Ivarplazmában lokalizált RHS-ek azonosítása DNS microarray tecnikával Drosophila melanogasterben = Identification of germ plasm specific RHAs by DNA microarray method in Drosophila

Drosophila melanogasterben az embrionális ivarsejtek azonosságát a pete poszterior csúcsán, az ivarplazmában lokalizált anyai géntermékek határozzák meg. Pályázatunk célja egy microarray alapú, genomszintű reverz genetikai kísérletsor végrehajtása volt ivarplazmában lokalizált RNS-ek azonosítása érdekében Drosophila melanogasterben. Genetikai módszerekkel ivarplazma hiányos és ivarplazmában túltengő petéket állítottunk elő és azok RNS tartalmát DNS microarray tecnikával hasonlítottuk össze. Polimeráz láncreakción alapuló egyszálú DNS jelölő technikát adaptáltunk pete in situ hibridizációs kísérletünkhöz, mellyel a mikroarray kísérlet eredményét tudjuk megerősíteni. Az ivarplazmában lokalizált RNS-ek funkcionális vizsgálatát kettősszálú RNS interferencia eljárással végeztük. A kettős szálú RNS-ek petébe való bejuttatására nagy tagszámú sorozatkísérlet kivitelezésére alkalmas gene gun technológiát adaptáltuk. Elvégeztük két ivarplazmában lokalizálódó RNS-t kódoló gén részletes funkcionális analízisét. | In Drosophila melanogaster, the embryonic germ cells develop under the control of factors that localize in the germ plasm, at the most posterior part of the egg. The goal of the project was to perform a genome-wide reverse genetic experiment in order to isolate novel germ plasm localized RNA species. Making use of special genetic backgrounds, we established germ plasm deficient and germ plasm overproducing Drosophila eggs and compared their RNA content by using microarray technique. The results of the microarray experiments were confirmed with a modified in situ RNA hybridization method in which gene specific single stranded labeled DNA probes were used. The functional analysis of the germ plasm localized RNAs was performed with the help of gene gun mediated double stranded RNA interference. Finally, detailed genetic and cell biological analyses were carried out in the case of two genes which encode for germ plasm localized RNAs

BMP signaling components in embryonic transcriptomes of the hover fly Episyrphus balteatus (Syrphidae)

<p>Abstract</p> <p>Background</p> <p>In animals, signaling of Bone Morphogenetic Proteins (BMPs) is essential for dorsoventral (DV) patterning of the embryo, but how BMP signaling evolved with changes in embryonic DV differentiation is largely unclear. Based on the extensive knowledge of BMP signaling in <it>Drosophila melanogaster</it>, the morphological diversity of extraembryonic tissues in different fly species provides a comparative system to address this question. The closest relatives of <it>D. melanogaster </it>with clearly distinct DV differentiation are hover flies (Diptera: Syrphidae). The syrphid <it>Episyrphus balteatus </it>is a commercial bio-agent against aphids and has been established as a model organism for developmental studies and chemical ecology. The dorsal blastoderm of <it>E. balteatus </it>gives rise to two extraembryonic tissues (serosa and amnion), whereas in <it>D. melanogaster</it>, the dorsal blastoderm differentiates into a single extraembryonic epithelium (amnioserosa). Recent studies indicate that several BMP signaling components of <it>D. melanogaster</it>, including the BMP ligand Screw (Scw) and other extracellular regulators, evolved in the dipteran lineage through gene duplication and functional divergence. These findings raise the question of whether the complement of BMP signaling components changed with the origin of the amnioserosa.</p> <p>Results</p> <p>To search for BMP signaling components in <it>E. balteatus</it>, we generated and analyzed transcriptomes of freshly laid eggs (0-30 minutes) and late blastoderm to early germband extension stages (3-6 hours) using Roche/454 sequencing. We identified putative <it>E. balteatus </it>orthologues of 43% of all annotated <it>D. melanogaster </it>genes, including the genes of all BMP ligands and other BMP signaling components.</p> <p>Conclusion</p> <p>The diversification of several BMP signaling components in the dipteran linage of <it>D. melanogaster </it>preceded the origin of the amnioserosa.</p> <p>[Transcriptome sequence data from this study have been deposited at the NCBI Sequence Read Archive (SRP005289); individually assembled sequences have been deposited at GenBank (<ext-link ext-link-id="JN006969" ext-link-type="gen">JN006969</ext-link>-<ext-link ext-link-id="JN006986" ext-link-type="gen">JN006986</ext-link>).]</p

Neural stem cell derived tumourigenesis

In the developing Drosophila CNS, two pools of neural stem cells, the symmetrically dividing progenitors in the neuroepithelium (NE) and the asymmetrically dividing neuroblasts (NBs) generate the majority of the neurons that make up the adult central nervous system (CNS). The generation of a correct sized brain depends on maintaining the fine balance between neural stem cell self-renewal and differentiation, which are regulated by cell-intrinsic and cell-extrinsic cues. In this review, we will discuss our current understanding of how self-renewal and differentiation are regulated in the two neural stem cell pools, and the consequences of the deregulation of these processes