Showing papers in "Behavior Genetics in 1988"

Differences between inbred strains of mice in Morris water maze performance.

Abstract: Four inbred strains of mice, BALB/cByJ, C3H/2Ibg, C57BL/6Ibg, and DBA/2Ibg, were tested for their learning ability in the Morris water maze. Two forms of learning were examined: cue learning, in which the mice were required to swim toward a submerged platform marked by a proximal visual cue; and place learning, in which the animals were required to use distal visual cues to find a submerged platform. C3H and BALB mice, which lack good visual acuity, were incapable of either form of learning. Both C57 and DBA mice were capable of cue learning, but DBA mice performed poorly at the place learning task. A selective impairment in place learning is typical of rats with disrupted hippocampal function. A similar impairment in DBA mice may indicate that abnormal hippocampal function exists under baseline conditions in this strain.

Kin recognition in birds.

Abstract: I develop the argument that for a true kin recognition system to evolve, selection must act on both parties: not only must recognition be favored in the donor of care, but reliable identification must be favored in the potential recipient of the care. This perspective suggests two complementary hypotheses, which I discuss and evaluate with data drawn from studies of birds. According to thesignature adaptation hypothesis, when the sender benefits by reliably identifying itself, selection will act directly on phenotypic characters so as to enhance their signature properties. I summarize our studies on parent-offspring recognition in four species of swallows which are consistent with this hypothesis. In particular, acoustical and perceptual analyses of chick calls show that the calls of colonial swallows are more individually distinctive than are the chick calls of noncolonial swallows. According to theantirecognition hypothesis, when the sender doesnot benefit by reliably identifying itself, selection will act so as to minimize signature characteristics. I suggest two contexts for research on this hypothesis. The first context occurs when parentage is uncertain due to extrapair copulations and/or egg-dumping, and the second context occurs when there is a long period between the onset of chick mobility and chick fledging, as occurs typically in gulls. In both instances, parents will be favored to recognize genetic relatedness of offspring but offspring will be favored to conceal it. To date, data from bird studies are consistent with the prediction that the interests of chicks win out in this situation.

Water-maze learning in the mouse correlates with variation in hippocampal morphology.

Abstract: We studied mouse learning performance in a water-maze task in order to explore the relations between heritable structural variation in the hippocampus and spatial learning abilities. Based on previous findings we hypothesized a relation between spatial learning abilities and the size of the intra- and infrapyramidal mossy fiber (iip-MF) terminal field. Factor analysis revealed that learning in this water maze has two components: one related to apparatus-induced activity and one related to maze-learning ability. The size of the iip-MF terminal field covaried negatively with the activity-related component but positively with the spatial-learning component. These findings are in agreement with previous results obtained for shuttle-box learning.

Inference about genetic correlations.

Abstract: In polygenic systems genetic correlations and the factors and specific genetic variances from genetic correlation matrices are often interpreted in terms of sets of genes common or specific to variables. While these inferences may indeed be true, a genetic correlation is not always sufficient evidence for the inferences. In some cases two variables with all genes in common can have low genetic correlations, and systems with only a few genes in common can have high genetic correlations. The assumptions about genic effects in polygenic systems and their effects on a genetic correlation are explicated and discussed. It is suggested that a distinction be made betweenbiological pleiotropism andstatistical pleiotropism to promote more accurate communication about the genetic associations among traits.

Resolving causes of developmental continuity or "tracking." I. Longitudinal twin studies during growth.

Abstract: Models of developmental continuity and change in quantitative phenotypes may be tested using longitudinal data from twins. We illustrate a procedure for establishing the power and required sample sizes for detecting developmental transmission against an alternative common-factor hypothesis. We explore the general effects of different heritabilities, different fidelities of environmental and genetic developmental transmission, and varying numbers of occasions of measurement. In addition, a constraint of wide application is postulated for the action of the environment; either environmental effects are transmitted (learned) and occasion specific or they exert a constant influence which is not transmitted (learned). While the situations we examine are necessarily restricted here, our explorations of power show that, providing that we measure on at least four occasions, it is easy to detect developmental transmission with workable sample sizes.

Assortative mating for IQ and personality due to propinquity and personal preference.

Abstract: The role of personal preference as an active process in mate selection is contrasted with the more passive results of limitations of available mates due to social, educational, and geographical propinquity The role of personal preference estimated after removing the effects of variables representing propinquity was still significant for IQ and Eysenck's extraversion-introversion and inconsistency (lie) scales, even though small

Preweaning experience in the control of mating preferences by genes in the major histocompatibility complex of the mouse.

Abstract: The major histocompatibility complex (MHC) of genes of the mouse influences mate choice. Typically, inbred males prefer to mate with females that differ from themselves at this gene complex. Previous studies documenting differences between mating preferences of inbred and F2-generation males, as well as a possible effect of ambient mouse odors on preference, indirectly implicate rearing history as an influence in the determination of mating preference according to MHC types. To test directly the role of rearing history, entire litters were fostered onto parents of the same or different MHC types. Fostering of males onto parents of different MHC types reversed the natural preference; under these conditions, matings with females of the same MHC type as the fostered male were more frequent. Thus, male mating bias appears to be acquired during early development through exposure to parental MHC-controlled signals. Preliminary studies of mating biases in fostered females demonstrated a mating bias that was unaffected by fostering experiences. These studies indicate that the same set of genes involved in regulation of immune function also determines, in part, mate choice. A male bias in favor of females whose MHC types differ from the male's parental MHC types could serve to promote heterozygosity at the MHC.

A Developmental-Genetic Analysis of Aggressive Behavior in Mice. II. Cross-Sex Inheritance

Abstract: Differences in aggression produced by selective breeding for differential aggressiveness among male mice are also inherited by females: the expression of these differences in female mice depends on the conditions of assessment. In the standard opponents tests after isolation housing, consistent line differentiation was clear in males to the S 8 generation, but no aggressive behavior occurred at all in female tests. In contrast, in postpartum tests and in repeated intruder trials over the life span of group-reared animals, females from the line of high-aggressive males were more aggressive than females from the line of low-aggressive males. These findings indicate that the genetic pathways that mediate aggressive behavior in male and female mice are not entirely independent.

Dominance alone is not enough.

Abstract: It has often been noted that the correlation between dizygotic (DZ) twins is smaller than predicted from the monozygotic (MZ) correlation under a simple additive genetic model. Possible genetic explanations of this finding are considered. It is shown that duplicate gene interactions between pairs of moderately frequent alleles at polygenic loci are sufficient to produce surprisingly small (approximately 0.12) genetic correlations between siblings.

Spectral analysis of Drosophila courtship songs: D. melanogaster, D. simulans, and their interspecific hybrid.

Abstract: Digital signal processing methods have revealed spectral components inDrosophila melanogaster's andD. simulans' male courtship songs that had gone undetected in previous studies. We found that a bout of courtship hum (“sine song”) inD. simulans typically consists of a narrowband fundamental frequency, accompanied by second and third harmonics that can comprise a major fraction of the power in the signal. The pulse song spectra consisted of single broad-band peaks of highly variable frequencies, which, nevertheless, are characteristically different in these two species. Genetic elements of the newly discovered song components were examined by analysis of theD. melanogaster/D. simulans hybrid. Such males were found to be intermediate in production of sine song harmonics as well as in other parameters of courtship song, except for sine song and intrapulse frequency bandwidths, for which there may be dominant factors inD. simulans.

The ontogeny of sibling recognition in rodents: Superfamily muroidea

Abstract: A brief review of the relevant literature indicates that familiarization is the primary (and possibly sole) proximate mechanism mediating the development of sibling recognition in muroid rodents. Littermates that are raised together are discriminated from unfamiliar agemates. Previously unencountered kin may be recognized through their resemblance to familiar relatives (a process ofindirect familiarization). A recent experiment with spiny mice reveals that phenotypic similarity among full siblings can be discerned by other conspecifics, even those that are not their kin. Olfactory signatures involved in social recognition are the product of a complex interaction between genotypic and environmental components.

Genetic changes occurring over 500 generations in lines of Drosophila melanogaster selected divergently for geotaxis.

Abstract: Populations of Drosophila melanogaster selected divergently and intermittently over 600 generations for geotaxis were analyzed genetically by assaying individual chromosomes and their interactions. Effects were found for each of the three major chromosomes from both the negatively and the positively geotactic lines, as were interactions among chromosomes from the latter. This situation differs from an assay performed about 500 generations earlier (Erlenmeyer-Kimling, L.,Dissert. Abstr. 22:1262–1263, 1961) in which (a) significant effects were reported for only two of the three chromosomes from each line and (b) no significant interactions among chromosomes were found. The amount of evolutionary change in each line may well be even greater than reported here because the chromosomal assay cannot detect all effects. However, the comparison indicates a large magnitude of genetic change due to the effects of long-term selection.

Genetic basis for remating in Drosophila melanogaster. II. Response to selection based on the behavior of one sex.

Abstract: Selection for fast and slow remating was carried out, with selection being based on the behavior of one sex. None of the male selection lines produced a significant response to selection, in lines selected either on the basis of the first male to mate with a female or on the basis of the second male to mate with a female. In contrast, three of four female selection lines showed significant responses to selection. Males in the female selection lines were tested for changes in their mating speed when paired with unselected females. These tests suggest that genes affecting remating speed in females are largely sex limited in their action. The gender difference in response to selection is discussed in terms of sexual selection theory.

Estimation of heritability of learning behavior in honeybees (Apis mellifera capensis).

Abstract: The learning behavior of Cape honeybees (Apis mellifera capensis) is examined using conditioning of the proboscis extension reflex. The bees are tested cumulatively with several learning tests. The genetic influence on differences in the learning scores is calculated by means of heritability (h 2) estimations obtained by different methods. Theh 2 values of the sum of the trials derived by each method range between 0.39 and 0.54. This shows that the proboscis extension reflex paradigm is suitable for the characterization and selection of genetic differences in learning behavior. Heritabilities in the narrow sense and in the broad sense are in the same range. The small differences obtained are discussed with respect to the type of selection existing in natural populations.

Genetic analysis of cercarial emergence rhythms of Schistosoma mansoni.

Abstract: Using two chronobiological variants ofSchistosoma mansoni (a blood fluke infecting man) from Guadeloupe (French West Indies), we carried out experimental crossbreeding between schistosomes with an early and those with a late cercarial shedding pattern. The results obtained on the F1 (intermediate shedding patterns) and F2 generations (early, intermediate, and late patterns) demonstrate that the cercarial emergence rhythms of schistosomes are genetically determined. This genetic variability is interpreted as a consequence of the selective pressure exerted by the two different hosts (man and rat) implicated in the life cycle ofS. mansoni from the Guadeloupean focus of schistosomiasis.

Anorexia and sexual maturity in female white rock chickens. I. Increasing the feed intake.

Abstract: Long-term selection for low juvenile body weight has resulted in a line of chickens where sexual maturity is retarded or prevented because of anorexia.Ad libitum-fed pullets which had not commenced egg production by 240 days of age were randomly assigned to be force-fed or fedad libitum. Increasing food intake via force-feeding caused a significantly greater proportion of females to commence egg production than was noted forad libitum-fed controls. Moreover, of those pullets that commenced lay, age at onset was significantly earlier in those force-fed than in those fedad libitum.

Ecological correlates and potential functions of kin recognition and kin association in anuran larvae.

Abstract: The larvae of seven species of anurans differ significantly in their abilities to discriminate between kin and nonkin. The ontogeny of kin recognition in certain species is greatly influenced by the environment in which they are reared. In other species, the rearing regime has little affect on the development of kin recognition. Larvae of some anurans develop a kin recognition system in the absence of cues from other individuals. Natural conditions of embryonic development, larval dispersal characteristics, and aggregation behavior are correlated with the kin recognition system of most anurans examined. However, these ecological characteristics are not consistent with the kin recognition systems displayed by a few species. Warning relatives, through the release of chemical signals, and enhancement of growth and development are potential functions of kin association. Intraspecific competition and cannibalism directed toward nonkin are possible functions of kin recognition.

The ontogeny of kin discrimination cues in the honey bee, Apis mellifera.

Abstract: Cues used in the discrimination of relatives from nonrelatives by the honey bee reflect both genetic and environmental differences between groups. Discrimination is behaviorally expressed by acceptance into or agonistic rejection from the social group. We examine the development of these cues in field colonies and in controlled laboratory settings. Newly emerged worker honey bees are accepted by honey bee social groups at a high frequency. When bees are kept in a controlled laboratory environment for 5 days, acceptability into laboratory groups is determined largely by relatedness. Cues indicating relatedness develop in the laboratory within 12 h after the adult bee emerges. Bees older than 12 h are not accepted by field colonies regardless of relatedness. Bees maintained in a hive until 5 days after emergence are not accepted by related or unrelated laboratory groups (this is termed the “hive effect”). Bees maintained in hives for times as short as 5 h acquired the hive effect. In a cross-fostering experiment, the hive effect completely masked genetic differences.

Inheritance of burrow building in Peromyscus.

Abstract: Burrow construction abilities of laboratory-reared oldfield mice (Peromyscus polionotus), deermice (P. maniculatus), and their F1 hybrids were compared using a spacious earth-filled test chamber. Mated paris with nursing litters were individually introduced into the chamber for 4 days in each test. Oldfield mice bred in metal or plastic cages for 20 or more generations constructed elaborate burrows, with entrance and escape tunnels, tunnel plugs, next chambers, and nests, essentially like those of wild mice of this species. Prairie deermice maintained for 25 or more generations in captivity constructed shallow or superficial burrows characteristic of deermice in nature. F1 hybrids made burrows like those of oldfield mice, complete in all particulars. First-generation backcross animals tested for burrow building exhibited a spectrum of performances. Species difference in burrow construction is principally genetic in origin, and during 20–25 generations in captivity no substantial loss of this ability occurred. F1 hybrid data indicate that the more complex burrow building exhibits genetic dominance, and backcross results show that at least two and probably more gene loci strongly influence the trait.

Covariation between intelligence and speed of cognitive processing: genetic and environmental influences.

Abstract: This study is the first analysis of the etiology of the relationship between general intelligence and speed of cognitive processing. The genetic and environmental sources of this covariation were examined using data from 60 pairs of twins (30 monozygotic and 30 same-sexed dizygotic), ages 8–18. Full-Scale IQ scores on the Wechsler Intelligence Scale for Children-Revised (WISC-R) served as an index of general intelligence. Measures of speed of processing employed were the Rapid Automatic Naming tests and Colorado Perceptual Speed tests. Results of multivariate biometrical genetic analyses revealed the importance of genetic influences underlying the IQ/speed association. The relative importance of correlated genetic effects, however, appeared to be dependent upon the specific speed-of-processing measure. Our results indicate that the phenotypic relationship between the measures of general intelligence and the measures of speed of processing employed are due largely to correlated genetic effects. While correlated specific environmental effects were less important, correlated common environmental effects were negligible. In general, the findings support the notion of some common biological mechanism(s) underlying both general intelligence and speed-of-processing measures.

Frequency of social contact and intrapair resemblance of adult monozygotic cotwins--or does shared experience influence personality after all?

Abstract: To establish effects of shared experience on adult personality resemblance, we evaluated intrapair resemblance for short-form Extraversion (E) and Neuroticism (N) scale scores in 2320 pairs of adult monozygotic (MZ) twins who were classified by the frequency of their social interactions with one another. Our analysis parallels MZ cotwin control designs, where environmental differences within pairs provide an incisive measure of idiosyncratic experience, unconfounded by genetic differences; here, experiential differences between MZ pairs yield a sensitive measure of shared experience, again free of genetic confounds. We found that MZ pairs in more frequent interaction were significantly more alike for both personality dimensions. Hierarchical multiple regressions evaluated effects of social contact on intrapair similarity after the influence of both age and gender were removed; results confirmed that social interaction significantly contributes to the prediction of a twin's E or N scores from those of the cotwin. Finally, for both these MZ twins and 4824 agematched DZ (dizygotic) twin pairs, adult resemblance was associated with the age at separation. These data, obtained from a nonselected, population-based cohort of twins, challenge the widespread assumption that experiences shared by siblings make little or no contribution to similarities in their adult personalities.

Circadian period in mice: analysis of genetic and maternal contributions to inbred strain differences.

Abstract: Differences of approximately 25 min in the free-running period of a circadian rhythm for wheel-running activity were observed among four inbred mouse strains (Mus musculus). Two sets of reciprocal hybrid crosses among the strains showed approximately intermediate values for circadian period in one cross and dominance for a short period in the other. Neither set of crosses showed evidence of significant maternal effects on circadian period. These results indicate that the inbred strain differences in circadian period are imposed primarily by direct effects of allelic differences among the strains, rather than through maternally mediated mechanisms.

Consequences of consanguinity on cognitive behavior.

Abstract: In order to study the effects of consanguinity on IQ, a survey was conducted among the Ansari Muslims of Bhagalpur residing in suburban and rural areas. Both outbred (N=390 from suburban areas andN=358 from rural areas) and inbred (N's=300 and 266, respectively) children aged 9 to 12 years from socioeconomically middle-class families were administered the Weschler Intelligence Scale for Children—Revised [WISC(R)-74]. The coefficient of inbreeding, F, was .0625. The inbred children showed lower verbal (20 and 22%) and performance (30 and 20%) subtest scores and lower verbal (11 and 11%), performance (17 and 12%), and full-scale (15 and 12%) IQs. A three-factor analysis of variance performed on the full-scale IQ scores indicated that both consanguinity and locality affect IQ. The interaction between these two facors was also significant. Neither age nor sex affected these scores. Overall, subjects' performance scores were lower than verbal scores.

Behavior, stress, and variability.

Abstract: Genetic variability of behavioral traits under optimal and stressful environments is considered with examples fromDrosophila, rodents, and our own species. In agreement with direct fitness and life history traits, behavioral traits show a maximization of preexisting andde novo variation under stress. In order to understand evolutionary change,it appears necessary to emphasize those traits showing interactions with habitats under conditions of environmental stress; this can be shown at the behavioral level especially for domestication and adaptation to novel habitats.

Direct marital assortment for cognitive and personality variables

Abstract: Recent advances in linear modeling in human genetics permit the resolution of the sources of assortative mating. Using these methods we examined the multivariate assortment relationships among education, general cognitive ability, and personality traits in two large samples of spouses from the Colorado Adoption Project (N=334 couples) and the Hawaii Family Study of Cognition (N=1165 couples). Results indicate a direct pairing of mates on the basis of eductional level and general intelligence but no cross-assortment between the two. Thus, the indirect marital correlation between education in one spouse and intelligence in the other is due only to the direct pairing on education and on intelligence and to the within-person correlation between the two traits. We also found direct isomorphic assortment as well as direct cross-assortment on some personality characteristics. However, there was no cross-assortment between the personality and the cognitive domains. Results from models based on conditional path assortment parameters differ markedly from those obtained directly from observed marital correlations.

Sister, aunt-niece, and cousin recognition by social wasps.

Abstract: In blind laboratory observations, gynes (potential queens) of the social waspPolistes fuscatus discriminated nestmate sisters from unrelated nonnestmate gynes but failed to discriminate between nestmate sisters and nonnestmate aunts and nieces. Gynes treat nonnestmate aunts and nieces as nestmate sisters, indicating that gynes recognize kin other than nestmates (i.e., aunts and nieces) by using genetic odors. In blind field observations, femaleP. fuscatus discriminated between nestmate sisters and nonnestmate first cousins and unrelated nonnestmates. However, females failed to discriminate between nonnestmate first cousins and unrelated nonnestmates. The results of the laboratory and field studies provide additional support for the cue similarity threshold model of recognition, which has important sociobiological implications for social wasps.

Differences between CBA/H and NZB mice on intermale aggression. II. Maternal effects.

Abstract: Previously published results by the present authors have shown that CBA/HOrl (H) and NZB/BlN//Orl (N) males differ on several features of attack behavior. Moreover, the two reciprocal F1's differ; HNF1 males exhibit a higher level of attack behavior than NHF1 males. Two experiments were conducted to test for maternal effects. (1) A crossfostering experiment clearly demonstrated that the performances of strains H and N are not modified by H or N postnatal maternal environments. (2) The ovarian transplantation method was used to test for uterine plus postnatal maternal effects. Results showed that differences between H and N males in attack behavior are independent of the uterine and postnatal maternal environments (H or N vs HNF1). These findings strongly suggest that there are genetic or cytoplasmic correlates for attack behavior in the H and N strains.

Kin discrimination and reproductive behavior in muroid rodents.

Abstract: The literature on nonreproductive behavior includes much theory and many data showing preferential association with and treatment of kin. However, there are both costs and benefits to mating with kin. This leaves the experimenter with neither firm predictions nor tightly constrained interpretations of data. The mixed nature of the data on kinship and reproductive behavior in muroid rodents suggests the existence of a balance between the costs and the benefits of inbreeding and outbreeding.

Analysis of a genetic recognition system in wild house mice.

Abstract: Wild female house mice have strong preferences for odors of male mice whose t-complex genotype is +/+ rather than for males carrying deleterious mutations (+/t) at the t complex. In this review of a large number of studies examining the basis for this preference, we suggest the following: first, preferences of +/+ females are greatly influenced by environmental factors and probably do not have a large genetic component: second, preferences of +/t females are less dependent upon environmental factors and hence may have a strong genetic component: third, the lethal factors within the t complex are involved in both the production of the cue by males and the expression of the preference in females: and fourth, there may be a second gene or genes within the t complex involved in the expression of female preference.

Sexual isolation and courtship behavior in Drosophila simulans, D. mauritiana, and their interspecific hybrids.

Abstract: The cosmopolitan sibling speciesDrosophila simulans andD. melanogaster are sympatric over most of their range but both are allopatric toD. mauritiana. D. melanogaster is sexually isolated from both of the other species, whereas betweensimulans andmauritiana isolation is asymmetric. The interspecific hybrid females derived from these two species copulate readily with hybrid males and with males of both parental species. Differences in the expression of the components of male courtship behavior betweensimulans andmauritiana are quantitative rather than qualitative in nature, and the differences in the duration of courtship to copulation and the amount of scissoring in the male wing display are influenced by both autosomal and sex-linked genes. The asymmetric isolation appears to involve both the conspecific recognition mechanism and the effects of sexual selection.