Search results for "Genetic architecture"

Genetic architecture of motives for leisure-time physical activity: a twin study

2017

The aim of this study was to estimate the contribution of genetic and environmental influences on motives for engaging in leisure‐time physical activity. The participants were obtained from the FinnTwin16 study. A modified version of the Recreational Exercise Motivation Measure was used to assess the motives for leisure‐time physical activity in 2542 twin individuals (mean age of 34.1 years). Linear structural equation modeling was used to investigate the genetic and environmental influences on motive dimensions. The highest heritability estimates were found for the motive dimensions of “enjoyment” [men 33% (95% CI 23–43%), women 53% (95% CI 45–60%)] and “affiliation” [men 39% (95% CI 0.28–…

Genome-wide association studies identify 137 genetic loci for DNA methylation biomarkers of aging

2021

Abstract Background Biological aging estimators derived from DNA methylation data are heritable and correlate with morbidity and mortality. Consequently, identification of genetic and environmental contributors to the variation in these measures in populations has become a major goal in the field. Results Leveraging DNA methylation and SNP data from more than 40,000 individuals, we identify 137 genome-wide significant loci, of which 113 are novel, from genome-wide association study (GWAS) meta-analyses of four epigenetic clocks and epigenetic surrogate markers for granulocyte proportions and plasminogen activator inhibitor 1 levels, respectively. We find evidence for shared genetic loci ass…

Genome-wide association analysis in dilated cardiomyopathy reveals two new players in systolic heart failure on chromosomes 3p25.1 and 22q11.23

2021

Abstract Aims  Our objective was to better understand the genetic bases of dilated cardiomyopathy (DCM), a leading cause of systolic heart failure. Methods and results  We conducted the largest genome-wide association study performed so far in DCM, with 2719 cases and 4440 controls in the discovery population. We identified and replicated two new DCM-associated loci on chromosome 3p25.1 [lead single-nucleotide polymorphism (SNP) rs62232870, P = 8.7 × 10−11 and 7.7 × 10−4 in the discovery and replication steps, respectively] and chromosome 22q11.23 (lead SNP rs7284877, P = 3.3 × 10−8 and 1.4 × 10−3 in the discovery and replication steps, respectively), while confirming two previously identif…

Factors Affecting Male Song Evolution in Drosophila montana

2005

D. montana (a species of the D. virilis group) has spread over the northern hemisphere, populations from different areas showing both genetic and phenotypic divergence. The males of this species produce an elaborate courtship song, which plays a major role both in species recognition and in intraspecific mate choice. The genetic architecture and physical constraints, as well as the importance of the signal for species recognition, set boundaries within which this signal can vary. Within these limits, courtship song parameters may change, depending on the males' physical condition and on the environment they inhabit. Females are likely to affect song evolution by exerting directional selecti…

Why are viral genomes so fragile? The bottleneck hypothesis

2021

If they undergo new mutations at each replication cycle, why are RNA viral genomes so fragile, with most mutations being either strongly deleterious or lethal? Here we provide theoretical and numerical evidence for the hypothesis that genetic fragility is partly an evolutionary response to the multiple population bottlenecks experienced by viral populations at various stages of their life cycles. Modelling within-host viral populations as multi-type branching processes, we show that mutational fragility lowers the rate at which Muller’s ratchet clicks and increases the survival probability through multiple bottlenecks. In the context of a susceptible-exposed-infectious-recovered epidemiolog…

Manipulating genetic architecture to reveal fitness relationships

2014

Evidence for shared environmental contributions to attention-deficit/hyperactivity traits. A twin study

2019

Background and objectives: Behavior-genetic analyses have shown that measurements of inattention and hyperactivity-impulsivity are genetically-influenced. In view of limited studies on ADHD (Attention deficit hyperactivity disorder) in Spanish samples, this study aims to explore the genetic architecture of ADHD symptoms; inattention and hyperactivity-impulsivity in a Spanish twin schoolchildren sample. Methods: Participants were 258 pairs of adolescent Spanish twins. Symptoms of ADHD, inattention and hyperactivity-impulsivity were assessed by means of a sub-scale of the Strengths and Difficulties Questionnaire. Univariate twin models, according to sex, were run to assess the heritability of…

Genetic variability at neutral markers, quantitative trait loci and trait in a subdivided population under selection

2003

Abstract Genetic variability in a subdivided population under stabilizing and diversifying selection was investigated at three levels: neutral markers, QTL coding for a trait, and the trait itself. A quantitative model with additive effects was used to link genotypes to phenotypes. No physical linkage was introduced. Using an analytical approach, we compared the diversity within deme (HS) and the differentiation (FST) at the QTL with the genetic variance within deme (VW) and the differentiation (QST) for the trait. The difference between FST and QST was shown to depend on the relative amounts of covariance between QTL within and between demes. Simulations were used to study the effect of se…

Genetic Diversity and Evolution of Viral Populations

2021

Abstract Population genetic diversity plays a prominent role in viral evolution, pathogenesis, immune escape, and drug resistance. Different mechanisms are responsible for creating and maintaining genetic diversity in viruses, including error-prone replication, repair avoidance, and genome editing, among others. This diversity is subsequently modulated by natural selection and random genetic drift, whose action in turn depends on multiple factors including viral genetic architecture, viral demography, and ecology. Understanding these processes should contribute to the development of more efficient control and treatment strategies against viral pathogens.

Causes of the genetic architecture of south-west European high mountain disjuncts

2008

Background: Postglacial climatic warming in south-western Europe and the retreat of cold-adapted species into higher elevations, starting in the Sierra Nevada and proceeding northwards to the Pyrenees and Alps, should have resulted in a pattern of ‘successive vicariance’. Alternatively, long-distance dispersal might explain the extant distribution pattern of mountain species in this region. Aims: Here, we report an investigation of two alpine plants, Saxifraga oppositifolia and S. stellaris, which co-occur in the Sierra Nevada, the Pyrenees, and the south-western Alps/Massif Central. Our aim was to distinguish between (successive) vicariance and long-distance dispersal as alternative explan…