07-P022 Applications of lentiviral transgenesis in the chick

We have previously shown that lentiviral vectors can be used to generate transgenic chickens efficiently and that expression of introduced transgenes is not silenced on transmission through the germline. Transgene expression can be targeted in the predicted tissue-restricted manner, for example: muscle-specific expression is restricted to skeletal muscle using the rat myosin light chain 3 gene enhancer/promoter and oviduct-specific expression is demonstrated using regulatory elements of the chicken ovalbumin gene. We also produced transgenic chicken lines expressing GFP ubiquitously using the CMV IE enhancer fused to the chicken b-actin promoter/intron. High levels of GFP protein are visible at all stages of developing transgenic embryos. GFP embryos have been wildly used in cell-fate experiments where the grafted cells can be visualised and followed during embryo development. Here we are extending the repertoire of reporter genes with the development of transgenic lines that ubiquitously express membrane-localized GFP or monomericCherry (red), which will make invivo tracing cell shape changes and cell interactions possible. Founder males chimeric for transgenes coding for membrane-localized fluorescent proteins have been raised to sexual maturity and crossed to screen for transgenic offspring. In addition, we are generating transgenic lines carry photo-activatable GFP or photo-switchable CFP that should allow marking of cells insitu for lineage tracing studies without the need for grafting.