Comparative expression of mouse and chicken shisa homologues during early development

Abstract

During vertebrate embryogenesis, fibroblast growth factor (FGF) and Wnt signaling have been implicated in diverse cellular processes, including cell growth, differentiation, and tissue patterning. The recently identified Xenopus Shisa protein promotes head formation by inhibiting Wnt and FGF signaling through its interaction with the immature forms of Frizzled and FGF receptors in the endoplasmic reticulum, which prevents their posttranslational maturation. Here, we describe the mouse and chicken homologues of Xenopus Shisa. The mouse and chicken Shisa proteins share, respectively, 33.6% and 33.8% identity with the Xenopus homolog. In situ hybridization analysis shows that mouse shisa is expressed throughout embryonic development, predominantly in the anterior visceral endoderm, headfolds, somites, forebrain, optic vesicle, and limb buds. Cross-species comparison shows that the expression pattern of cshisa closely mirrors that of mshisa. Our observations indicate that the Shisa family genes are typically expressed in tissues known to require the modulation of Wnt and FGF signaling.

Wnt signaling in the heart fields: Variations on a common theme

“…Shisa2 is not found in mice. In Xenopus, Shisa1 and Shisa2 (Silva et al, ) were described and their pattern of expression resembles mouse Shisa1 (Filipe et al, ). Shisas inhibit Wnt signaling by trapping Fzd in the endoplasmic reticulum, preventing exposure of mature Fzd on the plasma membrane.…”

Generating asymmetries in the early vertebrate embryo: the role of the Cerberus-like family

“…We have performed a differential screening using a generated transgenic mouse line in which EGFP is expressed in the AVE, under the control of the promoter region of the Cerl-1 gene. Gene expression profiling using GeneChips ® (Affymetrix ®) identified novel differentially expressed transcripts at the very early stages of A-P axis establishment (Mário Filipe, unpublished), some of them now currently being studied at our laboratory Filipe et al, 2006;Salgueiro et al, 2006). We expect that this approach will allow us to learn more about asymmetry generation, tissue patterning and specification during early vertebrate development and that this knowledge can be applied in the future to regenerative medicine.…”

Wnt signaling in eye organogenesis

“…Several ocular tissues express multiple components of Wnt/Frizzled pathways during development. [2][3][4][5][6][7][8][9][10][11][12][13][14] Substantial progress has been made in the past few years in understanding the role of Wnt signaling during vertebrate eye development. Gain and loss of function-studies reveal that Wnt/Frizzled pathways are involved in coordinating critical processes during ocular tissue development, which will be summarized here.…”