Microbubble-enhanced sonoporation: efficient gene transduction technique for chick embryos

The gene transduction technique is a useful method to study gene functions that underlie vertebrate embryogenesis. In this study, a new gene transduction technique is reported using microbubble-enhanced sonoporation (hereafter referred to as sonoporation) to achieve ectopic and transient gene expression for several embryonic organs including embryonic chick limb bud mesenchymes. The technique proposed in this study has the advantages of 1) relatively simple gene transduction procedures, and 2) efficient exogenous gene transduction and expression with lower damages to embryos. Green fluorescent protein (GFP) or LacZ was misexpressed in limb bud mesenchymes by sonoporation, with the introduced expression transiently detected in the injected sites. Most of the transduced chick embryos survived without showing significant embryonic abnormalities or cell death after sonoporation. To demonstrate its efficacy for assessing the effect of transient gene transduction, the Shh (sonic hedgehog) was transduced into the developing chick limb bud. The transduced limb bud displayed limb malformations including partial digit duplication. Advantages and possible future applications in relation to this method are discussed.