Cloning of heat shock protein genes (hsp90 andhsc70) and their expression during larval diapause and cold tolerance acquisition in the rice stem borer,Chilo suppressalis Walker

Abstract

The complete cDNA sequences of heat shock protein 90 (hsp90) and of heat shock cognate protein 70 (hsc70) were cloned by reverse transcription polymerase chain reaction from the rice stem borer, Chilo suppressalis Walker. They potentially encode a 717-amino-acids (hsp90) and a 652-amino-acids (hsc70) protein, with calculated molecular weight of 82.5 and 71.3 kDa, respectively. The deduced amino acid sequence of hsp90 showed the highest homology of 97.2% to Spodoptera frugiperda hsp90. The closest match of C. suppressalis hsc70 was with Manduca sexta hsc70 at 98.0% identity. Expression of hsp90 in diapausing larvae was higher than that in non-diapausing larvae. No such up-regulation in diapausing larvae was observed for hsc70. In non-diapausing larvae, but not in diapausing ones, hsp90 expression was up-regulated by cold acclimation. Hsc70 expression slightly decreased during cold acclimation irrespective of the state of diapause. Involvement of hsp90 and hsc70 in larval diapause and cold tolerance acquisition in C. suppressalis is discussed.

Up-regulation of heat shock proteins is essential for cold survival during insect diapause

“…It is also evident that the same Hsps are not consistently involved in diapause. Although Hsp90 is down-regulated in pupal diapause of S. crassipalpis (20), it is up-regulated in the diapauses of both D. antiqua (26) and C. suppressalis (27).…”

“…After our initial reports on the diapause up-regulation of Hsp23 and Hsp70 (17,18), Hsps were found to be up-regulated during diapause in a number of additional species, including adult diapause of the Colorado potato beetle, Leptinotarsa decemlineata (24), pupal diapauses of the solitary bee, Megachile rotundata (25) and the onion maggot Delia antiqua (26), larval diapause of the rice stem borer Chilo suppressalis (27), and embryonic diapause of the silkmoth Bombyx mori (28). These published reports, together with our data on five additional species, provide evidence that Hsps are commonly up-regulated during diapause in diverse insect taxa, including Diptera, Lepidoptera, Coleoptera, and Hymenoptera and in diapauses that occur in embryonic, larval, pupal, and adult stages.…”

<I>Mamestra brassicae</I> Nucleopolyhedrovirus Infection and Enhancing Effect of Proteins Derived From <I>Xestia c-nigrum granulovirus</I> in Larvae of <I>Mamestra brassicae</I> and <I>Helicoverpa armigera</I> (Lepidoptera: Noctuidae) on Cabbage

“…The level of Xc-HSP70 expression and transcription was increased after thermal stress treatments in different developmental stages, which suggests that Xc-HSP70s are closely associated with insect resistance to thermal stress (Sonoda et al 2006;Zhang & Denlinger 2010). The intensity of the temperature responses also varies among HSP70 genes in different insects.…”

“…Interestingly, the relative accumulated amounts of mRNA from large HSP70s, including HSC70 and HSP70, may increase or decrease as larval and pupal development progress, depending on the species (Sonoda et al 2006). In X. c-nigrum, the relative transcript levels of Xc-HSC70 and Xc-HSP70 decreased with the developmental progress of the pupa.…”

Heat shock proteins in encysted and anhydrobiotic eutardigrades

“…Hsp90 proteins are essential molecular chaperones involved in signal transduction, cell-cycle control, stress management, folding, degradation and transports of proteins and have a specific function during recovery from stress, being especially important in the reactivation of stress-inactivated protein (Gkouvitsas et al 2009). Hsp90 genes are also implicated in developmental regulation and diapause in insects and during the dauer stage of nematodes (Dalley, and Golomb 1992;Marcus 2001;Sonoda et al 2006). …”