Search results for "sea urchin."
showing 10 items of 317 documents
cis-Regulation and chromatin dynamics of the hbox12 gene during the embryogenesis of Paracentrotus lividus.
2014
The GRN specifying the dorsal-ventral (D-V) axis of the sea urchin embryo is currently under investigation. An early input for D-V polarity is given by a redox gradient probably generated by an asymmetrical distribution of maternal mitochondria (1). Only on the future ventral side, the oxidizing environment induces the expression of the nodal gene, an essential regulator of D-V polarization (2). By contrast, on the future dorsal side, a reducing environment activates the hypoxia inducible factor (HIF-1α) (3). The hbox12 transcription repressor is an early marker of the dorsal side of the embryo, in which it negatively regulates the expression of nodal (4, 5). Interestingly, by in silico ana…
Genome wide mapping of the MBF-1 binding sites during embryogenesis of the sea urchin reveals it is a chromatin organizer.
2015
The Zinc-finger MBF1 factor is a transcription activator involved in the expression of the early histone genes during development of the sea urchin embryo (1). The DNA-binding domain of MBF1 shares high sequence similarity with that of the CTCF chromatin organizer but, unexpectedly, extensive in silico analysis failed to identify the sea urchin CTCF ortholog (2, 3). This led us to speculate that MBF1 could have co-opted the function of CTCF during evolution of the echinoderms. To support this hypothesis, we performed the genome-wide MBF1-binding sites mapping in the P. lividus genome, by chromatin immunoprecipitation coupled to next generation sequencing (ChIP-Seq). We observed that MBF1 bi…
Exposure to cytotoxic concentrations of manganese and effects on development
2009
Manganese is one of the most abundant metals present in nature in trace amounts, which is accumulated and utilized by all forms of life. It plays a multitude of biological roles, but exposure of cells/organisms to high levels causes toxicity. In the marine environment, increasing concentrations of bio-available ions often result from anthropogenic activities, and, consequently, manganese represents a new emergent factor in environmental contamination. To study cyto-toxicity of manganese on development, we used an excellent model system as sea urchin embryos Paracentrotus lividus. In this work, we show results from two-dimensional gel electrophoresis (2DE) analysis that highlighted qualitati…
The echinoid hbox12 multigene family: copy number variation and spatiotemporal expression
2016
Sea urchin embryos cadmium exposed as an experimental model system for studying the relationship between autophagy and apoptosis
2012
Population structure of the sea urchins Paracentrotus lividus and Arbacia lixula across a depth gradient
2006
Sea urchins are considered to have a paramount role in structuring rocky shallow communities. Under certain conditions, grazing by sea-urchins has been reported to produce a shift from macroalgae-dominated communities to barren habitat dominated by encrusting algae. However, this process is not recorded at all depths. The effect of depth on the structure of the sea-urchin populations may be thus a key feature to understand the origin and maintenance of the barren habitat within certain depths. In the present study, the structure of Paracentrotus lividus (Lam.) and Arbacia lixula (L.) populations are analyzed across a depth gradient in the Ustica Island MPA (NW Mediterranean), where the barr…
Chromatin dynamics during sea urchin embryogenesis: effects on the neural alpha tubulin PlTa2 gene expression
2011
Expression of PlTa2 gene during sea urchin P. lividus development, is spatially confined to the neural territory and temporally activated from the blastula stage. To evaluate a possible involvement of chromatin modifications in regulation of PlTa2 gene expression we first searched for DNaseI hypersentive sites. We found four sites localized in the introns of the gene, when we used chromatin extracted from embryos at gastrula stage but not from morula stage. This result suggests a possible functional role of the introns in the activation of the expression of PlTa2 gene. Moreover, we used specific antibodies for RNA polymerase II and for different modified form of lysine 9, lysine 27 and lysi…