On the architecture of regulatory systems: evolutionary insights and implications.
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Animals↗
Biomedical subjects
W J Dickinson
Publications and source records attributed to W J Dickinson.
Complex developmental regulation of the Drosophila affinidisjuncta alcohol dehydrogenase gene in Drosophila melanogaster.
During development, the alcohol dehydrogenase genes of Drosophila melanogaster and D. affinidisjuncta are expressed in similar, yet distinct, tissue- and stage-specific patterns. Transcripts from both of these genes arise from two promoters (distal and proximal) that also display tissue and stage specificity. We used P-element-mediated transformation to introduce the D. affinidisjuncta Adh gene into the germ line of D. melanogaster. We show that the D. affinidisjuncta Adh gene is expressed at comparable overall levels in both species and that the tissue- and stage-specific expression for this gene (including promoter utilization) is similar in the donor and the host species. However, in some details, the expression of the D. affinidisjuncta gene in D. melanogaster resembles the host pattern, and one novel tissue-specific expression phenotype is displayed by transformants. In general, our results suggest that there has been strong conservation of cis- and trans-acting regulatory factors since the divergence of the two species but that this conservation has not been perfect.
Alcohol Dehydrogenase↗
Complex cis-acting regulators and locus structure of Drosophila tissue-specific ADH variants.
Diverse patterns of tissue-specific expression of alcohol dehydrogenase (ADH) among species of the grimshawi subgroup of Hawaiian picture-winged Drosophila suggests control by complex or multiple, independently acting regulatory elements. These elements act by controlling Adh mRNA accumulation in individual tissue types. Restriction mapping of the Adh loci from these species reveals several insertion/deletion differences, one of which lies just outside the 5' end of the structural sequences and correlates with differences in larval patterns of ADH expression. No tissue-specific rearrangement of Adh sequences was observed.
Alcohol Dehydrogenase↗
Developmentally regulated RNA transcripts coding for alcohol dehydrogenase in Drosophila affinidisjuncta.
The organization of the gene coding for alcohol dehydrogenase (Adh) in Drosophila affinidisjuncta has been determined by physically mapping Adh RNA transcripts to cloned genomic DNA. Two distinct transcript types accumulate with developmental specificity. Because only a single genomic Adh locus is detected in D. affinidisjuncta, and since all Adh transcripts appear to be identical except at their termini, the two Adh RNA types are products of the same gene. One type of transcript, abundant in adults, contains a small 5' terminal exon that is completely lacking in the other type of transcript, which accumulates in larvae. This 5' end difference suggests that the D. affinidisjuncta Adh gene, like the homologous gene from the distantly related species D. melanogaster, is expressed from two promoters. According to the transcription map, these D. affinidisjuncta promoters are separated by approximately 560 base pairs of genomic DNA sequence. D. affinidisjuncta Adh transcripts also resemble D. melanogaster Adh transcripts in both their overall organization and their developmental distribution. Multiple 3' ends are responsible for the size heterogeneity of both types of D. affinidisjuncta Adh RNA, and some of these also appear with stage specificity.
Alcohol Dehydrogenase↗
Two alternative transcripts coding for alcohol dehydrogenase accumulate with different developmental specificities in different species of picture-winged Drosophila.
Two alternate transcripts of the single copy Alcohol dehydrogenase (Adh) gene accumulate with developmental specificity in all of 12 species of Hawaiian picture-winged Drosophila which have been examined. Relative to the paradigm species D. affinidisjuncta, the Adh transcript normally restricted to larvae is found to accumulate in both larval and adult tissues in D. formella. The other Adh transcript, which normally accumulates only in adults, accumulates in third-instar D. prostopalpis larvae as well. In species hybrids, the D. formella phenotype shows additive inheritance. These observations document the existence of a novel type of genetic variability. Furthermore, such variants suggest specific properties for the biological systems that regulate ADH expression in Drosophila, and they should facilitate further experimental investigations.
Alcohol Dehydrogenase↗
Regulation of the tissue specificity of an enzyme by a cis-acting genetic element: evidence from interspecific Drosophila hybrids.
Homologous genes for alcohol dehydrogenase (alcohol:NAD+ oxidoreductase, EC 1.1.1.1) are expressed in qualitatively different patterns during the development of two closely related species of Hawaiian Drosophila. In interspecific hybrids, each parental structural allele is expressed according to the developmental program characteristic of the species from which it is derived. This provides strong evidence for a cis acting control element.
Alcohol Oxidoreductases↗
Genetic control of enzyme expression in Drosophila: a locus influencing tissue specificity of aldehyde oxidase.
A natural genetic variant in Drosophila melanogaster with a highly tissue specific effect on the level of an enzyme (aldehyde oxidase) is described. This variant causes overproduction of the enzyme by a factor of 2- to 3-fold in paragonia (male accessory sex glands) while having no significant effect on the enzyme level in other tissues. This difference is controlled by a single genetic element in the vicinity of the aldehyde oxidase structural gene that operates in a strictly cis-active mode. It is not associated with any change in enzyme primary structure detectable by a variety of physical, chemical and immunochemical tests. The most likely explanation for all of these observations is that the variant defines a cis-active regulatory element adjacent to the structural site.
Aldehyde Oxidoreductases↗
Gene regulation in Drosophila: independent expression of closely linked, related structural loci.
A number of biochemical and genetic features shared by aldehyde oxidase and pyridoxal oxidase in Drosophila melanogaster indicate a close relationship between these enzymes. The present work shows that probable structural genes for these enzymes are within about 0.08 map unit of each other. Comparison with intensively studied regions of the genome suggests that this value is of the order of magnitude expected for adjacent functional units. Despite this close linkage, there is no indication of coordinate expression of the two enzymes. These results are consistent with the idea that each structural gene is under control of its own regulatory region, but alternative explanations are possible.
Age Factors↗
A genetic locus affecting the developmental expression of an enzyme in Drosophilia melanogaster.
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Aldehyde Oxidoreductases↗
Nucleotide sequence of the genomic region encoding alcohol dehydrogenase in Drosophila affinidisjuncta.
The DNA sequence of a 3886-bp genomic region containing the alcohol dehydrogenase (Adh) gene from Drosophila affinidisjuncta, and the RNA sequences of the D. affinidisjuncta Adh transcripts, are presented. These data support the conclusion that two Adh promoters generate distinct, developmentally regulated Adh transcripts. Correlations between these sequences and the transcription map are discussed. Comparisons between these and equivalent data from D. melanogaster are also presented. We note the following observations: (1) Except at the extreme 3' end, the two genes are identically organized. (2) Drosophila Adh protein accumulates amino acid replacements at the rate of approximately 0.5 per million years. (3) Among the non-protein-coding DNA sequences, putative homologies occur in the two promoter regions.
Alcohol Dehydrogenase↗