 |
||
| Labor: | ||
| Teilprojekt | ||
| The aim of this
research project is the identification of genes that are involved in the
control of asymmetric cell divisions in the CNS of Drosophila. The stem
cells of the CNS, so called neuroblasts, delaminate from the
neuroectodermal epithelium and subsequently undergo a series of asymmetric
cell divisions, generating a ganglion mother cell and another neuroblast
in each division. The prerequisite for the asymmmetric division of
neuroblasts is the establishment of an intrinsic apical-basal cell
polarity that becomes apparent by the asymmetric localization of several
proteins and mRNAs and by the stereotypical orientation of the mitotic
spindle. To identify additional maternally and zygotically expressed genes that are involved in the control of asymmetric neuroblast divisions, we perform two genetic screens. Mutant embryos are triply stained with antibodies against polarity markers and with a DNA dye to determine the polarity and the cell cycle stage of individual neuroblasts. Mutants isolated in the screens are further analyzed by life imaging using a variety of transgenic fly lines expressing GFP fusion proteins with asymmetric localization in neuroblasts. Genes that turn out to be functionally relevant for asymmetric neuroblast division after these phenotypic analyses will be cloned and analyzed at the molecular level. |
||
 |
Subcellular localization of Bazooka and
Miranda in metaphase neuroblasts of wild type and lgl mutant embryos. The lgl mutation was isolated in a genetic screen for mutations in maternal effect genes with a function in neuroblast division. (a) In a wild type neuroblast, Bazooka (blue) is localized to the apical cortex and Miranda (red) to the basal cortex in a mutually exclusive fashion. (b) In neuroblasts of lgl mutant embryos, Bazooka is localized apically as in wild type, but Miranda is distributed all around the cortex and is also found on the mitotic spindle and in the cytoplasm. Apical is in the upper left corner in both panels. neuroblasts are marked by an arrow. |
|