Heat‐shock protein 90 is down‐regulated during pupal diapause in the flesh fly, <i>Sarcophaga crassipalpis</i>, but remains responsive to thermal stress

Rinehart, Joseph P.; Denlinger, David L.

doi:10.1046/j.1365-2583.2000.00230.x

Cited by 130 publications

(86 citation statements)

References 18 publications

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“…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).…”

Section: Resultsmentioning

confidence: 94%

“…Attempts to further boost expression of the Hsps with temperature shocks or other stresses have not been successful; thus, these two Hsps appear to be maximally expressed during diapause. During diapause, a cognate of Hsp70, Hsc70, remains unchanged in expression (18), and Hsp90 is down-regulated (20). Thus, Hsp expression during diapause provides an interesting contrast to the typical stress response in which all Hsps are up-regulated.…”

Section: Resultsmentioning

confidence: 99%

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

Rinehart

Yocum

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

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483

409

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Diapause, the dormancy common to overwintering insects, evokes a unique pattern of gene expression. In the flesh fly, most, but not all, of the fly's heat shock proteins (Hsps) are up-regulated. The diapause up-regulated Hsps include two members of the Hsp70 family, one member of the Hsp60 family (TCP-1), at least four members of the small Hsp family, and a small Hsp pseudogene. Expression of an Hsp70 cognate, Hsc70, is uninfluenced by diapause, and Hsp90 is actually down-regulated during diapause, thus diapause differs from common stress responses that elicit synchronous up-regulation of all Hsps. Up-regulation of the Hsps begins at the onset of diapause, persists throughout the overwintering period, and ceases within hours after the fly receives the signal to reinitiate development. The up-regulation of Hsps appears to be common to diapause in species representing diverse insect orders including Diptera, Lepidoptera, Coleoptera, and Hymenoptera as well as in diapauses that occur in different developmental stages (embryo, larva, pupa, adult). Suppressing expression of Hsp23 and Hsp70 in flies by using RNAi did not alter the decision to enter diapause or the duration of diapause, but it had a profound effect on the pupa's ability to survive low temperatures. We thus propose that up-regulation of Hsps during diapause is a major factor contributing to cold-hardiness of overwintering insects.cold tolerance ͉ overwintering ͉ stress proteins ͉ RNAi

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Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 99%

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

Rinehart

Yocum

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

483

409

View full text Add to dashboard Cite

show abstract

“…The hsp90 gene has various roles in different species (Siriani et al, 2005; Z.-C. Lü and F.-H. Wan Yamada et al, 2007). While it can be associated with heat shock tolerance (Rinehart and Denlinger, 2000;Yamada et al, 2007), it has also been shown to play a role in developmental regulation. For instance, hsp90 has been identified as a capacitor for morphological evolution in Drosophila (Rutherford and Lindquist, 1998) and plays a key role in organism development (Rutherford and Lindquist, 1998;Rutherford et al, 2007).…”

Section: Discussionmentioning

confidence: 99%

Using double-stranded RNA to explore the role of heat shock protein genes in heat tolerance in Bemisia tabaci (Gennadius)

Wan

2011

Journal of Experimental Biology

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SUMMARYThe whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) biotype B, is one of the most destructive invasive pests of field and glasshouse crops, and has a high tolerance to heat. Our previous work found that whitefly females are more heat tolerant than males. In the present study, real-time PCR and double-stranded RNA (dsRNA) methods were used to explore the role of heat shock protein (Hsp) genes in whitefly of both sexes; this provided further evidence of the mechanism underlying the differential heat tolerance abilities of females and males. The results showed that both hsp23 and hsp70 mRNA expression levels were higher in females than in males from 37.5 to 42°C, while at the extreme temperature of 44°C the hsp70 mRNA level was higher in males than in females. There was no significant difference in hsp90 mRNA expression between females and males under heat shock conditions. Furthermore, the survival rate of females fed hsp23 or hsp70 dsRNA significantly decreased following heat shock at 44°C for 1h, but male survival rate was not significantly affected. Additionally, the survival rate of both females and males showed no significant change after they were fed with hsp90 dsRNA. Collectively, the present study shows that the optimum mRNA expression of Hsp genes in females promotes a higher survival rate under heat shock conditions; hsp23 and hsp70 play a key role for heat tolerance in females but not in males, and hsp90 shows no significant role in heat tolerance in either females or males. Further, our study indicates that feeding with dsRNA is an effective method by which to study gene function, and the simplicity of this approach opens the way for further research on gene function in different sexes and diverse groups of species.

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“…hexane) that trigger ecdysteroid production and initiate adult morphogenesis (Denlinger, 2002). Numerous studies have used ecdysteroids or hexane to rapidly terminate diapause in flesh flies and have identified rapid, post-treatment changes in the expression of stress response proteins, metabolite pools, metabolic enzymes, proteins involved in cell cycling and several regulatory pathways including ERK/MAPK and insulin signaling (Fujiwara and Denlinger, 2007;Michaud and Denlinger, 2007;Ragland et al, 2010;Rinehart and Denlinger, 2000;Tammariello and Denlinger, 1998). This is an excellent approach for characterizing downstream gene action, but it cannot reveal processes that occur upstream of the ecdysteroid pulse that signals diapause termination.…”

Section: Introductionmentioning

confidence: 99%

Developmental trajectories of gene expression reveal candidates for diapause termination: a key life-history transition in the apple maggot flyRhagoletis pomonella

Ragland

Egan

Feder

et al. 2011

Journal of Experimental Biology

137

127

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SUMMARYThe timing of dormancy is a rapidly evolving life-history trait playing a crucial role in the synchronization of seasonal life cycles and adaptation to environmental change. But the physiological mechanisms regulating dormancy in animals remain poorly understood. In insects, dormancy (diapause) is a developmentally dynamic state, and the mechanisms that control diapause transitions affect seasonal timing. Here we used microarrays to examine patterns of gene expression during dormancy termination: a crucial life-history transition in the apple maggot fly Rhagoletis pomonella (Walsh). This species is a model system for host race formation and ecological speciation via changes in diapause regulation of seasonality. Our goal was to pinpoint the timing of the transition from diapause to post-diapause development and to identify candidate genes and pathways for regulation of diapause termination. Samples were taken at six metabolically defined developmental landmarks, and time-series analysis suggests that release from metabolic depression coincides with preparation for or resumption of active cell cycling and morphogenesis, defining the ʻendʼ of diapause. However, marked changes in expression, including members of pathways such as Wnt and TOR signaling, also occur prior to the metabolic rate increase, electing these pathways as candidates for early regulation of diapause termination. We discuss these results with respect to generalities in insect diapause physiology and to our long-term goal of identifying mechanisms of diapause adaptation in the Rhagoletis system. Supplementary material available online at

show abstract

Heat‐shock protein 90 is down‐regulated during pupal diapause in the flesh fly, Sarcophaga crassipalpis, but remains responsive to thermal stress

Cited by 130 publications

References 18 publications

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

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

Using double-stranded RNA to explore the role of heat shock protein genes in heat tolerance in Bemisia tabaci (Gennadius)

Developmental trajectories of gene expression reveal candidates for diapause termination: a key life-history transition in the apple maggot flyRhagoletis pomonella

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