Oocyte shuttle, a recombinant protein transporting donor DNA into the oocyte .

The newly developed oocyte shuttle protein contains a streptavidin moiety that tightly binds biotinylated DNA. Injected intravenously into adult females, the protein-DNA complex is rapidly transported through the bloodstream and, within the ovary, the vitellogenin ligand present in the protein binds to the receptors at the surface of the oocytes. The bound complex is internalized and translocates into the oocyte nucleus thanks to an SV40 nuclear localization signal, enhanced by an adjacent casein kinase phosphorylation site.

Retinal patterning by Pax6-dependent cell adhesion molecules.

Long-standing evidence gained from Pax6 mutant embryos pointed to an involvement of Pax6-dependent cell adhesion molecules in patterning the central nervous system and, in particular, the retina. However, direct evidence for such pathways remained elusive. We here present direct evidence that knockdown of Pax6 expression by morpholino antisense molecules in Xenopus embryos and knockdown of maternal N-cadherin (mNcad), N-cadherin (Ncad) and neural cell adhesion molecule (NCAM) produce similar phenotypes.

Expression of alphasmooth muscle actin in lens epithelia from human donors and cataract patients.

In order to re-evaluate functional implications of alphasmooth muscle actin (alphaSMA) expression in lens epithelial cells (LECs), we assessed its presence in donor lenses without visible opacities (DON), lenses with mature cataract (CAT), and cataractous lenses with posterior subcapsular opacities (PSO) or anterior subcapsular fibrosis (ASF). The levels of alphaSMA and transforming growth factor-beta2 (TGFbeta2) mRNAs were measured by classical and real-time PCR. Expression and structural organisation of alphaSMA protein and beta-catenin were monitored by Western blotting and confocal microscopy.

Antisense inhibition of Xbrachyury impairs mesoderm formation in Xenopus embryos.

Expression of the Xbrachyury (Xbra) gene was inhibited by antisense RNA synthesized in situ from an expression vector read by RNA polymerase III, injected into the fertilized egg or the 2-cell stage embryo of Xenopus laevis. Antisense-treated embryos had markedly reduced levels of Xbra mRNA and protein, and showed deficiencies in mesodermal derivatives and axis formation. In particular, organization of the posterior axis was affected, but often the anterior axis was also reduced.

Xenopus helveticus, an endangered species?

This review traces the history of Xenopus research in Switzerland, its worldwide beginnings and British chapters having been summarised previously (Gurdon and Hopwood, 2000). As in other countries, Xenopus was initially used in the pharmaceutical industry at Basel for pregnancy testing. Developmental biologists became interested in this peculiar amphibian because it may be induced to ovulate all year round.