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At least 19 recordsLinked to original sources
PubMed2005

Maternal trait anxiety, depression and life event stress in pregnancy: relationships with infant temperament.

AIMS: To assess whether links exist between maternal trait anxiety (STAI), perceived life event (LE) stress and depression (Edinburgh scale) and infant temperament. STUDY DESIGN AND SUBJECTS: Women in the third trimester of pregnancy returned psychological self-report questionnaires; infant temperament was evaluated at 4 and 6 months by maternal and paternal report, while depression (concurrent Edinburgh scale) was also assessed at four and six months. As data were returned inconsistently at 4 and 6 months, we combined these two time points for simplicity of reporting and optimisation of numbers. RESULTS: Univariate logistic regressions on 970 subjects indicated that the pregnancy STAI (>40) scores were associated with 2.56- and 1.57-fold increases (maternal and paternal, respectively), in the odds of "difficult" infant temperament at 4 or 6 months. Concurrent Edinburgh scores (OR of 3.06 and 2.64 for maternal reports, respectively) were also predictive of infant temperament. Age, education, income, marital status, obstetric complications, infant gender and prematurity were not predictive of infant temperament. In stepwise multiple logistic regression analyses, the antenatal trait STAI (odds ratio 1.96) significantly predicted maternal reports of "difficult" temperament at 4 or 6 months independent of both antenatal and postnatal depression scores. There were similar trends for paternal reports of "difficult" temperament but these were not significant. Antenatal depression and perceived LE stress were not predictive of temperament. Finally, women (N=14) reporting domestic violence (DV) in pregnancy had highly significant increased Edinburgh and STAI scores. CONCLUSIONS: Maternal trait anxiety was predictive of "difficult" infant temperament, independent of "concurrent" depression and key sociodemographic and obstetric risk factors. These findings, while needing replication using objective measures of infant temperament, suggest that antenatal psychological interventions aimed at minimising anxiety may optimize infant temperament outcomes. There may be some benefit in shaping specific interventions to women reporting specific risk factors such as DV or past abuse.

Anxiety Disorders↗
PubMed1985

Additive and heterosis effects on preweaning traits, maternal ability and reproduction from crossing of the Angus and brown Swiss breeds in Florida.

Angus (A), Brown Swiss (S) and A X S reciprocal F1 (AS) dams were mated to A, S and AS (also reciprocal F1) sires resulting in nine breed groups of progeny with varying proportions of Angus and Brown Swiss breeding. Breed group of dam and of sire significantly influenced birth weight, preweaning daily gain, weaning weight, 205-d weight, condition score and frame size. The means for birth weight and weaning weight were 33 and 213 kg, respectively. Brown Swiss bulls sired calves with the heaviest birth and weaning weights. Calves produced by S dams likewise were heavier at birth and weaning. Pregnancy rates were influenced significantly by year, age and breed of dam and averaged 79, 95 and 92% for S, AS and A cows, respectively. Survival rate averaged 97% and was not influenced significantly by any of the effects examined. Because survival rates were similar for all breed groups, the results for weaning rate paralleled those for pregnancy rate. Genetic influences on preweaning growth traits and survival rate were partitioned into additive breed differences (B) and heterosis (H) effects for direct (d) and maternal (m) components. Pregnancy and weaning rates were examined using similar analyses except that genotype of service sire of dam replaced that of the offspring for the direct additive breed and direct heterosis components. The Bd values indicated that the Angus breed was inferior (P less than .01) to the Brown Swiss breed for all preweaning growth traits except for condition score, in which the Angus breed surpassed (P less than .01) the Brown Swiss. The Bm values also showed an advantage for the Brown Swiss breed for all preweaning growth traits. The additive maternal effect (the genotype of the females exposed), Bm, was important for pregnancy rate and weaning rate (P less than .001 and P less than .05) but not for survival rate (P greater than .10). The direct additive breed effect was not important for any reproductive trait. Direct heterosis did not affect any of the preweaning or reproduction traits; however, maternal heterosis (Hm) significantly affected all traits except birth weight, frame score and survival rate. The Hm estimates were 12.0 and 8.4 kg for weaning weight and 205-d weight, respectively. The Hm estimates for pregnancy rate, survival rate and weaning rate were 10, 2 and 13%, respectively.

Animals↗
PubMed1992

Heterosis and recombination effects in Hampshire and Landrace swine: I. Maternal traits.

Hampshire and Landrace sows and crossbreds of the two breeds were used to determine heterosis and recombination effects for milk production, milk composition, and litter traits at birth and d 21. Twelve mating types were represented in this study: two purebred, two F1, two F2, two F3, and four backcross. Information was gathered on a total of 358 litters over four farrowing seasons. Milk production was measured at d 10 and 20 of litter age according to the weigh-suckle-weigh procedure. Milk samples were collected at d 10 and 20 of litter age and evaluated for percentages of fat (PCFA), protein (PCPR), lactose (PCLA), and solids-not-fat (PCSN). The model used to evaluate litter traits at birth included main effects of mating type, parity, and farrowing season. The model used for milk production and milk composition traits included these main effects and number of pigs nursed as a covariate. Estimates of maternal genetic effects showed that Landrace females were superior to Hampshire females for number born (NB), number born alive (NBA), litter birth weight (LBW), adjusted 21-d litter weight (ALW), and milk production at d 10 of litter age (WT10). Hampshires were superior to Landrace for PCPR at d 10 of litter age and PCSN at d 10 and 20 of litter age. Heterosis effects were significant (P less than .05) for NBA (.97) and LBW (1.46 kg). Maternal heterosis effects were significant for LBW (3.94 kg; P less than .01). Epistatic recombination losses in the offspring were significant for LBW (6.80 kg; P less than .05). Differences in maternal performance of reciprocal F1 dams were generally not significant. Heterosis and recombination effects were not significant for milk production or milk composition.

Animals↗
PubMed1992

Breed effects and heterosis in advanced generations of composite populations for reproduction and maternal traits of beef cattle.

Heterosis effects in F1 dams producing F2 progeny and retained heterosis in combined F2 and F3 dams producing F3 and F4 progeny were evaluated in dams 2 yr old, in dams greater than or equal to 5 yr old, and in dams of all ages. Traits included pregnant percentage, calf crop born percentage, calf crop weaned percentage, 200-d calf weight per heifer or cow exposed, and 200-d calf weight. Breed effects were evaluated in the nine parental breeds (Red Poll [R], Hereford [H], Angus [A], Limousin [L], Braunvieh [B], Pinzgauer [P], Gelbvieh [G], Simmental [S], and Charolais [C]) that contributed to the three composite populations (MARC I = 1/4 B, 1/4 C, 1/4 L, 1/8 H, 1/8 A; MARC II = 1/4 G, 1/4 S, 1/4 H, 1/4 A; and MARC III = 1/4 R, 1/4 P, 1/4 H, 1/4 A). Breed effects were significant for all traits evaluated in the three age groupings and generally were greatest in 2-yr-old dams and smallest in dams greater than or equal to 5 yr old. Heterosis effects for 200-d calf weight were relatively uniform among age groupings and among the three composite populations and heterosis retained was equal to, or greater than, expectation based on retained heterozygosity. Heterosis effects in animals of all ages for reproductive traits in F1 dams producing F2 progeny differed among the three composite populations, as did heterosis retained in combined F2 and F3 dams producing F3 and F4 progeny. In dams of all ages, heterosis retained for reproductive traits in F2 and F3 dams producing F3 and F4 progeny did not differ (P greater than .05) from expectation based on retained heterozygosity in two of the three composite populations, but loss of heterosis was greater (P less than .05) than expectation based on retained heterozygosity in one of the three composite populations for calf crop born percentage, calf crop weaned percentage, and 200-d calf weight per heifer or cow exposed. This reduction was the result of increased fetal loss between pregnancy diagnosis and parturition.(ABSTRACT TRUNCATED AT 400 WORDS)

Age Factors↗
PubMed1980

Inheritance of teat number and its relationship to maternal traits in swine.

The relationship of teat number to seven measures of female reproduction was evaluated in the University of Nebraska Gene Pool population. Teat number was recorded for 7,513 pigs, ovulation rate for 2,794 gilts and litter size and weight at birth and weaning (42 days) for 789 gilts. Paternal half-sib and full-sib analyses were used to estimate heritabilities for each trait and to estimate the genetic and phenotypic correlations of teat number with the measures of reproduction. The direct response to selection for ovulation rate and the correlated response in teat number were also evaluated from the regressions of line differences (Select-Control) on generation number (10 generations of selection) and cumulative selection differential for ovulation rate. The paternal half-sib heritabililty for teat number was .32, and the paternal half-sib heritabilities for ovulation rate and the litter traits were similar to previous estimates from this population. Most of the genetic and phenotypic correlations with teat number were negative and all were nonsignificant. The realized heritability for ovulation rate was .46 +/- .10. The regression of response in teat number on generation number number was .08 +/- .03 (P < .10). An estimate of .44 was obtained for the realized genetic correlation of teat number with ovulation rate.

Animals↗
PubMed2004

Heritability of progeny size in a terrestrial isopod: transgenerational environmental effects on a life history trait.

Maternal effects, the environment that mothers provide to their offspring, their provision of nutrients and the environment that offspring of the same clutch share, have come to be recognized as an important influence on offspring fitness. In addition, in invertebrates, maternal effects and common environment may change according to a mother's diet. We tested for the changes in quantitative genetic parameters in a half-sib design where mothers were fed diets varying in nutrient content. Surprisingly, we found that not only maternal and common environmental variance changed with experimental diets but also there were significant changes in narrow-sense heritabilities, with corresponding h(2) values of 0.61 (high protein), 0.08 (high carbohydrate) and 0.001 (equal carbohydrate:protein). Our results show how an environmentally driven evolutionary process could occur in nature, since the response to selection could change dramatically according to the composition of the diet that females are ingesting.

Animal Feed↗
PubMed2006

Complex social behaviour derived from maternal reproductive traits.

A fundamental goal of sociobiology is to explain how complex social behaviour evolves, especially in social insects, the exemplars of social living. Although still the subject of much controversy, recent theoretical explanations have focused on the evolutionary origins of worker behaviour (assistance from daughters that remain in the nest and help their mother to reproduce) through expression of maternal care behaviour towards siblings. A key prediction of this evolutionary model is that traits involved in maternal care have been co-opted through heterochronous expression of maternal genes to result in sib-care, the hallmark of highly evolved social life in insects. A coupling of maternal behaviour to reproductive status evolved in solitary insects, and was a ready substrate for the evolution of worker-containing societies. Here we show that division of foraging labour among worker honey bees (Apis mellifera) is linked to the reproductive status of facultatively sterile females. We thereby identify the evolutionary origin of a widely expressed social-insect behavioural syndrome, and provide a direct demonstration of how variation in maternal reproductive traits gives rise to complex social behaviour in non-reproductive helpers.

Aging↗
PubMed1989

Variance heterogeneity in direct and maternal weight traits by sex and percent purebred for Simmental-sired calves.

Phenotypic variances for linear and transformed weight traits were partitioned into residual, direct genetic (D) and maternal genetic (M) components using REML techniques with American Simmental Association data from calves born 1969 to 1985. Variance components were estimated separately from subclasses defined by sex (male, female) and percent Simmental (50, greater than or equal to 75). The model included fixed effects of contemporary group and age-of-dam (less than 3, 3 to 5, greater than 5 yr). Additive relationships among sires and maternal grandsires were included. Results follow for a sire-maternal grandsire model for greater than or equal to 75% Simmental untransformed data based on 143,280 male and 281,805 female weaning weights (WW) representing 4,763 and 7,406 sires, respectively. Female results are bracketed. For computational simplification, 47,650 [30,909] postweaning gain (PW) records were included in the analysis only for 114,404 [182,255] calves with birth weight (BW). Phenotypic standard deviations (kg) were: BW, 4.5 [4.1]; WW, 26.9 [23.2]; and PW, 25.9 [19.9]. Heritabilities were: BWD, .40 [.45]; WWD, .32 [.39]; PWD, .26 [.32]; BWM, .13 [.15]; WWM, .20 [.16]; and PWM, .01 [.01]. These heritabilities are higher than previously used for genetic evaluations in this breed. Moderate and positive correlations .26 to .50, existed between direct effects and were similar for both sexes. Direct and maternal effects on the same trait were correlated negatively: BW, -.45 [-.31]; and WW, -.27 [-.34]. Genetic correlation between BWM and WWM was .53 [.49]. First-cross progeny exhibited less genetic and residual variation and had lower heritabilities than Simmental calves of higher percent. Correlations between sire evaluations on the subsets were consistent with those expected given a perfect genetic correlation between traits for each sex and percent Simmental. Logarithmic transformed records were no more homogeneous than untransformed records.

Analysis of Variance↗
PubMed1990

Selection response in traits with maternal inheritance.

Maternal inheritance is the non-Mendelian transmission of traits from mothers to their offspring. Despite its presence in virtually all organisms, acting through a variety of mechanisms, the evolutionary consequences of maternal inheritance are not well understood. Here we review and extend a model of the inheritance and evolution of multiple quantitative characters with complex pathways of maternal effects. Extensions of the earlier model include common family environmental effects not associated with maternal phenotype, sexual dimorphism, and paternal effects (non-Mendelian influence of the father on offspring traits). We find that, in contrast to simple Mendelian inheritance, maternal inheritance produces qualitatively different evolutionary dynamics for two reasons: (1) the response to selection on a set of characters depends not only on their additive genetic variances and covariances, but also on maternal characters that influence them, and (2) time lags in the response to selection create a form of evolutionary momentum. These results have important implications for evolution in natural populations and practical applications in the economic improvement of domesticated species. We derive selection indices that maximize either the economic improvement in a single generation of artificial selection or the asymptotic rate of improvement in long-term selection programmes, based on individual merit or a combination of individual and family merit. Numerical examples show that accounting for maternal inheritance can lead to considerable increases in the efficiency of artificial selection.

Animals↗
PubMed1981

Polygamy: a cultural trait and maternal and child health.

This study indicates that it is probable that the cultural trait of polygamy was instituted as an adaptive measure in a particular ecology within a particular tribal group. Polygamy perpetuated because of its positive contribution to maternal and child health. The study further indicates that it is also probable that monogamy as a foreign cultural trait and its introduction without concomitant changes in other spheres of the ecosystem (biophysical and social environment) must have produced a negative effort on maternal and child health. The particular ecosystem is described and its effects on maternal and child health are pointed out.

Africa, Western↗
PubMed2000

Selection against late emergence and small offspring in Atlantic salmon (Salmo salar).

Timing of breeding and offspring size are maternal traits that may influence offspring competitive ability, dispersal, foraging, and vulnerability to predation and climatic conditions. To quantify the extent to which these maternal traits may ultimately affect an organism's fitness, we undertook laboratory and field experiments with Atlantic salmon (Salmo salar). To control for confounding effects caused by correlated traits, manipulations of the timing of fertilization combined with intraclutch comparisons were used. In the wild, a total of 1462 juveniles were marked at emergence from gravel nests. Recapture rates suggest that up to 83.5% mortality occurred during the first four months after emergence from the gravel nests, with the majority (67.5%) occurring during the initial period ending 17 days after median emergence. Moreover, the mortality was selective during this initial period, resulting in a significant phenotypic shift toward an earlier date of and an increased length at emergence. However, no significant selection differentials were detected thereafter, indicating that the critical episode of selection had occurred at emergence. Furthermore, standardized selection gradients indicated that selection was more intense on date of than on body size at emergence. Timing of emergence had additional consequences in terms of juvenile body size. Late-emerging juveniles were smaller than early-emerging ones at subsequent samplings, both in the wild and in parallel experiments conducted in seminatural stream channels, and this may affect success at subsequent size-selective episodes, such as winter mortality and reproduction. Finally, our findings also suggest that egg size had fitness consequences independent of the effects of emergence time that directly affected body size at emergence and, in turn, survival and size at later life stages. The causality of the maternal effects observed in the present study supports the hypothesis that selection on juvenile traits may play an important role in the evolution of maternal traits in natural populations.

Animals↗
PubMed2026

Weathering the storm: Most maternal and environmental drivers of individual reproductive success do not scale up to population recruitment in a large herbivore.

Population growth depends upon individual survival and reproduction, but do drivers of individual reproductive success scale up to population recruitment? Factors affecting individuals may have little effect on population dynamics if individuals within a population experience different conditions. When seasonal resource availability is unpredictable and breeding season long, average conditions over a breeding cycle may poorly reflect the environment experienced by many individuals. We compared the drivers of individual reproductive success and population recruitment in an asynchronously breeding large herbivore, the eastern grey kangaroo (Macropus giganteus). We analysed 18&#x2009;years of individual-based data using multivariate hierarchical Bayesian models to first identify the causal mechanisms relating population density, environmental conditions and maternal traits to individual success. We then assessed whether the drivers of individual reproductive success scaled up to determine population recruitment. Most maternal and environmental covariates strongly influenced individual reproductive success, with distinct effects on juvenile survival before and after pouch exit. Maternal traits had a greater influence in the pouch, whereas environmental conditions became increasingly important once young exited the pouch. Most drivers of individual reproductive success did not affect population recruitment. Recruitment increased with population density and mean body condition of adult females. Weather harshness had a weak positive effect on recruitment, which appeared independent of female age structure, previous recruitment or forage. Most drivers of individual reproductive success did not scale up to population recruitment. Birth asynchrony could buffer population recruitment against environmental variation such that variables affecting individual reproduction have little impact at the population level. Large herbivores that reproduce asynchronously may therefore be more resilient to environmental variability than synchronous breeders.

Bayesian modelling↗
PubMed1991

Genetic improvement programs in livestock: swine testing and genetic evaluation system (stages).

Genetic evaluations for the U.S. swine industry are conducted by the eight purebred associations of the National Association of Swine Records. Within-herd evaluations of the growth traits (days to 105 kg [market] and backfat depth) were first reported in 1986. Analyses of the maternal traits (litter size at birth and weaning, and litter 21-d weight) were inaugurated in 1987. Expected progeny differences (EPD) are reported for all traits and for general, paternal, and maternal bioeconomic indexes. A sow productivity index combining only maternal traits is available. All records are adjusted according to National Swine Improvement Federation (NSIF) guidelines for effects such as number of pigs transferred at crossfostering and age at recorded observation prior to the BLUP evaluation. Within-herd analyses of individual contemporary groups are conducted immediately on receipt of performance records at each breed association office. All parents in the herd and the young pigs in the current group are evaluated. A report is returned to the breeder for use in herd selection and the EPD are placed in the pedigree file. The genetic base of each herd is defined as the first n tested pigs or litters, where n is the number of pigs registered annually within the herd. Change in mean EPD between groups is indicative of genetic trend. Periodic across-herd analyses are used to update interim within-herd analyses and a national sire summary is published.

Animals↗
PubMed1991

Temperament and family characteristics as predictors of children's reactions to hospitalization.

Findings from a study of 47 children 4 to 12 years old who received tonsillectomies at a children's hospital indicated that adjustment before hospitalization was the strongest predictor of postsurgical adjustment. However, certain temperamental and mother-child relationship factors also were strongly related to and predictive of posthospitalization outcomes. Children who displayed the most positive reactions were temperamentally more rhythmical (i.e., had regular, predictable behavior), more approaching to new experiences and people, more adaptable to change and positive in mood, and more responsive. Although family adaptability and cohesion were not significantly associated with children's reactions to hospitalization, maternal trait anxiety and maternal overprotection, rejection, and overindulgence of the child were correlated with poorer adjustment. The findings have practical implications to helping children adjust more effectively to surgery and hospitalization, and they contribute to our understanding of resiliency and vulnerability in children.

Adaptation, Psychological↗
PubMed2001

Approximation of reliabilities for multiple-trait model with maternal effects.

Reliabilities for a multiple-trait maternal model were obtained by combining reliabilities obtained from single-trait models. Single-trait reliabilities were obtained using an approximation that supported models with additive and permanent environmental effects. For the direct effect, the maternal and permanent environmental variances were assigned to the residual. For the maternal effect, variance of the direct effect was assigned to the residual. Data included 10,550 birth weight, 11,819 weaning weight, and 3,617 postweaning gain records of Senepol cattle. Reliabilities were obtained by generalized inversion and by using single-trait and multiple-trait approximation methods. Some reliabilities obtained by inversion were negative because inbreeding was ignored in calculating the inverse of the relationship matrix. The multiple-trait approximation method reduced the bias of approximation when compared with the single-trait method. The correlations between reliabilities obtained by inversion and by multiple-trait procedures for the direct effect were 0.85 for birth weight, 0.94 for weaning weight, and 0.96 for postweaning gain. Correlations for maternal effects for birth weight and weaning weight were 0.96 to 0.98 for both approximations. Further improvements can be achieved by refining the single-trait procedures.

Animals↗
PubMed2005

Genetic basis and consequences of niche construction: plasticity-induced genetic constraints on the evolution of seed dispersal in Arabidopsis thaliana.

Because seed dispersal influences the environment experienced by seeds, that environment can change as dispersal evolves. The evolutionary potential of dispersal can in turn change as dispersal evolves, if its expression of genetic variation depends on the postdispersal environment. We examined whether seed dispersion patterns have a detectable genetic basis (and therefore evolutionary potential) and determined whether that genetic basis changed depending on one postdispersal environmental factor: conspecific density. We grew replicates of 12 ecotypes of Arabidopsis thaliana at high and low density and measured seed dispersion patterns and maternal traits associated with dispersal under controlled conditions. We found density-dependent ecotypic variation for maternal traits that influence dispersal. Significant genetic variation for postdispersal sibling density was detected only when plants were grown at high density, suggesting that if dispersal evolves to result in lower postdispersal densities, the expression of genetic variation for dispersal would be reduced. This dynamic could lead to a plasticity-induced constraint on the evolution of dispersal. The ability of organisms to alter the environment they experience and the ability of that environment to evolve can alter evolutionary dynamics by augmenting or reducing evolutionary potential and thereby facilitating or constraining evolutionary responses to selection.

Arabidopsis↗