Search results for "Genetic Variation"
showing 10 items of 836 documents
Gene–alcohol interactions in the metabolic syndrome
2007
Abstracts Aims Recent studies have reported that moderate alcohol consumption is associated with a lesser prevalence of the metabolic syndrome (MetS). However, this relationship is still confusing and the presence of gene–environment interactions has been suggested. Our aim is to summarize evidence for gene–alcohol interactions in the MetS. Data synthesis Research in gene–alcohol interactions applied to MetS is very complex due to the difficulties surrounding the definition of phenotype, environment and genotype, as well as in estimating the influence of the social context. In the MetS there is a constellation of metabolic disturbances the definition of which is still changing. Thus, most s…
FOXP2 expression and gray matter density in the male brains of patients with schizophrenia
2021
Common genetic variants ofFOXP2may contribute to schizophrenia vulnerability, but controversial results have been reported for this proposal. Here we evaluated the potential impact of the commonFOXP2rs2396753 polymorphism in schizophrenia. It was previously reported to be part of a risk haplotype for this disease and to have significant effects on gray matter concentration in the patients. We undertook the first examination into whether rs2396753 affects the brain expression ofFOXP2and a replication study of earlier neuroimaging findings of the influence of this genetic variant on brain structure.FOXP2expression levels were measured in postmortem prefrontal cortex samples of 84 male subject…
Two distinct genomic regions, harbouring the period and fruitless genes, affect male courtship song in Drosophila montana
2012
Acoustic signals often have a significant role in pair formation and in species recognition. Determining the genetic basis of signal divergence will help to understand signal evolution by sexual selection and its role in the speciation process. An earlier study investigated quantitative trait locus for male courtship song carrier frequency (FRE) in Drosophila montana using microsatellite markers. We refined this study by adding to the linkage map markers for 10 candidate genes known to affect song production in Drosophila melanogaster. We also extended the analyses to additional song characters (pulse train length (PTL), pulse number (PN), interpulse interval, pulse length (PL) and cycle nu…
An association analysis to identify genetic variants linked to asthma and rhinoconjunctivitis in a cohort of Sicilian children
2018
Abstract Asthma and rhino-conjunctivitis are common chronic diseases in childhood. In this cross-sectional study, we performed a gene association analysis with current asthma and rhino-conjunctivitis in a cohort of Sicilian children aged 10–15 years. Overall, our findings reveal the importance of different genetic variants at 4p14, 16p12.1, 17q12, 6p12.2 and 17q21.1, identifying possible candidate genes responsible for susceptibility to asthma and rhino-conjunctivitis.
Variant toxin B and a functional toxin A produced by Clostridium difficile C34.
2001
A particular property of Clostridium difficile strain C34 is an insertion of approximately 2 kb in the tcdA-C34 gene that does not hinder expression of a fully active TcdA-C34 molecule. Intoxication with TcdA-C34 induced an arborized appearance in eukaryotic cells (D-type cytopathic effect); intoxication with TcdB-C34 induced a spindle-like appearance of cells (S-type cytopathic effect). Inactivation of GTPases with purified toxins revealed that Rho, Rac, Cdc42, and Rap are substrates of TcdA-C34. The variant cytotoxin TcdB-C34 inactivated Rho, Rac, Cdc42, Rap, Ral, and R-Ras. Hence, this is the first ‘S-type’ cytotoxin which inactivates both Rho and R-Ras, and is coexpressed with a ‘D-type…
Geographic distribution and inheritance of three cytoplasmic incompatibility types in Drosophila simulans.
1991
Abstract Wolbachia-like microorganisms have been implicated in unidirectional cytoplasmic incompatibility between strains of Drosophila simulans. Reduced egg eclosion occurs when females from uninfected strains (type W) are crossed with males from infected strains (type R). Here we characterize a third incompatibility type (type S) which is also correlated with the presence of Wolbachia-like microorganisms. Despite the fact that the symbionts cannot be morphologically distinguished, we observed complete bidirectional incompatibility between R and S strains. This indicates that the determinants of incompatibility are different in the two infected types. S/W incompatibility is unidirectional …
Co-adaptation of pheromone production and behavioural responses in Drosophila melanogaster males
1999
0016-6723 (Print) Journal Article Research Support, Non-U.S. Gov't; In Drosophila melanogaster, male courtship behaviour is genetically controlled and is influenced by sex pheromones. 7-tricosene (7-T) induces a dose-dependent inhibition of male-male courtship, whereas 7,11-dienes stimulate male courtship of females. There is a geographical quantitative variation in the production of two predominant male hydrocarbons, 7-T and 7-pentacosene (7-P). We have previously found that 7-P, the main hydrocarbon from males of West African strains, stimulates males that mainly produce 7-T. Using both 'natural' and genetically engineered strains, we find that genetic factors coding for low levels of 7-P…
Males influence maternal effects that promote sexual selection: a quantitative genetic experiment with dung beetles Onthophagus taurus
2003
J.S.K. was funded by the Academy of Finland, L.W.S. by the Australian Research Council, J.H. by an Australian Postgraduate Award, and J.L.T. by a postdoctoral research fellowship from the University of Western Australia. Recently, doubt has been cast on studies supporting good genes sexual selection by the suggestion that observed genetic benefits for offspring may be confounded by differential maternal allocation. In traditional analyses, observed genetic sire effects on offspring phenotype may result from females allocating more resources to the offspring of attractive males. However, maternal effects such as differential allocation may represent a mechanism promoting genetic sire effects…
Polymorphisms in endothelin system genes, arsenic levels and obesity risk.
2015
Background/objectivesObesity has been linked to morbidity and mortality through increased risk for many chronic diseases. Endothelin (EDN) system has been related to endothelial function but it can be involved in lipid metabolism regulation: Receptor type A (EDNRA) activates lipolysis in adipocytes, the two endothelin receptors mediate arsenic-stimulated adipocyte dysfunction, and endothelin system can regulate adiposity by modulating adiponectin activity in different situations and, therefore, influence obesity development. The aim of the present study was to analyze if single nucleotide polymorphisms (SNPs) in the EDN system could be associated with human obesity.Subjects/methodsWe analyz…
Cuticular hydrocarbons: their evolution and roles in Drosophila pheromonal communication
2005
0001-8244 (Print) Journal Article Review; I review the recent literature on cuticular hydrocarbons (CHs) in Drosophila. First, the major structural features of CHs are examined in a variety of species with regard to phylogeny. The genetic bases of the CH variation between and within species have been investigated with some of the genes involved characterized and manipulated. The effect of non-genetic factors as temperature, food and development is also examined with regard to CH production. Using a model involving the stimulating or the inhibiting role of CHs, it is possible to speculate on the mechanisms of CH perception and on the role(s) that these substances could play on sexual isolati…