Culture of lymphocytes from adult Xenopus laevis (Daudin) (a pipid anuran amphibian) with mitogens (PHA, ConA, LPS and PWM) reveals a wide variation in the mitogen sensitivity of these cells: relatively high concentrations of mitogen are required to stimulate Xenopus lymphocytes compared with the concentrations appropriate for mammalian lymphocytes. Significantly better responses are obtained u...

The Xenopus lymphosarcoma agent is resistant to freezingthawing, freeze-drying, and antibiotics, but sensitive to heat, ether, and chloroform. It passes a 100-nui filter, and remains in the supernatant fluid following centrifugaron at 30,000 X g for 1 hr. The agent is passed from toad to toad through the water in which the Xenopus live. Phytohemagglutinin injection did not alter the latent peri...

INTRODUCTION A METHOD by which nuclei can be successfully transplanted into Amphibian eggs was first worked out by Briggs & King (1952) for the eggs of Ranapipiens. Xenopus laevis is an atypical Anuran since its eggs can be obtained throughout the year, and the resulting embryos can be reared to maturity within 12 months under laboratory conditions. Because of these advantages we have used Xeno...

Connexin-50 (Cx50) is among the most frequently mutated genes associated with congenital cataracts. While of these disease-linked variants cause loss-of-function due to misfolding or aberrant trafficking, others directly alter channel properties. The mechanistic bases for such functional defects are mostly unknown. We investigated and structural properties a cataract-linked mutant, Cx50T39R (T3...

BACKGROUND Signals from anterior endodermal cells that express the homeobox gene Hex initiate development of the most rostral tissues of the mouse embryo. The dorsal/anterior endoderm of the Xenopus gastrula, which expresses Hex and the putative head-inducing gene cerberus, is proposed to be equivalent to the mouse anterior endoderm. Here, we report the origin and signalling properties of this ...

How cells integrate multiple patterning signals to achieve early endoderm regionalization remains largely unknown. Between gastrulation and neurulation, retinoic acid (RA) signaling is required, while Wnt/β-catenin signaling has to be repressed for the specification of the pancreas, oesophagus, stomach, and duodenum primordia in Xenopus embryos. In attempt to screen for RA regulated genes in Xe...

Axolotls (Ambystoma mexicanum) can completely regenerate lost limbs, whereas Xenopus laevis frogs cannot. During limb regeneration, a blastema is first formed at the amputation plane. It is thought that this regeneration blastema forms a limb by mechanisms similar to those of a developing embryonic limb bud. Furthermore, Xenopus laevis frogs can form a blastema after amputation; however, the bl...

One of the most striking features of the Xenopus system is the versatility in providing a unique range of both in vitro and in vivo models that are rapid, accessible and easily manipulated. Here we present an overview of the diverse contribution that Xenopus has made to advance our understanding of tumour biology and behaviour; a contribution that goes beyond the traditional view of Xenopus as ...