Differential expression of the Groucho-related genes 4 and 5 during early development of Xenopus laevis

Abstract

Recently, we demonstrated that the Xenopus Wnt effector XTcf-3 interacts with Groucho-related transcriptional repressors (Roose et al., 1998. Nature 395, 608-612). A long form of the Groucho-related genes, XGrg-4, was shown to repress axis formation in the Xenopus embryo, whereas a short form, XGrg-5, acted as a potentiator. In this study, the temporal and spatial expression of XGrg-4 and XGrg-5 is described in Xenopus laevis embryos. Both genes are maternally expressed. In the gastrula, transcripts of both genes are present in the animal as well as the vegetal region. At later stages, XGrg-4 and XGrg-5 show specific patterns of expression in the central nervous system (CNS), cranial ganglia, eyes, otic vesicles, stomodeal-hypophyseal anlage, cement gland, head mesenchyme, branchial arches, neural crest and derivatives, somites, pronephros, pronephric duct, heart and tailbud. Differences in the expression of XGrg-4 and XGrg-5 were found in the CNS, cranial ganglia, olfactory placodes, stomodeal-pharyngeal anlage, cement gland, head mesenchyme and ectoderm.

Bowline, a novel protein localized to the presomitic mesoderm, interacts with Groucho/TLE in Xenopus

“…Together, these findings (1-4) indicate that Bowline downregulates X-Delta-2 expression in cooperation with XGrg-4, which is localized in the PSM at tailbud stage (Molenaar et al, 2000). In this downregulation, it is considered that Bowline regulates the activity of XGrg-4 by (i) modulating interaction of Groucho/TLE with a DNA binding transcription factor which interacts with Groucho/TLE via the WRPW or WRPY motif (Hairy/HES for example), or by (ii) mediating interaction of Groucho/TLE with a DNA binding protein which alone does not interact with Groucho/TLE, since no DNA binding motifs are identified in the Bowline sequence (Chen and Courey, 2000, Fisher et al, 1996, Grbavec and Stifani, 1996.…”

FoxD3 and Grg4 Physically Interact to Repress Transcription and Induce Mesoderm in Xenopus

“…We examined the interaction of FoxD3 and Grg4 (Groucho-related gene 4), a Groucho family member that is ubiquitously expressed throughout early Xenopus development (42). The C-terminal region of FoxD3 (residues 194 -371) was fused to GST, and (FoxD3-(1-296)).…”

“…A number of transcriptional regulatory proteins have been identified in Drosophila that recruit Groucho to repress transcription during development, including the basic helix-loop-helix protein Hairy, the homeodomain protein Engrailed, and the NFB-related protein Dorsal, which regulate neurogenesis, segment polarity, and dorsal-ventral patterning, respectively (37)(38)(39)(40)(41). In Xenopus, two Groucho family genes, Grg4 and Grg5, are ubiquitously expressed during early embryogenesis (42). Grg4 is a functional transcriptional corepressor, whereas Grg5 lacks several essential domains and functions as a dominant inhibitory Groucho (43).…”

Expression and regulation of groucho‐related genes in the embryonic chicken feather bud

“…Expression of Grgs has been detected in areas of interactive signaling between the epithelium and underlying mesenchyme, as well as in the embryonic and postnatal nervous system (Dehni et al, 1995;Koop et al, 1996;Leon and Lobe, 1997;Allen and Lobe, 1999;Molenaar et al, 2000;Sugiyama et al, 2000). Degenerate and RACE PCR were used to amplify sequences for four chicken Grg genes (Fig.…”