Search results for "GENETIC VARIABILITY"
showing 10 items of 200 documents
Adaptive trends of sequence compositional complexity over pandemic time in the SARS-CoV-2 coronavirus
2021
In the brief time since the outbreak of the COVID 19 pandemic, and despite its proofreading mechanism, the SARS-CoV-2 coronavirus has accumulated a significant amount of genetic variability through recombination and mutation events. To test evolutionary trends that could inform us on the adaptive process of the virus to its human host, we summarize all this variability in the Sequence Compositional Complexity (SCC), a measure of genome heterogeneity that captures the mutational and recombinational changes accumulated by a nucleotide sequence along time. Despite the brief time elapsed, we detected many differences in the number and length of compositional domains, as well as in their nucleot…
Tumor Biology and Natural History
2021
Tumors are not uniform diseases but heterogeneous entities consisting of cell populations called cell clones, with different genetic and molecular features. The ability of a tumor to evolve and fit to host microenvironment, by developing often resistance mechanisms to the anticancer therapies, is dependent on this biological variability. In fact, the variability observed within individual tumors, known as intra-tumor heterogeneity, represents the crucial step in cancer clonal evolution process, by promoting and driving a genetic mechanism able to select the fittest cell clones. A single clonal origin is usually shown by most of tumors at the early stages of the disease, whereas advanced-sta…
Genetic variability and evolutionary analysis of parietaria mottle virus: role of selection and genetic exchange
2015
[EN] The genetic variability and evolution of parietaria mottle virus (PMoV) of the genus Ilarvirus was studied by analyzing nucleotide sequences of 2b and CP genes from isolates collected in different countries. Phylogenetic analysis showed that PMoV isolates clustered in different clades: one (clade I) composed of only Italian isolates and three clades (clades II-IV) including the Spanish isolates. The Greek isolate GrT-1 used in this study was in clade IV for the CP phylogenetic tree whereas it formed a separate branch in the 2b phylogenetic tree. The nucleotide sequence diversity of both the 2b and CP genes was low (0.062 +/- A 0.006 and 0.063 +/- A 0.006 for 2b and CP, respectively) bu…
Effect of nitrogen nutrition on Medicago truncatula resistance against Aphanomyces euteiches
2016
Nitrogen (N) is a major limiting factor for plant growth. N availability can also impact plant resistance to pathogens by regulating plant immunity. To better understand the links between N nutrition and plant defense, we analyzed the impact of N availability of plant on Medicago truncatula resistance to the root pathogen, Aphanomyces euteiches, taking into account plant genetic variability. This oomycete is considered as the most limiting factor for legume production. Two conditions of N nutrition, non-limiting or deprived in N, and ten plant genotypes were tested in vitro. The results showed that the resistance is modulated by nutritional conditions, depending on plant genotype. Analysis …
Molecular characterization of the black Aspergillus isolates responsible for ochratoxin A contamination in grapes and wine in relation to taxonomy of…
2009
This work examines ochratoxigenic mycobiota in grapes by ap-PCR analysis sequence analysis of the ITS and IGS regions and ability to produce OTA. A comparison was also made with many reference strains of Aspergillus section Nigri. Based on ap-PCR profiles, derived from two microsatellite primers, three main groups were obtained by UPGMA cluster analysis corresponding to A. carbonarius, A. niger and A. tubingensis. The cophenetic correlation values corresponding to ap-PCR UPGMA analysis revealed a higher genetic variability in A. niger and A. tubingensis than in A. carbonarius. In addition, no genotypical differences could be established between OTA producers and nonproducers in all species …
A polyphasic approach to the identification of ochratoxin A-producing black Aspergillus isolates from vineyards in Sicily.
2008
Aspergillus strains belonging to section Nigri isolated during a two year survey in eight Sicilian vineyards located on the slopes of Mount Etna (Sicily, Italy) were analysed analyzed in order to characterize species responsible for ochratoxin A (OTA) contamination of grapes. The polyphasic approach permitted analysis of biodiversity of Aspergillus isolates in relation to their morphology, ochratoxigenicity and genetic variability. We assessed OTA production by A. carbonarius, A. niger, A. tubingensis and A. japonicus using an enzyme-linked immunosorbent assay. A. carbonarius isolates were the strongest OTA producers. A subset of 66 representative strains was selected for further DNA-based …
The Human Biodiversity in the Middle of the Mediterranean. Study of native and settlers populations on the Sicilian context
2020
[IT] Negli ultimi 200.000 anni, la specie umana si è diffusa in tutta la Terra, adattando la sua morfologia e fisiologia a un'ampia gamma di habitat. Lo scheletro umano ha quindi registrato i principali effetti ambientali e di conseguenza i reperti scheletrici assumono grande importanza nell'indagine dei processi evolutivi. Oggi le moderne tecniche di indagini quantitative delle principali caratteristiche morfologiche consentono di metterle in relazione con la variabilità genetica. La posizione geografica della Sicilia, l'isolamento e la sua lunga e dinamica storia di colonizzazione (diversi e numerosi contributi culturali e biologici) hanno creato un contesto peculiare che consente uno stu…
Association Between Interleukin-10 Polymorphisms and Alzheimer's Disease: A Systematic Review and Meta-Analysis
2012
UNLABELLED It has been hypothesized that polymorphisms of interleukin (IL)-10 genes affect the risk of developing late onset Alzheimer's disease (AD). However, results of different studies are often inconsistent. Our aim was to investigate by meta-analysis the association of the common polymorphisms comprehensively defining the genetic variability of the IL-10 gene with AD risk. Fifteen studies investigating the association between IL-10 polymorphisms (-1082, -819, -592) and AD were found and analyzed. The model-free approach was applied to meta-analyze these case-control genetic association studies. Available data suggested an association between -1082 polymorphism and AD risk with a margi…
Molecular-genetic-based contribution to the taxonomy of theAcanthocyclops robustusgroup
2013
Long-standing taxonomic problems involving the Acanthocyclops robustus–vernalis complex of freshwater cyclopoids have not been resolved. After Kiefer's designation of A. robustus Sars as an older synonym of Acanthocycops americanus Marsh, a lot of data indicating their differentiation have been accumulated. To handle this taxonomical problem, representative populations from type localities of the respective taxa and from other European and US sites were analyzed morphologically and genetically using mitochondrial COI and 12S rRNA. Molecular-genetic analysis revealed that the three species described at the end of the nineteenth century: A. robustus, A. americanus and A. vernalis are well-sep…
Lead contamination affects the primary productivity traits, biosynthesis of macromolecules and distribution of metal in durum wheat (Triticumdurum L.)
2021
Highlights • The growth, biosynthesis of pigments and other macromolecules appeared to be strong predictors in appraisal of Pb tolerance/susceptibility in durum wheat. • Germplasm of CBD59, CBD63 and CBD66 can be exploited for future selection and breeding programs. • The bioaccumulation of metal in grains of some cultivars of durum wheat much below than permissible limits set by FAO/WHO is of great significance owing to its implications for food safety.