Search results for "centro"
showing 10 items of 643 documents
Autophagy is required for sea urchin oogenesis and early development.
2016
SummaryAutophagy is a major intracellular pathway for the degradation and recycling of cytosolic components. Emerging evidence has demonstrated its crucial role during the embryo development of invertebrates and vertebrates. We recently demonstrated a massive activation of autophagy in Paracentrotus lividus embryos under cadmium stress conditions, and the existence of a temporal relationship between induced autophagy and apoptosis. Although there have been numerous studies on the role of autophagy in the development of different organisms, information on the autophagic process during oogenesis or at the start of development in marine invertebrates is very limited. Here we report our recent …
Hsp40 Is Involved in Cilia Regeneration in Sea Urchin Embryos
2003
In a previous paper we demonstrated that, in Paracentrotus lividus embryos, deciliation represents a specific kind of stress that induces an increase in the levels of an acidic protein of about 40 kD (p40). Here we report that deciliation also induces an increase in Hsp40 chaperone levels and enhancement of its ectodermal localization. We suggest that Hsp40 might play a chaperoning role in cilia regeneration.
Nickel toxicity in P. lividus embryos: Dose dependent effects and gene expression analysis.
2018
Abstract Many industrial activities release Nickel (Ni) in the environment with harmful effects for terrestrial and marine organisms. Despite many studies on the mechanisms of Ni toxicity are available, the understanding about its toxic effects on marine organisms is more limited. We used Paracentrotus lividus as a model to analyze the effects on the stress pathways in embryos continuously exposed to different Ni doses, ranging from 0.03 to 0.5 mM. We deeply examined the altered embryonic morphologies at 24 and 48 h after Ni exposure. Some different phenotypes have been classified, showing alterations at the expenses of the dorso-ventral axis as well as the skeleton and/or the pigment cells…
Response to metals treatment of Fra1, a member of the AP-1 transcription factor family, in P. lividus sea urchin embryos
2018
Abstract Lithium (Li), Nickel (Ni), and Zinc (Zn) are metals normally present in the seawater, although they can have adverse effects on the marine ecosystem at high concentrations by interfering with many biological processes. These metals are toxic for sea urchin embryos, affecting their morphology and developmental pathways. In particular, they perturb differently the correct organization of the embryonic axes (animal-vegetal, dorso-ventral): Li is a vegetalizing agent and Ni disrupts the dorso-ventral axis, while Zn has an animalizing effect. To deeply address the response of Paracentrotus lividus embryos to these metals, we studied the expression profiling of Pl-Fra transcription facto…
An Intronic cis-Regulatory Element Is Crucial for the Alpha Tubulin Pl-Tuba1a Gene Activation in the Ciliary Band and Animal Pole Neurogenic Domains …
2017
In sea urchin development, structures derived from neurogenic territory control the swimming and feeding responses of the pluteus as well as the process of metamorphosis. We have previously isolated an alpha tubulin family member of Paracentrotus lividus (Pl-Tuba1a, formerly known as Pl-Talpha2) that is specifically expressed in the ciliary band and animal pole neurogenic domains of the sea urchin embryo. In order to identify cis-regulatory elements controlling its spatio-temporal expression, we conducted gene transfer experiments, transgene deletions and site specific mutagenesis. Thus, a genomic region of about 2.6 Kb of Pl-Tuba1a, containing four Interspecifically Conserved Regions (ICRs…
Diversification of spatiotemporal expression and copy number variation of the echinoid hbox12/pmar1/micro1 multigene family
2017
Changes occurring during evolution in the cis-regulatory landscapes of individual members of multigene families might impart diversification in their spatiotemporal expression and function. The archetypal member of the echinoid hbox12/pmar1/micro1 family is hbox12-a, a homeobox-containing gene expressed exclusively by dorsal blastomeres, where it governs the dorsal/ventral gene regulatory network during embryogenesis of the sea urchin Paracentrotus lividus. Here we describe the inventory of the hbox12/pmar1/micro1 genes in P. lividus, highlighting that gene copy number variation occurs across individual sea urchins of the same species. We show that the various hbox12/pmar1/micro1 genes grou…
Effects of exposure to gadolinium on the development of geographically and phylogenetically distant sea urchins species.
2016
Gadolinium (Gd), a metal of the lanthanide series used as contrast agent for magnetic resonance imaging, is released into the aquatic environment. We investigated the effects of Gd on the development of four sea urchin species: two from Europe, Paracentrotus lividus and Arbacia lixula, and two from Australia, Heliocidaris tuberculata and Centrostephanus rodgersii. Exposure to Gd from fertilization resulted in inhibition or alteration of skeleton growth in the plutei. The similar morphological response to Gd in the four species indicates a similar mechanism underlying abnormal skeletogenesis. Sensitivity to Gd greatly varied, with the EC50 ranging from 56 nM to 132 μM across the four species…
Whole genome sequences reveal Vibrio hemicentroti Kim et al. 2013 as a later heterotypic synonym of Vibrio splendidus (Beijerinck 1900) Baumann et al…
2017
The synonymy between Vibrio hemicentroti Kim et al. 2013 and Vibrio splendidus (Beijerinck 1900) Baumann et al. 1981 was suggested after a recent multilocus sequence analysis of the Splendidus clade, which included the type strains of both species. To clarify their status, we have determined genomic indexes from whole genome sequences of strains V. hemicentroti CECT 8714T and V. splendidus NCCB 53037T. Average Nucleotide Identities of 96.0–96.7 % and an in silico DNA–DNA hybridization value of 70.2 %, as well as similarity levels of selected housekeeping gene sequences support the consideration of V. hemicentroti as a later heterotypic synonym of V. splendidus .
The dark side of centromeres: types, causes and consequences of structural abnormalities implicating centromeric DNA
2018
Centromeres are the chromosomal domains required to ensure faithful transmission of the genome during cell division. They have a central role in preventing aneuploidy, by orchestrating the assembly of several components required for chromosome separation. However, centromeres also adopt a complex structure that makes them susceptible to being sites of chromosome rearrangements. Therefore, preservation of centromere integrity is a difficult, but important task for the cell. In this review, we discuss how centromeres could potentially be a source of genome instability and how centromere aberrations and rearrangements are linked with human diseases such as cancer.
Stress and immune response to bacterial LPS in the sea urchin Paracentrotus lividus (Lamarck, 1816).
2018
The immune system of the sea urchin species Paracentrotus lividus is highly complex and, as yet, poorly understood. P. lividus coelomocytes mediate immune response through phagocytosis and encapsulation of non-self particles, in addition to the production of antimicrobial molecules. Despite this understanding, details of exactly how these processes occur and the mechanisms which drive them are still in need of clarification. In this study, we show how the bacterial lipopolysaccharides (LPS) is able to induce a stress response which increases the levels of the heat shock proteins HSP70 and HSP90 only a few hours after treatment. This study also shows that LPS treatment increases the expressi…