Maternal defensive aggression towards humans reflects poor sow welfare and undermines stockpersons’ safety. Selection on young boars using proxies for human-directed defensive aggression would be advantageous because their high reproductive contribution allows them to substantially influence the genetic composition of subsequent generations. We analysed feeding behaviours expected to reflect individual personality and social influences, in pre-pubertal male pigs and estimated their genetic correlations with maternal defensive aggression. Automatically recorded feeding data were available for group-housed Swiss Landrace (n = 725) and Swiss Large White (n = 943) boars and castrated males, from which we derived five traits: Average Daily Intake, Average Daily feeding Duration, Average Interval between Successive feeder Visits, Average Time from the group-level Peak of Activity at the feeder and Average Proportion of Visits at Night. Maternal defensive aggression was assessed in Swiss Landrace sows applying a Piglet Handling Test (n = 376) and a Farmers’ Aggressiveness Score (n = 406). Genetic parameters were estimated using Bayesian linear mixed models, with a genomic relationship matrix computed based on 60 K SNP-chip genotypes. Feeding traits’ heritabilities were moderate to high (estimate ± SE: 0.25 ± 0.04 to 0.50 ± 0.04). Average Daily Intake and Average Time from the Peak of Activity were genetically correlated with the Piglet Handling Test (0.28 ± 0.27) and the Farmers’ Aggressiveness Score (-0.33 ± 0.23), respectively. Higher intake and visiting the feeder at busier times were genetically associated with sows’ higher aggressiveness towards humans. Pre-pubertal feeding strategies are promising indirect selection criteria for calmer sows.
We studied lifespan and lifetime reproductive success (LRS) in mice from a selection experiment that includes 4 replicate High Runner (HR) lines bred for voluntary wheel-running behavior and 4 non-selected Control (C) lines. HR mice typically run threefold farther on a daily basis, leading to substantially increased energy expenditure and food consumption, and are also more active and eat more when housed without wheels. HR and C mice have been shown to differ for many other traits that could affect reproduction, including body mass and composition, aerobic capacity, hormonal profile (including corticosterone and leptin), and other behavioral traits (e.g., maternal care, thermoregulatory nesting, anxiety-like behavior in an elevated plus maze). At generation 97, male–female pairs were maintained until end of life in standard cages without wheels, with ad lib food and water. The number of pups weaned (LRS) ranged from 0–80, with a mean of 29.1 ± 8.1 (SE) for C lines and 25.8 ± 4.4 for HR (P = 0.73). Thus, artificial selection for high voluntary exercise did not significantly alter LRS. In addition, we found no statistical difference in average lifespan for dams or sires. However, replicate lines differed significantly for several traits, presumably due primarily to random genetic drift. At the level of individual variation, correlations among reproductive traits and lifespan provided little evidence for negative associations, and LRS was not negatively related to parental longevity. Overall, long-term selection on voluntary locomotor behavior did not produce detectable reductions in reproductive output or lifespan under standard laboratory conditions.
Behavioral dysfunction is a common characteristic of many neurodevelopmental and mental health disorders. While the causes of these disorders vary, aberrant behaviors may arise from alterations in transcriptional regulation during early neural development. Because transcription factors (TFs) often belong to families of closely related members, disruption of a single TF may indirectly influence the functionality of other family members. Consequently, mutations in TFs within the same family may lead to overlapping, yet distinct, phenotypes. This feature of TF function has important implications for understanding behavioral phenotypes, but detailed analyses across a single TF family are still lacking. In this study, we present a comprehensive behavioral analysis of adult zebrafish harboring mutations in individual members of the TALE and Hox TF families, that are essential for nervous system development. Using a battery of validated behavioral assays, we uncover elevated stress responses among all TF mutant lines, as well as TF-specific dysregulation in social interaction, locomotion, and endurance. The shared behavioral abnormalities across mutants suggest TF family members converge on core developmental pathways for stress-related behavioral regulation, while mutation-specific phenotypes indicate unique roles for individual TFs in fine-tuning neural function. Our findings provide a systematic behavioral characterization of TALE and Hox mutants in a vertebrate model and provide a framework for understanding how genetic variation within TF families may differentially contribute to vulnerability for neurodevelopmental and mental health disorders.
Attention-deficit/hyperactivity disorder (ADHD) symptoms are strongly associated with lower academic performance, yet the nature of this association remains uncertain. We analyzed data from twins and siblings in the Adolescent Brain Cognitive Development (ABCD) Study® to examine the relationship between ADHD symptoms and school grades using genetically informed models. ADHD symptoms were assessed via the Child Behavior Checklist, and grades were caregiver-reported for the previous school year. Both phenotypes were modeled as ordinal variables. We applied Direction of Causation (DoC) and Mendelian randomization extensions (MR-DoC and MR-DoC2) incorporating polygenic risk scores for ADHD and educational attainment. DoC and MR-DoC comparisons did not distinguish directionality (e.g., DoC forward path estimate = − 0.16, 95
