scholarly journals Correct temperature induction and developmental regulation of a cloned heat shock gene transformed into the Drosophila germ line.

1984 ◽  
Vol 4 (12) ◽  
pp. 2883-2889 ◽  
Author(s):  
E P Hoffman ◽  
V G Corces

We have constructed a size variant of the Drosophila hsp28 gene by deleting 207 base pairs of the protein coding region, beginning 33 base pairs downstream of the ATG protein initiation codon. After transformation of Drosophila melanogaster rosy (ry506) flies with this altered gene, using the P transposable element system, it was found that the transformed gene was regulated correctly both after temperature elevation and during the development of the flies. Levels of the variant mRNA were as high as those of the endogenous hsp28 during all patterns of expression, and the variant mRNA appeared in all cases to be processed correctly and to be as stable as the endogenous mRNA. Nevertheless, the chromosomal locus of the transformed gene did not puff after heat shock, suggesting that normal transcription of the gene does not require puffing of the locus. The deleted hsp28 gene retained the reading frame of the endogenous one, and a protein of the expected molecular weight of 18,500 was made after heat shock at levels comparable to those of the endogenous hsp28.

1984 ◽  
Vol 4 (12) ◽  
pp. 2883-2889
Author(s):  
E P Hoffman ◽  
V G Corces

We have constructed a size variant of the Drosophila hsp28 gene by deleting 207 base pairs of the protein coding region, beginning 33 base pairs downstream of the ATG protein initiation codon. After transformation of Drosophila melanogaster rosy (ry506) flies with this altered gene, using the P transposable element system, it was found that the transformed gene was regulated correctly both after temperature elevation and during the development of the flies. Levels of the variant mRNA were as high as those of the endogenous hsp28 during all patterns of expression, and the variant mRNA appeared in all cases to be processed correctly and to be as stable as the endogenous mRNA. Nevertheless, the chromosomal locus of the transformed gene did not puff after heat shock, suggesting that normal transcription of the gene does not require puffing of the locus. The deleted hsp28 gene retained the reading frame of the endogenous one, and a protein of the expected molecular weight of 18,500 was made after heat shock at levels comparable to those of the endogenous hsp28.


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.


1984 ◽  
Vol 4 (8) ◽  
pp. 1454-1459
Author(s):  
M S Ellwood ◽  
E A Craig

Saccharomyces cerevisiae contains a family of genes related to Hsp70, the major heat shock gene of Drosophila melanogaster. The transcription of three of these genes, which show no conservation of sequences 5' to the protein-coding region, was analyzed. The 5' flanking regions from the three genes were fused to the Escherichia coli beta-galactosidase structural gene and introduced into yeasts on multicopy plasmids, putting the beta-galactosidase production under yeast promoter control. Analysis of beta-galactosidase mRNA and protein production in these transformed strains revealed that transcription from the three promoters is differentially regulated. The number of transcripts from one promoter is vastly increased for a brief period after heat shock, whereas mRNA from another declines. Transcripts from a third gene are slightly enhanced upon heat shock; however, multiple 5' ends of the mRNA are found, and a minor species increases in amount after heat shock. Transcription of these promoters in their native state on the chromosome appears to be modulated in the same manner.


1984 ◽  
Vol 4 (8) ◽  
pp. 1454-1459 ◽  
Author(s):  
M S Ellwood ◽  
E A Craig

Saccharomyces cerevisiae contains a family of genes related to Hsp70, the major heat shock gene of Drosophila melanogaster. The transcription of three of these genes, which show no conservation of sequences 5' to the protein-coding region, was analyzed. The 5' flanking regions from the three genes were fused to the Escherichia coli beta-galactosidase structural gene and introduced into yeasts on multicopy plasmids, putting the beta-galactosidase production under yeast promoter control. Analysis of beta-galactosidase mRNA and protein production in these transformed strains revealed that transcription from the three promoters is differentially regulated. The number of transcripts from one promoter is vastly increased for a brief period after heat shock, whereas mRNA from another declines. Transcripts from a third gene are slightly enhanced upon heat shock; however, multiple 5' ends of the mRNA are found, and a minor species increases in amount after heat shock. Transcription of these promoters in their native state on the chromosome appears to be modulated in the same manner.


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.


1993 ◽  
Vol 13 (8) ◽  
pp. 5034-5042
Author(s):  
C L Wellington ◽  
M E Greenberg ◽  
J G Belasco

The protein-coding region of the c-fos proto-oncogene transcript contains elements that direct the rapid deadenylation and decay of this mRNA in mammalian cells. The function of these coding region instability determinants requires movement of ribosomes across mRNAs containing them. Three types of mechanisms could account for this translational requirement. Two of these possibilities, (i) that rapid mRNA decay might be mediated by the nascent polypeptide chain and (ii) that it might result from an unusual codon usage, have experimental precedent. Here, we present evidence that the destabilizing elements in the c-fos coding region are not recognized in either of these two ways. Instead, the ability of the c-fos coding region to function as a potent mRNA destabilizer when translated in the +1 reading frame indicates that the signals for rapid deadenylation and decay reside in the sequence or structure of the RNA comprising this c-fos domain.


Genome ◽  
1989 ◽  
Vol 31 (2) ◽  
pp. 677-683 ◽  
Author(s):  
S. C. Lakhotia

The 93D locus in Drosophila melanogaster and the 93D-like loci in other species of Drosophila, collectively termed hsr ω (heat shock RNA omega) locus, display several unique and intriguing features: (i) developmental regulation and selective induction by several agents like benzamide, colchicine, thiamphenicol, vit-B6; (ii) functional conservation in the genus but a very rapid DNA base sequence divergence; (iii) in spite of the rapid DNA sequence divergence, a strong conservation of organization (a 5′ unique region and a 3′ long tandem repeat region) and the pattern of multiple ω transcripts in the genus; (iv) a general nontranslatability of all the three major species of ω transcripts (an ~ 10-kb ω1, a 2.0-kb ω2, and a 1.2-kb ω3 species) although some recent evidence favours translatability of a small open reading frame (~ 23 – 27 amino acid long) in the ω3 transcript; (v) dispensability of the hsr ω locus for heat shock protein synthesis but indispensability for viability of flies. The heat shock inducibility of the 93D locus of D. melanogaster is selectively repressed by (i) combination of heat shock with another inducer of 93D; (ii) rearing of larvae at 10 °C; (iii) heterozygous deficiency for the 93D region; and (iv) conditions that alter levels of beta-alanine. In all cases of repression of the 93D locus during heat shock, the 87A and 87C loci (the two duplicate loci harbouring multiple copies for hsp70 and the alpha–beta repeat sequences (at 87C)) develop unequal puffs. The hsr ω locus appears to be under a complex system of regulation involving autoregulation as well as regulation by other factors in the cell which possibly operate through different control elements on the locus.Key words: benzamide, colchicine, beta-alanine, hsr ω, heat shock puffs, Drosophila.


1988 ◽  
Vol 8 (7) ◽  
pp. 2925-2932 ◽  
Author(s):  
Z F Zakeri ◽  
D J Wolgemuth ◽  
C R Hunt

A unique member of the mouse HSP70 gene family has been isolated and characterized with respect to its DNA sequence organization and expression. The gene contains extensive similarity to a heat shock-inducible HSP70 gene within the coding region but diverges in both 3' and 5' nontranslated regions. The gene does not yield transcripts in response to heat shock in mouse L cells. Rather, the gene appears to be activated uniquely in the male germ line. Analysis of RNA from different developmental stages and from enriched populations of spermatogenic cells revealed that this gene is expressed during the prophase stage of meiosis. A transcript different in size from the major heat-inducible mouse transcripts is most abundant in meiotic prophase spermatocytes and decreases in abundance in postmeiotic stages of spermatogenesis. This pattern of expression is distinct from that observed for another member of this gene family, which was previously shown to be expressed abundantly in postmeiotic germ cells. These observations suggest that specific HSP70 gene family members play distinct roles in the differentiation of the germ cell lineage in mammals.


2020 ◽  
Vol 86 (3) ◽  
pp. 201-209
Author(s):  
T E Peretolchina ◽  
T Ya Sitnikova ◽  
D Yu Sherbakov

Abstract Here, we present the complete mitochondrial (mt) genomes of four members of the Baicaliidae Fisher, 1885, a truncatelloidean family that is endemic to Lake Baikal (East Siberia). The mt genomes are those of Korotnewia korotnevi (15,171 bp), Godlewskia godlewskii (15,224 bp), Baicalia turriformis (15,127) and Maackia herderiana (15,154 bp). All these mt genomes contain 13 protein-coding genes, 2 ribosomal RNA (rRNA) genes and 22 transfer RNA (tRNA) genes. We detected non-canonical base pairs in some of the tRNA genes and variable numbers of non-coding spacers; some tRNAs do not have a TψC loop. We found gene order to be highly conserved in these Lake Baikal species and similar to the majority of caenogastropod mt genomes available on GenBank. A position of the putative control region is delimited to the non-coding region between trnF and the cox3 gene. It contains the ‘GAA(A)nT’ motif at the 3′ end and is similar to the replication origin found in most Caenogastropoda studied to date. We also compared the evolutionary rates of different genes to evaluate their use in different kinds of population or phylogenetic studies of this group of gastropods.


1990 ◽  
Vol 10 (2) ◽  
pp. 492-500 ◽  
Author(s):  
M Baur ◽  
I Potrykus ◽  
J Paszkowski

To study DNA topological requirements for homologous recombination in plants, we have constructed pairs of plasmids that contain nonoverlapping deletions in the neomycin phosphotransferase gene [APH(3')II], which, when intact, confers kanamycin resistance to plant cells. Protoplasts isolated from Nicotiana tabacum were cotransformed with complementary pairs of plasmids containing these truncated gene constructs. Homologous recombination or gene conversion within the homologous sequences (6 to 405 base pairs) of the protein-coding region of the truncated genes led to the restoration of the functional APH(3')II gene, rendering these cells resistant to kanamycin. Circular plasmid DNAs recombined very inefficiently, independent of the length of the homologous region. A double-strand break in one molecule only slightly increased the recombination frequency. The most favorable substrates for recombination were linear molecules. In this case, the recombination frequency was positively correlated with the length of the homologous regions. The recombination frequency of plasmids linearized at sites proximal to the deletion-homology junction was significantly higher than when linearization was distal to the homologous region. Vector homology within cotransformed plasmid sequences also increased the recombination frequency.


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