Inbreeding affects locomotor activity in Drosophila melanogaster at different ages.

The ability to move is essential for many behavioural traits closely related to fitness. Here we studied the effect of inbreeding on locomotor activity (LA) of Drosophila melanogaster at different ages under both dark and light regimes. We expected to find a decreased LA in inbred lines compared to control lines.

dMyc functions downstream of Yorkie to promote the supercompetitive behavior of hippo pathway mutant cells.

Genetic analyses in Drosophila epithelia have suggested that the phenomenon of "cell competition" could participate in organ homeostasis. It has been speculated that competition between different cell populations within a growing organ might play a role as either tumor promoter or tumor suppressor, depending on the cellular context. The evolutionarily conserved Hippo (Hpo) signaling pathway regulates organ size and prevents hyperplastic disease from flies to humans by restricting the activity of the transcriptional cofactor Yorkie (yki).

The impact of genetic parental distance on developmental stability and fitness in Drosophila buzzatii.

Measures of genetic parental distances (GPD) based on microsatellite loci (D(2) and IR), have been suggested to be better correlated with fitness than individual heterozygosity (H), as they contain information about past events of inbreeding or admixture. We investigated if GPD increased with increasing genetic divergence between parental populations in Drosophila buzzatii and if the measures indicate past events of admixture. Further we evaluated the relationship between GPD, fitness and fluctuating asymmetry (FA) of size and shape.

Fitness variation in response to artificial selection for reduced cell area, cell number and wing area in natural populations of Drosophila melanogaster.

Background: Genetically based body size differences are naturally occurring in populations of Drosophila melanogaster, with bigger flies in the cold. Despite the cosmopolitan nature of body size clines in more than one Drosophila species, the actual selective mechanisms controlling the genetic basis of body size variation are not fully understood. In particular, it is not clear what the selective value of cell size and cell area variation exactly is.

Thermal plasticity in Drosophila melanogaster: a comparison of geographic populations.

Background: Populations of Drosophila melanogaster show differences in many morphometrical traits according to their geographic origin. Despite the widespread occurrence of these differences in more than one Drosophila species, the actual selective mechanisms controlling the genetic basis of such variation are not fully understood. Thermal selection is considered to be the most likely cause explaining these differences.

Migration matrices and surnames in populations with different isolation patterns: Val di Lima (Italian Apennines), Val di Sole (Italian Alps), and La Cabrera (Spain).

Biodemographic methods are widely used to infer the genetic structure of human populations. In this study, we revise and standardize the procedures required by the migration matrix model of Malécot ([1950] Ann Univ Lyon Sci [A] 13:37-60), testing it in large historical-demographic databases of 85 populations from three mountain valleys with different degrees of isolation: Val di Lima (Italian Apennines, 21 parishes), Val di Sole, (Italian Alps, 27 parishes), and La Cabrera (Spain, 37 parishes). An add-on package (Biodem) for the R program is proposed to perform all calculations.

Developmental instability of the Drosophila wing as an index of genomic perturbation and altered cell proliferation.

We experimentally induced different levels of instability affecting the development of specific wing regions of Drosophila melanogaster using the UAS-GAL4 system. A common index of developmental instability is fluctuating asymmetry (FA), that is, random differences between body sides of single individuals. We studied the FA in transgenic strains carrying random genomic insertions (UAS strains), as well as insertions in the regulatory region of genes involved in the organization of wing development (GAL4 strains).

The tumor suppressor gene fat modulates the EGFR-mediated proliferation control in the imaginal tissues of Drosophila melanogaster.

Molecules involved in cell adhesion can regulate both early signal transduction events, triggered by soluble factors, and downstream events involved in cell cycle progression. Correct integration of these signals allows appropriate cellular growth, differentiation and ultimately tissue morphogenesis, but incorrect interpretation contributes to pathologies such as tumor growth. The Fat cadherin is a tumor suppressor protein required in Drosophila for epithelial morphogenesis, proliferation control and epithelial planar polarization, and its loss results in a hyperplastic growth of imaginal tissues.

The human protein Hugl-1 substitutes for Drosophila lethal giant larvae tumour suppressor function in vivo.

Drosophila lethal giant larvae: (lgl), discs large (dlg) and scribble (scrib) are tumour suppressor genes acting in a common pathway, whose loss of function leads to disruption of cell polarity and tissue architecture, uncontrolled proliferation and growth of neoplastic lesions. Mammalian homologues of these genes are highly conserved and evidence is emerging concerning their role in cell proliferation control and tumorigenesis in humans. Here we investigate the functional conservation between Drosophila lethal giant larvae and its human homologue Hugl-1(Llgl1).

Unisexuality and molecular drive: bag320 sequence diversity in bacillus taxa (insecta phasmatodea).

Satellite DNA variability follows a pattern of concerted evolution through homogenization of new variants by genomic turnover mechanisms and variant fixation by chromosome redistribution into new combinations with the sexual process. Bacillus taxa share the same Bag320 satellite family and their reproduction ranges from strict bisexuality (B. grandii) to automictic (B.

EXPERIMENTAL EVOLUTION OF HSP70 EXPRESSION AND THERMOTOLERANCE IN DROSOPHILA MELANOGASTER.

To examine whether recent evolutionary history affects the expression of Hsp70, the major heat-induced-heat shock protein in Drosophila melanogaster, we measured Hsp70 expression, thermotolerance, and hsp70 gene number in replicate populations undergoing laboratory evolution at different temperatures. Despite Hsp70's ancient and highly conserved nature, experimental evolution effectively and replicably modified its expression and phenotype (thermotolerance). Among five D.

Suppressors of the vestigial mutant phenotype increase the level of expression of the gene.

Suppressor genes of the vestigial phenotype have been isolated in a wild-type population. These suppressors have an effect on different wing mutants and are allele-specific in the case of vestigial. In a vg background they produced overgrowth of the imaginal wing disc.

CHROMOSOMAL ANALYSIS OF HEAT-SHOCK TOLERANCE IN DROSOPHILA MELANOGASTER EVOLVING AT DIFFERENT TEMPERATURES IN THE LABORATORY.

We investigated the heat tolerance of adults of three replicated lines of Drosophila melanogaster that have been evolving independently by laboratory natural selection for 15 yr at "nonextreme" temperatures (18°C, 25°C, or 28°C). These lines are known to have diverged in body size and in the thermal dependence of several life-history traits. Here we show that they differ also in tolerance of extreme high temperature as well as in induced thermotolerance ("heat hardening").