advance the study on the structure and function of genes in pigs.

Comparison of differentially expressed genes in longissimus dorsi muscle of Diannan small ears, Wujin and landrace pigs using RNA-seq

“…Wujin pig (WJ) is another excellent local breed found in the plateau regions of Yunnan, Sichuan, and Guizhou in China. It has valuable characteristics such as strong disease resistance, high fecundity, good mothering, strong adaptability, and high-quality pork products (10). As a typical fatty pig breed, WJ has become a famous high-quality ham product both domestically and internationally due to its delicious meat, abundant nutrition, elevated amino acid content, heavy collagen, and delicate flavor (11).…”