Search results for "Sea urchin development"
showing 5 items of 5 documents
Gadolinium perturbs expression of skeletogenic genes, calcium uptake and larval development in phylogenetically distant sea urchin species
2018
Chelates of Gadolinium (Gd), a lanthanide metal, are employed as contrast agents for magnetic resonance imaging and are released into the aquatic environment where they are an emerging contaminant. We studied the effects of environmentally relevant Gd concentrations on the development of two phylogenetically and geographically distant sea urchin species: the Mediterranean Paracentrotus lividus and the Australian Heliocidaris tuberculata. We found a general delay of embryo development at 24 h post-fertilization, and a strong inhibition of skeleton growth at 48 h. Total Gd and Ca content in the larvae showed a time- and concentration-dependent increase in Gd, in parallel with a reduction in C…
Metallothionein genes in sea urchin embryos and their induction by cadmium
2012
Metallothioneins (MTs) are proteins that play a major role in metal homeostasis and as a reservoir. The MT gene/protein systems of sea urchins are an invaluable model for the study of gene expression regulation and MT isoform-specific functionality of these proteins. We isolated five paralogous MT isogenes and we studied their expression in the sea urchin embryo Paracentrotus lividus. The Cadmium-dependent transcriptional activation of the five isogenes was assessed using quantitative Real Time PCR. Two of the five P. lividus MT (MT-7 and MT-8) isogenes appeared to be constitutively expressed and upregulated upon cadmium treatment. Three isogenes (MT-4/MT-6) are not transcribed in control e…
p38 MAPK activation is required for Paracentrotus lividus skeletogenesis
2008
We investigated the p38 MAPK role during sea urchin, Paracentrotus lividus, development. We found that at the morula stage, before the onset of skeletogenesis, p38 MAPK shows a peak of activity, and we tested whether p38 MAPK activity has any effect on skeletogenesis. By immunohistochemistry on whole-mount embryos we show the preferential localization of the active p38 form both in the presumptive PMCs and bilateral spiculo- genesis centers in control embryos, and in the radialized supernumerary spiculogenesis centers induced by NiCl2 treatment. By using SB203580, a p38 MAPK specific inhibitor, we show that p38 activity is required both for the initial triradiate spicule rudiments formation…
Regulatory sequences driving expression of the sea urchin Otp homeobox gene in oral ectoderm cells.
2005
Abstract PlOtp (Orthopedia), a homeodomain-containing transcription factor, has been recently characterized as a key regulator of the morphogenesis of the skeletal system in the embryo of the sea urchin Paracentrotus lividus . Otp acts as a positive regulator in a subset of oral ectodermal cells which transmit short-range signals to the underlying primary mesenchyme cells where skeletal synthesis is initiated. To shed some light on the molecular mechanisms involved in such a process, we begun a functional analysis of the cis -regulatory sequences of the Otp gene. Congruent with the spatial expression profile of the endogenous Otp gene, we found that while a DNA region from −494 to +358 is s…
The Paracentrotus lividus metallothionein gene family: structure and expression.
2014
Metallothioneins are metal binding proteins that play a pivotal role in metal homeostasis and detoxification. Since their initial discovery, they have been extensively studied in a variety of organisms ranging from microbes to plants and animals. Organisms often possess multiple genes encoding metallothionein homologs with distinct properties, such as varying affinities for different metals, and in many cases different functions. Despite the plethora of available studies, very little information is known about sea urchin P. lividus MT (1, 2). We previously identified five Pl-MT embryonic cDNAs and we studied their induction after cadmium treatment (3). Now we studied their expression during…