Comparison of morpholino based translational inhibition during the development of Xenopus laevis and Xenopus tropicalis

Morpholino (MO) based inhibition of translational initiation represents an attractive methodology to eliminate gene function during Xenopus developmen t (Heasman et al., 2000). However, the degree to which a given target prote in can be eliminated and the longevity of this effect during embryogenesis has not been documented. To examine the efficacy of MOs, we have used trans genic Xenopus lines that harbour known numbers of integrations of a GFP rep orter under the control of the ubiquitous and highly expressed CMV promoter (Fig. 1a). In addition we have investigated the longevity of the inhibitor y effect by using transgenic lines expressing GFP specifically in the lens of tadpoles. These transgenic lines represent the ideal control for the tec hnique as the promoters are highly expressed and GFP can be easily detected by fluorescence and immunoblotting. Moreover, as GFP has no function in de velopment, the levels of inhibition can be tested in an otherwise normal in dividual. Here we report that MOs are able to efficiently and specifically inhibit the translation of GFP in transgenic lines from Xenopus laevis and Xenopus tropicalis and the inhibitory effect is long-lived, lasting into th e tadpole stages, genesis 30:110-113, 2001. (C) 2001 Wiley-Liss, Inc.