Search results for "molecolare"

Caratterizzazione della biodiversità della grotta dei santi a Licodia Eubea (Catania, Sicilia)

2009

Il complesso rupestre, di cui fa parte la Grotta dei Santi, si sviluppa su due terrazzamenti nel territorio di Licodia Eubea, in Contrada Alia. Le testimonianze archeologiche e documentarie lasciano ipotizzare che il sito abbia subito, a partire dalla tarda antichità, varie frequentazioni. Rivestì un’importante ruolo sociale e religioso, fino almeno al XV secolo, quando fu completamente abbandonato, per essere riscoperto solo durante il secolo scorso. La denominazione della Grotta, è riconducibile alla presenza di tracce di pannelli raffiguranti una teoria di Santi, la quale doveva ornare le pareti dell’antro rivolto a nord-est, destinato in epoca paleocristiana alla sepoltura di importanti…

Enhancer, chromatin insulator, non-coding RNA and α-histone gene expression during embryogenesis of the sea urchin Paracentrotus lividus.

2009

Core promoters and chromatin insulators (ins) may direct a transcriptional enhancer (enh) to prefer a specific promoter in complex genetic loci. Enh and ins flank the sea urchin Paracentrotus lividus α-histone H2A transcription unit in a tandem repeated cluster containing the five histone genes. In vivo competition assays of enh and ins functions reveal that the H2A enh-bound MBF-1 activator participates also in the expression of the H3 gene and that the sns5 ins buffers the downstream H1 promoter from the H2A enh. These results suggest that both the H2A enh and the sns5 ins may account for the diverse accumulation of the linker vs core nucleosomal histones during early development of the s…

The sea urchin sns5 chromatin insulator settles a gene therapy vector into an independent domain of expression in the vertebrate genome

2014

One of the critical aspects of introducing a transgene into the eukaryotic genome is the great variability of gene expression due to position effects (1). Chromatin-dependent repressive states could be overcome by incorporation in the transgene of chromatin insulators, functioning to establish and delimit domains of expression. We have previously demonstrated that the sea urchin sns5 DNA element has the typical features of an insulator: by acting as enhancer blocker, it shields promoters from neighboring regulatory elements, and by acting as barrier it buffers a transgene from the propagation of condensed chromatin (2,3). We have investigated the use of sns5 in the field of gene therapy. Ou…

Suppression of nodal expression in prospective dorsal cells of the early sea urchin embryo by the hbox12 homeodomain regulator

2014

Dorsal/Ventral (DV) axis formation in the sea urchin embryo depends upon the expression of nodal on the ventral side, which behaves as a DV organizing centre. However, only fuzzy clues are known as to the early symmetry-breaking steps that lead to the positioning of such an organizer. An extremely interesting candidate for this role is the hbox12 homeobox-containing gene. In Paracentrotus lividus, hbox12 expression is antecedent and complementary with respect to that of nodal, being confined in prospective dorsal cells. We show that ectopic expression of Hbox12 provokes DV abnormalities and attenuates nodal as well as nodal-dependent gene transcription. By blastomere transplantation, we als…

Functional studies of regulatory genes in the sea urchin embryo.

2009

The sea urchin histone H2A enhancer-binding protein MBF-1 is needed for maximal expression also for the H3 gene, while is buffered by the sns5 insula…

2009

Enhancers are DNA elements which increase the transcription of associated gene in a position and distance independent manner relative to the transcription initiation site. Molecular mechanisms must operate to direct enhancers to specific promoters in complex genetic loci. The sea urchin a-histone genes are organized in several hundred tandem repeated units, each containing one copy of the five histone genes in the order 5’-H4-H2B-H3-H2A-H1-3’. Transcription is limited to the early cleavage and reaches its maximum at morula stage. After hatching these genes are repressed and maintained in the silenced state for whole life cycle of the animal. In Paracentrotus lividus, the MBF-1 activator bin…

A compact cis-regulatory module defines the exclusive expression of the Hbox12 homeobox-containing gene in the presumptive aboral ectoderm

2009

In the sea urchin embryo, a number of genes encoding transcription factors display territorial restricted expression. Among these, the zygotic Hbox12 homeobox gene is transiently transcribed in a limited number of cells of the animal-lateral half of the early Paracentrotus lividus embryo, whose descendants will constitute part of the ectoderm territory. We have explored the cis-regulatory apparatus of the gene and found that the intergenic region of the tandem Hbox12 repeats drives GFP expression in the presumptive aboral ectoderm and that a 234 bp fragment, defined Aboral Ectoderm Module, accounts for the restricted expression of the transgene. Within this module, a consensus sequence for …

Combined effect of cadmium and sulfonamides on sea urchin development

2013

Echinoderms play a key role in the maintenance of the integrity of the ecosystem where they live. They are constantly exposed to pollutants, particularly in their early planktonic life stages. Sulfamethoxazole with trimethoprim (TMP/SMX) is a fixed antibiotic combination whose concentration is significantly increasing in the coastal waters due to human medicine and also intensive husbandry and aquaculture activities. Previously, we studied the defense strategies activated by P. lividus embryos in response to sublethal doses of CdCl2. Although toxic effects of cadmium on embryo development are not morphologically detectable before 24 hours of exposure, we found upregulation in mRNAs related …

ZF-MED: Zebrafish and other aquatic models in Mediterranean labs; ZEBRAFISH AS ANIMAL MODEL FOR DRUG DISCOVERY AND TOXICOLOGY: MUCH MORE THAN A “TOOL”

2017

APOE and longevity: study of a population of Sardinian Centenarians

2011

Apolipoprotein E is a major determinant in lipoprotein metabolism and cardiovascular disease, it has emerged as an important molecule in several biological processes including Alzheimer's disease and cognitive function. ApoE is a polymorphic protein (ε2, ε3, ε4) with three proteic isoforms, ApoE2, ApoE3, ApoE4 (1). The aim of the study was to verify the frequencies of allelic variants a population of healthy elderly people. ApoE polymorphisms were determined by Real Time-PCR. The genotype frequencies of ApoE in our group of 71 centenarians (mean age 100.9 ±1.3) were: ε2/ε3 (12.67%); ε3/ε4 (5.63%). In the control group, consisting of 97 individuals (mean age 92.98 ±2.53), the genotype freque…