The genetic signature of Neolithic in Greece

The Neolithic is characterized by the transition from a subsistence economy, based on hunting and gathering, to one based on food producing. This important change was paralleled by one of the most significant demographic increase in the recent history of European populations. The earliest Neolithic sites in Europe are located in Greece. However, the debate regarding the colonization route followed by the Middle-eastern farmers is still open. Based on archaeological, archaeobotanical, craniometric and genetic data, two main hypotheses have been proposed. The first implies the maritime colonization of North-eastern Peloponnesus from Crete, whereas the second points to an island hopping route that finally brought migrants to Central Greece. To test these hypotheses using a genetic approach, 206 samples were collected from the two Greek regions proposed as the arrival point of the two routes (Korinthian district and Euboea). Expectations for each hypothesis were compared with empirical observations based on the analysis of 60 SNPs and 26 microsatellite loci of Y-chromosome and mitochondrial DNA hypervariable region I. The analysis of Y-chromosome haplogroups revealed a strong genetic affinity of Euboea with Anatolian and Middle-eastern populations. The inferences of the time since population expansion suggests an earlier usage of agriculture in Euboea. Moreover, the haplogroup J2a-M410, supposed to be associated with the Neolithic transition, was observed at higher frequency and variance in Euboea showing, for both these parameters, a decreasing gradient moving from this area. The time since expansion estimates for J2a-M410 was found to be compatible with the Neolithic and slightly older in Euboea. The analysis of mtDNA resulted less informative. However, a higher genetic affinity of Euboea with Anatolian and Middle-eastern populations was confirmed. These results taken as a whole suggests that the most probable route followed by Neolithic farmers during the colonization of Greece was the island hopping route.

Study of thiabendazole resistance and volatile organic compounds production of Penicillium expansum strains

The years of excessive use of thiabendazole to control Penicillium expansum has induced the development of resistance. Sensitivity of fourty eight strains collected from orchards and packinghouses in Emilia Romagna to pure and commercial TBZ was determined in vitro on TBZ amended medium (400μg/mL). Out of 48 strains, 35 were thiabendazole-sensitive (S) and 13 were thiabendazole-resistant (R). Microtiter assay adapted to P. expansum, showed EC50 values ranging from 54 to 320 μg/mL for ten TBZ-resistant strains. At the highest dose (50 μg/mL), resistant strains growth was not inhibited and the reported MICs value were >1000 μg/mL. Therefore, preliminary screening combined with microtiter assay, can be a good strategy to test susceptibility to TBZ. Mutations in the β-tubulin gene were studied on amino acid sequences from residue 167 to residue 357 of 10 P. expansum strains. Mutation at codon 198 was associated with TBZ-resistance. However, its absence in 3 resistant strains can be explained by the involvement of other mechanisms. Moreover, a P. expansum strain LB8/99 showed good antifungal effect against some fungal pathogens through double petri dish assay. It inhibited both mycelium growth and conidia germination of B. cinerea, C. acutatum, and M. laxa, and reduced significantly by 53% and 18% respectively P. expansum. Three major VOCS: geosmin, phenethyl alcolhol (PEA) and an unknown substance were identified by GC-MS analysis. Consistent fumigation of fungal pathogens with PEA (1230 mg/mL), inhibited both conidia germination and mycelium growth of all pathogens, except conidia germination of P. expansum that was reduced by 90% with respect to control. While, the concentration of PEA produced naturally by LB8/99 was ineffective in controlling the pathogens and seemed to have a synergic or additive effect with the other VOCS. Investigations to study the biofumigant effect of LB8/99 on other commodities like seeds and seedlings are in progress.

Epigenetic signature in persons with Down Syndrome

Persons affected by Down Syndrome show a heterogeneous phenotype that includes developmental defects and cognitive and haematological disorders. Premature accelerated aging and the consequent development of age associated diseases like Alzheimer Disease (AD) seem to be the cause of higher mortality late in life of DS persons. Down Syndrome is caused by the complete or partial trisomy of chromosome 21, but it is not clear if the molecular alterations of the disease are triggered by the specific functions of a limited number of genes on chromosome 21 or by the disruption of genetic homeostasis due the presence of a trisomic chromosome. As epigenomic studies can help to shed light on this issue, here we used the Infinium HumanMethilation450 BeadChip to analyse blood DNA methylation patterns of 29 persons affected by Down syndrome (DSP), using their healthy siblings (DSS) and mothers (DSM) as controls. In this way we obtained a family-based model that allowed us to monitor possible confounding effects on DNA methylation patterns deriving from genetic and environmental factors. We showed that defects in DNA methylation map in genes involved in developmental, neurological and haematological pathways. These genes are enriched on chromosome 21 but localize also in the rest of the genome, suggesting that the trisomy of specific genes on chromosome 21 induces a cascade of events that engages many genes on other chromosomes and results in a global alteration of genomic function. We also analysed the methylation status of three target regions localized at the promoter (Ribo) and at the 5’ sequences of 18S and 28S regions of the rDNA, identifying differently methylated CpG sites. In conclusion, we identified an epigenetic signature of Down Syndrome in blood cells that sustains a link between developmental defects and disease phenotype, including segmental premature aging.

Identification of a molecular signature as potential biomarker in blood of symptomatic and asymptomatic patients with carotid atherosclerosis

Background and Objectives: Carotid revascularization to prevent future vascular events is reasonable in patients with high-grade carotid stenosis. Currently, several biomarkers to predict carotid plaque development and progression have been investigated, among which microRNAs (miRs) are promising tools for the diagnosis of atherosclerosis. Methods and Results: A total of 49 participants were included in the study, divided into two main populations: Population 1 comprising symptomatic and asymptomatic inpatients, and Population 2 comprising asymptomatic outpatients. The study consisted of two main phases: a preliminary discovery phase and a validation phase, applying different techniques. MiR-profiles were performed on plasma and plaque tissue samples obtained from 4 symptomatic and 4 asymptomatic inpatients. MiRs emerging from profiling comparisons, i.e. miR-126-5p, miR-134-5p, miR-145-5p, miR-151a-5p, miR-34b, miR-451a, miR-720 and miR-1271-5p, were subjected to validation through RT-qPCR analysis in the total cohort of donors. Comparing asymptomatic and symptomatic inpatients, significant differences were reported in the expression levels of c-miRs for miR-126-5p and miR-1271-5p in blood, being more expressed in symptomatic subjects. In contrast, simultaneous evaluation of the selected miRs in plaque tissue samples did not confirm data obtained by the miR profiling, and no significant differences were observed. Using Receiver-Operating Characteristic (ROC) analysis, a circulating molecular signature (mir-126-5p, miR-1271-5p, albumin, C-reactive protein, and monocytes) was identified, allowing the distinction of the two groups in Population 1 (AUC = 0.795). Conclusions: Data emerging from this thesis suggest that c-miRs (i.e. miR-126-5p, miR-1271-5p) combined with selected haemato-biochemical parameters (albumin, C-reactive protein, and monocytes) produced a good molecular 'signature' to distinguish asymptomatic and symptomatic inpatients. C-miRs in blood do not necessarily reflect the expression levels of the same miRs in carotid plaque tissues since different mechanism can influence their expression.