Developmental expression of Shisa-2 in Xenopus laevis

Abstract

Shisa is an antagonist of Wnt and FGF signaling, that functions cell autonomously in the endoplasmic reticulum (ER) to inhibit the post-translational maturation of Wnt and FGF receptors. In this paper we report the isolation of a second Xenopus shisa gene (Xshisa-2). Xenopus Shisa-2 shows 30.7% identity to Xshisa. RT-PCR analysis indicated that Xshisa-2 mRNA is present throughout early development and shows an increased expression during neurula and tailbud stages. At neurula stages Xenopus shisa-2 is initially expressed in the presomitic paraxial mesoderm and later in the developing somites. The expression profiles and pattern of Xshisa and Xshisa-2 differ significantly. During gastrulation only Xshisa mRNA is present in the SpemannMangold organizer and later on becomes restricted to the neuroectoderm and the prechordal plate.

The cavefish genome reveals candidate genes for eye loss

“…3b). Shisa2 -LG6 had a more complex expression pattern, reminiscent of what was described in Xenopus 37 and zebrafish38, and included expression in the branchial arches, cranial ganglia, epidermis, olfactory epithelium (like shisa2 -LG2), retina and lens (Fig. 3c).…”

Secreted and Transmembrane Wnt Inhibitors and Activators

“…In Xenopus, three paralogous genes to XShisa1 were identified: XShisa2, -3, and -4 (Nagano et al 2006; Silva et al 2006). XShisa2 is expressed in somitic mesoderm and like Shisa1 inhibits both Wnt and FGF signaling, thereby regulating segmental patterning during somitogenesis (Nagano et al 2006).…”

Nodal signaling: developmental roles and regulation

“…Despite the multifunctional ability of Cerberus to antagonize BMP and Wnt signaling in Xenopus (Silva et al, 2003), the mouse Cerberus proteins are primarily Nodal inhibitors (Marques et al, 2004;Perea-Gomez et al, 2002). In addition to secreted inhibitors of Nodal signaling, several membrane-associated proteins, such as Tomoregulin-1 (Tmeff1) and Nicalin, have been proposed to represent pathway antagonists (Haffner et al, 2004;Harms and Chang, 2003).…”