scholarly journals Flounder antifreeze protein synthesis under heat shock control in transgenic Drosophila melanogaster.

1987 ◽  
Vol 7 (6) ◽  
pp. 2188-2195 ◽  
Author(s):  
D E Rancourt ◽  
V K Walker ◽  
P L Davies

The gene coding for the most abundant antifreeze protein (AFP) in the winter flounder was placed downstream of the Drosophila melanogaster hsp70 promoter and introduced into the D. melanogaster germ line by P-element-mediated transformation. In each of six transgenic strains tested, heat shock treatment induced the expression of two major AFP gene transcripts and one minor one. All three transcripts were spliced despite the lack of an obvious D. melanogaster internal intron-splicing sequence. The variation in transcript length was caused by selection of different polyadenylation sites. Western blots showed the presence of immunoreactive AFP in hemolymph from heat-shocked transformants. The immunoreactive material had a molecular weight of 6,200, which is consistent with the loss of the signal sequence from the primary translation product and the retention of the pro sequence. Thus, all the signals for flounder pre-mRNA and preprotein processing were recognized in D. melanogaster.

1987 ◽  
Vol 7 (6) ◽  
pp. 2188-2195
Author(s):  
D E Rancourt ◽  
V K Walker ◽  
P L Davies

The gene coding for the most abundant antifreeze protein (AFP) in the winter flounder was placed downstream of the Drosophila melanogaster hsp70 promoter and introduced into the D. melanogaster germ line by P-element-mediated transformation. In each of six transgenic strains tested, heat shock treatment induced the expression of two major AFP gene transcripts and one minor one. All three transcripts were spliced despite the lack of an obvious D. melanogaster internal intron-splicing sequence. The variation in transcript length was caused by selection of different polyadenylation sites. Western blots showed the presence of immunoreactive AFP in hemolymph from heat-shocked transformants. The immunoreactive material had a molecular weight of 6,200, which is consistent with the loss of the signal sequence from the primary translation product and the retention of the pro sequence. Thus, all the signals for flounder pre-mRNA and preprotein processing were recognized in D. melanogaster.


1986 ◽  
Vol 6 (2) ◽  
pp. 663-673 ◽  
Author(s):  
E Hoffman ◽  
V Corces

The transcriptional regulation of the Drosophila melanogaster hsp27 (also called hsp28) gene was studied by introducing altered genes into the germ line by P element-mediated transformation. DNA sequences upstream of the gene were defined with respect to their effect on steroid hormone-induced and heat-induced transcription. These two types of control were found to be separable; the sequences responsible for 80% of heat-induced expression were located more than 1.1 kilobases upstream of the RNA initiation site, while the sequences responsible for the majority of ecdysterone induction were positioned downstream of the site at -227 base pairs. We have determined the DNA sequence of the intergenic region separating hsp23 and hsp27 and have located putative heat shock and ecdysterone consensus sequences. Our results indicate that the heat shock promoter of the hsp27 gene is organized quite differently from that of hsp70.


1987 ◽  
Vol 7 (3) ◽  
pp. 973-981
Author(s):  
E P Hoffman ◽  
S L Gerring ◽  
V G Corces

The effect of various types of DNA sequence alterations on the activity of the ovarian, ecdysterone, and heat-shock-responsive promoters of the Drosophila 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 hsp70, although basal expression was correlated with the presence of more proximal heat shock consensus sequences.


1986 ◽  
Vol 6 (2) ◽  
pp. 663-673
Author(s):  
E Hoffman ◽  
V Corces

The transcriptional regulation of the Drosophila melanogaster hsp27 (also called hsp28) gene was studied by introducing altered genes into the germ line by P element-mediated transformation. DNA sequences upstream of the gene were defined with respect to their effect on steroid hormone-induced and heat-induced transcription. These two types of control were found to be separable; the sequences responsible for 80% of heat-induced expression were located more than 1.1 kilobases upstream of the RNA initiation site, while the sequences responsible for the majority of ecdysterone induction were positioned downstream of the site at -227 base pairs. We have determined the DNA sequence of the intergenic region separating hsp23 and hsp27 and have located putative heat shock and ecdysterone consensus sequences. Our results indicate that the heat shock promoter of the hsp27 gene is organized quite differently from that of hsp70.


1987 ◽  
Vol 7 (3) ◽  
pp. 973-981 ◽  
Author(s):  
E P Hoffman ◽  
S L Gerring ◽  
V G Corces

The effect of various types of DNA sequence alterations on the activity of the ovarian, ecdysterone, and heat-shock-responsive promoters of the Drosophila 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 hsp70, although basal expression was correlated with the presence of more proximal heat shock consensus sequences.


Genetics ◽  
1999 ◽  
Vol 151 (2) ◽  
pp. 749-760 ◽  
Author(s):  
Armin Schmidt ◽  
Gioacchino Palumbo ◽  
Maria P Bozzetti ◽  
Patrizia Tritto ◽  
Sergio Pimpinelli ◽  
...  

Abstract The sting mutation, caused by a P element inserted into polytene region 32D, was isolated by a screen for male sterile insertions in Drosophila melanogaster. This sterility is correlated with the presence of crystals in spermatocytes and spermatids that are structurally indistinguishable from those produced in males carrying a deficiency of the Y-linked crystal (cry) locus. In addition, their morphology is needle-like in Ste+ flies and star-shaped in Ste flies, once again as observed in cry– males. The sti mutation leads to meiotic drive of the sex chromosomes, and the strength of the phenomenon is correlated with the copy number of the repetitive Ste locus. The same correlation is also true for the penetrance of the male sterile mutation. A presumptive sti null allele results in male sterility and lethal maternal effect. The gene was cloned and shown to code for a putative protein that is 866 amino acids long. A C-terminal domain of 82 amino acids is identified that is well conserved in proteins from different organisms. The gene is expressed only in the germline of both sexes. The interaction of sting with the Ste locus can also be demonstrated at the molecular level. While an unprocessed 8-kb Ste primary transcript is expressed in wild-type males, in X/Y homozygous sti males, as in X/Y cry– males, a 0.7-kb mRNA is produced.


1986 ◽  
Vol 6 (12) ◽  
pp. 4548-4557
Author(s):  
J Hirsh ◽  
B A Morgan ◽  
S B Scholnick

We delimited sequences necessary for in vivo expression of the Drosophila melanogaster dopa decarboxylase gene Ddc. The expression of in vitro-altered genes was assayed following germ line integration via P-element vectors. Sequences between -209 and -24 were necessary for normally regulated expression, although genes lacking these sequences could be expressed at 10 to 50% of wild-type levels at specific developmental times. These genes showed components of normal developmental expression, which suggests that they retain some regulatory elements. All Ddc genes lacking the normal immediate 5'-flanking sequences were grossly deficient in larval central nervous system expression. Thus, this upstream region must contain at least one element necessary for this expression. A mutated Ddc gene without a normal TATA boxlike sequence used the normal RNA start points, indicating that this sequences is not required for start point specificity.


Development ◽  
1988 ◽  
Vol 104 (Supplement) ◽  
pp. 85-93 ◽  
Author(s):  
Stephen J. Poole ◽  
Thomas B. Kornberg

The engrailed gene is required for segmentation of the Drosophila embryo and is expressed in cells constituting the posterior developmental compartments. In mutant embryos lacking engrailed function, portions of the cuticular pattern in each segment are deleted, resulting in fusion of adjacent denticle bands. Using P-element-mediated transposition, we generated flies that express the engrailed gene under the control of an hsp70 promoter, and found that ectopic, heat-shock-induced, engrailed expression caused pattern defects similar to those in embryos lacking engrailed function. Sensitivity to heat shock was only during the cellular blastoderm and early gastrulation periods. This window of sensitivity corresponds to the time when wildtype engrailed protein localizes into segmentally reiterated stripes and represents only a small portion of the normal period of engrailed gene expression.


Genetics ◽  
1998 ◽  
Vol 148 (1) ◽  
pp. 267-275
Author(s):  
Isabelle Busseau ◽  
Sophie Malinsky ◽  
Maria Balakireva ◽  
Marie-Christine Chaboissier ◽  
Danielle Teninges ◽  
...  

Abstract I factors in Drosophila melanogaster are non-LTR retrotransposons similar to mammalian LINEs. They transpose at very high frequencies in the germ line of SF females resulting from crosses between reactive females, devoid of active I factors, and inducer males, containing active I factors. The vermilion marked IviP2 element was designed to allow easy phenotypical screening for retrotransposition events. It is deleted in ORF2 and therefore cannot produce reverse transcriptase. IviP2 can be mobilized at very low frequencies by actively transposing I factors in the germ line of SF females. This paper shows that IviP2 can be mobilized more efficiently in the germ line of strongly reactive females in the absence of active I factors, when it is trans-complemented by the product of ORF2 synthesized from the hsp70 heat-shock promoter. This represents a promising step toward the use of marked I elements to study retrotransposition and as tools for mutagenesis.


1986 ◽  
Vol 6 (5) ◽  
pp. 1640-1649 ◽  
Author(s):  
H Steller ◽  
V Pirrotta

We have transformed Drosophila melanogaster with modified P-element transposons, which express the transposase function from the heat-inducible hsp70 heat shock promoter. The Icarus transposon, which contains a direct hsp70-P fusion gene, behaved like a very active autonomous P element even before heat shock induction. Although heat shock led to abundant somatic transcription, transposition of the Icarus element was confined to germ line cells. To reduce the constitutive transposase activity observed for the Icarus element, we attenuated the translational efficiency of the transposase RNA by inserting the transposon 5 neomycin resistance gene between the hsp70 promoter and the P-element sequences. The resulting construct, called Icarus-neo, conferred resistance to G418, and its transposition was significantly stimulated by heat shock. Heat shocks applied during the embryonic or third instar larval stage had similar effects, indicating that transposition of P elements is not restricted to a certain developmental stage. Both Icarus and Icarus-neo destabilized snw in a P-cytotype background and thus at least partially overcome the repression of transposition. Our results suggest that the regulation of P-element transposition occurs at both the transcriptional and posttranscriptional levels.


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