SEARCH · PubMed Health

Results for “mating”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 685 records · Page 38Linked to original sources

PubMed2000

Effects of multiple mating on female reproductive output in the cat flea (Siphonaptera: Pulicidae).

Multiple mating behavior of female cat fleas, Ctenocephalides felis (Bouché), was confirmed in this study, and its effects on fecundity and fertility were investigated as well. The number of fertile eggs produced by mated females was close to nil within 7 d after removal of males, but it was resumed when females were exposed to males again on day 7. Multiple-mated females displayed significantly higher fecundity (400.3 eggs per female) and fertility (182.8 viable eggs per female) than single-mated females (61.7 and 19.0, respectively) in the 24-d period, suggesting that multiple mating by females is an advantageous strategy for cat fleas. The duration of first mating averaged 63.1 min. The high ratio (55.56%) and short duration (34.0 min) of impotent mating suggested that cryptic female choice may be involved during copulation.

Animals↗

PubMed2001

Off-host observations of mating and postmating behaviors in the cat flea (Siphonaptera: Pulicidae).

A blood meal was necessary for a male cat flea, Ctenocephalides felis (Bouché), to display the mating attempts to an unfed or fed female. More mating pairs resulted when both sexes were fed. Copulation occurred when fed fleas were placed on surfaces with temperatures from 34 to 42 degrees C. This article not only describes the mating and postmating behaviors of cat fleas, but also compares them with those of other fleas. The sequence of mating behavior began when a male approached a female ventrally, and the male's antennae and claspers became erect to attach to the abdomen of the female. Clasper attachment lasted until copulation ended, whereas the male retrieved his antennae immediately after genitalia linkage. The male generally grasped the female's tarsi with his claws during mating. The length of the mating interval terminated by the male ranged from 25 to 110 min and was significantly longer than that terminated by the female (averaging 12.11 min). After the mating pair separated, the male displayed a series of postmating behaviors discussed herein. This article documents grasping and postmating behaviors of the male cat flea.

Animals↗

PubMed1980

Relative contributions of oestradiol and progesterone to the maintenance of sexual receptivity in mated female hamsters.

Sexual receptivity was measured as total lordosis duration (TLD) per 10 min test period with mating tests standardized across 24 h by giving the first test at the time when the lights were switched off (0 h) during a schedule of 14 h light : 10 h hardness and re-testing at intervals of 2 h. Long-term (14 days), high-level oestrogen treatment was necessary to achieve TLD scores similar to those found in female hamsters treated with oestrogen plus progesterone for 3 days. Mating of female animals treated with oestrogen only always resulted in a significant decrease in TLD scores at later tests (0 v. 2 h). If progesterone was given after the test at 0 h, a significant increase in TLD score was found at the test at 2 h and this increase was maintained across several tests. By 8 h TLD scores had decreased significantly in progesterone-treated mated female hamsters. Progesterone appeared to have, therefore, at least two roles in the regulation of sexual responsiveness in the female hamster: (a) under normal conditions of oestrogen exposure (1--3 days) progesterone was necessary for the induction of sexual receptivity and (b) progesterone was necessary for the maintenance of sexual responsiveness following short-term (10 min) mating in female hamsters treated with oestrogen only. In the oestrogen- and progesterone-treated female animal which is no longer receptive as a result of previous exposure to progesterone plus having been mated, sexual receptivity can be re-induced by treatment with a larger dose of progesterone. These findings have indicated that progesterone is the primary hormonal agent which regulates sexual receptivity in the mated female hamster. Furthermore, the eventual inhibitory effect of progesterone on sexual receptivity was not absolute even in the mated female animal but rather represent some form of habituation to that particular dosage of progesterone to which the animal had been previously exposed.

Animals↗

PubMed1981

Plasma prolactin and progesterone responses to mating are altered in ages rats.

The effects of varying amounts of copulatory stimulation on patterns of plasma concentrations of prolactin and progesterone were evaluated in 3- and 12-month-old female rats. The 12-month-old group included rats which still exhibited oestrous cycles and rats in persistent vaginal oestrus (PVO). The extent of copulatory stimulation was defined by the number of intromissions received during mating: less than or equal to 5, 15 or greater than 50. Blood samples were drawn over the 8 days after mating through a cannula inserted into the right external jugular vein. Plasma from the samples was assayed for prolactin and progesterone. In aged but still cyclic rats, pregnancy rates were positively correlated with the number of intromissions received during mating. Only one rat in PVO became pregnant. All animals which became pregnant and rats in PVO which, after mating, exhibited a disruption of the pattern of PVO, showed the nocturnal surge of plasma prolactin characteristic of pregnant and pseudopregnant rats. While these surges persisted until day 8 after mating in pregnant animals, they were absent by this time in the rats in PVO. Prolactin surges were present in some but not all of the aged rats which did not become pregnant. Progesterone concentrations were raised in all pregnant animals except the one pregnant rat in PVO and, while not related to the number of intromissions, concentrations were higher 8 days after mating in young compared with those in aged pregnant rats. Plasma progesterone was low in rats in PVO regardless of disruption of the pattern of PVO. We have concluded that the failure of limited copulatory stimulation to induce pregnancy in older rats results, at least in part, from its failure to initiate nocturnal prolactin surges. Nevertheless, our data suggest that matings which are not experimentally limited should provide ample stimulation to establish such surges. Although reduced plasma concentrations of prolactin and progesterone at pro-oestrus and reduced plasma progesterone through part of gestation may contribute to decreasing fertility in aged rats, other unidentified factors appear to be involved in mediating the capacity of extensive copulatory stimulation to induce pregnancy in these animals.

Aging↗

PubMed2004

Chemical and visual communication during mate searching in rock shrimp.

Mate searching in crustaceans depends on different communicational cues, of which chemical and visual cues are most important. Herein we examined the role of chemical and visual communication during mate searching and assessment in the rock shrimp Rhynchocinetes typus. Adult male rock shrimp experience major ontogenetic changes. The terminal molt stages (named "robustus") are dominant and capable of monopolizing females during the mating process. Previous studies had shown that most females preferably mate with robustus males, but how these dominant males and receptive females find each other is uncertain, and is the question we examined herein. In a Y-maze designed to test for the importance of waterborne chemical cues, we observed that females approached the robustus male significantly more often than the typus male. Robustus males, however, were unable to locate receptive females via chemical signals. Using an experimental set-up that allowed testing for the importance of visual cues, we demonstrated that receptive females do not use visual cues to select robustus males, but robustus males use visual cues to find receptive females. Visual cues used by the robustus males were the tumults created by agitated aggregations of subordinate typus males around the receptive females. These results indicate a strong link between sexual communication and the mating system of rock shrimp in which dominant males monopolize receptive females. We found that females and males use different (sex-specific) communicational cues during mate searching and assessment, and that the sexual communication of rock shrimp is similar to that of the American lobster, where females are first attracted to the dominant males by chemical cues emitted by these males. A brief comparison between these two species shows that female behaviors during sexual communication contribute strongly to the outcome of mate searching and assessment.

Analysis of Variance↗

PubMed1983

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↗

PubMed1985

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↗

PubMed1975

Theory of inbreeding and covariances between relatives under full-sib mating in diploids.

A generation matrix theory of full-sib mating is developed in which 13 mating "classes" are distinguished according to identity of genes in individuals mated and identity of genotypes as belonging to homozygous, parental, or offspring sets. The 13 times 13 matrix reveals some properties of the full-sib mating system not shown by previous work. The eigenvalues and a set of eigenvectors for the generation matrix, and the general solution for the frequencies of mating classes among descendants of an original mating of genotypes ab times cd, are given. The genotypic array of descendants in an arbitrary generation is also given. A new formula is derived for the coefficient of inbreeding in generation n + m in terms of coefficients of inbreeding in earlier generations. An algorithm is presented for calculating the probability of a given situation of identity of alleles carried by two individuals given only the indices of their own respective generations and the generation of their most recent common ancestor. The application of such probabilities to obtaining covariances between relatives in a full-sib mating system, under the assumptions of independence and non-interaction among loci, is illustrated. All results are shown to agree with previous work in special cases. All possible full sib, generation n - 1 parent-generation n + m offspring, and generation n uncle-generation n + m nephew covariances for 1 less than n + m less than or equal to 8 are obtained using the given algorithm.

Alleles↗

PubMed2001

[The reliability of vaginal cytology in determining the optimal mating time in the bitch].

The reliability of vaginal cytology for determining the optimal mating period is controversial. The importance of the site for obtaining the smear (the vestibule or the vagina) and the best staining method are also unclear. Therefore, we investigated the reliability of vaginal cytology as compared to plasma progesterone concentrations for determining the optimal mating period. Additionally, the influence of different locations for obtaining the smears and of the staining methods, i.e. May-Grünwald-Giemsa or Papanicolaou, a method that stains keratin in superficial cells, was examined. In total, the vaginal cytology of 35 bitches during the follicular phase was examined three times a week, until the optimal time for mating was established, based on plasma progesterone concentrations measured with a 125Iodine radio-immunoassay. The results indicate that vaginal cytology is not useful for determining the optimal mating period in bitches, since mating according to cytological findings would have resulted in only 28% of the bitches being mated at the proper time. The site for obtaining the smear and the staining method did not affect accuracy. It is therefore concluded that cytology is not useful in breeding management to determine the optimal mating period. It can be used, however, to determine the stage of the cycle in general, e.g. the early part of the follicular phase or the metoestrus and the detection of disorders in the follicular phase. For this purpose, a smear from the vestibule, stained with a morphological staining method, provides sufficient information.

Animals↗

PubMed2002

The neural mechanisms of mate choice: a hypothesis.

Scientists have described many physical and behavioral traits in avian and mammalian species that evolved to attract mates. But the brain mechanisms by which conspecifics become attracted to these traits is unknown. This paper maintains that two aspects of mate choice evolved in tandem: 1) traits that evolved in the "display producer" to attract mates and, 2) corresponding neural mechanisms in the "display chooser" that enable them to become attracted to these display traits. Then it discusses our (in-progress) fMRI brain scanning project on human romantic attraction, what we believe is a developed form of "courtship attraction" common to avian and mammalian species as well as the primary neural mechanism underlying avian and mammalian mate choice. The paper hypothesizes that courtship attraction is associated with elevated levels of central dopamine and norepinephrine and decreased levels of central serotonin in reward pathways of the brain. It also proposes that courtship attraction is part of a triune brain system for mating, reproduction and parenting. 1)The sex drive evolved to motivate birds and mammals to court any conspecifics. 2) The attraction system evolved to enable individuals to discriminate among potential mating partners and focus courtship activities on particular individuals, thereby conserving mating time and energy. 3) The neural circuitry for attachment evolved to enable individuals to complete species-specific parental duties.

Brain Mapping↗

PubMed2005

Outbreeding depression, but no inbreeding depression in haplodiploid Ambrosia beetles with regular sibling mating.

In sexual reproduction the genetic similarity or dissimilarity between mates strongly affects offspring fitness. When mating partners are too closely related, increased homozygosity generally causes inbreeding depression, whereas crossing between too distantly related individuals may disrupt local adaptations or coadaptations within the genome and result in outbreeding depression. The optimal degree of inbreeding or outbreeding depends on population structure. A long history of inbreeding is expected to reduce inbreeding depression due to purging of deleterious alleles, and to promote outbreeding depression because of increased genetic variation between lineages. Ambrosia beetles (Xyleborini) are bark beetles with haplodiploid sex determination, strong local mate competition due to regular sibling mating within the natal chamber, and heavily biased sex ratios. We experimentally mated females of Xylosandrus germanus to brothers and unrelated males and measured offspring fitness. Inbred matings did not produce offspring with reduced fitness in any of the examined life-history traits. In contrast, outcrossed offspring suffered from reduced hatching rates. Reduction in inbreeding depression is usually attributed to purging of deleterious alleles, and the absence of inbreeding depression in X. germanus may represent the highest degree of purging of all examined species so far. Outbreeding depression within the same population has previously only been reported from plants. The causes and consequences of our findings are discussed with respect to mating strategies, sex ratios, and speciation in this unusual system.

Analysis of Variance↗

PubMed2005

Mating success of males with and without wing patch in Drosophila biarmipes.

Some males of D. biarmipes--synonym of D. rajasekari and D. raychaudhuri have a black patch on the wing. The patch extends from the apical margin of wing to the third longitudinal vein. Field and laboratory studies have been carried out in D. biarmipes to study role of male's wing patch in mating success. The field study shows that nature favors D. biarmipes males with patch. Although males without patch mated, males with patch have higher mating success suggesting the role of wing patch during courtship. Further, among mating males, males with patch had longer wings than males without patch. During courtship, males with patch oriented and mated faster; performed courtship acts such as tapping, scissoring, vibration, licking and twist dance more times than males without patch in both competitive and non-competitive situations. The results indicate that there is a casual relationship between the presence of wing patch, mating speed and success. Also there is a correlation between presence of wing patch, size of the flies and mating success.

Animals↗

PubMed2005

Patterns of sperm precedence are not affected by female mating history in Drosophila melanogaster.

In promiscuously mating species, there is strong selection on males to maximize their share of paternity through both defensive and offensive means. This has been most extensively examined using the Drosophila melanogaster model system. In these studies, sperm competition has been examined by mating a virgin female to two consecutive males and then determining the fertilization success of both the first male (defending, P1) and the second male (offending, P2). Recent evidence suggests that male defense may be influenced by female mating history (i.e., virgin versus nonvirgin). Here, by mating females to males with three different genotypes, we show that female mating history does not affect male defensive or offensive abilities in sperm competition. We also show that, although female lifetime fecundity was not correlated with the number of times that she mated, it was reduced by increased exposure to males. These data indicate that measures of P1 and P2 previously reported in D. melanogaster may be robust to the specific mating history of the females used in these studies.

Animals↗

PubMed2005

Potato late blight in Morocco: characterization of Phytophthora infestans populations (virulence and mating type).

Late blight caused by Phytophthora infestans, is the most important disease of potato in Morocco. Use of partially resistant cultivars should be an essential component of a sustainable management strategy of potato late blight, provided the durability of this form of resistance. It is therefore important to determine the nature of P. infestans Moroccan populations. Mating types were determined for 91 strains of P. infestans collected in the northern (Larache-northern plain), north western (Kénitra) and north eastern (Méknès, Middle Atlas) potato cropping areas of Morocco in 1999-2000, 2000-2001 and 2003-2004. They showed a clear regional structure of these populations, with the presence of both mating types (A1 and A2). Of all isolates collected since 1999, A2 mating type constituted 56% (54 isolates), following by A1 mating type (40.7%, 31 isolates) and A1-A2 (self-fertile) mating type (3.30%, 3 isolates). Populations from Méknès and Kénitra consisted mainly of A2 mating type, whereas populations from Larache predominantly included A1 mating type. Physiological race study revealed the presence of 19 races of P. infestans in the first collection of 25 isolates tested between 1999 and 2001. All known virulence genes were detected in western and northern Moroccan isolates, except virulence for resistance genes R2, R5, and R6 which were absent. All isolates were able to overcome two or more R genes except one isolate (5-1) corresponding to race 1.

Disease Susceptibility↗

PubMed1979

Metabolism of alpha-factor by a mating type cells of Saccharomyces cerevisiae.

When a mating type cells of Saccharomyces cerevisiae are exposed to the mating pheromone alpha-factor in liquid cultures, there is a time-dependent loss of alpha-factor activity from the culture fluid. This loss of biological activity can be directly correlated with the proteolysis of the pheromone by a mating type cells. The metabolism of alpha-factor by a mating type cells may be measured by using either in vitro 125I-labeled or in vivo 35S-labeled pheromone. Addition of chloroquine to growing cultures of a mating type cells at concentrations which cause no detectable alterations in cell growth produces a potentiation of alpha-factor mediated cell cycle arrest. This potentiation of alpha-factor activity is directly correlated with the inhibition of alpha-factor proteolysis. Thus, while proteolytic digestion of alpha-factor appears to be related to the mechanism whereby a mating type cells "detoxify" alpha-factor and recover from cell cycle arrest, proteolysis of the mating factor is not necessary for alpha-factor mediated cell cycle arrest.

Chloroquine↗

PubMed1981

Genetic implications of mating structure in a Caribbean isolate.

Mating patterns in the population of St. Barthélémy, French West Indies, are examined to evaluate the expected genetic consequences of consanguinity avoidance and of failure to mate due to celibacy and emigration. Nearly 60% of all individuals reaching mating age on "St. Bart" never contribute to the gene pool of succeeding generations. This greatly reduces the effective population size and, therefore, increases genetic drift or random inbreeding. The consequent loss of heterozygosity is partially countered by the fact that the individuals who fail to reproduce within the population tend to be more closely related to the population than are those who do reproduce. This nonrandom failure to mate results in nonrandom inbreeding, which reduces total pedigree inbreeding. Total inbreeding is also reduced by consanguinity avoidance. However, the effect of avoiding close consanguineous matings is, to some extent, reversed by an apparent preference for more distant relationships, especially with second cousins. Generally similar results are found for the related Northside French population of St. Thomas. U.S. Virgin Islands. A recently developed mathematical model predicts the expected effect on heterozygosity of partial or complete avoidance of, or preference for, any combination of consanguineous matings, and also takes into account nonrandom failure to mate. Application of this model to these two populations suggests that under some circumstances nonrandomness in celibacy and emigration may have a greater influence on genotype distributions than does consanguinity avoidance.

Consanguinity↗

PubMed1997

Nonrandom mating in pikas Ochotona princeps: evidence for inbreeding between individuals of intermediate relatedness.

The extent and effect of inbreeding in natural populations remain largely undetermined. Pikas Ochotona princeps have been considered a likely candidate for close inbreeding in natural populations due to observations of frequent juvenile philopatry (colonization of natal home range or neighbouring home range) and high levels of spatial overlap and social tolerance between neighbouring individuals of the opposite sex. A 4-year investigation of inbreeding in pikas, however, has revealed that dispersal and mating patterns are uncoupled in this species, i.e. explained by different hypotheses. DNA fingerprinting analysis revealed that band-sharing scores between mated pairs, identified via parentage analysis, were not commensurate with band-sharing among known first-order relatives, but were similar to scores for a small sample of known second-order relatives (i.e. half-siblings grandparent-grandchild pairs). Band-sharing scores between mated pairs were then compared with those between potential mated pairs within the population to assess whether mating was random or nonrandom with respect to genetic similarity. The results of Monte Carlo randomization tests show that pikas mated with individuals with intermediate genetic similarity in greater proportion than would be expected by chance. These data suggest mate choice in pikas may be based upon intermediate levels of relatedness.

Animals↗

PubMed1997

Factors associated with prolonged weaning-to-mating interval among sows on farms that wean pigs early.

OBJECTIVE: To determine factors associated with weaning-to-mating interval among sows on commercial farms that wean pigs early. DESIGN: Cohort study. ANIMALS: 11,861 farrowing sows. PROCEDURE: Production, farrowing, and feed intake records were reviewed for sows on 16 farms for which mean duration of lactation was between 14.9 and 18.9 days. RESULTS: Among sows with high feed intake during lactation (> or = 5.6 kg/d [12.3 lb/d]), lactation duration was not associated with weaning-to-mating interval, but among sows with low feed intake during lactation (< 5.6 kg/d), weaning-to-mating interval increased as lactation duration decreased. Furthermore, among sows with the lowest feed intake during lactation (< 4.2 kg/d [9.2 lb/d]), those that had heavier litter weights at weaning (> 54 kg [119 lb]) had a longer weaning-to-mating interval than did those that had lighter litter weights at weaning. Sows with low feed intake and high litter weight at weaning accounted for 5 to 20% of sows on each farm. In general, weaning-to-mating interval increased as parity decreased, but the change in weaning-to-mating interval associated with a particular change in lactation duration varied with parity. CLINICAL IMPLICATIONS: When feed intake during lactation is maximized (> or = 5.6 kg/d), lactation duration is not significantly associated with weaning-to-mating interval. Producers should consider fostering or partially weaning litters when sows with high litter weights are not consuming sufficient feed.

Analysis of Variance↗