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Results for “functional traits”

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PubMed2005

Impulsive-aggressive traits, serotonin function, and alcohol-enhanced aggression.

Although alcohol consumption is involved in most acts of violence, most people do not become violent when they drink. Individuals also respond differently to alcohol on laboratory measures of aggression. The objective of this study was to determine whether individual differences in the effects of alcohol on a laboratory measure of aggression are related to specific personality traits and/or serotonin function, as measured by prolactin response to pharmacochallenge. Psychometric scales for impulsiveness, aggression, and anger, as well as a probe for suspiciousness, were administered to 10 healthy male social drinkers. Trait serotonin function was determined by citalopram challenge. The effect of alcohol on the Point Subtraction Aggression Paradigm was determined by comparing aggression scores with and without 1 g/kg alcohol. Impulsivity scores were significantly correlated with the change in aggressive responding after alcohol. Aggression, anger, and suspiciousness scores were not. Prolactin response did not predict the effect of alcohol on aggressive responding. The results suggest that trait impulsiveness may mediate the effects of alcohol on aggression in normal males.

Adult↗

PubMed2026

Phylogenetic Constraints and Environmental Filtering Jointly Drive Adaptive Evolution in Phragmites australis: From Genetic Structure to Trait Decoupling on the Mongolian Plateau.

The Mongolian Plateau, a typical arid and semi-arid zone in Eurasia, is characterized by highly heterogeneous and fragmented wetland habitats. Phragmites australis, a common wetland species in this region, exhibits remarkable adaptability. Unraveling the coordination between phylogenetic history and local environmental filtering is crucial for elucidating its adaptive mechanisms. Integrating landscape genomics and trait-based phylogenetic analyses, we analyzed transcriptome-wide SNPs, multidimensional functional traits, and environmental variables across 90 individuals from 30 natural P. australis populations. This study aims to reveal the genetic and phenotypic variation patterns underlying population genetic structure and trait variation, specifically distinguishing the roles of geographic isolation, environmental filtering, and phylogenetic history. Results reveal a significant drainage-dependent pattern in genetic structure. Populations in hydrologically connected basins show extensive admixture, whereas those in isolated endorheic basins form distinct lineages. While geographic isolation underpins genetic differentiation, environmental filtering independently explains ~33.84% of the genetic variation, driven primarily by moisture heterogeneity (precipitation seasonality and soil moisture). Crucially, we observed differentiated evolutionary trajectories across functional traits. Structural traits (e.g., plant height, leaf thickness) are phylogenetically conserved; in contrast, physiological traits (e.g., water use efficiency) are decoupled from phylogeny, showing patterns consistent with high plasticity regulated by local environments. This evolutionary decoupling strategy enables P. australis to flexibly adapt to heterogeneous habitats while maintaining structural stability. This study uncovers the synergistic mechanisms by which geographic isolation and environmental filtering jointly shape the genetic patterns of this cosmopolitan species at a regional scale, clarifies that its evolutionary responses may depend heavily on the differentiated plasticity of trait types, and provides valuable regional insights into how widespread wetland species adapt to heterogeneous environments under global change.

Mongolia Plateau↗

PubMed2004

Analysis of the relationship between type traits and functional survival in US Holstein cattle using a Weibull proportional hazards model.

Survival analysis with a Weibull proportional hazards model was used to evaluate the effects of 15 linear type traits, 5 composite traits, and final score on the functional longevity of US Holstein cows. Culling data and type classification scores (measured in first lactation) from 891,524 cows with first calving from 1993 to 2000 were used. The data were divided into 9 geographical regions to determine whether the relationship between type traits and longevity differed according to climate or management system. Functional survival was defined as the number of days from first calving until culling or censoring, after correction for 305-d mature equivalent combined fat and protein yield. The Weibull model included time-dependent effects of herd-year-season, parity-stage of lactation, and within herd-year quintile ranking for combined fat and protein yield (nested within biennium), as well as time-independent effects of age at first calving and type classification score (type traits were analyzed one at a time). Type classification scores were rounded to the nearest 5 points, and the impact of each type trait on functional survival in each region was evaluated. Mean failure time ranged from 694 d in the South to 758 d in the North East. Risk of culling differed by region for several linear type traits, and differences were greatest for regions that were most dissimilar in climate and herd management (e.g., South East, East North Central, and West). Udder depth, fore udder attachment, udder cleft, and rear legs side view were consistently associated with functional longevity, regardless of region, but, the importance of some secondary traits, such as stature or dairy form, differed by region. The survival model applied in this study easily described both linear and nonlinear relationships between type traits and longevity while accounting for important time-dependent and time-independent explanatory variables.

Animals↗

PubMed1988

Phenotypic and genetic relationship between linear functional type traits and milk yield for five breeds.

Lactation records of cows first calving between 18 and 35 mo were combined with linear type ratings assigned during the same lactation if before 43 mo. Phenotypic relationships were examined between final score and 13 type appraisal traits and first lactation milk yield from 2935 Ayrshire, 3154 Brown Swiss, 13,110 Guernsey, 50,422 Jersey, and 924 Milking Shorthorn records. Most phenotypic correlations between type and milk yield were low. Linear correlations of final score with first lactation milk yield were .18 to .38. Of the linear functional type traits, correlations with first lactation yield had greatest absolute values for dairy character (.19 to .53), udder depth (-.26 to -.30), and rear udder width (.20 to .31). Multiple correlations of all type appraisal traits with first lactation milk yield ranged from .41 to .59. Herd-year-season components of variance averaged 25% for type traits. Herd-year-season with sire interaction averaged 4%. Heritability estimates for final score from paternal half-sib analysis were from .11 to .21. Heritability estimates for linear traits ranged from .01 to .37. Genetic correlation between milk and final score was positive for Guernseys (.25) and Jerseys (.21). Genetic correlations between yield and most linear type traits were low to moderate except for dairy character (.53 to .77).

Animals↗

PubMed2004

Effect of maternal age on milk production traits, fertility, and longevity in cattle.

Longevity is the economically most important functional trait in cattle populations. However, with an increased productive lifespan, the number of offspring born by older dams increases. A higher maternal age might have negative effects on the performance of offspring. The objective of this study was to investigate the effect of maternal age on production (energy-corrected milk yield [ECM]) and functional traits (fertility; somatic cell score, and functional longevity) in Austrian dual-purpose Simmental cows. Age of dam had a significant effect on ECM yield and longevity. The ECM yield of daughters decreased with age of dam. Although the risk of culling slightly increased with age of dam, it was lowest for daughters of oldest dams. Results for fertility were non-significant, and results for somatic cell scores were inconsistent across parities.

Aging↗

PubMed1998

Testis function, carcass traits, and aggressive behavior of beef bulls actively immunized against gonadotropin-releasing hormone.

We assessed testis function, aggressive behavior, and carcass traits in beef bulls actively immunized against GnRH at 1, 4, or 6 mo of age. In addition, we examined the effect of combining immunization with insertion of estrogen-containing implants (Synovex C) at 1 mo of age. Unimmunized bulls and steers were included as control animals. All immunized calves received a secondary immunization at 12 mo of age. Anti-GnRH titer was evident at slaughter in all immunized animals. Neither age at primary immunization nor implant status affected (P > .05) anti-GnRH titer at slaughter. Immunization, but not implant status, reduced (P < .05) serum concentration of testosterone and testis weight at slaughter. The final live weight and feedlot gain of immunized and unimmunized bulls were comparable (P > .05). In contrast, aggressive behavior was reduced (P < .05) and carcass quality was improved (P < .05) by immunization. These data suggest that active immunization against GnRH is a practical, noninvasive alternative to physical castration in the management of bull calves.

Aggression↗

PubMed2000

Statistical models for estimating the genetic basis of repeated measures and other function-valued traits.

The genetic analysis of characters that are best considered as functions of some independent and continuous variable, such as age, can be a complicated matter, and a simple and efficient procedure is desirable. Three methods are common in the literature: random regression, orthogonal polynomial approximation, and character process models. The goals of this article are (i) to clarify the relationships between these methods; (ii) to develop a general extension of the character process model that relaxes correlation stationarity, its most stringent assumption; and (iii) to compare and contrast the techniques and evaluate their performance across a range of actual and simulated data. We find that the character process model, as described in 1999 by Pletcher and Geyer, is the most successful method of analysis for the range of data examined in this study. It provides a reasonable description of a wide range of different covariance structures, and it results in the best models for actual data. Our analysis suggests genetic variance for Drosophila mortality declines with age, while genetic variance is constant at all ages for reproductive output. For growth in beef cattle, however, genetic variance increases linearly from birth, and genetic correlations are high across all observed ages.

Aging↗

PubMed1987

Pulmonary function in sickle cell trait.

Pulmonary function abnormalities, which have been reported to occur in persons with sickle cell trait (hemoglobin AS), could intensify the hypoxic stimulus for the systemic formation of sickle cells at high altitude. We sought to determine whether pulmonary function abnormalities occur as a result of exposure to high altitudes in persons with hemoglobin AS. In a prospective study, 13 men with hemoglobin AS ("cases") and 13 controls (hemoglobin AA) matched by age, sex, and race were exposed to five to seven altitude simulations (ranging from 1524 to 7620 m [5000 to 25,000 ft]) in a hypobaric chamber. Measurements of diffusing capacity for carbon monoxide (DLco), forced vital capacity, forced expiratory volume in one second, and forced midexpiratory flow were obtained before and after each exposure. Data before exposures did not differ statistically between cases and controls. Altitude had no systematic effect on DLco or spirometric values in cases compared with values in controls (p greater than 0.05). Individual declines in forced vital capacity or DLco of more than 10% occurred with similar frequency in both groups. Measurements made after the series of exposures showed no change from those made before. We conclude that short serial exposures to hypoxia at high altitudes does not acutely or cumulatively alter DLco or spirometric values in healthy, nonexercising persons with sickle cell trait.

Adult↗

PubMed2006

A bivariate quantitative genetic model for a threshold trait and a survival trait.

Many of the functional traits considered in animal breeding can be analyzed as threshold traits or survival traits with examples including disease traits, conformation scores, calving difficulty and longevity. In this paper we derive and implement a bivariate quantitative genetic model for a threshold character and a survival trait that are genetically and environmentally correlated. For the survival trait, we considered the Weibull log-normal animal frailty model. A Bayesian approach using Gibbs sampling was adopted in which model parameters were augmented with unobserved liabilities associated with the threshold trait. The fully conditional posterior distributions associated with parameters of the threshold trait reduced to well known distributions. For the survival trait the two baseline Weibull parameters were updated jointly by a Metropolis-Hastings step. The remaining model parameters with non-normalized fully conditional distributions were updated univariately using adaptive rejection sampling. The Gibbs sampler was tested in a simulation study and illustrated in a joint analysis of calving difficulty and longevity of dairy cattle. The simulation study showed that the estimated marginal posterior distributions covered well and placed high density to the true values used in the simulation of data. The data analysis of calving difficulty and longevity showed that genetic variation exists for both traits. The additive genetic correlation was moderately favorable with marginal posterior mean equal to 0.37 and 95% central posterior credibility interval ranging between 0.11 and 0.61. Therefore, this study suggests that selection for improving one of the two traits will be beneficial for the other trait as well.

Bayes Theorem↗

PubMed2000

Effect of time of day on intraindividual variability in ambulatory blood pressure.

The aim of this study was to determine whether intraindividual blood pressure (BP) variability, measured by noninvasive ambulatory monitoring, differs between the active (daytime) and inactive (nighttime) periods of the day. We obtained ambulatory BP recordings in 143 healthy adults (95 men, 48 women) from Rochester, Minnesota. Readings were obtained every 10 min for a 24-h period. We calculated the standard deviation of each individual's BP readings about the means for the active period and for the inactive period as measures of intraindividual BP variability. In men, mean within-individual standard deviations for both systolic (SBP) and diastolic blood pressure (DBP) were significantly greater during the inactive period than during the active period (for SBP: 10.3 +/- 2.1 v 11.9 +/- 2.7, P < .0001; for DBP: 8.8 +/- 2.0 v 9.7 +/- 2.5, P = .0027). In women, the mean within-individual standard deviation for SBP did not differ significantly between the active and inactive periods (9.7 +/- 2.2 v 10.3 +/- 2.4, P = 0.225) but for DBP was significantly greater during the inactive period than during the active period (8.1 +/- 2.0 v 9.2 +/- 2.3, P = .020). Statistically significant predictors of intraindividual BP variability included measures of age and body size, metabolic traits, neuroendocrine traits, erythrocyte cation traits, and renal function traits. This study demonstrates that intraindividual BP variability, as measured by noninvasive ambulatory monitoring, is as great or greater during the inactive period as during the active period of the day.

Adult↗

PubMed2002

Non-parametric exploratory analysis of the covariance structure for genetic analysis of repeated measures and other function-value traits.

In the analysis of longitudinal data, before assuming a parametric model, an idea of the shape of the variance and correlation functions for both the genetic and environmental parts should be known. When a small number of observations is available for each subject at a fixed set of times, it is possible to estimate unstructured covariance matrices, but not when the number of observations over time is large and when individuals are not measured at all times. The non-parametric approach, based on the variogram, presented by Diggle & Verbyla (1998), is specially adapted for exploratory analysis of such data. This paper presents a generalization of their approach to genetic analyses. The methodology is applied to daily records for milk production in dairy cattle and data on age-specific fertility in Drosophila.

Animals↗

PubMed1995

Reliability of psychophysiological responding as a function of trait anxiety.

This study examined the temporal stability of three psychophysiological responses (frontal electromyographic activity, hand surface temperature, and heart rate) recorded over four sessions (days 1, 2, 8, and 28) on 34 subjects, 17 with high Spielberger Trait Anxiety Inventory scores and 17 with low scores. Each session consisted of a 20-minute adaptation period, a baseline condition, and two stressors (one cognitive, the other physical). Two forms of reliability coefficients were employed, intraclass correlations and Pearson Product Moment; the two types of reliability coefficients arrived at the same conclusions. Results indicated that reliability coefficients for the two anxiety groups did not differ on frontal EMG or heart rate responses; however, hand surface temperature responding was considerably less reliable for high anxious individuals than low anxious individuals. Reliability coefficients on absolute scores were, for the most part, reliable. Treating the responses as relative measures (percent change from baseline or simple change scores from baseline) produced smaller and less reliable coefficients. Magnitudes of the three physiological responses did not significantly differ as a function of high or low trait anxiety. Findings are discussed in terms of their clinical, as well as basic psychophysiological, importance.

Adult↗

PubMed2000

Can relative spermatozoal galactosyltransferase activity be predictive of dairy bull fertility?

The best and poorest bovine semen samples used commercially for artificial insemination in dairy cattle typically differ in pregnancy rates by 20 to 25% but are within a range that pregnancy rates cannot be predicted consistently by commonly used laboratory assays. Sperm motility and morphology are the characteristics most often evaluated. Laboratory assays that measure other functional traits of sperm may be useful as supplemental assays to increase the reliability of predicting fertility. One such functional trait is the ability of sperm to bind to the zona pellucida, a process mediated by complementary receptors on each gamete. On mouse sperm, beta1,4-galactosyltransferase acts as a receptor for the zona pellucida. Beta1,4-galactosyltransferase is expressed on sperm from many mammals, including bovine sperm, and is a candidate for a zona pellucida receptor. The ability of sperm to bind to the zona pellucida may be related to the amount of beta1,4-galactosyltransferase present on sperm. The aim of this work was to determine if bull sperm beta1,4-galactosyltransferase activity was related to fertility. Beta1,4-galactosyltransferase enzyme assays were performed on sperm from 24 bulls whose fertility was estimated by nonreturn rate and on sperm from a second group of seven bulls whose fertility was ranked by in vivo competitive fertilization. Beta1,4-galactosyltransferase activity varied between individual bulls but was not correlated to fertility as estimated by nonreturn rate or by competitive fertilization. These results demonstrate that beta1,4-galactosyltransferase activity on sperm varies between animals, but that beta1,4-galactosyltransferase activity alone is not an accurate indicator of fertility in dairy bulls.

Animals↗

PubMed2026

Genome-wide association studies of plant traits and functional analysis of leaf development-related genes in citrus.

Labor-saving and high-light-efficiency tree architecture is a key breeding objective for woody fruit trees like citrus. However, population genetics information on these traits remains limited. In this study, tree architecture, thorn, and leaf traits were evaluated in 353 F2 progeny derived from a cross between Clementine mandarin and precocious trifoliate orange-an early-flowering variety. A random subset of 300 offspring was sequenced for a genome-wide association study (GWAS), which detected 10 216 significantly associated SNPs and defined several major quantitative trait loci (QTLs) for the target traits. Subsequent bulked segregant analysis (BSA) and GWAS on individuals with extreme compound leaf phenotypes mapped the causal gene(s) to a 0.8 Mb region (22.15-22.95 Mb) on chromosome 4. Genetic analysis across multiple hybrid combinations confirmed that the compound leaf trait in trifoliate orange is dominantly inherited and follows Mendelian segregation. Transcriptome profiling of parental leaves at different developmental stages identified a KNOX gene, CiKNAT6, as a candidate. Further validation using CAPS markers and Hi-Tom sequencing demonstrated tight linkage between an InDel polymorphism in CiKNAT6 and leaf shape across diverse citrus species and the F2 population, with co-segregation observed for the compound leaf trait. Due to alternative splicing producing seven splice variants, the CiKNAT6 DNA sequence was selected for genetic transformation experiments. Functional analysis revealed that the Clementine mandarin allele of CiKNAT6 is non-functional owing to an InDel, whereas ectopic expression of the trifoliate orange allele in tobacco and lemon induced leaf curling and reduced leaf size. CRISPR-Cas9 knockout of CiKNAT6 in trifoliate orange resulted in increased leaf area. These findings provide valuable genetic resources and insights for future studies on tree architecture and leaf morphology.

Plant Leaves↗

PubMed2005

Tryptophan depletion disrupts the motivational guidance of goal-directed behavior as a function of trait impulsivity.

Serotonin (5-HT) is well known to affect the motivational properties of stimuli predictive of rewards as well as the inhibitory control of behavior. Here, central 5-HT depletion was induced by the acute tryptophan (TRP) depletion (ATD) procedure in young healthy volunteers to examine the role of 5-HT in motivated action and prepotent response inhibition. A novel reaction-time task, tailored to individual differences in general cognitive speed, was employed to measure the guidance of behavior by motivationally relevant signals predictive of reinforcement likelihood, while the stop-signal reaction-time task was used to measure response inhibition. Following the TRP-balancing control drink, cues predictive of high-reinforcement certainty induced faster, but less accurate responses compared with cues predictive of lower reinforcement certainty. Depletion of central 5-HT modulated this coupling between motivation and action by slowing responses and increasing accuracy as a function of incentive certainty. These effects of ATD on motivated action correlated highly with individual differences in the personality trait of Nonplanning Impulsiveness (Barratt Impulsivity Scale (BIS-11)), so that strongest effects on motivated action were observed in high-impulsive individuals. By contrast, ATD left unaltered the ability to inhibit prepotent responses. Our findings may have implications for a variety of neuropsychiatric disorders including impulsive aggressive disorders and depression.

Adult↗

PubMed2026

Genome-Resolved Metagenomics Revealed the Functional Potential of Core Novel and Known Genera Key to Processes in Full-Scale Aerobic Granular Sludge Plants.

Microbial communities are critical for nutrient removal in aerobic granular sludge (AGS) wastewater treatment plants (WWTPs). Despite the stable long-term operation of full-scale AGS WWTPs, the microbial populations and functional traits sustaining stable long-term performance remain poorly resolved. To address this gap, the recovered MAG catalog from nine full-scale AGS WWTPs across five countries was analyzed. From this catalog, 74 high-quality core MAGs were identified and used for downstream taxonomic characterization and functional analyses. These high-quality core MAGs spanned 48 established and 7 novel genera, representing 31 known and 43 novel species. Functional analysis linked core MAGs to key WWTP processes: polyphosphate accumulation (9), glycogen accumulation (12), denitrification (62), and nitrification (1). These included four novel MAGs with glycogen-accumulating (3) and polyphosphate-accumulating (1) potential and 11 capable of nitrous oxide reduction, critical for mitigating greenhouse gas emissions. Ca. Phosphoribacter was the most abundant genus, highlighting its underestimated role caused by misclassification as Tetrasphaera in 16S rRNA surveys. Specifically, Ca. P. hodrii was the dominant species, exhibiting enhanced sugar uptake and amino acid synthesis as likely drivers of its enrichment in the AGS WWTPs. Overall, this study resolves for the first time the taxa and functional traits consistently enriched in full-scale AGS systems, enabling a shift from an empirical performance assessment toward biologically informed process interpretation.

Sewage↗

PubMed2006

Discovery of quantitative trait loci for resistance to parasitic nematode infection in sheep: I. Analysis of outcross pedigrees.

BACKGROUND: Currently most pastoral farmers rely on anthelmintic drenches to control gastrointestinal parasitic nematodes in sheep. Resistance to anthelmintics is rapidly increasing in nematode populations such that on some farms none of the drench families are now completely effective. It is well established that host resistance to nematode infection is a moderately heritable trait. This study was undertaken to identify regions of the genome, quantitative trait loci (QTL) that contain genes affecting resistance to parasitic nematodes. RESULTS: Rams obtained from crossing nematode parasite resistant and susceptible selection lines were used to derive five large half-sib families comprising between 348 and 101 offspring per sire. Total offspring comprised 940 lambs. Extensive measurements for a range of parasite burden and immune function traits in all offspring allowed each lamb in each pedigree to be ranked for relative resistance to nematode parasites. Initially the 22 most resistant and 22 most susceptible progeny from each pedigree were used in a genome scan that used 203 microsatellite markers spread across all sheep autosomes. This study identified 9 chromosomes with regions showing sufficient linkage to warrant the genotyping of all offspring. After genotyping all offspring with markers covering Chromosomes 1, 3, 4, 5, 8, 12, 13, 22 and 23, the telomeric end of chromosome 8 was identified as having a significant QTL for parasite resistance as measured by the number of Trichostrongylus spp. adults in the abomasum and small intestine at the end of the second parasite challenge. Two further QTL for associated immune function traits of total serum IgE and T. colubiformis specific serum IgG, at the end of the second parasite challenge, were identified on chromosome 23. CONCLUSION: Despite parasite resistance being a moderately heritable trait, this large study was able to identify only a single significant QTL associated with it. The QTL concerned adult parasite burdens at the end of the second parasite challenge when the lambs were approximately 6 months old. Our failure to discover more QTL suggests that most of the genes controlling this trait are of relatively small effect. The large number of suggestive QTL discovered (more than one per family per trait than would be expected by chance) also supports this conclusion.

Animals↗

PubMed2006

A method to define breeding goals for sustainable dairy cattle production.

The objective of this study was to present a method to define breeding goals for sustainable dairy cattle production by adding nonmarket values to market economic values for functional traits in the breeding goal. A nonmarket value can represent the value of improved animal welfare or societal influences for animal production. The nonmarket value for mastitis resistance, conception rate, and stillbirth were derived based on how much farmers or breeding companies were willing to lose in selection response for milk yield to improve functional traits. The desired response for milk yield corresponding to a given percent loss was obtained using desired gain indices. By allowing a 5% loss in the selection response for milk yield, the nonmarket value was found to be 40.4 euro for mastitis resistance, 16.1 euro for conception rate, and 9.7 euro for stillbirth. The nonmarket value increased proportionally with increasing loss in the selection response for milk yield, but the selection response was lower for conception rate than for mastitis resistance because of differences in market economic value and heritability. To increase the response for conception rate, the nonmarket value was also derived for 2 situations, in which the desired responses for milk yield, mastitis resistance, and conception rate were specified. The method can be used to define breeding goals for sustainable production and to increase the response for traits that are at critically low levels. When defining breeding goals for sustainable production, breeding organizations should predict the selection response based on market economic value and add non-market value for traits with unacceptable selection responses.

Animals↗