Latitudinal relationships of esterase-6 and phosphoglucomutase gene frequencies in Drosophila melanogaster

Abstract

SUMMARYGeographic variation in Esterase-6 (Est-6) and Phosphoglucomutase (Pgm) gene frequencies in Australasian populations ot Drosophila melanogaster are compared with analogous data collated from 16 previous reports tor North America and Europe/Asia. A large-scale latitudinal dine is found on all three zoogeographic zones for Est-6 and overall, Est-61°°f requency increases from about 20 per cent around 20° latitude to about 80 per cent approaching 50°l atitude. In contrast, there is no consistent evidence for a latitudinal dine in Pgm gene frequencies in any of the three zones, with Pgm1°° frequency generally about 85 per cent and Pgm 1•20 and Pgm°7° frequencies each between 5 per cent and 10 per cent. The consistent Est-6 dines are attributed to latitudinal selection gradients but no consistent correlations are found between Est-6 gene frequencies and maximum or minimum temperature or rainfall which might be associated with these gradients. The directions of the Est-6 dines in tact run counter to expectations based on the in Vitro thermostabilities of the respective allozymes.

Molecular population genetics and selection in the glycolytic pathway

“…In addition, many clines in allozyme genes have been described, the most famous being in genes for alcohol dehydrogenase (Adh) and glycerol 3-phosphate dehydrogenase (Gpdh) (Oakeshott et al, 1981;Oakeshott et al, 1982;Oakeshott et al, 1983;Berry and Kreitman, 1993). These clines can reflect a long-term balance between selection and migration, or cases of recent adaptation in the spreading source population.…”

Latitudinal clines of allelic frequencies in Mediterranean populations of Ceratitis capitata (Wiedemann)

“…When neighboring populations of a species are compared, one finds that they usually differ from one another, slightly or appreciably, in a number of characteristics, eg, size, color or any other morphological or physiological character (Halkka et al, 1975;Rhomberg and Singh, 1989). Huxley (1942) Adh, a-Gpd, G-6-pd, Odh, 6-Pgd, Aph, Est-C, and Mdh (Voelker et al, 1977(Voelker et al, , 1978Anderson, 1981;Oakeshott et al, 1981Oakeshott et al, , 1982David, 1982;Anderson and Oakeshott, 1984). The seasonal cycle in Mpi and the latitudinal clines of other loci suggest that alternative alleles have different optimal temperatures or other environmental variables (see also Tomiuk and Wohrmann, 1984).…”

TheperiodGene Thr-Gly Polymorphism in Australian and AfricanDrosophila melanogasterPopulations: Implications for Selection

“…One further classic way of differentiating between natural selection and drift in the generation of a latitudinal cline is to study the polymorphism in a different continent (Oakeshott et al 1981). D. melanogaster was probably introduced into Australia $100 years ago (Bock and Parsons 1981).…”

“…D. melanogaster was probably introduced into Australia $100 years ago (Bock and Parsons 1981). Nevertheless, D. melanogaster shows a number of latitudinal clines in morphological characteristics such as body size ( James et al 1997) or in frequencies of various metabolic genes (Oakeshott et al 1981(Oakeshott et al , 1984 on this continent, suggesting that selection, in the face of considerable drift and migration, has already made its mark. While we might expect selection to be stronger on such morphological and biochemical phenotypes compared to more ephemeral behavioral characters, we have nevertheless examined the Thr-Gly length polymorphism on this continent.…”