Search results for "sea urchin."

EGTA treatment causes the synthesis of heat shock proteins in sea urchin embryos.

2000

Paracentrotus lividus embryos, at post-blastular stage, when subjected to a rise in temperature from physiologic (20 degrees C) to 31 degrees C, synthesize a large group of heat shock proteins (hsps), and show a severe inhibition of bulk protein synthesis. We show, by mono- and two-dimensional electrophoresis, that also EGTA (ethylene glycol-bis[beta-aminoethyl ether] tetraacetic acid) treatment induces in sea urchin embryos both marked inhibition of bulk protein synthesis and the synthesis of the entire set of hsps. Furthermore, EGTA-treated sea urchin embryos are able to survive at a temperature otherwise lethal (35 degrees C) becoming thermotolerant. Because incubation with a different c…

Cadmium induces an apoptotic response in sea urchin embryos.

2007

Cadmium is a heavy metal toxic for living organisms even at low concentrations. It does not have any biological role, and since it is a permanent metal ion, it is accumulated by many organisms. In the present paper we have studied the apoptotic effects of continuous exposure to subacute/sublethal cadmium concentrations on a model system: Paracentrotus lividus embryos. We demonstrated, by atomic absorption spectrometry, that the intracellular amount of metal increased during exposure time. We found, using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay, that long treatments with cadmium triggered a severe DNA fragmentation. We demonstrated, by immunocytochemistry …

Highly restricted expression at the ectoderm–endoderm boundary of PIHbox 9, a sea urchin homeobox gene related to the human HB9 gene

1998

Abstract Characterisation of a sea urchin (P. lividus) homeobox gene PIHbox 9 is reported. The homeodomain of PIHbox9 is 95% identical to the homeodomain of the human HB9 gene, indicating that the two genes are highly related. Temporal expression analysis during sea urchin embryogenesis showed an absence of transcripts at early cleavage stages. At late gastrula stage, transcripts were barely detectable and reached the highest abundance at prism/early pluteus stages. By whole mount in situ hybridisation we observed a highly restricted expression in a few cells of the ectoderm–endoderm boundary of embryos at the prism stage. At pluteus stages, expression of PIHbox 9 was confined around the an…

Green Extraction Strategies for Sea Urchin Waste Valorization

2021

Commonly known as “purple sea urchin,” Paracentrotus lividus occurs in the Mediterranean Sea and the eastern Atlantic Ocean. This species is a highly appreciated food resource and Italy is the main consumer among the European countries. Gonads are the edible part of the animal but they represent only a small fraction (10–30%) of the entire sea urchin mass, therefore, the majority ends up as waste. Recently, an innovative methodology was successfully developed to obtain high-value collagen from sea urchin by-products to be used for tissue engineering. However, tissues used for the collagen extraction are still a small portion of the sea urchin waste (<20%) and the remaining part, main…

Topology testing of phylogenies using least squares methods

2006

[Background] The least squares (LS) method for constructing confidence sets of trees is closely related to LS tree building methods, in which the goodness of fit of the distances measured on the tree (patristic distances) to the observed distances between taxa is the criterion used for selecting the best topology. The generalized LS (GLS) method for topology testing is often frustrated by the computational difficulties in calculating the covariance matrix and its inverse, which in practice requires approximations. The weighted LS (WLS) allows for a more efficient albeit approximate calculation of the test statistic by ignoring the covariances between the distances.

Sea Urchin Granuloma

2005

Sea urchin granuloma is a chronic focal response to the puncture of sea urchin spines, induced by the permanence of prickle remnants in the wound. Until recent years, it was thought to represent a foreign body reaction but, following the description, in 2001, of its several histologic forms, the spectrum of its likely pathogenetic mechanisms has widened to include the immune responses to different non-self antigens. Depending on individual reactivity, in most cases, a limited number of granulomas is observed, however numerous the punctures may be. We report a case with more than 200 lesions and a tuberculoid histologic pattern, indicative of an immune reaction.

EFFECT OF Γ-AMINOBUTYRRIC ACID (GABA) EXPOSURE ON EMBRYOGENESIS OF PARACENTROTUS LIVIDUS AND IDENTIFICATION OF GABA-RECEPTOR GENES IN SEA URCHINS

2015

Developmental processes are controlled by regulatory genes encoding for transcription factors and signaling molecules. Functional relationships between these genes are described by gene regulatory networks (GRN), models which allow integration of various levels of information. The sea urchin embryo is an experimental model system which offers many advantages for the analysis of GRN. Recently, the GRN that governs the biomineralization of the sea urchin embryonic skeleton has begun to be deciphered. Preliminary evidence suggest that the γ- aminobutyric acid (GABA) signaling pathway is involved in skeletal morphogenesis during development of the sea urchin. GABA is a molecule synthesized by n…

Autophagy induction in sea urchin embryos exposed to gadolinium ions

2014

Sea urchin embryos are highly sensitive to several kinds of stressors, and able to activate different defense strategies. Gadolinium (Gd) is a metal of the lanthanide series of the elements: its chelates are employed as contrast agents for magnetic resonance imaging since the 1980s. Gd complexes are released in the aquatic environment, making Gd an emergent environmental pollutant. In this study we focused on the effects of Gd ions on sea urchin embryos development. The study was conducted looking at three different processes: general development, apoptosis and autophagy. At the whole morphological level, Paracentrotus lividus sea urchin embryos continuously exposed to Gd ions displayed mor…

Gadolinium induces autophagy in sea urchin embryos

2014

Enhanced hybridization labeling signals in Southern blotted DNAs fractionated with voltage gradient gel electrophoresis.

1998

An enhancement of hybridization labeling signals is demonstrated in Southern blotted DNAs, fractionated by voltage gradient gel electrophoresis. This enhancement is due to a reduced thickness of each single nucleic acid band in the gel as a consequence of the gradient effect, corresponding to an increased concentration of DNA per unit area.