Heat shock response in ovarian nurse cells of Anopheles stephensi.
Date
1989-06
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Abstract
Transcriptional and translational changes following temperature shock at 37,
39 or 41°C to ovarian cells of Anopheles stephensi were studied. Temperature shock at
39°C induced 6 puffs on polytene chromosomes in the nurse cells as revealed by [3H]
uridine incorporation studies. Only the 2R-19B puff was induced at 37°C and was found to
be a major temperature shock locus remaining most active at all the 3 temperatures tested.
Other temperature shock loci were activated only at 39°C. There was progressive inhibi
tion of general chromosomal transcription with the rise of temperature. Transcription was
drastically inhibited at 41°C but all the temperature shock loci still remained relatively
active. Examination of [35S]methionine labelled newly synthesized ovarian proteins using
sodium dodecyl sulphate-polyacrylamide slab gels revealed that all the heat shock polypeptides
except the HSP 70 were synthesized in ovarian cells even at control temperature
(29°C). Temperature shock induced the synthesis of HSP 70 and elevated the levels of
other heat shock polypeptides (82, 30, 29, 23 and 17 KD). Present results suggest that the
threshold level for induction of a complete heat shock response in mosquitos is higher
(39°C) than the other dipteran insects studied and that a 41°C treatment is not lethal as in
the case of Drosophila, Chironomus etc. These features reflect the adaptations of mosquitos
to tropical climate and their dietary habit of warm blood meal.
Description
Keywords
Temperature shock, mosquito, heat shock polypeptides, polytene chromo somes puffs, thermotolerance
Citation
B B Nath, Lakhotia S C. Heat shock response in ovarian nurse cells of Anopheles stephensi. Journal of Biosciences. 1989 Jun; 14(2): 143-152.