Guillaume Pézeron

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Sleep is a fundamental biological process conserved across the animal kingdom. The study of how sleep regulatory networks are conserved is needed to better understand sleep across evolution. We present a detailed description of a sleep state in adult zebrafish characterized by reversible periods of immobility, increased arousal threshold, and place(More)
We report evidence for a mechanism for the maintenance of long-range conserved synteny across vertebrate genomes. We found the largest mammal-teleost conserved chromosomal segments to be spanned by highly conserved noncoding elements (HCNEs), their developmental regulatory target genes, and phylogenetically and functionally unrelated "bystander" genes.(More)
During gastrulation, dramatic movements rearrange cells into three germ layers expanded over the entire embryo [1-3]. In fish, both endoderm and mesoderm are specified as a belt at the embryo margin. Mesodermal layer expansion is achieved through the combination of two directed migrations. The outer ring of precursors moves toward the vegetal pole and(More)
The secreted frizzled-related proteins (Sfrp) are a family of soluble proteins with diverse biological functions having the capacity to bind Wnt ligands, to modulate Wnt signalling, and to signal directly via the Wnt receptor, Frizzled. In an enhancer trap screen for embryonic expression in zebrafish we identified an sfrp1 gene. Previous studies suggest an(More)
Activity of zebrafish hoxb4a in the developing brain was analyzed in comparison to hoxa4a and hoxd4a using unique enhancer detection transgenes. Cytoplasmic YFP revealed shape and axonal projections of neurons in animals with insertions near the Hox4 genes and provided a means for the identification of neuronal subtypes. Despite an early activity of the(More)
The expression of zebrafish hoxb3a and hoxb4a has been found to be mediated through five transcripts, hoxb3a transcripts I-III and hoxb4a transcripts I-II, driven by four promoters. A "master" promoter, located about 2 kb downstream of hoxb5a, controls transcription of a pre-mRNA comprising exon sequences of both genes. This unique gene structure is(More)
The EGF-CFC factor Oep/Cripto1/Frl1 has been implicated in embryogenesis and several human cancers. During vertebrate development, Oep/Cripto1/Frl1 has been shown to act as an essential coreceptor in the TGFbeta/Nodal pathway, which is crucial for germ layer formation. Although studies in cell cultures suggest that Oep/Cripto1/Frl1 is also implicated in(More)
Methods We use a mouse knock-out mutant line, Ftm, to identify the role of Rpgrip1l in cortical neurogenesis. Two distinct pools of progenitors undergo extensive cell divisions to form cortical projection neurons. Radial Glial Cells (RGCs) divide either symmetrically to expand the progenitor pool or asymmetrically to self-renew and produce an Intermediate(More)
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