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W Sofer

Publications and source records attributed to W Sofer.

31 records · Page 2Linked to original sources
PubMed1980

Alcohol dehydrogenase in Drosophila: isolation and characterization of messenger RNA and cDNA clone.

The mRNA for alcohol dehydrogenase (ADH) in D. melanogaster has been identified by translation in a cell-free system. The in vitro synthesized polypeptide, specifically precipitated by anti-ADH antibody, has identical subunit molecular weight (25,000 daltons) and tryptic peptide profile to the in vivo synthesized ADH. The poly A containing ADH-mRNA has been purified by specific precipitation of ADH-polysomes using anti-ADH antibody and S. aureus. Transformation of E. coli with the dA-tailed ADH-mRNA-complementary DNA hybrid annealed to the dT-tailed pBR322 yielded one plasmid which has been identified as the ADH-cDNA clone. The identification involved hybridization selection of ADH-mRNA and in vitro translation, in situ hybridization to the Adh locus on salivary gland polytene chromosomes and DNA sequencing. This ADH-cDNA plasmid contains 349 bases of the C-terminal protein coding and 180 bases of the 3' untranslated region.

Alcohol Oxidoreductases↗
PubMed1980

Adh-negative mutants: detection of an altered tryptic peptide in a mutant enzyme of Drosophila.

Adhnll is an ethyl methanesulfonate induced mutant that lacks detectable alcohol dehydrogenase activity. A number of indirect lines of evidence have indicated that the mutation responsible for this loss in enzyme activity is localized in the Adh structural gene. We present more direct evidence for this hypothesis here. Utilizing a newly developed procedure for comparing tryptic peptides of Drosophila alcohol dehydrogenase obtained from different strains, we show that the alcohol dehydrogenase-like protein isolated from Adhnll exhibits an altered peptide profile when compared to that of wild type. The implications of this finding as well as the utility of the method for attacking other genetic and developmental problems are discussed.

Alcohol Oxidoreductases↗
PubMed1979

Drosophila alcohol dehydrogenase activity in vitro and in vivo: effects of acetone feeding.

When adult Drosophila are placed on medium containing 0.5% acetone, their level of alcohol dehydrogenase activity drops rapidly. At the same time, the proportion of activity in the various electrophoretic forms of the enzyme shifts; most of the activity becomes localized in what is ordinarily a minor form of the enzyme. Moreover, the loss of enzyme activity occurs in vivo as well, as shown by sensitivity to ethanol poisoning, insensitivity to pentenol treatment, and inability to utilize ethanol as an energy source. These observations are discussed in light of a model advanced for the origin of the multiple forms of alcohol dehydrogenase in Drosophila.

Acetone↗
PubMed1977

Genetic and cytogenetic analysis of the Adh region in Drosophila melanogaster.

Eighteen Adh-negative mutations were selected with 1-pentyn-3-ol after feeding of formaldehyde. Twelve of the 18 were shown by cytological and genetic analysis to be deletions. Cytological examination of the deletions allowed us to localize the Adh gene to a region including bands 35B3-5 on the left arm of chromosome 2. The deletions were also used to order known visible loci located near Adh.--The vital loci near Adh were also investigated. A total of 109 lethal mutations were generated with EMS and 33 of these, localized within a region defined by the overlap of two of the deletions, were found to belong to 13 complementation groups. If one includes three other loci known to belong there (el, Adh and Sco) a total of 16 complemetation groups have been identified in the region close to Adh.

Alcohol Oxidoreductases↗
PubMed1976

Chemical selection of mutants that affect ADH activity in Drosophila. III. Effects of ethanol.

A chemical selection scheme is presented for the isolation of rare Adh-positive Drosophila. It makes use of the fact that flies lacking detectable ADH activity die as adults or larvae on relatively low concentrations of ethanol in the medium. We have demonstrated that this procedure is a practical one by crossing two Adh-negative alleles, screening 1.5 x 10(6) embryos, and isolating 14 Adh-positive survivors.

Aging↗
PubMed1976

Alcohol dehydrogenase-negative mutants in Drosophila: defects at the structural locus?

Sixteen Adh-negative mutants (induced by ethyl methanesulfonate) were examined for the presence of inactive alcohol dehydrogenase (ADH) protein. Four techniques were utilized in an effort to detect this protein: hybrid enzyme formation, intra-cistronic complentation, sodium dodecyl sulfate electrophoresis and antibody precipitation. Eleven of the sixteen negative strains showed evidence of inactive ADH protein and are preseumably mutations in the strutural element. These results are discussed in light of some recent models of gene organization in higher organisms.

Alcohol Oxidoreductases↗
PubMed1975

Chemical selection of mutants that affect alcohol dehydrogenase in Drosophila. II. Use of 1-pentyne-3-ol.

We describe a procedure for the selection of alcohol dehyrogenase negative mutants in Drosophila. The method consists of exposing eggs and larvae to low concentrations of 1-pentyne-3-ol dissolved in the culture medium. Only those flies with greatly reduced levels of alcohol dehydrogenase activity survive. In addition, genotypically negative flies die if their mothers are alcohol dehydrogenase positive. Using this procedure and formaldehyde to generate mutants, we were able to detect seven alcohol dehydrogenase negative mutants out of 350,000 individuals subjected to selection. At least five of the mutants contain small deletions that include the alcohol dehydrogenase locus.

Alcohol Oxidoreductases↗