Recombinase mediated gene interference in developing Xenopus larvae

• Applicant: Professor Dr. Gerhart U. Ryffel
• Subject Area: Developmental Biology
• Term: from 2004 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5443797

The frog Xenopus laevis is a well established system to analyze vertebrate development. By RNA and oligonucleotide injection, genetic manipulations are restricted to early stages of embryogenesis. To manipulate at later stages, transgenic techniques are required that allow a spatial and temporal controlled manipulation. We have recently applied transgenesis in Xenopus to label cell lineages in Xenopus by Cre mediated activation of fluorescent proteins. We propose to use this method for the conditional expression of a regulatory factory. As regulator we have chosen HNF1b, a transcription factor, we have shown to play a prominent role in kidney formation and whose mutation in humans leads to renal defects. The conditional expression of HNF1b will be achieved by crossing activator strains, encoding a recombinase, with effector strains encoding HNF1b derivatives. We have already established effector strains in Xenopus that allow the efficient identification of suitable activator strains expressing inducible recombinases. Using this binary system, we can overexpress HNF1b at well defined time points allowing the identification of the developmental window critical for HNF1b function. Furthermore, we can dissect the molecular events in the establishment of the kidney anlage. In the long run this approach will be most useful for different labs by sharing activator and effector strains.

• DFG Programme: Research Grants
• Participating Person: Dr. Christoph Waldner