Roles for alpha 1 connexin in morphogenesis of chick embryos revealed using a novel antisense approach

Gap junctional communication has been implicated in embryonic development a nd pattern formation. The gap junction protein, alpha 1 connexin (Cx43) is expressed in dynamic and spatially restricted patterns in the developing ch ick embryo and iis expression correlates with many specific developmental e vents. High levels of expression are found in regions of budding, which lea ds to shaping and appears to be a necessary prelude for tissue fusions. in order to investigate the rote of alpha 1 connexin in these morphogenetic ev ents, we developed a novel method of applying unmodified antisense deoxyoli gonucleotides (ODNs) to chick embryos. The use of pluronic gel to deliver a ntisense ODNs has allowed us io regulate the expression of al connexin prot ein, both spatially and temporally. This "knockdown" results in some striki ng developmental defects thai mimic some common congenital abnormalities, s uch as spina bifida, anencephaly,myeloschisis, limb malformation, cleft pal ate, failure of hematopoiesis, and cardiovascular deformity. The results im ply a major role for alpha 1 connexin communication in the integration of s ignaling required for pattern formation during embryonic development. This novel antisense technique may also be widely applicable. (C) 1999 Wiley-Lis s, Inc.