| short-range genetic structure of drosophila melanogaster populations in an afrotropical urban area and its significance. | alcohol dehydrogenase (adh) (alcohol:nad+ oxidoreductase, ec 1.1.1.1) gene frequencies and ethanol tolerance in drosophila melanogaster are known to exhibit long-range latitudinal variations on different continents; this has led to the argument that the clines are adaptive. accordingly, tropical populations are characterized both by a low frequency of adh-f and by a low ethanol tolerance. in the urban area of brazzaville (congo) under an equatorial african climate, an original genetic structure ... | 1989 | 2510164 |
| phenotypic expression of adh regulatory genes in drosophila melanogaster: a comparative study between a paleartic and a tropical population. | in vitro adh activity was studied in d. melanogaster males from two sets of third chromosome substitution lines, one from a paleartic population (gigean, france), the other from a tropical population (brazzaville, congo). as a linear model with raw adh activity dependent on fresh weight was significant in both sets of lines, the raw activity was adjusted by regression on weight. two main results were found: (a) the well-known substantial intrapopulation variability; and (b) third chromosome geog ... | 1994 | 7729695 |
| sexual isolation of genetically differentiated sympatric populations of drosophila melanogaster in brazzaville, congo: the first step towards speciation? | two sympatric populations of drosophila melanogaster were collected in the brazzaville area in congo, one from the suburban countryside and the other from a brewery located in the city. they were compared for several genetically determined traits including morphology, allozymes, microsatellites, cuticular hydrocarbons, and sexual behaviour. the two populations were similar to other african populations for morphological traits, but differed significantly from each other for all other characters. ... | 2000 | 10849071 |
| reproductive isolation in natural populations of drosophila melanogaster from brazzaville (congo). | the aim of this work is to analyze the homogamy previously detected between two natural populations of drosophila melanogaster from brazzaville. it is shown that mating isolation was still maintained under laboratory conditions 10 years after the populations samples were trapped. isolation seemed to be due mainly to premating isolation and we checked for any suggestion of post-mating mortality of hybrids. pre-mating isolation was not symmetrical, and significant chi2 values were found in 3/4 pos ... | 2002 | 12555780 |
| microspatial structure of drosophila melanogaster populations in brazzaville: evidence of natural selection acting on morphometrical traits. | two genetically distinct habitat races of drosophila melanogaster coexist in brazzaville (congo). one is the typical field type of afrotropical populations, the other mainly breeds in beer residues in breweries. these two populations differ in their ethanol tolerance, in their allelic frequencies at several enzyme and microsatellite loci and in the composition of their cuticular hydrocarbons. the brewery population is quite similar to european temperate populations with regard to all these trait ... | 2003 | 14576736 |
| pre-reproductive isolation as a consequence of allopatric differentiation between populations of drosophila melanogaster. | while pre-reproductive isolations are more and more frequently described between closely related species or within species, very little is known about their conditions of emergence. in brazzaville, two populations (kronenbourg and loua) of drosophila melanogaster show a premating isolation. two hypotheses were proposed to explain such a situation: a local sympatric differentiation or an allopatric divergence followed by a secondary contact. a microsatellite analysis, using markers on all chromos ... | 2005 | 16202097 |