ADH and phylogenetic relationships ofDrosophila lebanonensis (Scaptodrosophila)

Abstract

Increasing data on Drosophila alcohol dehydrogenase (ADH) sequences have made it possible to calculate the rate of amino acid replacement per year, which is 1.7 x 10(-9). This value makes this protein suitable for reconstructing phylogenetic relationships within the genus for those species for which no molecular data are available such as Scaptodrosophila. The amino acid sequence of Drosophila lebanonensis is compared to all of the already known Drosophila ADHs, stressing the unique characteristic features of this protein such as the conservation of an initiating methionine at the N-terminus, the unique replacement of a glycine by an alanine at a very conserved position in the NAD domain of all dehydrogenases, the lack of a slow-migrating peptide, and the total conservation of the maximally hydrophilic peptide. The functional significance of these features is discussed. Although the percent amino acid identity of the ADH molecule in Drosophila decreases as the number of sequences compared increases, the conservation of residue type in terms of size and hydrophobocity for the ADH molecule is shown to be very high throughout the genus Drosophila. The distance matrix and parsimony methods used to establish the phylogenetic relationships of D. lebanonensis show that the three subgenera, Scaptodrosophila, Drosophila, and Sophophora separated at approximately the same time.

Phylogeny of Drosophila and related genera inferred from the nucleotide sequence of the Cu,Zn Sod gene

“…This is supported by all our data. The presence of the second Sod intron in Scaptodrosophila (as well as in Ceratitis and Chymomyza), and its absence in the species of the Sophophora and Drosophila subgenera, definitely places the phylogenetic divergence of Scaptodrosophila before the Drosophila radiations (a position also endorsed by Grimaldi 1990;and DeSalle and Grimaldi 1991; but see Villarroya and Juan 1991). Grimaldi (1990) has accordingly raised Scaptodrosophila to the taxonomic status of "genus.…”

Drosophila Alcohol Dehydrogenase: Acetate–Enzyme Interactions and Novel Insights into the Effects of Electrostatics on Catalysis

“…All other known DADH sequences have either Thr or Ser at this position. 57,58 D. orena ADH has Ser at this position and may be expected to show properties characteristic of DmADH-S, DADH-FChD and D. simulans ADH. Another enzyme, D. lebanonensis ADH has threonine at position 214 but the side-chain does not form any clear hydrogen bond with any nearby residue.…”

Nucleotide sequence of the genomic region encompassing Adh and Adh-Dup genes of D. lebanonensis (Scaptodrosophila): Gene expression and evolutionary relationships

“…lebanonensis is an interesting species since its alcohol tolerance is nearly twice as high as that of D. melanogaster, which is itself much more tolerant than most Drosophila species (David et al 1974(David et al , 1979. In these two species the high ethanol tolerance is correlated with a high alcohol dehydrogenase activity and the higher ADH activity in D. lebanonensis is due to a fourfold increase in content of ADH enzyme (Villarroya and Juan 1991). D. melanogaster and D. lebanonensis, which belong to different subgenera, seem to represent two independent origins of high ADH activity and ethanol tolerance.…”

“…The first molecular datum for the species of the Scaptodrosophila subgenus was the amino acid sequence of D. Iebanonensis ADH which was used to derive the phylogenetic relationships with the other species of the genus at the molecular level (Villarroya and Juan 1991). Although D. lebanonensis was clearly separated from the species of the other subgenus, the order of divergence was ambiguous.…”

“…The phylogenetic tree obtained by UPGMA using synonymous substitution rates for Adh shows that Sophophora and Scaptodrosophila diverged shortly after the separation from the Drosophila subgenus; thus the ambiguous order of divergence obtained with the amino acid sequence data (Villarroya and Juan 1991) disappears. However, the UPGMA constructed with Kimura's two-parameter model for the whole coding region of Adh gives the same ambiguity as with amino acid data (data not shown).…”