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D Voss

Publications and source records attributed to D Voss.

At least 19 recordsLinked to original sources

Novel potassium channels encoded by the Shaker locus in Drosophila photoreceptors.

The Shaker gene, responsible for A-type potassium channels in Drosophila muscle, encodes a large family of transcripts capable of generating a variety of kinetically distinct A channels when expressed in oocytes. We describe a distinct class of A channel encoded by the Shaker gene in a novel preparation of dissociated Drosophila photoreceptors. Whole-cell recordings reveal a rapidly inactivating A current that is absent in Shaker mutants and that can be readily isolated in cell-attached patches. Although very similar to their muscle counterparts, the photoreceptor A channels show a striking 40-50 mV negative shift in their voltage-operating range. Two mutations (ShE62 and T(1;Y)W32), which exclude only certain classes of Shaker transcripts, were used to show that photoreceptor A channels are encoded by multiple transcripts distinct from those encoding muscle A channels, while PCR techniques identified four transcripts (ShA1, ShA2, ShG1, and ShG2) in mRNA from dissected retina.

Animals

Upstream sequences modulate in vitro transcription from Drosophila yolk protein genes I and II.

A Drosophila transcription system was employed to study transcription in vitro from templates carrying yolk polypeptide I and II (YPI, YPII) promoter regions. The transcription start sites of YPI and YPII genes are linked by 1225 base pairs of intergenic DNA and the genes are transcribed in divergent directions. Transcription was studied in vitro from templates carrying YPI or YPII promoter regions separately. We have successively deleted intergenic DNA upstream of the YPI or the YPII transcription start site and have assayed the dependence of transcription efficiency an template concentration. The results indicate that in vitro YPI and YPII transcript synthesis is controlled by separate cis-acting DNA sequence elements, which are located between 86 and 159 base pairs upstream of the YPI transcription start site and between 161 and 341 base pairs upstream of the YPII transcription start site. These elements stimulate in vitro transcription up to fivefold. Transcription was also studied with templates which contained both YP promoters. The transcription data indicate that the intergenic DNA contains additional DNA motif(s), which apparently modulate in vitro transcription coordinately from both YP promoters in an orientation-dependent manner.

Animals

[Iron deficiency].

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Anemia, Hypochromic