Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Mate Selection”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources
PubMed1989

Evolution of resistance with sequential application of insecticides in time and space.

The effect, on the evolution of resistance, of alternating two unrelated insecticides in space or in time (or both) is studied. Transient polymorphism is shown to occur under certain conditions of mating, selection and migration. In some situations, the transient polymorphism can show a sharp decline before the alleles recover to fixation. Alternating a single insecticide in space, and in space and time, is also considered. Neither alternation in space nor in time shows any advantage with regard to delaying the onset of resistance. The most promising mode is to alternate the presence and absence of a single insecticide in both space and time, especially if it is applied at the larval stage and if some form of biological control is used in the regions where no insecticide is applied.

Animals↗
PubMed1995

Discrimination by female mice between the odours of parasitized and non-parasitized males.

The detection and avoidance of parasitized males has been proposed to be a component of female mate choice. We investigated whether or not female laboratory mice, Mus musculus domesticus, could discriminate between parasitized and non-parasitized males on the basis of odour. Female mice were given a choice between the urine and other odorous secretions of either a male mouse sub-clinically infected for five days with the naturally occurring, enteric, single host, protozoan parasite, Eimeria vermiformis, or an uninfected male. Females showed a marked preference for the odours of non-parasitized male mice over those of the parasitized males; as measured by number of investigations, time spent per investigation, and total investigation time of the odours in a choice situation. Female mice also displayed an overwhelming initial, or first choice, preference for the odours of the non-parasitized male mice over those of the parasitized males. These observations show that female mice can distinguish between the odours of parasitized and non-parasitized males, and discriminate against parasitized males on the basis of odour. We suggest that the detection and avoidance of infected males by female mice through odour cues may function to reduce parasite transmission and potentially serve as a component of female mate selection or choice.

Animals↗
PubMed1999

Good genes, oxidative stress and condition-dependent sexual signals.

The immune and the detoxication systems of animals are characterized by allelic polymorphisms, which underlie individual differences in ability to combat assaults from pathogens and toxic compounds. Previous studies have shown that females may improve offspring survival by selecting mates on the basis of sexual ornaments and signals that honestly reveal health. In many cases the expression of these ornaments appears to be particularly sensitive to oxidative stress. Activated immune and detoxication systems often generate oxidative stress by an extensive production of reactive metabolites and free radicals. Given that tolerance or resistance to toxic compounds and pathogens can be inherited, female choice should promote the evolution of male ornaments that reliably reveal the status of the bearers' level of oxidative stress. Hence, oxidative stress may be one important agent linking the expression of sexual ornaments to genetic variation in fitness-related traits, thus promoting the evolution of female mate choice and male sexual ornamentation, a controversial issue in evolutionary biology ever since Darwin.

Animals↗
PubMed2001

Female body odour is a potential cue to ovulation.

Human body odours have been reported to influence female mate choice. Women prefer the odours of immunocompatible men and, during their fertile period, judge the body odours of men with symmetrical bodies--which is indicative of genetic quality--as sexy and pleasant. The reproductive success of men largely depends on mating with fertile women, but it is not known whether men can detect a woman's fertile period. We asked women who had regular menstrual cycles and who were not using hormonal contraceptives to wear a T-shirt for three consecutive nights during their late follicular (ovulatory) phase and another T-shirt during the luteal (non-ovulatory) phase of their menstrual cycle. Male raters judged the odours of T-shirts worn during the follicular phase as more pleasant and sexy than odours from T-shirts worn during the luteal phase. The odour differences between the follicular and luteal phases did not dissipate quickly over time as male raters were able to detect and judge follicular phase body odours as more pleasant and sexy than the odours from the luteal phase even after the T-shirts were kept at room temperature for one week. These findings suggest that ovulation may not be concealed and that men could use ovulation-linked odours in their mate selection.

Adult↗
PubMed2001

Characterization of clustered MHC-linked olfactory receptor genes in human and mouse.

Olfactory receptor (OR) loci frequently cluster and are present on most human chromosomes. They are members of the seven transmembrane receptor (7-TM) superfamily and, as such, are part of one of the largest mammalian multigene families, with an estimated copy number of up to 1000 ORs per haploid genome. As their name implies, ORs are known to be involved in the perception of odors and possibly also in other, nonolfaction-related, functions. Here, we report the characterization of ORs that are part of the MHC-linked OR clusters in human and mouse (partial sequence only). These clusters are of particular interest because of their possible involvement in olfaction-driven mate selection. In total, we describe 50 novel OR loci (36 human, 14 murine), making the human MHC-linked cluster the largest sequenced OR cluster in any organism so far. Comparative and phylogenetic analyses confirm the cluster to be MHC-linked but divergent in both species and allow the identification of at least one ortholog that will be useful for future regulatory and functional studies. Quantitative feature analysis shows clear evidence of duplications of blocks of OR genes and reveals the entire cluster to have a genomic environment that is very different from its neighboring regions. Based on in silico transcript analysis, we also present evidence of extensive long-distance splicing in the 5'-untranslated regions and, for the first time, of alternative splicing within the single coding exon of ORs. Taken together with our previous finding that ORs are also polymorphic, the presented data indicate that the expression, function, and evolution of these interesting genes might be more complex than previously thought.

Amino Acid Sequence↗
PubMed2005

Role of resistant Drh1 locus in chemical carcinogen-induced hepatocarcinogenesis in rats: analysis with a speed congenic strain.

The DRH is an inbred rat strain established by selective mating of the 3'-Me-DAB resistant progeny of closed colony Donryu rats over 20 generations. Genetic analysis shows that two semidominant QTLs, Drh1 and Drh2, are responsible for strong resistance to chemical-induced hepatocarcinogenesis in DRH strain rats. To evaluate the effect of the single Drh1 locus on various stages of liver carcinogenesis, we constructed a speed congenic strain DRH.F344-Drh1 by transferring a susceptible Drh1 allele of F344 to DRH rats by marker-assisted backcrossing. The DRH.F344-Drh1 rats had a approximately 43 cM segment of chromosome 1 bearing Drh1 but the Drh2 was of the DRH allele. After oral administration of 3'-Me-DAB for 8 weeks, DRH.F344-Drh1 had as many enzyme altered foci as F344, whereas the quantitative parameters of fibrosis, enzyme altered foci, GST-P expression and proliferation of liver cells in DRH.F344-Drh1 rats were intermediate between F344 and DRH. In the liver of carcinogen-fed DRH rats, there was intensive apoptosis as detected by TUNEL stain, but not in the liver of F344 and DRH.F344-Drh1 rats. Injection of lead nitrate (100 micromol/kgB.W) induced a wave of liver cell proliferation, as seen by BrdU uptake within a few days in F344 and DRH.F344-Drh1 rats, but not in DRH rats. Instead, there were numerous TUNEL-positive nuclei in the DRH liver after lead nitrate injection. Apparently, the hepatocytes were removed by apoptosis during transition from G0 to G1. The major role of Drh1 is effective removal of the hepatocytes newly recruited to proliferate after chemical injury. Resistance to preneoplastic lesions in DRH rats may well be based on similar mechanism.

Administration, Oral↗
PubMed1989

Modeling IQ change: evidence from the Texas Adoption Project.

An analysis of genetic and environmental contributions to intellectual change was carried out by means of a path model applied to IQ data from the Texas Adoption Project, an adoption study in which children were measured on 2 occasions approximately 10 years apart. Included in the model were assortative mating, selective placement, genotype-environment correlation, a measure of socioeconomic status, and alternative hypotheses about cross-generation environmental transmission and the persistence of a trait over time. Some form of environmental transmission across generations was necessary, but either of the 2 forms tested was sufficient. The data were best fit by considering persistence over time to occur at the level of the developed trait. The effect of both genes and family environment was significant at the time of the first measurement, but only the genes made an additional contribution between the first and the second, suggesting the necessity of revising some popular stereotypes about development.

Adolescent↗
PubMed2005

Chromosomal mapping of hyperserum IgA and glomerular IgA deposition in a high IgA (HIGA) strain of DdY mice.

BACKGROUND: The high IgA (HIGA) strain of ddY mice is an inbred model of IgA nephropathy (IgAN), established by selective mating of outbred ddY mice. HIGA mice show high levels of serum IgA and glomerulonephritis with mesangial IgA deposition. To identify the genetic loci responsible for hyperserum IgA and glomerular IgA deposition in this strain, quantitative trait loci analysis was carried out. METHODS: By crossing HIGA with BALB/c mice, 244 F2 generations were produced. Serum IgA levels and glomerular IgA deposition were examined at 40 weeks of age. Genetic markers were typed at 105 microsatellites and the quantitative trait loci of hyperserum IgA and glomerular IgA deposition were confirmed using Map Manager QTX software. RESULTS: Two significant quantitative trait loci of hyperserum IgA were identified on chromosome 2 [logarithm of odds (LOD) = 5.01] and chromsome 4 (LOD = 4.45), and a suggestive quantitative trait locus of hyperserum IgA was located on chromosome 1 (LOD = 3.49). On chromosome 15, a significant quantitative trait locus of glomerular IgA deposition was identified (LOD = 4.40) without the hyperserum IgA locus. Serum IgA level was weakly correlated with the intensity of glomerular IgA in 244 F2 mice; however, the quantitative trait loci of hyperserum IgA were not significantly associated with glomerular IgA deposition. CONCLUSION: These findings indicate that, in HIGA mice, glomerular IgA deposition is mainly regulated by a quantitative trait locus on chromosome 15, and hyperserum IgA synergistically but weakly affect glomerular IgA deposition. The immune disturbance similar to IgAN was revealed to be under multigenic control in HIGA mice.

Animals↗
PubMed1994

Could seborrhoeic dermatitis be implicated in the pathogenesis of parkinsonism?

The spouses of a group of aged sufferers have been demonstrated to have multifarious differences relevant to parkinsonism from matched controls, which were difficult to explain by selective mating, learned or reactive behaviour. Could parkinsonism be transmissible? The frequency of inflammation and scaling on head or neck was greater (P = 0.05) in these spouses (19 available) than in controls (36), the best discriminating site of inflammation being scalp (P = 0.02). Both seborrhoeic dermatitis and overt, or pre-clinical, parkinsonism occurred in sufferers and spouses: to presume they are not causally related is to accept multiple entities. In favour of seborrhoeic dermatitis being causal for parkinsonism, rather than vice versa, is the involvement of a known organism, Pityrosporum ovale, in the dermatitis, and that the evidence of parkinsonism in the spouses indicated that they were only part way down the path towards the clinical condition.

Aged↗
PubMed1997

Advantages and limitations of nonhuman primates as animal models in genetic research on complex diseases.

The genetic similarity between humans and nonhuman primates makes nonhuman primates uniquely suited as models for genetic research on complex physiological and behavioral phenotypes. By comparison with human subjects, nonhuman primates, like other animal models, have several advantages for these types of studies: 1) constant environmental conditions can be maintained over long periods of time, greatly increasing the power to detect genetic effects; 2) different environmental conditions can be imposed sequentially on individuals to characterize genotype-environment interactions; 3) complex pedigrees that are much more powerful for genetic analysis than typically available human pedigrees can be generated; 4) genetic hypotheses can be tested prospectively by selective matings; and 5) essential invasive and terminal experiments can be conducted. Limitations of genetic research with nonhuman primates include cost and availability. However, the ability to manipulate both genetic and environmental factors in captive primate populations indicates the promise of genetic research with these important animal models for illuminating complex disease processes. The utility of nonhuman primates for biomedical research on human health problems is illustrated by examples concerning the use of baboons in studies of osteoporosis, alcohol metabolism, and lipoproteins.

Animals↗
PubMed1997

Bioacoustic behavior of African fishes (Mormyridae): potential cues for species and individual recognition in Pollimyrus.

An analysis of the natural bioacoustic signals made by two closely related African fishes (P. adspersus and P. isidori) revealed that these species separated along several acoustic dimensions that are likely to be important for species isolation. Both species produced grunts that were composed of a trains of pulses, but the pulse repetition rates were distinctly different (56 +/- 3 s.d. vs 44 +/- 4 s.d. pps). Complex tone bursts (moans) were also used, but the species differed substantially in the location of the fundamental peak (240 Hz +/- 12 s.d. vs 332 Hz +/- 34 s.d.). Some P. adspersus males sustained these tones for over a second (812 ms +/- 495 s.d.), whereas P. isidori produced shorter tones (121 ms +/- 35 s.d.). During interactions with females, the two species produced the grunts and moans in distinct species-typical patterns: P. adspersus males alternated grunts with moans and P. isidori produced a single grunt followed by a succession of moans. A detailed analysis of identified individual P. adspersus showed that acoustic features constituted individual signatures which could be used by conspecifics to identify individuals. Grunt spectral peak frequency was shown to be a good predictor of male mass, with peak frequency decreasing at 72 Hz per gram. Simulated standardized courtship encounters with females revealed that males differ markedly in their apparent ability to produce sustained moans and it is suggested that this may be particularly important to females in mate selection.

Acoustics↗
PubMed1998

Detection of auditory signals by frog inferior collicular neurons in the presence of spatially separated noise.

Detection of auditory signals by frog inferior collicular neurons in the presence of spatially separated noise. J. Neurophysiol. 80: 2848-2859, 1998. Psychophysical studies have shown that the ability to detect auditory signals embedded in noise improves when signal and noise sources are widely separated in space; this allows humans to analyze complex auditory scenes, as in the cocktail-part effect. Although these studies established that improvements in detection threshold (DT) are due to binaural hearing, few physiological studies were undertaken, and very little is known about the response of single neurons to spatially separated signal and noise sources. To address this issue we examined the responses of neurons in the frog inferior colliculus (IC) to a probe stimulus embedded in a spatially separated masker. Frogs perform auditory scene analysis because females select mates in dense choruses by means of auditory cues. Results of the extracellular single-unit recordings demonstrate that 22% of neurons (A-type) exhibited improvements in signal DTs when probe and masker sources were progressively separated in azimuth. In contrast, 24% of neurons (V-type) showed the opposite pattern, namely, signal DTs were lowest when probe and masker were colocalized (in many instances lower than the DT to probe alone) and increased when the two sound sources were separated. The remaining neurons demonstrated a mix of these two types of patterns. An intriguing finding was the strong correlation between A-type masking release patterns and phasic neurons and a weaker correlation between V-type patterns and tonic neurons. Although not decisive, these results suggest that phasic units may play a role in release from masking observed psychophysically. Analysis of the data also revealed a strong and nonlinear interaction among probe, masker, and masker azimuth and that signal DTs were influenced by two factors: 1) the unit's sensitivity to probe in the presence of masker and 2) the criterion level for estimating DT. For some units, it was possible to examine the interaction between these two factors and gain insights into the variation of DTs with masker azimuth. The implications of these findings are discussed in relation to signal detection in the auditory system.

Acoustic Stimulation↗
PubMed1980

Chromosome damaging agent of low molecular weight in the serum of New Zealand black mice.

Two substrains of NZB mice were developed by selective matings according to chromosome breakage frequencies in direct bone marrow preparations: HB, a line with increased chromosome breakage, and LB, a line with low or normal breakage rates. The serum of NZB mice from the HB strain contains a chromosome breaking factor that produces chromosome abnormalities in human lymphocytes. This clastogenic substance could not be detected in serum of NZB line. Nor does it exist in serum of Balb, C3H, C57 B1, Swiss, or AKR mice, in which no chromosomal breakage was observed in bone marrow. The breakage factor has a molecular weight between 1000 and 10,000 daltons.

Animals↗
PubMed1992

Factors influencing the idiopathic development of pulmonary hypertension in the fawn hooded rat.

Fawn hooded rats (FHR), a strain of rat with a hereditary bleeding tendency due to a genetic defect in platelet aggregation, have recently been found to develop pulmonary hypertension. However, whether the pulmonary hypertension in FHR has a genetic basis or simply reflects the influence of extrinsic factors known to increase pulmonary artery pressure in other rat strains has not been fully evaluated. To further examine the structural and hemodynamic changes of pulmonary hypertension in FHR, and to investigate the extent to which alveolar hypoxia may have promoted these abnormalities, hemodynamic and morphometric measurements were made in FHR (4 to 24 wk) and compared with age-matched Sprague-Dawley (SDR) control rats. Increases in mean pulmonary artery pressure, total pulmonary resistance, and right ventricular enlargement were present in both male and female FHR and were evident at an early age (4 wk). Morphometric analysis of barium gelatin-infused lungs revealed marked pulmonary vascular remodelling in FHR characterized as extension of muscle into more peripheral pulmonary vessels, medial hypertrophy of proximal vessels, and reduced number of barium-filled arteries. The increases in pulmonary artery pressure in FHR were not due to the influence of more severe hypoxia, hypoventilation, or polycythemia, as blood gas tension and hematocrit were similar in FHR and SDR. Moreover, we found that pulmonary hypertension could be transmitted to backcross and second filial generation offspring arising from selective matings between FHR and control Wistar Kyoto rats, confirming the heritable basis for pulmonary hypertension in the FHR.

Animals↗
PubMed1983

And they lived happily ever after: marriage concepts of older adolescents.

Children of divorced parents are themselves more likely to divorce. The transmission hypothesis has been variously explained by the role model learning, high risk mate selection, increased individual psychopathology and more recently by the explanation of the family's positive sanction of divorce. Conversely, studies without matched controls of adolescents' reaction to parents' separation and their own future marriage indicate that these adolescents are wary of marriage, planning to delay marriage until their late 20's or 30's and highly concerned with partner choice. A study of 18 and 19 year old college students (N = 140) was undertaken to see if the attitudes expressed by those from divorced families are unique to this group or representative of the attitude of the general teenage population towards marriage. The students completed the Tamashiro Marriage Concepts questionnaire and a demographic/social questionnaire. The majority, over 90%, scored on the first two stages of marriage concepts (magical or idealized conventional) consistent with previous findings for this age group. A sub sample of 17 adolescents with divorced parents was compared with 17 matched controls. No significant difference was found in marriage concepts, attitudes or social variables including predicted marital age, dating patterns and sexual experience. Thus older adolescents despite their previous experience tend to be less mature in cognitive style in their attitude to marriage than one would expect at this stage of ego development and, therefore, are at high risk for divorce with early marriage. Further, those adolescents whose background includes the experience of a parental separation and divorce show no difference in their attitude to marriage from their peers.

Adolescent↗
PubMed2003

Erotomania variants in dementia.

Erotomania is a delusional syndrome in which an affected individual is convinced that another person loves him or her. Erotomania usually occurs in middle-aged female patients. Only 3 cases have been described in dementia so far. The authors report 2 cases, in Alzheimer's disease and vascular dementia, in which erotomania emerged in the early stage of the underlying disorder. In both cases, erotomania partially responded to antipsychotic treatment. Erotomania may be understood in evolutionary terms as a pathologic deviation of an evolved psychological mechanism relating to mate selection and may therefore account for the typical sex distribution of the syndrome in favor of women and the onset of the disorder, usually during the late reproductive phase. The association of erotomania with dementing disorders may tentatively be interpreted to suggest that such complex psychological mechanisms and behaviors as involved here in "organic" delusions may have distinct, "hard-wired" representations in the human brain.

Aged↗
PubMed2002

Distribution of putative male sex pheromones among Lutzomyia sandflies (Diptera: Psychodidae).

Male Lutzomyia longipalpis produce terpene sex pheromones in glandular tissue underlying the cuticle. The pheromones are transmitted to the surface via cuticle-lined ducts (measuring 0.25 microm in diameter), each of which reaches the surface in the centre of a papule (measuring 3-3.5 microm in diameter). Similar papules, in a range of shapes but all characterized by the presence of a central pore and absence of macroserae, occur in some other species of sandfly. The aim of the present study was to determine the distribution of sex pheromones in sandflies of the genus Lutzomyia that do and do not have the papules. The results indicate that sex pheromones are not widely distributed amongst male Lutzomyia spp. Male members of the genus can be subdivided into three groups: those that produce terpenes and have cuticular papules; those that do not produce terpenes but still have the associated papules; and those that have neither terpenes nor papules. The papules seen in the species that do not synthesise sex pheromones are presumably vestigial, non-functional structures. Such species may have stopped producing pheromone as the result of changes in the way in which the females found and selected mates or changing feeding preferences. A similar event has occurred in the Lepidoptera, where vestigial pheromone-secreting structures remain in some species which no longer produce pheromone. Lutzomyia lenti collected in southern Brazil produced a novel diterpene whereas male L. lenti from north-eastern Brazil did not, supporting suggestions by others that L. lenti is, like L. longipalpis, a species complex.

Animals↗
PubMed2006

The generality and ultimate origins of the attractiveness of prototypes.

The relationship between category structure and affect, a core question about the affect-cognition interface, has been largely ignored by both literatures, with the exception of studies on the attractiveness of computer-averaged faces. This article reviews a number of the authors' recent and unpublished studies that demonstrate a robust positive correlation between prototypicality and attractiveness across diverse categories, and that systematically explore several hypotheses about the ultimate, that is, evolutionary, origins of this bias. A tentative dual-origin explanation is offered, in which prototypes of animal categories are preferred as a generalization of a mate-selection adaptation designed for human faces; coincidentally prototypes of artifacts (and possibly natural, nonanimal categories) are preferred by virtue of their subjective familiarity.

Affect↗