35 research outputs found

    Haplotype affinities resolve a major component of goat (<i>Capra hircus</i>) MtDNA D-loop diversity and reveal specific features of the Sardinian stock

    Get PDF
    Goat mtDNA haplogroup A is a poorly resolved lineage absorbing most of the overall diversity and is found in locations as distant as Eastern Asia and Southern Africa. Its phylogenetic dissection would cast light on an important portion of the spread of goat breeding. The aims of this work were 1) to provide an operational definition of meaningful mtDNA units within haplogroup A, 2) to investigate the mechanisms underlying the maintenance of diversity by considering the modes of selection operated by breeders and 3) to identify the peculiarities of Sardinian mtDNA types. We sequenced the mtDNA D-loop in a large sample of animals (1,591) which represents a non-trivial quota of the entire goat population of Sardinia. We found that Sardinia mirrors a large quota of mtDNA diversity of Western Eurasia in the number of variable sites, their mutational pattern and allele frequency. By using Bayesian analysis, a distance-based tree and a network analysis, we recognized demographically coherent groups of sequences identified by particular subsets of the variable positions. The results showed that this assignment system could be reproduced in other studies, capturing the greatest part of haplotype diversity. We identified haplotype groups overrepresented in Sardinian goats as a result of founder effects. We found that breeders maintain diversity of matrilines most likely through equalization of the reproductive potential. Moreover, the relevant amount of inter-farm mtDNA diversity found does not increase proportionally with distance. Our results illustrate the effects of breeding practices on the composition of maternal gene pool and identify mtDNA types that may be considered in projects aimed at retrieving the maternal component of the oldest breeds of Sardinia.</br

    Trophic niches of four sympatric rainforest anurans from southern Nigeria: does resource partitioning play a role in structuring the community ?

    Get PDF
    Le partage des ressources est un mécanisme qui peut réduire l'intensité de la compétition interspécifique dans un cortège d'espèces syntopiques, morphologiquement et éco-éthologiquement semblables. La documentation du partage des ressources, entre quatre espèces d'Anoures sympatriques, a été recherchée par l'examen du régime alimentaire (par dissection stomacale) de spécimens obtenus auprès de fournisseurs de viande de brousse dans le sud-est du Nigéria. Pour l'ensemble des quatres espèces, nous avons trouvé au total 32 différents types de proies. Ptychadena oxyrhynchus en a consommé 28, contre 17 pour P. aequiplicata, 15 pour Bufo maculatus et 10 seulement pour Hoplobatrachus occipitalis. Pour les courbes cumulatives de diversité des trois premières espèces un plateau a été atteint, montrant que la composition des régimes pouvait être considérée comme correctement établie. Les proies communes, consommées par les quatre espèces d'Anoures, étaient des Formicoidea, des Coléoptères adultes, des Aranéides, des Isopodes, des Oligochètes et des Pulmonés. Les proies communes, consommées par trois des quatre amphibiens, étaient des Dermaptères, des Hémiptères, des Odonates adultes et des Orthoptères. Les largeurs de tête variaient significativement entre les espèces d'Anoures ; toutefois, les deux espèces de Ptychadena ne montraient pas de différence significative entre elles sur ce point Pour trois espèces, la largeur de tête était significativement corrélée au volume de proies dans l'estomac. Le partage des ressources (en termes de types de proies) a été trouvé particulièrement net entre deux espèces de Ptychadena étroitement apparentées. La divergence entre Ptychadena oxyrhynchus et P. aequiplicata apparut telle que des analyses multivariées ont placé chacune d'elles, du point de vue alimentaire, plus près de Hoplobatrachus occipitalis ou de Bufo maculatus que de son congénère. Une divergence si forte semblerait jouer un rôle majeur dans le maintien de la structure de ce peuplement mixte d'Anoures.Resource partitioning is a mechanism that can reduce the intensity of inter-specifie competition between morphologically and eco-ethologically similar, syntopic species . Evidence for resource partitioning, between four syntopic anuran species, was investigated by examining the diet (through stomach dissection) of frogs bought from bush meat traders in southeastern Nigeria . Considering the four species together, a total of 32 different prey types were found. Ptychadena oxyrhynchus consumed 28 of them, while P. aequiplicata consumed 17 , Bufo maculatus 15 and Hoplobatrachus occipitalis only 10. For the first three species, the cumulative-diversity curves indicated that a plateau phase was reached, i .e . that the prey composition could be considered reliably assessed. Common prey items, which were consumed by all four anuran species, were : Formicoidea, Coleoptera adults, Araneidae, Jsopoda, Oligochaeta, and Pulmonata. Common prey items, which were consumed by three of the four amphibians, were : Dermaptera, Hemiptera, Odonata adults, and Orthoptera. Head width varied significantly between species, but there was no statistical difference between the two Ptychadena species. Head width was significantly correlated with prey volume in the stomach in each of three species. Resource partitioning (in terms of prey types) was found to be particularly strong between two closely related species of Ptychadena. The divergence bewteen Ptychadena oxyrhynchus and P. aequiplicata was such that multivariate analyses placed each one of them closer in feeding ecology to either Hoplobatrachus occipitalis or Bufo maculatus, than to their congener. Such strong divergence is hypothesized to play a major role in maintaining the structure of this mixed anuran community

    Application of a new method for GWAS in a related case/control sample with known pedigree structure: identification of new loci for nephrolithiasis

    Get PDF
    In contrast to large GWA studies based on thousands of individuals and large meta-analyses combining GWAS results, we analyzed a small case/control sample for uric acid nephrolithiasis. Our cohort of closely related individuals is derived from a small, genetically isolated village in Sardinia, with well-characterized genealogical data linking the extant population up to the 16(th) century. It is expected that the number of risk alleles involved in complex disorders is smaller in isolated founder populations than in more diverse populations, and the power to detect association with complex traits may be increased when related, homogeneous affected individuals are selected, as they are more likely to be enriched with and share specific risk variants than are unrelated, affected individuals from the general population. When related individuals are included in an association study, correlations among relatives must be accurately taken into account to ensure validity of the results. A recently proposed association method uses an empirical genotypic covariance matrix estimated from genome-screen data to allow for additional population structure and cryptic relatedness that may not be captured by the genealogical data. We apply the method to our data, and we also investigate the properties of the method, as well as other association methods, in our highly inbred population, as previous applications were to outbred samples. The more promising regions identified in our initial study in the genetic isolate were then further investigated in an independent sample collected from the Italian population. Among the loci that showed association in this study, we observed evidence of a possible involvement of the region encompassing the gene LRRC16A, already associated to serum uric acid levels in a large meta-analysis of 14 GWAS, suggesting that this locus might lead a pathway for uric acid metabolism that may be involved in gout as well as in nephrolithiasis

    Haplotype Affinities Resolve a Major Component of Goat (Capra hircus) MtDNA D-Loop Diversity and Reveal Specific Features of the Sardinian Stock

    Get PDF
    Goat mtDNA haplogroup A is a poorly resolved lineage absorbing most of the overall diversity and is found in locations as distant as Eastern Asia and Southern Africa. Its phylogenetic dissection would cast light on an important portion of the spread of goat breeding. The aims of this work were 1) to provide an operational definition of meaningful mtDNA units within haplogroup A, 2) to investigate the mechanisms underlying the maintenance of diversity by considering the modes of selection operated by breeders and 3) to identify the peculiarities of Sardinian mtDNA types. We sequenced the mtDNA D-loop in a large sample of animals (1,591) which represents a non-trivial quota of the entire goat population of Sardinia. We found that Sardinia mirrors a large quota of mtDNA diversity of Western Eurasia in the number of variable sites, their mutational pattern and allele frequency. By using Bayesian analysis, a distance-based tree and a network analysis, we recognized demographically coherent groups of sequences identified by particular subsets of the variable positions. The results showed that this assignment system could be reproduced in other studies, capturing the greatest part of haplotype diversity

    Racial differences in systemic sclerosis disease presentation: a European Scleroderma Trials and Research group study

    Get PDF
    Objectives. Racial factors play a significant role in SSc. We evaluated differences in SSc presentations between white patients (WP), Asian patients (AP) and black patients (BP) and analysed the effects of geographical locations.Methods. SSc characteristics of patients from the EUSTAR cohort were cross-sectionally compared across racial groups using survival and multiple logistic regression analyses.Results. The study included 9162 WP, 341 AP and 181 BP. AP developed the first non-RP feature faster than WP but slower than BP. AP were less frequently anti-centromere (ACA; odds ratio (OR) = 0.4, P &lt; 0.001) and more frequently anti-topoisomerase-I autoantibodies (ATA) positive (OR = 1.2, P = 0.068), while BP were less likely to be ACA and ATA positive than were WP [OR(ACA) = 0.3, P &lt; 0.001; OR(ATA) = 0.5, P = 0.020]. AP had less often (OR = 0.7, P = 0.06) and BP more often (OR = 2.7, P &lt; 0.001) diffuse skin involvement than had WP.AP and BP were more likely to have pulmonary hypertension [OR(AP) = 2.6, P &lt; 0.001; OR(BP) = 2.7, P = 0.03 vs WP] and a reduced forced vital capacity [OR(AP) = 2.5, P &lt; 0.001; OR(BP) = 2.4, P &lt; 0.004] than were WP. AP more often had an impaired diffusing capacity of the lung than had BP and WP [OR(AP vs BP) = 1.9, P = 0.038; OR(AP vs WP) = 2.4, P &lt; 0.001]. After RP onset, AP and BP had a higher hazard to die than had WP [hazard ratio (HR) (AP) = 1.6, P = 0.011; HR(BP) = 2.1, P &lt; 0.001].Conclusion. Compared with WP, and mostly independent of geographical location, AP have a faster and earlier disease onset with high prevalences of ATA, pulmonary hypertension and forced vital capacity impairment and higher mortality. BP had the fastest disease onset, a high prevalence of diffuse skin involvement and nominally the highest mortality

    Isolation and characterization of two different 5S rDNA in Anguilla anguilla and in Anguilla rostrata: Possible markers of evolutionary divergence

    No full text
    We cloned and sequenced the Hae III 350-bp 5S ribosomal DNA (rDNA) band of Anguilla rostrata and designed specific primers from this sequence. Polymerase chain reaction performed with these primers is able to distinguish DNA samples obtained from European ( Anguilla anguilla ) and American ( Anguilla rostrata ) eels. Two amplicons of 1200 bp and 600 bp were obtained, respectively, from A. rostrata and A. anguilla, and the whole 5S rDNA repeated unit from these eels was cloned and sequenced. Southern blot experiments, using four different restriction enzymes and the 5S nontranscribed spacers regions as probe, are able to point out specific diversity in these eels

    Timed Up and Go in men and women with Multiple Sclerosis: effect of muscular strength

    No full text
    Objective: People with Multiple Sclerosis (pwMS) often exhibit generalized weakness that affects several activities of daily life, particularly those relying on balance and gait. While it is known that such a symptom has a strong impact on mobility, to what extent muscular strength is linked with functional mobility in men and women with MS remains mostly unexplored. The aim of this study is to assess the existence of possible sex-related differences in functional mobility in pwMS, also considering the muscular strength capacity. Methods: Functional mobility and hand-grip strength (HGS) were assessed in 49 pwMS with mild- moderate disability using instrumental Timed-up-and-go (TUG) test carried out using an inertial sensor and digital dynamometry. We investigated the existence of sex-related differences in the duration of each TUG sub-phase and their correlation with the HGS. Results: No sex-related differences in TUG performance (either in terms of overall or sub-phase time) were found. Similar large negative correlations were found in men and women with MS between HGS and overall TUG and walking phase duration. However, changes in strength have a more marked impact in women as indicated by the different slope of the HGS-TUG time relationship., In women, HGS also appears signi!cantly correlated with all TUG sub-phases, while in men this occurs only for overall TUG and walking time. Conclusions: Rehabilitation and training programs for pwMS should take into account the peculiar features associated with the interaction between strength and mobility speci!c for each individual's sex to optimize their effectiveness

    A 23Na NMR study of the effect of D(+) and L(-) arabitol on NaDNA in aqueous solution.

    No full text
    The 23Na NMR quadrupolar relaxation in NaDNA aqueous solutions has been investigated in the presence of D(+) and L(-) arabitol. Quite different results were produced by the enantiomers, i.e. the addition of D(+) arabitol produced a small increase of the 23Na NMR relaxation rates, while in the presence of L(-) arabitol a significant decrease was observed. These findings were analysed and discussed in terms of an effective interaction of L(-) arabitol with DNA

    A 23Na NMR STUDY OF THE EFFECT OF (D+) AND L(-) ARABITOL ON Na-DNA IN AQUEOUS SOLUTION

    No full text

    Cytotoxic phloroglucinols from the leaves of Myrtus communis

    No full text
    Bioactivity-guided fractionation of a dichloromethane extract of the leaves of Myrtus communis led to the isolation of phloroglucinol derivatives. The structures of the new myrtucommulones J, K, and L (1-3) and the previously known myrtucommulone A (4) were elucidated on the basis of extensive 1D and 2D NMR experiments as well as high-resolutionmass spectrometry. Myrtucommulone J was obtained as a tautomeric pair (1/1a). The compounds were tested in vitro for their cytotoxic and antibacterial activities
    corecore