Genetics and the study of gap junctions in Drosophila
Drosophila melanogaster is a model genetic organism that can be employed to identify genes that interact with gap junctions without having any a priori knowledge of what the interactor genes might be, or what biological roles gap junctions perform during development. The images shown above provide examples of phenotypes arising through abnormal development. Screening for mutations that modify these phenotypes (enhancer/suppressor screens, St. Johnston 2002) should identify genes that interact directly or indirectly with innexin molecules or at least with the 'process' of gap junction-mediated intercellular communication.
Dominant connexin mutants have previously been reported in the published literature and are often associated with human diseases (Laird, 2008, Yan et al. 2008). The types of mutation giving rise to dominant gap junction mutants, and the mechanisms underlying their phenotypes, should be easier to investigate now that they are known to exist in a model genetic organism. The results of this analysis may highlight important similarity, or possibly divergence, between connexin- and innexin-based gap junctions.