Ségrégation et différenciation des cellules à l'origine des palpes maxillaires et des antennes de la tête adulte de drosophile

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Mechanical impact of epithelial-mesenchymal transition on epithelial morphogenesis in Drosophila.

International audienc

Molecular basis for the inhibition of Drosophila eye development by Antennapedia

Hox genes encoding homeodomain transcriptional regulators are known to specify the body plan of multicellular organisms and are able to induce body plan transformations when misexpressed. These findings led to the hypothesis that duplication events and misexpression of Hox genes during evolution have been necessary for generating the observed morphological diversity found in metazoans. It is known that overexpressing Antennapedia (Antp) in the head induces antenna-to-leg as well as head-to-thorax transformation and eye reduction. At present, little is known about the exact molecular mechanism causing these phenotypes. The aim of this study is to understand the basis of inhibition of eye development. We demonstrate that Antp represses the activity of the eye regulatory cascade. By ectopic expression, we show that Antp antagonizes the activity of the eye selector gene eyeless. Using both in vitro and in vivo experiments, we demonstrate that this inhibitory mechanism involves direct protein–protein interactions between the DNA-binding domains of EY and ANTP, resulting in mutual inhibition

A fluorescent toolkit for spatiotemporal tracking of apoptotic cells in living Drosophila tissues

International audienc

A P-insertion screen identifying novel X-linked essential genes in Drosophila.

The recent determination and annotation of the entire euchromatic sequence of the Drosophila melanogaster genome predicted the existence of about 13600 different genes (Science 287 (2000) 2185; http://www.fruitfly.org/annot/index.html). In parallel, the Berkeley Drosophila Genome Project (BDGP) has undertaken systematic P-insertion screens, to isolate new lethals and misexpressing lines. To date, however, the genes of the X chromosome have been under-represented in the screens performed. In order both to characterize several X-linked genes of prime interest to our laboratories and contribute to the collection of lethal P-insertions available to the community, we performed a P-insertion mutagenesis of the X chromosome. Using the PlacW and PGawB P-elements as mutagens, we generated two complementary sets of enhancer-trap lines, l(1)(T)PL and l(1)(T)PG, respectively, which both contain a reporter gene whose developmental expression can be monitored when driven by nearby enhancer sequences. We report here the characterization of 260 new insertions, mapping to 133 different genes or predicted CGs. Of these, 83 correspond to genes for which no lethal mutation had yet been reported. For 64 of those, we could confirm that lethality was solely due to the P-element insertion. The primary molecular data, reporter gene expression patterns (observed in embryos, third instar larvae and adult ovaries) and proposed CG assignment for each strain can be accessed and updated on our website at the following address: http://www-cbd.ups-tlse.fr:8080/screen