Meat Sci 2019 Jul 19;153:117-125. Epub 2019 Mar 19.
Instituto de Farmacología y Morfofisiología, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile. Electronic address:
The objective of this study was to investigate early postmortem (0.5 h) gene expression in beef Longissimus thoracis (LT) muscles from carcasses with NORMAL (<5.8) and HIGH (>5.9) ultimate pH (pH). A total of 53 transcripts were differentially expressed (P-value <.05): 40 showed up-regulation and 13 showed down-regulation in HIGH pH carcasses. Four up-regulated (PDK4, GADD45B, MAOA, METTL21C) genes were confirmed (P < .05) by q-PCR. HIGH pH samples resulted with lower values in glycolytic potential and AMP-activated protein kinase activity compared to NORMAL at 0.5 and 24 h postmortem (P < .05). Functional pathway analysis showed that calcium transport and GADD45 signaling pathways are associated with the development of HIGH pH meat. Genes involved in stress-related signaling, such as GADD45B, METTL21C and MAOA were overexpressed. These genes are involved in stress signaling that might be affecting Ca transport and oxidative metabolism pathways in HIGH pH muscles.