Behavior Genetics最新文献

Head grooming in Drosophila consists of repeated sweeps of the legs across the head, comprising regular cycles. We used the GAL4-UAS system to study the effects of overexpressing shibire^ts1 and of Adar knockdown via RNA interference, on the period of head-grooming cycles in Drosophila. Overexpressing shibire^ts1 interferes with synaptic vesicle recycling and thus with cell communication, while Adar knockdown reduces RNA editing of neuronal transcripts for a large number of genes. All transgenic flies and their controls were tested at 22° to avoid temperature effects; in wild type, cycle frequency varied with temperature with a Q₁₀ of 1.3. Two experiments were performed with transgenic shibire^ts1: (1) each fly was heat-shocked for 10 min at 30° immediately before testing at 22° and (2) flies were not heat shocked. In both experiments, cycle period was increased when shibire^ts1 was overexpressed in all neurons, but was not increased when shibire^ts1 was overexpressed in motoneurons alone. We hypothesize that grooming cycles in flies overexpressing shibire^ts1 are lengthened because of synaptic impairment in neural circuits that control head-grooming cycles. In flies with constitutive, pan-neuronal Adar knockdown, cycle period was more variable within individuals, but mean cycle period was not significantly altered. We conclude that RNA editing is essential for the maintenance of within-individual stereotypy of head-grooming cycles.

One long-standing analytic approach in adoption studies is to examine correlations between features of adoptive homes and outcomes of adopted children (hereafter termed ‘measured environment correlations’) to illuminate environmental influences on those associations. Although results from such studies have almost uniformly suggested modest environmental influences on adopted children’s academic achievement, other work has indicated that adopted children’s achievement is routinely higher than that of their reared-apart family members, often substantially so. We sought to understand this discrepancy. We examined academic achievement and literacy-promotive features of the home in 424 yoked adoptive/biological families participating in the Early Growth and Development Study (EGDS; i.e., adopted children, adoptive mothers, birth mothers, and biological siblings of the adopted children remaining in the birth homes) using an exhaustive modeling approach. Results indicated that, as anticipated, adopted children scored up to a full standard deviation higher on standardized achievement tests relative to their birth mothers and reared-apart biological siblings. Moreover, these achievement differences were associated with differences in the literacy-promotive features of the adoptive and birth family homes, despite minimal measured environment correlations within adoptive families. A subsequent simulation study highlighted noise in measured environmental variables as an explanation for the decreased utility of measured environment correlations. We conclude that the field’s heavy focus on measured environment correlations within adoptive families may have obscured detection of specific environmental effects on youth outcomes, and that future adoption studies should supplement their measured environment analyses with mean differences between reared-apart relatives.

This study tested interactions among puberty-related genetic risk, prenatal substance use, harsh discipline, and pubertal timing for the severity and directionality (i.e., differentiation) of externalizing and internalizing problems and adolescent substance use. This is a companion paper to Marceau et al. (2021) which examined the same influences in developmental cascade models. Data were from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort (n = 4504 White boys, n = 4287 White girls assessed from the prenatal period through 18.5 years). We hypothesized generally that later predictors would strengthen the influence of puberty-related genetic risk, prenatal substance use exposure, and pubertal risk on psychopathology and substance use (two-way interactions), and that later predictors would strengthen the interactions of earlier influences on psychopathology and substance use (three-way interactions). Interactions were sparse. Although all fourteen interactions showed that later influences can exacerbate or trigger the effects of earlier ones, they often were not in the expected direction. The most robust moderator was parental discipline, and differing and synergistic effects of biological and socially-relevant aspects of puberty were found. In all, the influences examined here operate more robustly in developmental cascades than in interaction with each other for the development of psychopathology and transitions to substance use.

Although earlier research has shown that individual differences on the spectrum of attention deficit hyperactivity disorder (ADHD) are highly heritable, emerging evidence suggests that symptoms are associated with complex interactions between genes and environmental influences. This study investigated whether a genetic predisposition [Note that the term 'genetic predisposition' was used in this manuscript to refer to an estimate based on twin modeling (an individual's score on the latent trait that resembles additive genetic influences) in the particular population being examined.] for the symptom dimensions hyperactivity and inattention determines the extent to which unique-environmental influences explain variability in these symptoms. To this purpose, we analysed a sample drawn from the Twins Early Development Study (TEDS) that consisted of item-level scores of 2168 16-year-old twin pairs who completed both the Strengths and Difficulties Questionnaire (SDQ; Goodman, in J Child Psychol Psychiatry 38:581-586, 1997) and the Strength and Weaknesses of ADHD Symptoms and Normal Behavior (SWAN; Swanson, in Paper presented at the meeting of the American Psychological Association, Los Angeles, 1981) questionnaire. To maximize the psychometric information to measure ADHD symptoms, psychometric analyses were performed to investigate whether the items from the two questionnaires could be combined to form two longer subscales. In the estimation of genotype-environment interaction, we corrected for error variance heterogeneity in the measurement of ADHD symptoms through the application of item response theory (IRT) measurement models. A positive interaction was found for both hyperactivity (e.g., [Formula: see text] = 2.20 with 95% highest posterior density interval equal to [1.79;2.65] and effect size equal to 3.00) and inattention (e.g., [Formula: see text] = 2.16 with 95% highest posterior density interval equal to [1.56;2.79] and effect size equal to 3.07). These results indicate that unique-environmental influences were more important in creating individual differences in both hyperactivity and inattention for twins with a genetic predisposition for these symptoms than for twins without such a predisposition.

Genotype-phenotype associations between the bovine genome and grazing behaviours measured over time and across contexts have been reported in the past decade, with these suggesting the potential for genetic control over grazing personalities in beef cattle. From the large array of metrics used to describe grazing personality behaviours (GP-behaviours), it is still unclear which ones are linked to specific genes. Our prior observational study has reported associations and trends towards associations between genotypes of the glutamate metabotropic receptor 5 gene (GRM5) and four GP-behaviours, yet the unbalanced representation of GRM5 genotypes occurring in observational studies may have limited the ability to detect associations. Here, we applied a subsampling technique to create a genotypically-balanced dataset in a quasi-manipulative experiment with free ranging cows grazing in steep and rugged terrain of New Zealand's South Island. Using quadratic discriminant analysis, two combinations of eleven GP-behaviours (and a total of fifteen behaviours) were selected to build an exploration model and an elevation model, respectively. Both models achieved ∼ 86% accuracy in correctly discriminating cows' GRM5 genotypes with the training dataset, and the exploration model achieved 85% correct genotype prediction of cows from a testing dataset. Our study suggests a potential pleiotropic effect, with GRM5 controlling multiple grazing behaviours, and with implications for the grazing of steep and rugged grasslands. The study highlights the importance of grazing behavioural genetics in cattle and the potential use of GRM5 markers to select individuals with desired grazing personalities and built herds that collectively utilize steep and rugged rangelands sustainably.

The recent interest in increasing diversity in genetic research can be useful in uncovering novel insights into the genetic architecture of mental health disorders - globally and in previously unexplored settings such as low- and middle-income settings like Nigeria. Genetic research into mental health is potentially promising in Nigeria and we reflect on the challenges and opportunities for twin research which may be particularly suited to Nigeria. The higher rates of twinning in Africa and Nigeria specifically, make the twin design an affordable and readily maintainable approach for genetic research in the country. Despite potential challenges with recruitment, data collection, data analysis and dissemination; the success of current efforts suggest that the twin design can tapped even further for greater impact in the country. We highlight some ways in which the scope of twin research can be increased and suggest some ways in which existing challenges can be overcome including recent Patient Participant Involve and Engagement activities.

This study examined the independent and interactive effects of alcohol use disorder genome-wide polygenic scores (AUD-PGS) and parenting and family conflict on early adolescent externalizing behaviors. Data were drawn from White (N = 6181, 46.9% female), Black/African American (N = 1784, 50.1% female), and Hispanic/Latinx (N = 2410, 48.0% female) youth from the adolescent brain cognitive development Study (ABCD). Parents reported on youth externalizing behaviors at baseline (T1, age 9/10), 1-year (T2, age 10/11) and 2-year (T3, age 11/12) assessments. Youth reported on parenting and family environment at T1 and provided saliva or blood samples for genotyping. Results from latent growth models indicated that in general externalizing behaviors decreased from T1 to T3. Across all groups, higher family conflict was associated with more externalizing behaviors at T1, and we did not find significant associations between parental monitoring and early adolescent externalizing behaviors. Parental acceptance was associated with lower externalizing behaviors among White and Hispanic youth, but not among Black youth. Results indicated no significant main effect of AUD-PGS nor interaction effect between AUD-PGS and family variables on early adolescent externalizing behaviors. Post hoc exploratory analysis uncovered an interaction between AUD-PGS and parental acceptance such that AUD-PGS was positively associated with externalizing rule-breaking behaviors among Hispanic youth, but only when parental acceptance was very low. Findings highlight the important role of family conflict and parental acceptance in externalizing behaviors among early adolescents, and emphasize the need to examine other developmental pathways underlying genetic risk for AUD across diverse populations.