Tissue-specific variation in Hsp70 expression and thermal damage in Drosophila melanogaster larvae.

1997 ◽  
Vol 200 (14) ◽  
pp. 2007-2015 ◽  
Author(s):  
R A Krebs ◽  
M E Feder

All tissues of larval Drosophila melanogaster express Hsp70, the major heat-shock protein of this species, after both mild (36 degrees C) and severe (38.5 degrees C) heat shock. We used Hsp70-specific immunofluorescence to compare the rate and intensity of Hsp70 expression in various tissues after these two heat-shock treatments, and to compare this with related differences in the intensity of Trypan Blue staining shown by the tissues. Trypan Blue is a marker of tissue damage. Hsp70 was rarely detectable before heat shock. Brain, salivary glands, imaginal disks and hindgut expressed Hsp70 within the first hour of heat shock, whereas gut tissues, fat body and Malpighian tubules did not express Hsp70 until 4-21 h after heat shock. Differences in Hsp70 expression between tissues were more pronounced at the higher heat-shock temperature. Tissues that expressed Hsp70 slowly stained most intensely with Trypan Blue. Gut stained especially intensely, which suggests that its sensitivity to heat shock may limit larval thermotolerance. These patterns further suggest that some cells respond primarily to damage caused by heat shock rather than to elevated temperature per se and/or that Hsp70 expression is itself damaged by heat and requires time for recovery in some tissues.

2019 ◽  
Author(s):  
Chengfeng Xiao ◽  
Danna Hull ◽  
Shuang Qiu ◽  
Joanna Yeung ◽  
Jie Zheng ◽  
...  

AbstractIt has been known for over 20 years that Drosophila melanogaster flies with twelve additional copies of the hsp70 gene encoding the 70 kDa heat shock protein lives longer after a non-lethal heat treatment. Since the heat treatment also induces the expression of additional heat shock proteins, the biological effect can be due either to HSP70 acting alone or in combination. This study used the UAS/GAL4 system to determine whether hsp70 is sufficient to affect the longevity and the resistance to thermal, oxidative or desiccation stresses of the whole organism. We observed that HSP70 expression in the nervous system or muscles has no effect on longevity or stress resistance but ubiquitous expression reduces the life span of males. We also observed that the down-regulation of Hsp70 using RNAi did not affect longevity.


1994 ◽  
Vol 14 (6) ◽  
pp. 3646-3659
Author(s):  
R P Dellavalle ◽  
R Petersen ◽  
S Lindquist

Following a standard heat shock, approximately 40% of Hsp70 transcripts in Drosophila melanogaster lack a poly(A) tail. Since heat shock disrupts other aspects of RNA processing, this observation suggested that heat might disrupt polyadenylation as well. We find, however, that as the temperature is increased a larger fraction of Hsp70 RNA is polyadenylated. Poly(A)-deficient Hsp70 RNAs arise not from a failure in polyadenylation but from the rapid and selective removal of poly(A) from previously adenylated transcripts. Poly(A) removal is highly regulated: poly(A) is (i) removed much more rapidly from Hsp70 RNAs than from Hsp23 RNAs, (ii) removed more rapidly after mild heat shocks than after severe heat shocks, and (iii) removed more rapidly after a severe heat shock if cells have first been conditioned by a mild heat treatment. Poly(A) seems to be removed by simple deadenylation rather than by endonucleolytic cleavage 5' of the adenylation site. During recovery from heat shock, deadenylation is rapidly followed by degradation. In cells maintained at high temperatures, however, the two processes are uncoupled and Hsp70 RNAs are deadenylated without being degraded. These deadenylated mRNAs are translated with low efficiency. Deadenylation therefore allows Hsp70 synthesis to be repressed even when degradation of the mRNA is blocked. Poly(A) tail shortening appears to play a key role in regulating Hsp70 expression.


1994 ◽  
Vol 14 (6) ◽  
pp. 3646-3659 ◽  
Author(s):  
R P Dellavalle ◽  
R Petersen ◽  
S Lindquist

Following a standard heat shock, approximately 40% of Hsp70 transcripts in Drosophila melanogaster lack a poly(A) tail. Since heat shock disrupts other aspects of RNA processing, this observation suggested that heat might disrupt polyadenylation as well. We find, however, that as the temperature is increased a larger fraction of Hsp70 RNA is polyadenylated. Poly(A)-deficient Hsp70 RNAs arise not from a failure in polyadenylation but from the rapid and selective removal of poly(A) from previously adenylated transcripts. Poly(A) removal is highly regulated: poly(A) is (i) removed much more rapidly from Hsp70 RNAs than from Hsp23 RNAs, (ii) removed more rapidly after mild heat shocks than after severe heat shocks, and (iii) removed more rapidly after a severe heat shock if cells have first been conditioned by a mild heat treatment. Poly(A) seems to be removed by simple deadenylation rather than by endonucleolytic cleavage 5' of the adenylation site. During recovery from heat shock, deadenylation is rapidly followed by degradation. In cells maintained at high temperatures, however, the two processes are uncoupled and Hsp70 RNAs are deadenylated without being degraded. These deadenylated mRNAs are translated with low efficiency. Deadenylation therefore allows Hsp70 synthesis to be repressed even when degradation of the mRNA is blocked. Poly(A) tail shortening appears to play a key role in regulating Hsp70 expression.


1996 ◽  
Vol 199 (8) ◽  
pp. 1837-1844 ◽  
Author(s):  
M E Feder ◽  
N V Cartaño ◽  
L Milos ◽  
R A Krebs ◽  
S L Lindquist

To determine how the accumulation of the major Drosophila melanogaster heat-shock protein, Hsp70, affects inducible thermotolerance in larvae and pupae, we have compared two sister strains generated by site-specific homologus recombination. One strain carried 12 extra copies of the Hsp70 gene at a single insertion site (extra-copy strain) and the other carried remnants of the transgene construct but lacked the extra copies of Hsp70 (excision strain). Hsp70 levels in whole-body lysates of larvae and pupae were measured by ELISA with an Hsp70-specific antibody. In both extra-copy and excision strains, Hsp70 was undetectable prior to heat shock. Hsp70 concentrations were higher in the extra-copy strain than in the excision strain at most time points during and after heat shock. Pretreatment (i.e. exposure to 36 degrees C before heat shock) significantly improved thermotolerance, and this improvement was greater and more rapid in larvae and pupae of the extra-copy strain than in those of the excision strain. The experimental conditions resemble thermal regimes actually experienced by Drosophila in the field. Thus, these findings represent the best evidence to date that the amount of a heat-shock protein affects the fitness of a complex animal in the wild.


Genetics ◽  
1984 ◽  
Vol 108 (4) ◽  
pp. 953-968
Author(s):  
S H Clark ◽  
S Daniels ◽  
C A Rushlow ◽  
A J Hilliker ◽  
A Chovnick

ABSTRACT Prior reports from this laboratory have described the experimental basis for our understanding of the genetic organization of the rosy locus (ry:3-52.0) of Drosophila melanogaster, as a bipartite genetic entity consisting of a structural element that codes for the xanthine dehydrogenase (XDH) peptide and a contiguous, cis-acting control element. The present report describes our progress in the analysis of the control element and its variants. Characterization of the control element variants reveals that, with respect to late third instar larval tissue distribution of XDH activity and cross-reacting material, i409H is associated with a large, tissue-specific increase in fat body which is not observed in malpighian tubules. Further data are presented in support of the inference that this differential expression must reflect differential production of XDH-specific RNA transcripts.—Gel blot analyses are described which demonstrate (1) that the phenotypic effects associated with variation in the rosy locus control element relate to differences in accumulation of XDH-specific poly-A+ RNA and (2) do not relate to differences in rosy DNA template numbers.—Experiments are described that provide for unambiguous mapping of control element sites through the use of half-tetrad recombination experiments and the recovery and phenotypic characterization of the reciprocal products of exchange between control element site variants. Thus, we are able to order the sites as follows: kar-i1005 i409-ry.


Genetics ◽  
1984 ◽  
Vol 106 (2) ◽  
pp. 249-265
Author(s):  
Jym Mohler ◽  
Mary Lou Pardue

ABSTRACT The region containing subdivisions 93C, 93D and 93E on chromosome 3 of Drosophila melanogaster has been screened for visible and lethal mutations. Treatment with three mutagens, γ irradiation, ethyl methanesulfonate and diepoxybutane, has produced mutations that fall into 20 complementation groups, including the previously identified ebony locus. No point mutations affecting the heat shock locus in 93D were detected; however, a pair of deficiencies that overlap in the region of this locus was isolated. Flies heterozygous in trans for this pair of deficiencies are capable of producing all of the major heat shock puffs (except 93D) and the major heat shock proteins. In addition, these flies show recovery of normal protein synthesis following a heat shock.


iScience ◽  
2021 ◽  
Vol 24 (4) ◽  
pp. 102288
Author(s):  
Annelie Blumrich ◽  
Georg Vogler ◽  
Sandra Dresen ◽  
Soda Balla Diop ◽  
Carsten Jaeger ◽  
...  

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