The ovarian, ecdysterone, and heat-shock-responsive promoters of the Drosophila melanogaster hsp27 gene react very differently to perturbations of DNA sequence.

Abstract

The effect of various types of DNA sequence alterations on the activity of the ovarian, ecdysterone, and heat-shock-responsive promoters of the Drosophla melanogaster hsp27 gene was studied by P element-mediated germ line transformation. Regions of DNA required for proper expression of the gene under these different conditions were identified. Wild-type levels of transcription during oogenesis are dependent on two elements respectively located within a 64-base-pair (bp) fragment in the transcribed untranslated region and between -227 and -958 bp upstream of the transcription start site. This ovarian expression is particularly sensitive to both chromosomal position effects and an increased distance between the distal upstream promoter element and the TATAA homology. The ecdysterone-mediated expression during metamorphosis is dependent on a 145-bp domain including the TATAA box and additional upstream sequences that augment transcription by two-to five-fold. Finally, sequences necessary for heat shock expression are located much further upstream from hsp27 than those previously found for hsp7O, although basal expression was correlated with the presence of more proximal heat shock consensus sequences.

Transcriptional derepression of the Saccharomyces cerevisiae HSP26 gene during heat shock.

“…Certain of the Drosophila small-hsp genes are induced during oogenesis, and members of the small-hsp gene family in lilies are induced during meiosis. For the Drosophila small-hsp genes, elements regulating heat shock induction are widely dispersed and readily separated from those regulating developmental expression (4,7,10,11,15,17,35). In contrast, none of our many HSP26 deletion mutations separated heat shock regulatory elements from developmental regulatory elements.…”

“…They do, however, contain an unusual VOL. 10,1990 on March 22, 2019 by guest http://mcb.asm.org/ Downloaded from number of partial elements, TTCs. Are these sequences, through a weak interaction with HSF, able to provide both basal expression and heat shock induction in this mutation?…”

“…This result also is unexpected. In the only other well-studied case, that of the Drosophila small-hsp genes, cis-regulatory sequences involved in stress induction are readily separated from those involved in developmental induction (4,7,10,11,15,17,35).…”

The expanding small heat-shock protein family, and structure predictions of the conserved “α-crystallin domain”

“…Two of the four Drosophila shsps are expressed in the egg chamber of the ovary during the meiotic period of oogenesis (Zimmerman et al 1983). The controlling regions for the heat shock and the ovarian induction are different (Hoffman et al 1987). The Saccharomyces shsp is induced during sporulation and meiosis (Kurtz et al 1986).…”

Multiple, compensatory regulatory elements specify spermatocyte-specific expression of the Drosophila melanogaster hsp26 gene.

“…Analysis of numerous Drosophila genes indicates that the expression of a single gene in multiple tissues involves, at least in part, distinct elements unique to each mode of expression (4,9,11,14,15,22,29). The mutational analyses of spermatocyte-specific (12; this report), nurse cell-specific (8,12), and heat-induced (8, 28; Glaser et al, in press) modes of hsp26 expression are consistent with the conclusion that each of these modes of hsp26 expression is mediated, at least in part, by unique regulatory elements.…”