Gene Expression and Enzymatic Activity of Alkaline Phosphatase in Different Tissues of Penaeus monodon

Black tiger shrimp (Penaeus monodon) is an economically significant seafood product in Vietnam and globally, yet shrimp farming faces various dangerous diseases leading to substantial economic losses. Understanding the molecular immune mechanisms of the shrimp is crucial for developing disease prevention solutions. Alkaline phosphatase (ALP) is an essential enzyme that influences the black tiger shrimp's immunity. However, knowledge about the enzyme’s distribution in different tissues of the shrimp and its specific spacial function remains limited. In this study, expression and enzymatic activity of ALP across six different tissues including body muscle, carapace, gill, head muscle, hemolymph, and hepatopancreas of P. monodon was investigated. Using reverse transcription quantitative polymerase chain reaction (RT-qPCR), the expression of ALP gene was found in the range: hepatopancreas > head muscle > carapace > gill, and not detectable in body muscle and hemolymph. The highest ALP gene expression occurs in the hepatopancreas, significantly differing from the other parts, 27.98, 28.87 and 75.79 times higher than head muscle, carapace, grill. Consistently, the enzymatic ALP activity was shown to be highest in the hepatopancreas (134.2 ± 16.05 mU/mg protein), followed by gill (8.6±3.5 mU/mg protein), carapace (3.3±2.2 mU/mg protein), head muscle (2.7±2.2 mU/mg protein, body muscle (1.4±0.02 mU/mg protein) and hemolymph (0.48 ± 0.022 mU/mg protein). Our results suggest that ALP expresses highest in hepatopancreas compared to other tissues in the black tiger shrimp.