Formation and specification of ventral neuroblasts is controlled by vnd in Drosophila neurogenesis

Article Abstract:

In Drosophila neurogenesis, specification and formation of ventral neuroblasts is regulated by vnd. In Drosophila neural development, neuroblasts come off of the laminated neuroectoderm of each hemisegment in the usual orthogonal array of 5 rows, 3 columns. The weight of the evidence seems to point to the fate of an individual neuroblast's being determined by the domain-specific expression of genes along the anteroposterior and dorsoventral axis. The role of Vnd, an NK-2 homeodomain protein, initially expressed in the ventral neuroectoderm next to the ventral midline, in the dorsoventral patterning of the neuroectoderm and the neuroblasts has been studied. It is seen that in vnd null mutants, most ventral neuroblasts are not formed, and the few that do form do not develop ventral fates, instead developing those that are of intermediate nature. Vnd influences the gene expression patterns in the ventral proneural clusters and neuroectoderm.

Central nervous system, Gene expression, Neurogenetics, Cell transformation

Combinatorial signaling codes for the progressive determination of cell fates in the Drosophila embryonic mesoderm

Article Abstract:

Mesoderm progenitors in Drosophila embryos come from discrete clusters of cells expressing lethal of scute (l'sc). Using targeted ectopic expression approaches and loss-of-function it has been shown that specific progenitors are specified by deployment, sequentially, of a unique and specific combination of intercellular signals. Distinct cellular identity codes are apparently generated by combinatorial activities of Decapentaplegic (Dpp), Wingless (Wg), FGF, and EGF signals in the progressive determination of embryo mesodermal cells. Through monitoring of expression of the diphosphorylated form of mitogen-associated protein kinase (MAPK) it was found that two receptor tyrosine kinases (RTKs) are activated in small clusters of cells in the original competence domain.

Spain, Cellular signal transduction, Protein kinases, Myogenesis, Tyrosine metabolism

Cell cycle-dependent and cell cycle-independent control of transcription by the Drosophila E2F/RB pathway

Article Abstract:

Research has been conducted on Drosophila E2F/RB pathway. The authors demonstrate that the activities of the pathway's components are integrated at the target gene promoters, and reveal the unexpected aspect of E2F/RB regulation.

Analysis, Physiological aspects, Proteins, Genetic regulation, Genetic transcription, Transcription (Genetics), Cell cycle, Genetic research