Resource Partitioning in Five Domestic Drosophila Species and Its Relationship to Ethanol Metabolism.

Abstract

The distributions of five Drosophila species living in the vicinity of a domestic compost heap in Canberra (Australia) have been compared across traps baited with different fruits and vegetables. In both the adults trapped directly on the baits and those emerging from eggs laid on the baits, D, busckii made up about 2% of the sample, D. hydei about 1% and D. immigrans 7%. The overall frequency of D. simulans was 80% in the trapped adults but 53% in emergences, while D , melanogaster represented 9% of trapped adults and 37% of emergences. In both types of collection the frequency of D. busckii relative to the other species was highest on vegetables, the relative frequencies of D. hydei and D. immigrans were highest on melons, and the relative frequencies of D. simulans and D , melanogaster were highest on fruits. Overall the relationship between the frequency of each species and the ethanol contents of the baits was significant and negative for D. busckii and D. immigrans, non-significant and negative for D. hydei, non-significant and positive for D. simulans, and significant and positive for D. melanogaster. These differences were correlated with differences between the species in alcohol dehydrogenase activity.

Temporal variation of Drosophila melanogaster Adh allele frequencies, inversion freqencies, and population sizes

“…However, whether the distributional differences between the sibling species in the field were indeed due to a greater temperature dependence of D. melanogaster needs further investigation. For example, food preferences and utilizations differ between the sibling species (Erk & Sang, 1966;Oakeshott et al, 1982b;Parsons, 1977 and references therein) and this may have contributed to the number distributions independently of temperature (see also McKenzie & Parsons, 1974a;Hoenigsberg, 1968;Tantawy, Mourad & Masri, 1970). Further, there may have been seasonally dependent differences in the attractions of the siblings to the banana/yeast baits, though McKenzie (1974) has reported when using very similar trapping procedures that the numbers of the siblings trapped were proportional to their respective population densities as estimated by handtrapping and mark-release-recapture experiments.…”

Structure and transcription of theDrosophila mullerialcohol dehydrogenase genes

“…The Adh-1 probe protects the 122 nucleotide RNA fragment in larval RNA only, and the Adh-2 probe protects the 130 nucleotide PM fragment in both larval and adult Rtb preparations (Figure 4). These results are predicted by ADH protein assays of larval and adult homogenates, which show that both ADH-l and ADH-2 are present in D. uleri third instar larvae, but that only ADH-2 is present in adult protein extracts (2,4).…”

“…melanogater Adh larval and adult promoters (2,3,4). Genetic analysis of electrophoretic variants of ADH-1 and ADH-2 in D. buzzatii (a species of the nulleri subgroup) provided evidence for the hypothesis that ADH-1 and ADH-2 are encoded by two closely-linked genes that are differentially expressed during development (2). HQwever, other possibilites such as alternate splicing of a single transcript to produce the two proteins could not be ruled out.…”

“…Conceptual translation of the two downstream Adh genes reveals that they differ by ten amino acids (underlined in Figure 2.) These differences identify the upstream gene as Adh-2 and the downstream gene as Adh-1, since AM-2 is the more basic protein (2). The region bearing the weakest haomlogy to all regions of the 1).…”

Mechanisms of naturally evolved ethanol resistance inDrosophila melanogaster

“…For example, a Malaysian tree shrew regularly consumes fermented nectar with in excess of 1% ethanol (Wiens et al, 2008), and breeding sites of the fruit fly Drosophila melanogaster can contain as much as 6-7% ethanol (McKenzie and McKechnie, 1979;Gibson et al, 1981;Oakeshott et al, 1982a). Although there is evidence that these and other species have evolved resistance to the toxic and sedating effects of ethanol (Bouletreau and David, 1981;Merçot et al, 1994;Wiens et al, 2008), little is known about the physiological basis of this resistance.…”