Transgenic Xenopus laevis strain expressing cre recombinase in muscle cells

Abstract

For reproducible analyses of gene function in Xenopus, the use of transgenic strains is a promising approach but has limitations when investigating factors interfering with development. Therefore, inducible systems are attractive alternatives, and a binary system based on recombinases is a most versatile approach. We have shown previously that Cre and FLP recombinases are active in Xenopus laevis and can induce a silent reporter gene in a corresponding reporter strain. Here, we describe the establishment of the transgenic Xenopus laevis strain A7 expressing Cre recombinase under the control of the muscle-specific cardiac actin promoter. Upon crossing to several distinct reporter strains, A7 is able to induce EYFP, DsRed2, or LacZ reporter genes in a muscle-specific manner. This first Cre-expressing strain allows conditional activation of any gene of interest in muscle cells and, thus, opens up the use of recombinases as a new experimental strategy in Xenopus. Developmental Dynamics 235:2220 -2228, 2006.

A guide to the productive poking, prodding and injection of cells

“…Finally, the method for generating transgenic X. laevis embryos described by Bryan Allen and Daniel Weeks (Chapter 9) is clearly exciting, but it is worth noting that since it was first described in 2005 (Allen andWeeks, 2005) no other lab has (apparently) published using the technique. In this light, a general review of other transgenic methods (Ogino et al, 2006;Waldner et al, 2006;L'Hostis-Guidet et al, 2009), as well as a discussion of the application of these methods to X. tropicalis, a diploid relative with a shorter generation time and a sequenced genome, would seem to be both appropriate and useful.…”

Xenopus as a model system for vertebrate heart development

“…Furthermore, the study showed that mutations in specific target genes could be identified by genomic TILLING. Finally, the ability of FLP and Cre recombinase [63][64][65] to function in Xenopus tissues suggests that targeted disruption of Xenopus genes may become a reality in the near future. Section through heart of embryo injected with myocardin MO.…”

Heat-shock inducible Cre strains to study organogenesis in transgenic Xenopus laevis

“…We have previously shown, that both Cre and FLP recombinases are functional in X. laevis (Werdien et al 2001) and used the Cre recombinase for labelling muscle cell lineages in stable transgenics . Furthermore, we have established a transgenic X. laevis strain expressing recombinase in a muscle restricted manner as well as several transgenic reporter strains that can be used for cell lineage labelling (Waldner et al 2006). …”

“…Such binary systems allow the controlled expression of regulators the activity of which is incompatible with normal development. So far, the GAL4/UAS system (Chae et al 2002;Hartley et al 2002) and the Cre/loxP system (Ryffel 2003;Waldner et al 2006) have successfully been adapted to Xenopus for the conditional expression of transgenes.…”