Reanalyses of the historical series of UK variety trials to quantify the contributions of genetic and environmental factors to trends and variability in yield over time

2010 ◽  
Vol 122 (1) ◽  
pp. 225-238 ◽  
Author(s):  
I. Mackay ◽  
A. Horwell ◽  
J. Garner ◽  
J. White ◽  
J. McKee ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Variety Trials ◽  
Historical Series ◽  
Genetic And Environmental Factors ◽  
Over Time

scholarly journals How Nonshared Environmental Factors Come to Correlate with Heredity

2020 ◽  
Author(s):  
Christopher Beam ◽  
Patrizia Pezzoli ◽  
Jane Mendle ◽  
S. Alexandra Burt ◽  
Michael C. Neale ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Genetic Models ◽  
Future Research ◽  
Longitudinal Models ◽  
Behavioral Genetic ◽  
Relative Contribution ◽  
Environment Effects ◽  
Gene Environment ◽  
Genetic And Environmental Factors ◽  
Over Time

Conventional longitudinal behavioral genetic models estimate the relative contribution of genetic and environmental factors to stability and change of traits and behaviors. Longitudinal models rarely explain the processes that generate observed differences between genetically and socially related individuals. We propose that exchanges between people and their environments (i.e., phenotype-environment effects) can explain the emergence of observed differences over time. Such models, however, require violation of the independence assumption of standard behavioral genetic models, that is, uncorrelated genetic and environmental factors (Beam & Turkheimer, 2013; de Kort, Dolan, & Boomsma, 2012; Dolan, De Kort, Van Beijsterveldt, Bartels, & Boomsma, 2014). We review how specification of phenotype-environment effects contributes to understanding observed changes in genetic variability over time and longitudinal correlations among nonshared environmental factors. We then provide an example using 30 days of positive and negative affect scores from an all-female sample of twins. Results demonstrate that the phenotype-environment effects explain how heritability estimates fluctuate as well as how nonshared environmental factors persist over time. We discuss possible mechanisms underlying change in gene-environment correlation over time, the advantages and challenges of including gene-environment correlation in longitudinal twin models, and recommendations for future research.

scholarly journals Cohort of birth modifies the association between FTO genotype and BMI

2014 ◽  
Vol 112 (2) ◽  
pp. 354-359 ◽  
Author(s):  
James Niels Rosenquist ◽  
Steven F. Lehrer ◽  
A. James O’Malley ◽  
Alan M. Zaslavsky ◽  
Jordan W. Smoller ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Complex Traits ◽  
Environmental Changes ◽  
The United States ◽  
Genetic Influences ◽  
Birth Cohorts ◽  
Environment Analysis ◽  
Period Effects ◽  
Genetic And Environmental Factors ◽  
Over Time

A substantial body of research has explored the relative roles of genetic and environmental factors on phenotype expression in humans. Recent research has also sought to identify gene–environment (or g-by-e) interactions, with mixed success. One potential reason for these mixed results may relate to the fact that genetic effects might be modified by changes in the environment over time. For example, the noted rise of obesity in the United States in the latter part of the 20th century might reflect an interaction between genetic variation and changing environmental conditions that together affect the penetrance of genetic influences. To evaluate this hypothesis, we use longitudinal data from the Framingham Heart Study collected over 30 y from a geographically relatively localized sample to test whether the well-documented association between the rs993609 variant of the FTO (fat mass and obesity associated) gene and body mass index (BMI) varies across birth cohorts, time period, and the lifecycle. Such cohort and period effects integrate many potential environmental factors, and this gene-by-environment analysis examines interactions with both time-varying contemporaneous and historical environmental influences. Using constrained linear age–period–cohort models that include family controls, we find that there is a robust relationship between birth cohort and the genotype–phenotype correlation between the FTO risk allele and BMI, with an observed inflection point for those born after 1942. These results suggest genetic influences on complex traits like obesity can vary over time, presumably because of global environmental changes that modify allelic penetrance.

Families of Children with Attention Deficit Hyperactivity Disorder: A Review

1996 ◽  
Vol 41 (6) ◽  
pp. 350-360 ◽  
Author(s):  
Lily Hechtman
Keyword(s):  
Environmental Factors ◽  
Family Members ◽  
Children With Adhd ◽  
Hyperactivity Disorder ◽  
Parent Child Interactions ◽  
Adhd Children ◽  
Genetic And Environmental Factors ◽  
Normal Controls ◽  
Over Time

Objectives: 1) To review the evidence of attention deficit hyperactivity disorder (ADHD) and other conditions in family members (siblings and parents) of children with ADHD and determine the importance of genetic and environmental factors in this condition. 2) To describe the prospective 10-year follow-up of 65 families with ADHD children and 43 families of matched normal controls. 3) To review various studies that have looked at parent–child interactions with ADHD children on and off stimulant medication, and such interactions over time. The paper thus provides an overview of family pathology and functioning of families of ADHD children over time. Method: The paper outlines twin, sibling, family and adoption studies with regard to possible genetic and environmental factors in ADHD. It also presents data of a prospective 10-year follow-up of 65 families with ADHD children and 43 families of normal controls. This family study evaluated sociocultural factors, child rearing practices, health of family members and relationships, as well as the parental view of the child's functioning over time. Results: A review of the literature suggests that ADHD has a strong genetic component, but that environmental factors also play an important role. Families of children with ADHD have more problems than families of normal controls, but these problems improve as the child with ADHD grows up and leaves home. Families of ADHD subjects can appreciate positive as well as negative changes in their children over time. Generally, family interactions with children with ADHD are problematic but improve when the child is on medication and when the child becomes an adult. Conclusions: This condition has strong genetic underpinnings; therefore, diagnosing and treating family members (parents and siblings) as well as the child with ADHD is important in improving parent–child interactions and better long-term outcome for the child and his or her family.

scholarly journals How nonshared environmental factors come to correlate with heredity

2020 ◽  
pp. 1-13
Author(s):  
Christopher R. Beam ◽  
Patrizia Pezzoli ◽  
Jane Mendle ◽  
S. Alexandra Burt ◽  
Michael C. Neale ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Genetic Models ◽  
Future Research ◽  
Longitudinal Models ◽  
Behavioral Genetic ◽  
Relative Contribution ◽  
Environment Effects ◽  
Gene Environment ◽  
Genetic And Environmental Factors ◽  
Over Time

Abstract Conventional longitudinal behavioral genetic models estimate the relative contribution of genetic and environmental factors to stability and change of traits and behaviors. Longitudinal models rarely explain the processes that generate observed differences between genetically and socially related individuals. We propose that exchanges between individuals and their environments (i.e., phenotype–environment effects) can explain the emergence of observed differences over time. Phenotype–environment models, however, would require violation of the independence assumption of standard behavioral genetic models; that is, uncorrelated genetic and environmental factors. We review how specification of phenotype–environment effects contributes to understanding observed changes in genetic variability over time and longitudinal correlations among nonshared environmental factors. We then provide an example using 30 days of positive and negative affect scores from an all-female sample of twins. Results demonstrate that the phenotype–environment effects explain how heritability estimates fluctuate as well as how nonshared environmental factors persist over time. We discuss possible mechanisms underlying change in gene–environment correlation over time, the advantages and challenges of including gene–environment correlation in longitudinal twin models, and recommendations for future research.

Reductionist thinking and animal models in neuropsychiatric research

2019 ◽  
Vol 42 ◽  
Author(s):  
Nicole M. Baran
Keyword(s):  
Animal Models ◽  
Mental Disorders ◽  
Environmental Factors ◽  
Neuropsychiatric Disorders ◽  
Model Organisms ◽  
Developmental Genetic ◽  
Term Study ◽  
Genetic And Environmental Factors ◽  
Mechanisms Of Plasticity

AbstractReductionist thinking in neuroscience is manifest in the widespread use of animal models of neuropsychiatric disorders. Broader investigations of diverse behaviors in non-model organisms and longer-term study of the mechanisms of plasticity will yield fundamental insights into the neurobiological, developmental, genetic, and environmental factors contributing to the “massively multifactorial system networks” which go awry in mental disorders.

scholarly journals Decreased heritability and emergence of novel genetic effects on pulse wave velocity from youth to young adulthood

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yisong Huang ◽  
Shaoyong Su ◽  
Harold Snieder ◽  
Frank Treiber ◽  
Gaston Kapuku ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Pulse Wave Velocity ◽  
Wave Velocity ◽  
Young Adulthood ◽  
Ethnic Differences ◽  
Genetic Factors ◽  
Pulse Wave ◽  
Environmental Influences ◽  
Genetic Effects ◽  
Over Time

AbstractIncreased arterial stiffness measured by pulse wave velocity (PWV) is an important parameter in the assessment of cardiovascular risk. Our previous longitudinal study has demonstrated that carotid-distal PWV showed reasonable stability throughout youth and young adulthood. This stability might be driven by genetic factors that are expressed consistently over time. We aimed to illustrate the relative contributions of genetic and environmental factors to the stability of carotid-distal PWV from youth to young adulthood. We also examined potential ethnic differences. For this purpose, carotid-distal PWV was measured twice in 497 European American (EA) and African American (AA) twins, with an average interval time of 3 years. Twin modelling on PWV showed that heritability decreased over time (62–35%), with the nonshared environmental influences becoming larger. There was no correlation between the nonshared environmental factors on PWV measured at visit 1 and visit 2, with the phenotypic tracking correlation (r = 0.32) completely explained by shared genetic factors over time. Novel genetic influences were identified accounting for a significant part of the variance (19%) at the second measurement occasion. There was no evidence for ethnic differences. In summary, novel genetic effects appear during development into young adulthood and account for a considerable part of the variation in PWV. Environmental influences become larger with age for PWV.

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