The gene expression response of the catadromous perciform barramundi Lates calcarifer to an acute heat stress

Abstract

The acute heat-shock response of the tropical estuarine fish species barramundi Lates calcarifer as indicated by the expression of genes within stress (hsp 90AA, hsp 90AB, hsp 70 and hsc 70), metabolic (cisy, cco II and ldh) and growth (igf1 and mstn 1) related pathways was examined following an increase in water temperature from 28 to 36° C over 30 min. Lates calcarifer were maintained at the acute stress temperature of 36° C for 1 h before being returned to 28° C and allowed to recover at this temperature for a further 2 weeks. Muscle tissue sampling over the experimental period allowed for the expression quantification of stress, metabolic and growth-related genes via quantitative real-time polymerase chain reaction (qrt-PCR) where a robust and reliable normalization approach identified both α-tub and Rpl8 as appropriate genes for the analysis of gene expression in response to an acute heat stress. hsp90AA and hsp70 of the inducible heat-shock response pathway showed a massive up-regulation of gene expression in response to heat stress, whilst the constitutive heat-shock genes hsp90AB and hsp70 showed no change over the course of the experiment and a small increase after 2 weeks of recovery, respectively. Of the three genes representing the metabolic pathway (cisy, cco II and ldh) only cco II changed significantly showing a decrease in gene expression, which may suggest a small suppression of aerobic metabolism. igf1 of the growth pathway showed no significant differences in response to an acute heat stress, whilst mstn1 increased at the beginning of the heat stress but returned to basal levels soon after. Overall, the results demonstrate that an acute heat stress in L. calcarifer caused a significant increase in the expression of genes from the stress response pathway and a possible decrease in aerobic metabolism with only relatively minor changes to the growth pathway highlighting the hardy nature of L. calcarifer and its resilience in coping with sudden temperature changes routinely encountered within its natural environment.

Selection and Validation of Reference Genes for qRT-PCR in Lentinula edodes under Different Experimental Conditions

“…Under heat and Cd 2+ as well as T. atroviride stress conditions, α-tub was demonstrated as the best reference gene by the results from the three statistical analyses, which was consistent with previous studies reporting that α-tub was stably expressed under many kinds of abiotic stresses in fungi ( V. volvacea and L. edodes ), animals and plants [23,26,41,42,43]. PPCI and Actin were identified as the second most stable genes by the three statistical methods.…”

Expression of Hsp70, Igf1, and Three Oxidative Stress Biomarkers in Response to Handling and Salt Treatment at Different Water Temperatures in Yellow Perch, Perca flavescens

“…There was a significant change in Hsp70 strength, as in all groups there was a lower expression of Hsp70 than immediately after handling. Temperature-induced increases in expression of Hsp70 in different species; in barramundi ( Lates calcarifer ) (Newton et al, 2012 ), the mRNA level of hsp70 increased after crowding stress (Gornati et al, 2004 ; Caipang et al, 2008a ; Salas-Leiton et al, 2010 ) have been reported. Changes in water temperaturesd (Place and Hofmann, 2005 ; Niu et al, 2008 ) lead to an upregulation of the expression of the inducible form of the heat shock protein 70 ( hsp70 ) gene in Dicentrarchus labrax (European sea bass) when subjected to transport stress (Poltronieri et al, 2007 ).…”

Facing warm temperatures during migration: cardiac mRNA responses of two adult Oncorhynchus nerka populations to warming and swimming challenges

“…Interestingly, a significant population difference existed in the expression of hsp90β , with expression being greater for the Nechako compared with the Chilko population. The hsp90β gene is considered to be the constitutive form of hsp90 (Hermesz et al , ) and is not considered thermally responsive (Newton et al , ). Although expression of hsp90α increased more than expression of hsp90β after warm treatment, hsp90β also increased significantly.…”