Examination of the genetic structure of the vairone Telestes souffia based on 10 nuclear markers (microsatellites) revealed little-to-moderate genetic differentiation between geographically adjacent populations in the eastern part of Lake Constance in central Europe. Results emphasize the critically endangered status of this freshwater fish in the upper Rhine River system.
View Article and Find Full Text PDFCichlid fishes compose an astonishingly large number of species and formed species flocks in record-breaking time. To facilitate efficient genome scans and comparisons of cichlid genomes, we constructed a medium-density genetic linkage map of microsatellite markers of Astatotilapia burtoni. The mapping cross was derived from two inbred laboratory lines to obtain F(2) progeny by intercrossing.
View Article and Find Full Text PDFThe burbot, Lota lota, is the only freshwater species of the codfish family and has a Holarctic distribution. Pleistocene glaciations caused significant geographical differentiation in the past, but its life history characterized by winter spawning migrations over large distances is likely to homogenize populations by contemporary gene flow. We investigated the population genetic structure of 541 burbots from Lake Constance and adjacent Rhine and Danube tributaries in Europe using the entire mitochondrial DNA (mtDNA) control region and 11 microsatellites.
View Article and Find Full Text PDFDiversity of ants of the Tetramorium caespitum/impurum complex was investigated in a multidisciplinary study. Focusing on morphologically hardly distinguishable Western Palearctic samples, we demonstrate the genetic and phenotypic diversity, demarcate phylogenetic entities, and discuss the clades in terms of biogeography. Sequences of 1113bp of the mitochondrial COI gene revealed 13 lineages.
View Article and Find Full Text PDFOne of the surprising insights gained from research in evolutionary developmental biology (evo-devo) is that increasing diversity in body plans and morphology in organisms across animal phyla are not reflected in similarly dramatic changes at the level of gene composition of their genomes. For instance, simplicity at the tissue level of organization often contrasts with a high degree of genetic complexity. Also intriguing is the observation that the coding regions of several genes of invertebrates show high sequence similarity to those in humans.
View Article and Find Full Text PDFMale swordtails in the genus Xiphophorus display a conspicuous ventral elongation of the caudal fin, the sword, which arose through sexual selection due to female preference. Females mate regularly and are able to store sperm for at least 6 months. If multiple mating is frequent, this would raise the intriguing question about the role of female choice and male-male competition in shaping the mating system of these fishes.
View Article and Find Full Text PDFThe Australian endemic ant Nothomyrmecia macrops is renowned for having retained a large proportion of 'primitive' morphological and behavioural characters. Another less studied peculiarity of this species is the production of short-winged (brachypterous) female sexuals, which presumably are poor dispersers. The males, in contrast, bear a full set of normally developed wings and thus may disperse widely.
View Article and Find Full Text PDFNaturwissenschaften
February 2002
Newly mated queens of monogynous (single queen) ants usually found their colonies independently, without the assistance of workers. In polygynous (multiple queen) species queens are often adopted back into their natal nest and new colonies are established by budding. We report that the Australian 'living-fossil' ant, Nothomyrmecia macrops, is exceptional in that its single queen can be replaced by one of the colony's daughters.
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