Search results for "VARIATION"
showing 10 items of 2124 documents
Comparative analysis of variation and selection in the HCV genome
2016
AbstractGenotype 1 of the hepatitis C virus (HCV) is the most prevalent of the variants of this virus. Its two main subtypes, HCV-1a and HCV-1b, are associated to differences in epidemic features and risk groups, despite sharing similar features in most biological properties. We have analyzed the impact of positive selection on the evolution of these variants using complete genome coding regions, and compared the levels of genetic variability and the distribution of positively selected sites. We have also compared the distributions of positively selected and conserved sites considering different factors such as RNA secondary structure, the presence of different epitopes (antibody, CD4 and C…
L'acacia au Sénégal
1996
La biodiversité des Glomales associés à #Acacia albida$ est étudiée en fonction de l'âge de l'arbre, des saisons et des propriétés physicochimiques du sol. Les Glomales sont récoltées jusqu'à 1,5 et 4,5 m dans les régions soudano-guinéennes et jusqu'à 16 et 35 m dans les régions sahéliennes. La culture in vitro de la forme intraracinaire des Glomales en présence de racines isolées a montré une diversité morphologique des souches. En complément à cette taxonomie morphologique, des marqueurs moléculaires ont permis d'étudier la variabilité génétique des Glomales en comparant les variations de séquences d'ADN extrait de spores et de fragments mycorhiziens. (Résumé d'auteur)
Assigning Elephant Ivory with Stable Isotopes
2016
The international ivory trade remains one of the world’s most controversial wildlife trade issues. One of the main arguments for the trade prohibition is the fact that it is very difficult to distinguish legal from illegal ivory in the markets, so that the legal ivory trade would provide a perfect cover for smuggling. The purpose of this study was to analyze the variability of isotope ratios in ivory samples from Appendix I and II elephant populations in Africa to validate their potential for forensic purposes more quantitatively. We selected a subset of 293 data of ivory samples from the www.ivoryid.org database that stores isotopic ratios of δ13C, δ15N, δ18O, δ2H, and δ34S from more than …
Genetic variation and evolutionary analysis of Cucumber mosaic virus in medicinal, aromatic and ornamental plants from Northern Italy
2011
The genetic variation and evolution of Cucumber mosaic virus (CMV) (1) infecting aromatic, medicinal and ornamental plants in Northern Italy were studied by sequence analysis of the movement protein gene and comparison with equivalent sequences of isolates from other countries. Comparison of nonsynonymous and synonymous substitutions at each codon suggested that 30% of amino acid sites were under negative selection and only one was under positive selection. Phylogenetic inference, nucleotide diversity estimation, neutrality tests and genetic differentiation analysis revealed a high nucleotide diversity of CMV in Northern Italy with respect to areas of other countries [1,2] and suggested tha…
Intronic Variant in CNTNAP2 Gene in a Boy With Remarkable Conduct Disorder, Minor Facial Features, Mild Intellectual Disability, and Seizures
2020
Introduction: Mutations in the contactin-associated protein-like 2 (CNTNAP2) gene (MIM#604569) encoding for CASPR2, a cell adhesion protein of the neurexin family, are known to be associated with autism, intellectual disability, and other neuropsychiatric disorders. A set of intronic deletions of CNTNAP2 gene has also been suggested to have a causative role in individuals with a wide phenotypic spectrum, including Pitt-Hopkins syndrome, cortical dysplasia–focal epilepsy syndrome, Tourette syndrome, language dysfunction, and abnormal behavioral manifestations. Case presentation: A 10-years-old boy was referred to the hospital with mild intellectual disability and language impairment. Moreove…
A Comparative Analysis of Copy Number Variation of the Sheep and Goat Genomes
2010
Recent studies have shown that copy number variants (CNVs) are important sources of variability of mammalian genomes. We applied a cross species array comparative genome hybridization (aCGH) experiment using as reference the cattle genome to investigate, for the first time, variability in the sheep and goat genomes derived from copy number variation and identified 431 and 358 CNVs, respectively. A comparison of these results to those obtained in other mammals for similar experiments is reported. The identified CNVs could be important in determining phenotypic and production differences between and within breeds. Further studies will be carried out to evaluate the identified CNVs from both f…
Les climats régionaux : observation et modélisation : actes du colloque
2012
6 pages; International audience; L'objectif de cette étude est de caractériser les variations spatio-temporelles des flux sédimentaires de la basse vallée du Mono-Couffo (bassin versant partagé par le Bénin et le Togo), à partir des données de matières en suspension (MES), de débits solides (TSS), de pluie, du débit et des données concernant l'occupation du sol pour mieux apprécier l'impact de la dégradation du couvert végétal sur le flux des sédiments terrigènes. Il ressort de l'analyse une diminution de plus de 60 % des formations naturelles entre les années 1956 et 2000, contribuant à une augmentation des apports spécifiques dans la basse vallée. Une charge solide considérable en matière…
Diurnal Variation of Non-Arboreal Pollen in the Air in Finland
1981
Abstract This study was carried out in Jyvaskyla and Turku, in central and southern Finland, with Burkard spore traps. The average diurnal variation of all non-arboreal pollen types found in sufficient quantities is presented. A high concentration of Artemisia pollen lasting 4–8 hours was found mainly in the morning. The highest concentrations of Brassicaceae, Calluna, Cyperaceae and Rosaceae occurred during the daylight hours, often with no definite peaks. The peak occurrence of Chenopodiaceae, Compositae and Plantago pollen was around 12.00 and of Rumex from 06.00 to 10.00. The diurnal variation of Poaceae pollen varies considerably depending on the species flowering at the time. Peaks oc…
Evidence for cryptic glacial refugia from North American mountain sheep mitochondrial DNA
2006
The separation of populations by ice sheets into large refugia can account for much of the genetic diversity found in present day populations. The evolutionary implications of small glacial refugia have not been as thoroughly explored. To examine refugial origins of North American mountain sheep Ovis spp., we analyzed a 604 bp portion of the mitochondrial DNA (mtDNA) control region from 223 O. dalli and O. canadensis. Major refugia were identified in eastern Beringia and southern North America, and we found evidence for two smaller refugia situated between the Laurentide and Cordilleran glaciers. Our results are the first to demonstrate support for survival of any organism in the latter two…
BCL2 gene polymorphisms and splicing variants in chronic myeloid leukemia.
2015
Recent data suggest that constitutional genetic variation in the antiapoptotic BCL2 gene could be associated with the susceptibility to develop chronic myeloid leukemia (CML) and the clinical outcome in several hematological malignancies. The present study examines whether BCL2 single nucleotide polymorphisms (SNPs) predispose to CML or may potentially influence the disease characteristics at diagnosis. Notably, no association was observed between the four candidate BCL2 SNPs and the risk of developing CML. Instead, the 4777C>A (rs2279115) and the 5735A>G (rs1801018) SNPs were significantly associated with the disease risk profile as determined by the Sokal score. We found that such polymor…