Copper nanowires as higly sensitivite electrode for nitrate ions in water
Agricultural and livestock sectors are the main sources of nitrate ions contamination in water and foodstuff. [1]. High nitrate concentration is dangerous for both environment (algae overgrowth) and human health. Nitrate ions can be converted in different harmful nitrogen based compound such as NO2-, NO, N-nitroso compounds [2] that are responsible of several diseases such as cancer, Parkinson [3-4]. For these reasons, the Environmental Protection Agency, has established the maximum amount of nitrate ions in drinkable water at 44 mg/l, limit that is valid in many European countries [5]. Generally, spectroscopy techniques are the most used because allow to carry out analyses with high precis…
The echinoderm innate humoral immune response
Abstract: Multicellular organisms have an immune system, which is essential for the survival of living beings. Interest in the immune system has been expanded since common characteristics of innate immunity between Drosophila melanogaster (Meigen, 1830) and mammals were discovered in the 1980. Since then, immunology has mainly focused on the adaptive immune system that seems to be restricted to vertebrates. Unlike the innate immunity, the adaptive one is acquired after exposure to a specific antigen (Ag) and includes: antigen-presenting cells such as macrophages, proliferation of B and T lymphocytes, Ag-specific antibody/cytokine production and immunological memory. Innate immunity is inste…
Homeobox-containing gene transiently expressed in a spatially restricted pattern in the early sea urchin embryo
In the sea urchin embryo, the lineage founder cells whose polyclonal progenies will give rise to five different territories are segregated at the sixth division. To investigate the mechanisms by which the fates of embryonic cells are first established, we looked for temporal and spatial expression of homeobox genes in the very early cleavage embryos. We report evidence that PlHbox12, a paired homeobox-containing gene, is expressed in the embryo from the 4-cell stage. The abundance of the transcripts reaches its maximum when the embryo has been divided into the five polyclonal territories--namely at the 64-cell stage--and it abruptly declines at later stages of development. Blastomere dissoc…
Response to metals treatment of Fra1, a member of the AP-1 transcription factor family, in P. lividus sea urchin embryos
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…
Nickel toxicity in P. lividus embryos: Dose dependent effects and gene expression analysis.
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…
DNA Damage and Developmental Defects After Exposure to UV and Heavy Metals in Sea Urchin Cells and Embryos Compared to Other Invertebrates
The depletion of the stratospheric ozone layer and the resulting increase in hazardous ultraviolet-B (UV-B) radiation reaching the Earth are of major concern not only for terrestrial but also for aquatic organisms. UV-B is able to penetrate clear water to ecologically significant depths. This chapter deals with the effects of UV radiation on DNA integrity in marine benthic organisms, in particular sea urchins in comparison to other marine invertebrates (sponges and corals). These animals cannot escape the damaging effects of UV-B radiation and may be additionally exposed to pollution from natural or anthropogenic sources. Besides eggs and larvae that lack a protective epidermal layer and ar…
Copper nanowire array as highly selective electrochemical sensor of nitrate ions in water
Contamination of water with nitrate ions is a significant problem that affects many areas of the world. The danger from nitrates is not so much their toxicity, rather low, as their transformation into nitrites and in particular into nitrosamines, substances considered to be a possible carcinogenic risk. For this reason, European legislation has set the maximum permissible concentration of nitrates in drinking water at 44 mg/l. Thus, it is clear that a continuous monitoring of nitrate ions is of high technological interest but it must be rapid, easy to perform and directly performed in situ. Electrochemical detection is certainly among the best techniques to obtain the above requirements. In…
Gene expression during early embryogenesis of sea urchin: The histone and homeobox genes
Transcriptional regulators are thought to play a key role in cell fate determination and territorial specification in sea urchin. Our goals are to clone transcription factors for studying embryonic development. One approach has been to use promoter binding and gene transfer technology to investigate the mechanisms of transcriptional activation and repression of the early H2A histone gene. By this analysis we identified a transcriptional activator, the MBF-1, that binds to the modulator element of the H2A gene and enhances the activity of the H2A promoter. However, the enhancer activity of the modulator and its interaction with MBF-1 also occurs at the gastrula stage when the early histone g…
The Greenland shark Somniosus microcephalus—Hemoglobins and ligand-binding properties
A large amount of data is currently available on the adaptive mechanisms of polar bony fish hemoglobins, but structural information on those of cartilaginous species is scarce. This study presents the first characterisation of the hemoglobin system of one of the longest-living vertebrate species (392 +/- 120 years), the Arctic shark Somniosus microcephalus. Three major hemoglobins are found in its red blood cells and are made of two copies of the same a globin combined with two copies of three very similar beta subunits. The three hemoglobins show very similar oxygenation and carbonylation properties, which are unaffected by urea, a very important compound in marine elasmobranch physiology.…
Expression of homeobox-containing genes in the sea urchin (Parancentrotus lividus) embryo
Two homeobox-containing genes that belong to different homeodomain classes have been isolated from a sea urchin geonomic library. One, PlHbox11, is the sea urchin homologue of the human and mouse Hox B3 gene, the other, PlHbox12, shows about 55% identity with paired class genes. Expression profile analysis of the two sea urchin Hbox genes suggests that they play different roles during embryogenesis. In fact, PlHbox11 transcripts are rare and are detected only in the pluteus larva and in the Aristotle's lantern and intestine of the adult. The PlHbox12 gene is, on the contrary, transiently expressed in the very early embryo already at the four cell stage; it accumulates at the 64 cell stage a…
mtDNA diversity in rabbit population from Sicily (Italy)
The European rabbit Oryctolagus cuniculus (O.c) lives all over the world and it represents an important resource for many predators. It has been classified as a Near-Threatened species in the Red List of Vertebrates of Italy. It is present in mediterranean basin as two known subspecies: O.c. cuniculus and O.c. algirus. The mediterranean geographic distribution of the two subspecies is still not well known. In particular, in Sicily, lacking of deep studies, is based on the body size and morphological characteristics; there wasn’t a complete description of the actual existing subspecies and previous studies only reported the morphological characteristics of the sicilian rabbit population. In …
Evolutionary conserved pathway of the innate immune response after a viral insult in Paracentrotus lividus sea urchin
Despite the apparent simplicity of the body organization of echinoderms, their immune system is competent to perform a complex innate immune response, which is far from being well understood. The echinoderms represent the most advanced invertebrates that form a bridge with the primitive chordates. In fact, they possess numerous receptors and effectors that are used to obtain a fast immune response. After an infection, the humoral and cellular immune response determines a network in which the main protagonists are membrane and endosomal receptors. The recognition of nonself molecules by specific membrane receptors triggers the immune response, stimulating consecutive intracellular events. We…
A member of the Tlr family is involved in dsRNA innate immune response in Paracentrotus lividus sea urchin
Abstract The innate immune response involves proteins such as the membrane receptors of the Toll-like family (TLRs), which trigger different intracellular signalling pathways that are dependent on specific stimulating molecules. In sea urchins, TLR proteins are encoded by members of a large multigenic family composed of 60–250 genes in different species. Here, we report a newly identified mRNA sequence encoding a TLR protein (referred to as Pl-Tlr) isolated from Paracentrotus lividus immune cells. The partial protein sequence contained the conserved Toll/IL-1 receptor (TIR) domain, the transmembrane domain and part of the leucine repeats. Phylogenetic analysis of the Pl-Tlr protein was acco…
Highly restricted expression at the ectoderm–endoderm boundary of PIHbox 9, a sea urchin homeobox gene related to the human HB9 gene
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…