Thermal stress influence on HSP70 gene expression and female broodstock reproductive performance of the giant freshwater prawn, macrobrachium rosenbergii

Abstract

The giant freshwater prawn, Macrobrachium rosenbergii is one of the important freshwater cultured species in the world especially in Asian countries due to its high market value. Temperature was found to significantly affect ovarian development, spawning performance, embryonic development and hatching success in crustaceans. Under thermal stress, stress proteins such as Hsp70 are induced and released into the extracellular environment. Hsp70 aids proper folding or refolding and by inhibiting possible damaging interactions or protein aggregations and assist in disassembling already formed protein aggregates thus protecting cells by maintaining the cellular homeostasis. This study was designed to determine the thermal stress influence on Hsp70 gene expression and female reproductive performance of M. rosenbergii. Using Hsp70 as biomarker, thermal stress impinges on reproductive organs, the ovary and hepatopancreas were analyzed by determining the expression of Hsp70 mRNA inside the organs. Reproductive performance parameters; reproductive molt duration and frequency, embryonic development and morphometry, incubation period and hatching success of the eggs were determined after the adult inter-molt females were subjected to thermal treatment at 35, 30 and 28 °C (Control).