- To identify human (or mouse) eye-expressed genes from the EST database, using information on mammalian and Drosophila eye mutants, and from sequence of immuno-screened dipteran photoreceptor membrane proteins. Map and assess as disease candidate genes.
- To isolate full length mammalian cDNA clones for selected ESTs, and clone into relevant Drosophila eye expression vectors. Create controlled over-expression Drosophila lines, and look for phenotype.
- To pinpoint gene function through identifying interacting genes by genetic crossing of selected over-expression lines with deficiency stocks, to reveal modifier genes.
- To identify and map mammalian homologues of modifier genes and assess as candidate disease genes.
Three groups with primary interest and expertise in human genetics, particularly in relation to eye disease, propose to team up with three Drosophila genetics groups, with special expertise in the analysis of eye development and function. The plan is to develop a Drosophila model system, which can be used to explore the function of newly, identified human (and mouse) genes, which are expressed in the developing and/or adult eye. Full-length mammalian cDNAs will be isolated for ESTs, which have been shown by RNA in situ and RNA blot hybridisation to be expressed in the eye. The cDNAs will be cloned into Drosophila vectors constructed using promoters/enhancers with temporally and spatially defined eye expression patterns. These will include GAL4/UAS gene-trap vectors as well as other eye-specific expression constructs. Transgenic Drosophila transformants with controlled over-expression in the eye will be produced in the strong expectation that these will exhibit various ey phenotypes. The Drosophila transgenics will be crossed with specific mutants, deficiency lines and P element insertion sets in order to define interacting genes which will provide insight into the function of the transgene, and help define the developmental and physiological pathways in which these genes participate.
The original ESTs and the putative interacting genes can be mapped in man and mouse in order to assess whether any of them may be considered as candidates for mammalian eye anomalies. As a test system, to assess the efficacy of this approach, mammalian homologues of known Drosophila eye genes (e.g. eyes absent, sine oculis, retinal degeneration B) wi11 be subjected to this analysis initially. In these cases complementation and modulation of the classical Drosophila mutant phenotype will be assessed, as well as the over expression phenotype.
Funding SchemeCSC - Cost-sharing contracts
EH9 3Jr Edinburgh