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 109 records · Page 6Linked to original sources

Female preference for symmetrical males as a by-product of selection for mate recognition.

Fluctuating asymmetry (FA) refers to the random, stress-induced deviations from perfect symmetry that develop during the growth of bilaterally symmetrical traits. Individual differences in the level of FA may influence mate choice: in a number of species, females prefer to mate with males that have more symmetrical sexual ornaments. As the degree of FA has been shown to reflect the ability of individuals to cope with a wide variety of environmental stresses, it has been suggested that mating preferences for symmetry evolve for adaptive reasons, because the degree of FA provides honest information about male quality. Here I use simple, artificial neural networks to show that such preferences are likely to arise in the absence of any link between symmetry and quality, as a by-product of selection for mate recognition.

Animals↗

Diurnal, premating, and postmating testosterone levels in roosters genetically selected for mating frequency.

Circulating testosterone (T) levels were measured in roosters from lines genetically selected for high (HM) and low (LM) mating frequency and the randombred control (AC) base population. Lights were provided from 0600 through 2000 hr. A dirunal profile was determined by sampling at 0600, 1200, 1800, and 2400 hr. Plasma T levels prior to mating, immediately after mating, and 1 and 3 hr after mating were measured. By 1800 hr, AC males had higher T levels than both HM and LM males, which had levels that were similar to each other. Testosterone was at a minimum at 0600 hr and peaked at 2400 hr. Lines differed significantly both before and after mating with AC males highest, HM males intermediate, and LM males lowest. Control males had higher than baseline values prior to and after mating. Testosterone levels of AC males were correlated with their mating frequencies.

Analysis of Variance↗

Validation of Bateman's principles: a genetic study of sexual selection and mating patterns in the rough-skinned newt.

Few studies have influenced thought on the nature of sexual selection to the extent of the classic paper of A. J. Bateman on mating patterns in Drosophila. However, interpretation of his study remains controversial, and a lack of modern empirical evidence prevents a consensus with respect to the perceived utility of Bateman's principles in the study of sexual selection. Here, we use a genetic study of natural mating patterns in the rough-skinned newt, Taricha granulosa, to investigate the concordance between Bateman's principles and the intensity of sexual selection. We found that males experienced strong sexual selection on tail height and body size, while sexual selection was undetectable in females. This direct quantification of sexual selection agreed perfectly with inferences that are based on Bateman's principles. Specifically, males (in comparison with females) exhibited greater standardized variances in reproductive and mating success, as well as a stronger relationship between mating success and reproductive success. Overall, our results illustrate that Bateman's principles provide the only quantitative measures of the mating system with explicit connections to formal selection theory and should be the central focus of studies of mating patterns in natural populations.

Animals↗

Developmental profile of plasma androgens in cockerels genetically selected for mating frequency.

Plasma levels of androstenedione (AE), testosterone (T), and dihydrotestosterone (DHT) were measured at 1, 56, 112, and 168 days of age by radioimmunoassay in lines of cockerels divergently selected for male mating frequency. Values for total androgen (total A = AE + DHT + T) were also computed. No significant differences in mean hormone values were found between lines at any age. Hormone patterns throughout development were also similar for both lines. Plasma AE and T increased between Days 1 and 56, stabilized through Day 112, and rose again prior to 168 days of age. In contrast, DHT levels were low throughout Day 112 and rose significantly by Day 168. Total A in the high mating line was low throughout Day 112 with significant increases occurring by Day 168. In the low mating line, total A was low on Day 1, increased significantly by Day 56, and it remained unchanged through Day 112. Peak values occurred by Day 168. Within line correlation analyses between AE, T, DHT, and total A revealed a more uniform hormonal state throughout development in the high mating line than in the low mating line. Because no differences were found between the mating lines in baseline levels of individual androgens or in concentration patterns of androgens up through the attainment of sexual maturity, it appears that neither posthatch baseline levels nor posthatch temporal androgen concentrations control male sexual behavior in the mating lines of birds.

Androgens↗

The signature of balancing selection: fungal mating compatibility gene evolution.

A key problem in evolutionary biology has been distinguishing the contributions of current and historical processes to the maintenance of genetic variation. Because alleles at self-recognition genes are under balancing selection, they exhibit extended residence times in populations and thus may provide unique insight into population demographic history. However, evidence for balancing selection and extended residence times has almost exclusively depended on identification of transspecific polymorphisms; polymorphisms retained in populations through speciation events. We present a broadly applicable approach for detecting balancing selection and apply it to the b1 mating type gene in the mushroom fungus Coprinus cinereus. The comparison of neutral molecular variation within and between allelic classes was used to directly estimate the strength of balancing selection. Different allelic classes are defined as encoding different mating compatibility types and are thus potentially subject to balancing selection. Variation within an allelic class, where all alleles have the same mating compatibility type, provided an internal standard of neutral evolution. Mating compatibility in this organism is determined by the complex A mating type locus, and b1 is one of several redundantly functioning genes. Consequently, we conducted numerical simulations of a model with two subloci and varying levels of recombination to show that balancing selection should operate at each sublocus. Empirical data show that strong balancing selection has indeed occurred at the b1 locus. The widespread geographic distribution of identical b1 alleles suggests that their association with differing A mating types is the result of recent recombination events.

Alleles↗

Selection for mating reluctance in females of a diploid parthenogenetic strain of Drosophila mercatorum.

A diploid parthenogenetic strain of Drosophila mercatorum was outcrossed to produce genetic variance among the impaternate female offspring. Selection experiments were carried out for reluctance of the parthenogenetic females to mate. After only two cycles of selection, a parthenogenetic strain which is significantly less receptive to males from three different bisexual strains was obtained. It was also found that there is some degree of sexual isolation among the three bisexual strains used. The results support the idea that selection can render a newly produced diploid parthenogenetic strain behaviorally different from its bisexual ancestor. This appears to provide a framework which can explain the natural coexistence of diploid bisexual and diploid parthenogenetic biotypes in some species of insects.

Animals↗

Response to bidirectional and reverse selection for mating behavior in Japanese quail Coturnix coturnix japonica.

Reported is a genetic analysis of mating behavior in male Japanese quail. Data were obtained from replicated experiments involving 12 generations of divergent selection for high and low cumulative number of completed matings (CNCM). No trait measured in the randombred control population changed significantly over time. Asymmetrical responses between the divergent lines were observed during various phases of selection. Reversed selection showed that additive genetic variance remains in the high lines. Small and unimportant were drift and error variances. Genetic and phenotypic relationships between CNCM and body weight were small but positive, while those between CNCM and relative aggressiveness were positive and intermediate. Also positive and intermediate were the correlations between CNCM and cloacal gland size.

Animals↗

Variability of vibratory signals and mate choice selectivity in the southern green stink bug.

The southern green stink bug, Nezara viridula, has a complex mate recognition system that implicates chemical and acoustic signals. To localise a sexual partner acoustically, a male and female alternate between the male courtship song (MCrS) and the female calling song type 1 (FCS1). Although previous research has revealed that both signals show geographical variability, until now no studies have explored the form of this variability. We analysed the temporal and spectral characteristics of MCrS and FCS1 pulse trains of males and females from a French and a Guadeloupe population. Pulse train duration of the MCrS varied within and between populations. Likewise, spectral and temporal parameters of FCS1 varied within and between the two populations. Although females did not show any behavioural responses to pre-recorded MCrS, males responded to pre-recorded FCS1 by emitting a higher number of MCrS per minute. Furthermore, males modulated the repetition rate of their MCrS pulse trains to match those of the FCS1. All males responded to FCS1 from French and Guadeloupe females despite the temporal differences in these songs; however, they responded with a shorter latency and a higher rate of MCrS/FCS1 pulse trains to the songs of females from their own population. In choice experiments with two alternatives, responses to FCS1 were inhibited when males received a simultaneous female call from another Pentatomidae sympatric species, Acrosternum hilare. We conclude that, although males prefer FCS1 from their own population, they recognise FCS1 from French and Guadeloupe N. viridula females as species-specific female calls. Variability of vibratory signals might play a role in mate choice.

Journal Article↗

The role of olfaction during mating in the southern temperate spiny lobster Jasus edwardsii.

Chemosensory communication may be crucial during mate choice and mating in the southern temperate spiny lobster Jasus edwardsii to ensure that females mate with large males capable of supplying adequate numbers of sperm during the short mating window. To clarify the role of pheromones during this process, three laboratory experiments were carried out. In an experiment where the output of urine, which contains sex-specific pheromones, from large and small catheterized males was switched, large post-molt females did not make a clear choice of mate. This indicates that while females distinguish among females, males, and juveniles using their chemosensory sense, they distinguish among males using visual and tactile senses in combination with olfaction. Further, two antennule-ablation experiments were carried out to determine if detection of pheromones by the antennules of females or males was critical for mate selection, courting, or mating. In both cases, we observed a (nonsignificant) trend of slightly delayed mating of treatment females. We found that disruption of female olfaction causes less impact on courtship or mating than ablation of male antennules which increased the variance in the length of the period between molting and mating and resulted in a systematic reduction in clutch size. This lesser impact of female ablation may be because females can still respond to their own internal cues about egg ripeness whereas males cannot. In J. edwardsii, unlike the American clawed lobster, Homarus americanus, one fully functional partner of either sex appears sufficient to initiate mating.

Animals↗

Combining ability in the F1 and F2 generations of diallel cross in hexaploid wheat (Triticum aestivum L. em. Thell).

The F(1) and F(2) progenies of a ten-parent diallel cross (excluding reciprocals) of hexaploid wheat (Triticum aestivum L. em. Thell) were analyzed for combining ability for quantitative and quality traits. The results indicated significant differences among the parents for general combining ability (gca) and crosses for specific combining ability (sca) for all the characters studied. The gca and sca components of variance were significant for all the traits. However, the gca component of variance was predominant indicating the predominance of additive gene effects for the traits studied. Among the parents Durgapura 65, HD 2285, Lok-1, Raj 1972 and HD 2329 were the best general combiners for grain yield and average to high combiners for tillers per plant, grain yield per spike, grains per spike and 1000-grain weight. The best specific crosses for grain yield were Sonalika x WH 157, HD 2428 x Durgapura 65, Durgapura 65 x Sonalika, HD 2428 x Lok-1 and CPAN 3004 x Raj 1972. The parent Raj 1972, Lok-1 and HD 2285 were the best general combiners for grain yield and protein content, however, Raj 3077 was the best general combiner for protein content. The most suitable specific crosses for protein content were HD 2329 x HD 2285, HD 2428 x Raj 1972 and CPAN 3004 x WH 157. Most of the specific crosses for grain yield as well as protein content involved high x average, average x average and average x poor general combiners. To ensure further increase in grain yield along with high protein, combinations of desirable yield components is advocated. Inclusion of F(1) hybrids showing high sca and having parents with good gca, into multiple crosses and/or bi-parental mating, or diallel selective mating could prove a worthwhile approach for further improvement of grain yield in bread wheat.

Analysis of Variance↗

Sexual selection and mating advantages in the giant sperm species, Drosophila bifurca.

Mate choice may be exercised by either sex; however, females are generally choosier than males because they invest more in their gametes. Female choice is often based on direct benefits, such as better reproductive output, whereas male choice appears to be based on differences in female fecundity. However, when gamete production is limited, sexual selection theories predict that mate choice will be decisive for reproductive success in both sexes. Here, we investigate how mating advantage is achieved in Drosophila bifurca, a giant sperm species in which both sexes produce only a few gametes. Our initial expectations were as follows: (1) females would discriminate against sperm-depleted males to avoid fertility cost; and (2) males would discriminate against inseminated females to reduce sperm competition and increase the assurance of paternity of individual gametes. Differences in courtship behaviors were analyzed with regard to the sexual maturity, which is reached after 22 days in males at 21 degrees C, and the reproductive history of both sexes (inseminated versus virgin for females, and sperm-depleted versus sperm-loaded for males). Our results show that: (1) sexual immaturity precludes mating in both sexes; (2) virgin females do not discriminate between sperm-loaded and sperm-depleted males, and (3) males mate preferentially with virgin females, because inseminated females fend off the male, which tended to bring male courtship to an end. Female remating was limited, but increased significantly when the first male was sperm-depleted. Contrary to our initial expectations, these findings suggest that male sperm depletion does not affect female mating preference, whereas the success of male courtship is driven by female behavior. The possibility that female remating was only promoted in response to low sperm transfer is discussed in relation to the gametic system of this species.

Animals↗

Laboratory colonization and life table statistics for geographic strains of Simulium decorum (Diptera: Simuliidae).

Colonization techniques were developed in order to select mating strains from four geographic populations of Simulium decorum. Although mating strains were established from each locale, emphasis was shifted toward developing permanent colonies from Dryden Lake, New York, USA and Warm Springs, Georgia, USA. The net reproductive rate (Ro) was computed for the parental, F1, and F2 generations of each strain in order to assess the effects of colonization through successive generations. Ro increased rapidly for both strains from parental (range of 0.34-3.5) through F2 generations (range of 16.2-21.6). Analysis of Ro components indicated that the increases in Ro were the result of two parameters that reflect the propensity of flies to mate in confinement, suggesting that selection for mating is rapid. Multiple regression analysis indicated no significant differences between strains or generations when tested against fecundity (range of 391-519) and survival of immatures (range of 90.3-97.2%). A slight positive correlation (regression coefficient of 0.0016, P less than .01) was observed between larval density (range of 284-4,439 larvae per rearing) and survival of immatures, suggesting that the limits of the rearing system with regard to crowding were not approached. Both strains readily adapt to the laboratory and are currently in the fifth generation.

Animals↗

Applying breeding objectives to dairy cattle improvement.

Otherwise well-researched definitions of breeding objectives and selection criteria may never be used in practice if those definitions do not take into account the perceptions and wishes of the breeders for whom they are designed. Finding selection criteria that are widely accepted and implemented is a daunting task that requires considerable time and full interaction between the scientists and the industry. We review various aspects of this process and, in particular, how scientific principles can be used to ensure that the outcome best meets both the perceptions and needs of the users while remaining as close as possible to the technical economic optimum. Alternative methods of presenting and delivering selection indexes, such as index expression, index formulation, focus on response to selection rather than on index weights, construction of component indexes, and the use of direct accounting for costs of constraints rather than rescaling methods can all help in improving acceptance of an index. Development and implementation of selection criteria also involve consideration of the selective mating decisions that form an integral part of selection decisions in the field. The technical basis of factors that foster emphasis on individual mating decisions in the field are discussed in relation to formulation of the breeding goal and selection index and in relation to nonlinear economic and genetic parameters. Strategies that focus on use of a linear index for the selection of sires and dams followed by selective mating of selected parents have the greatest potential for implementation in the industry. We focus on examples taken from the Canadian dairy industry, but principles apply generally.

Animals↗

[A study on the local marriage network in Korea].

Place of residence has traditionally been an important factor in Korea in mate selection. This study examines the local marriage network in Korean society, its variation by year of marriage, and general characteristics of the married women. Data are drawn from the 1986 national sample survey on the family life cycle implemented by the Korea Institute for Population and Health. Questionnaires were administered to 3013 wives aged 15-64. Major study findings follow. 1) The local marriage rate within the same region by birthplace is strikingly high in Kyongsangdo and Chonla-do. Local marriage rates are 79.5% in both of these regions, 33.5% in Seoul, 35.2% in Busan, 50% in Kyonggi-do, 48.1% in Kangwon-do, and 60.7% in Chungchung-do. 2) The local marriage rate within the same county or the same city be residence before marriage has rapidly been declining in rural areas since 1960. This is largely due to industrialization, urbanization, and better transportation. The marriage rate in rural areas was 62% among marriages in the 1940s, 47.1% in the 1960s, 43% in the 1980s, and 70.9%, 88.4%, and 70.7% respectively in urban areas. 3) The proportion of local marriages within the same city or county is 55.1% among arranged marriages and 72.3% among romantic marriages. 4) Pre-marital employment seems to have some effects on the extent of mate-selection. Wives who worked before marriage were more likely to marry men in the same city or county. The local marriage rate within the same city or county is 63.2% among wives with work experience, and 58.5% among wives without work experience. 5) The more educated the woman, the higher the local marriage rate within the same city or county. 56.6% of those who attended middle school married men in the same city or county as theirs, 61.4% of wives with a high school education, and 76.6% of wives with college or more education. 63.8% of wives who never attended school married men in the same city or county. In summary, restrictions on marriage between couples of different status has been diminishing due to introduction of democratic thought based on freedom and equality; the marriage network has also narrowed due to industrialization, urbanization, migration, and women's higher educational attainment.

Asia↗

Male mate choice selects for female coloration in a fish.

Although sexual selection theory has proved successful in explaining a wide array of male ornaments, the function of ornaments occurring in females is largely unknown. Traditionally, female ornaments have been considered nonfunctional, being merely a genetically correlated response to selection for male ornamentation. However, this hypothesis is only relevant to species in which the ornament is basically the same in the two sexes. Alternatively, female ornaments may be influenced by selection acting directly on the females, either through female-female competition or male choice. We tested the latter hypothesis in mate-choice experiments with two-spotted gobies (Gobiusculus flavescens). In this small marine fish, females have bright yellow-orange bellies during the breeding season, a conspicuous trait that is not present in males. We conducted two aquarium experiments to test whether males preferred to mate with more colorful females. In the first experiment, males had a choice between two females that varied in natural coloration (and belly roundness). In the second experiment, we manipulated belly coloration and kept roundness constant. Males spent more time with colorful than with drab females in both experiments and also performed far more courtship displays toward colorful females. Our study provides experimental evidence that males prefer ornamented females in a fish that is not sex-role reversed, supporting the hypothesis that female ornamentation is sexually selected.

Animals↗

Random mating and selection in families against homozygotes for HLA in south Amerindians.

We have examined HLA-A and HLA-B in a large sample of families of South Amerindians for non-random mating and for Mendelian segregation in their progeny. The proportion of couples sampled for mating averaged over 50% of the total matings with progeny for 10 of the 11 tribes with 10 or more known matings. In nearly all cases, HLA-sharing proportions were very close to those expected from random mating, suggesting strong negative-assortative mating for MHC is not present in these South Amerindians. In progeny from these matings and others in 23 tribes, there was a large deficiency of homozygotes (excess of heterozygotes) compared with Mendelian expectations. In particular, there was a deficiency in all types of matings except when the female was a homozygote and the male shared one allele with her; the reciprocal mating showed no such deficiency. This non-reciprocity suggests the importance of some type of maternal-fetal interaction. A model to describe these results showed very surprising properties for two alleles: no change in allelic frequency like neutrality, an excess of heterozygotes like heterozygote advantage, and a minimum fitness at intermediate allelic frequency like heterozygote disadvantage. For three or more alleles, the model has the qualities of a traditional balancing selection model.

Adolescent↗

Female mate choice and male behaviour in domestic fowl.

The purpose of this study was to use paired choice tests to examine mate selection by female domestic chickens, Gallus gallus domesticus. We examined five behavioural and six morphological traits of 34 pairs of males to determine which male features influenced female mate choice. The frequency of a behavioural display known as wingflapping was the only variable that differed significantly between males that were chosen and males that were not. Within trials, females selected males with the highest wingflapping rate. Across trials, the wingflapping rate of chosen males ranged widely (3-82 wingflaps/h) suggesting that females used a relative choice mechanism when selecting a mate. These results differ from earlier work on the closely related red junglefowl, G. g. murghi, in which females use morphological traits and a threshold choice mechanism when selecting mates. Copyright 1998 The Association for the Study of Animal Behaviour.

Journal Article↗

Positive selection for mating with functional heterokaryons in Tetrahymena pyriformis.

Allelic assortment of Tetrahymena pyriformis makes possible the isolation of cells which contain both a heterozygous germ line nucleus and a somatic nucleus which expresses phenotypes of only one member of allelic pairs. Cycloheximide-sensitive segregants have been isolated from the vegetative progeny of cells heterozygous for a dominant mutation conferring resistance to cycloheximide; such segregants are called functional heterokaryons. Since progeny from crosses of these cells are cycloheximide-resistant, addition of the drug provides positive selection for successful exconjugants. The timing for expression of the new phenotype during conjugation is presented and used to identify what appear to be immature progeny of round one mating in genomic exclusion. Usefulness of functional heterokaryons in a number of genetic and developmental studies is discussed.

Alleles↗