Search results for " sea urchin"

Identification and characterization of a constitutive HSP75 in sea urchin embryos.

1997

Abstract An antiserum against a hsp of the 70-kDa family was prepared, by means of a fusion protein, which was able to detect a constitutive 75-kDa hsc in the sea urchinP. lividus.This hsc was present both during oogenesis and at all developmental stages. A two-dimensional electrophoresis has revealed four isolectric forms of this 75-kDa hsc. The amino acid sequence of the fragment used to prepare the anti-hsp70 antibodies revealed a 43% identity with the corresponding part of sea urchin sperm receptor, and in mature eggs a brighter immunofluorescence was seen all around the cell cortex where the receptor for sea urchin sperm is localized. In oocytes the hsp75 was localized in the cytoplasm…

Temperature modulates the response of the thermophilous sea urchin Arbacia lixula early life stages to CO2-driven acidification

2014

The increasing abundances of the thermophilous black sea urchin Arbacia lixula in the Mediterranean Sea are attributed to the Western Mediterranean warming. However, few data are available on the potential impact of this warming on A. lixula in combination with other global stressors such as ocean acidification. The aim of this study is to investigate the interactive effects of increased temperature and of decreased pH on fertilization and early development of A. lixula. This was tested using a fully crossed design with four temperatures (20, 24, 26 and 27 °C) and two pH levels (pHNBS 8.2 and 7.9). Temperature and pH had no significant effect on fertilization and larval survival (2d) for te…

Impacts of weathered microplastics on bioavailability of pollutants in Paracentrotus lividus and Danio rerio: molecular and ecotoxicological approach…

2022

Plastic materials provide countless applications in every sector of human life, from food and health preservation to textiles and electronics industry (Cole et al., 2011;Thompson et al., 2009) which is resulting in huge amount of plastic waste. Recently, it was estimated that plastics account for the 80-90% of the whole marine litter (Derraik, 2002) and over 5 trillion microscopic plastic fragments are floating on the surface of the World Oceans (Eriksen et al., 2014). The predominant form of marine plastic litter is called “Microplastics (MPs)", terminology by Thompson et al. 2004, used to indicate small plastic fragments, fibers and granules of microscopic size (1 μm to 5 mm in diameter).…

MITOCHONDRIAL MASS, DISTRIBUTION AND ACTIVITY DURING SEA URCHIN OOGENESIS

2015

The sea urchin egg is a favourite model for studies of the molecular biology and physiology of fertilization and early development, yet we know sparingly little of its oocytes and of mitochondria behaviour during oogenesis. The process of oogenesis in most echinoderms is asynchronous so each ovary lobe has hundreds of oocytes at all stages of development. At the beginning of oogenesis, the oocyte is about 10 µm in diameter. During the vitellogenic phase of oogenesis, the oocyte accumulate yolk proteins and grow to ten times their original size to 80 to 100 µm in sea urchins. The oocyte, arrested at the prophase of the first meiotic division, is apparent with its large nucleus, the germinal …

Different mRNA localization patterns for metallothioneins (MTs) during embryo development

MTs play pivotal roles in physiological and redox homeostasis. They are also essential during embryo development of P. lividus sea urchin. At least five MT genes are expressed in P. lividus embryo. MT7 and MT8 are constitutively expressed; while, MT4, 5, and 6 are considered as metal-induced homologues. Whole mount in situ hybridization (WMISH) defined the MT mRNAs localization across the embryo territories of the sea urchin. At the gastrula stage, MT7 is localized principally in the endomesoderm, in the vegetal pole. Progressively, it becomes heavily expressed in the endoderm during archenteron specialization in midgut and hindgut and then in stomach and intestine at the pluteus stage. In …

Vanadium Modulates Proteolytic Activities and MMP-14-Like Levels during Paracentrotus lividus Embryogenesis

2022

The increasing industrial use of vanadium (V), as well as its recent medical use in various pathologies has intensified its environmental release, making it an emerging pollutant. The sea urchin embryo has long been used to study the effects induced by metals, including V. In this study we used an integrated approach that correlates the biological effects on embryo development with proteolytic activities of gelatinases that could better reflect any metal-induced imbalances. V-exposure caused morphological/morphometric aberrations, mainly concerning the correct distribution of embryonic cells, the development of the skeleton, and the embryo volume. Moreover, V induced a concentration change …

Symmetry Breaking and Establishment of Dorsal/Ventral Polarity in the Early Sea Urchin Embryo

2015

The mechanisms imposing the Dorsal/Ventral (DV) polarity of the early sea urchin embryo consist of a combination of inherited maternal information and inductive interactions among blastomeres. Old and recent studies suggest that a key molecular landmark of DV polarization is the expression of nodal on the future ventral side, in apparent contrast with other metazoan embryos, where nodal is expressed dorsally. A subtle maternally-inherited redox anisotropy, plus some maternal factors such as SoxB1, Univin, and p38-MAPK have been identified as inputs driving the spatially asymmetric transcription of nodal. However, all the mentioned factors are broadly distributed in the embryo as early as no…

Marine Invertebrates as Bioindicators of Heavy Metal Pollution

2014

Atmosphere, earth and water compose the environment. The presence of heavy metals in the environment has grown because of their large employment in some industrial and agricultural activities. Although these metals are terrestrial products, they flow into the sea through effluents and sewage or are directly discharged from industries placed on the seawater front. It should be considered that metals concentrations vary widely according to different seawater latitudes and depths and can be strongly influenced by fresh water discharges from heavily polluted rivers. In this review recent studies on heavy metal pollution in marine ecosystems and their organisms will be presented. Metal speciatio…

Sea urchin embryos exposed to cadmium as an experimental model for studying the relationship between autophagy and apoptosis

2014

The sea urchin embryo is a suitable model that offers an excellent opportunity to investigate different defence strategies activated in stress conditions. We previously showed that cadmium accumulates in a dose- and time-dependent manner into embryonic cells, activating different stress and defence mechanisms, including the synthesis of HSPs and the onset of apoptosis and/or autophagy. In this paper we investigated the functional relationship between autophagy and apoptosis, evaluating apoptosis signals in cadmium-exposed Paracentrotus lividus embryos with inhibited autophagy. We found that the inhibition of autophagy produced the concurrent reduction of apoptosis, suggesting that the two p…

Toxicity induced by Gadolinium ions on sea urchin embryos: comparison among phylogenetically distant species and focus on stress response and skeleto…

2016

Pharmaceuticals are a class of emerging environmental contaminants. Gadolinium (Gd) is a lanthanide metal whose chelates are employed as contrast agents for magnetic resonance imaging, and subsequently released into the aquatic environment. We investigated the effects of exposure to sublethal Gd concentrations on the development of four phylogenetically and geographically distant sea urchin species: two Mediterranean, Paracentrotus lividus and Arbacia lixula, and two from Australia, Heliocidaris tuberculata and Centrostephanus rodgersii. Sensitivity to Gd greatly varied, with EC50 ranging from 56 nM to 132 µM across the four species. Measures of the Gd and Ca content inside embryos showed a…