Expression analysis of the PEPCK gene in the shrimp Metapenaeus affinis under two different salinity conditions in Southern Iraq

Mohammed  M. Al-Othman; Fadhil J. Farhan; Abdul-Hussein H. Ghazi

Authors

Mohammed M. Al-Othman Department of Natural Marine science, College of Marine Sciences, University of Basrah
Fadhil J. Farhan Department of Natural Marine science, College of Marine Sciences, University of Basrah
Abdul-Hussein H. Ghazi Department of Natural Marine science, College of Marine Sciences, University of Basrah

Keywords:

Gene expression, PEPCK, Metapenaeus affinis, salinity, Iraq.

Abstract

Phosphoenolpyruvate carboxykinase (PEPCK) is a key enzyme in gluconeogenesis, playing a vital role in metabolic adjustments during environmental stress. The results indicate that the PEPCK gene is responsive to salinity changes in Metapenaeus affinis, as the qPCR assays demonstrated successful and reliable amplification, confirming the quality of the generated data. Shrimp collected from the low-salinity environment exhibited the highest gene expression levels, particularly in the hepatopancreas, which showed the lowest ΔC_t value 4.41 and the highest relative expression level (fold change = 8.53). In contrast, increasing salinity resulted in higher ΔC_t values and a marked reduction in gene expression, with this decrease being statistically significant in the hepatopancreas, whereas the reduction observed in the gills was not statistically significant. Furthermore, gene expression in the hepatopancreas was significantly higher than that in the gills under low-salinity conditions, while no significant differences between the two tissues were detected under high-salinity conditions. Overall, given that osmoregulation is a complex physiological process involving multiple regulatory pathways and genes, these findings demonstrate that the PEPCK gene is affected by salinity changes. Consequently, these expression patterns suggest that the PEPCK gene can be considered a reliable biomarker for monitoring physiological and ecological conditions in M. affinis, particularly in the hepatopancreas.

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