Location: Genetics and Animal BreedingTitle: The porcine muscle thanatotranscriptome
Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/15/2019
Publication Date: 1/15/2020
Citation: Nonneman, D.J., Dickey, A.M., King, D.A. 2020. The porcine muscle thanatotranscriptome [abstract]. In: Proceedings of XXVIII Plant and Animal Genome Conference, Swine Workshop. San Diego, CA, 11-15 Jan 2020. W1030.
Technical Abstract: While most gene expression studies for identification of meat quality candidate genes involve tissues collected immediately after harvest, several studies have shown that many genes are upregulated after death (thanatotranscriptome). It is generally accepted that anaerobic glycolysis is the primary postmortem metabolic pathway in the conversion of muscle to meat. However recent evidence shows that enough residual muscle oxygenation remains in postmortem muscle for hours to support mitochondrial function. This study was done to determine changes in gene expression with postmortem interval and how these genes and pathways are related to pork quality. RNAseq libraries were prepared from porcine longissimus muscle collected from five gilts ages 262-325 days, at 0, 24 and 48 hours after conventional harvest with electrical stunning and chilling. An average of 58.5 million paired-end reads were collected from each library, mapped to Sscrofa 11.1 and differential gene expression determined using DESeq2. Compared to 0 hour samples, 4 and 1943 more highly expressed genes, and 132 and 2280 lower expressed genes were found at 24 and 48 hours, respectively, with log2 fold changes ranging from -7.15 to 2.55. The most overrepresented pathways included ribosomal protein, translation, oxidative phosphorylation and cytochrome-C oxidase activity. ELISA for 3 proteins (HSP6a, CCL21 and EPB42) with gene expression fold changes of 5.1, 2.94 and 4.4 at 48 hours showed protein content changes of 88.01%, 42.19% and -37.17% at 48 hours. These results imply that gene expression and protein translation continues to occur in postmortem muscle and could impact meat quality.