Neuroendocrine regulation of development timing and body size in Drosophila Melanogaster

Christina Holm Jensen, Nathiya Arunagirinathan, Gizem Henden, Magdalena Mitternöckler, Mika Kaan, Rie Juul Jensen & Stine Hesselholt Sloth

Studenteropgave: Speciale

Abstrakt

The process of development and metamorphosis in Drosophila melanogaster is a complex interaction of several different hormones, proteins and growth factors. It is known that growth and molting is mainly regulated by three hormones, namely the juvenile hormone (JH), the prothoracicotropic hormone (PTTH) which triggers the release of ecdysone, the third important hormone. The release of PTTH is thought to be influenced by a number of proteins and growth factors, although the precise effects are mostly unknown. Therefore, the aim of this project is to reach a better understanding of the effects of Ras signalling on PTTH and in turn on ecdysone and the developmental timing of D.melanogaster. Such studies on D.melanogaster may provide insight about the regulation of growth and development in humans. In order to identify the role and importance of the mentioned hormones and proteins, crosses have been set up to over-express or reduce the activities of Ras signalling components in the PTTH producing neurons. Subsequently, the timing of metamorphosis was observed and the levels of PTTH and ecdysone-inducible genes were measured by proceeding quantitative real-time polymerase-chain-reaction (qPCR). The results suggest that the Ras signalling has an impact in the synthesis and/or release of PTTH and therefore in the timing of development. The pathway is influenced in a positive way by over-expressing Ras whereas it is affected negatively by reducing Raf signalling. This reveals an important step within the regulation of PTTH signalling during development of D. melanogaster.

UddannelserMolekylærbiologi, (Bachelor/kandidatuddannelse) Kandidat
SprogEngelsk
Udgivelsesdato1 jan. 2011