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PubMed1979

[Vaginal smear cycle in 4-day cyclic Chinese hamsters, Cricetulus griseus].

The contents of vaginal smear of 4-day cyclic Chinese hamster (Cricetulus griseus) was investigated every 3 hours for 5 days. A light-dark cycle of 14--10 hr was used with the lights turned on at 6 : 00 a.m. Estrous cycle of the Chinese hamster determined by vaginal smears can be divided into 6 periods. The proestrous phase started at about 0 : 00 of day 1, the day of the proestrous phase was designated as day 1 of the estrous cycle. In the afternoon of the same day 1, nucleated epithelial cells gradually increased in number (proestrus : I), and the vaginal contents became to consist solely of nucleated epithelial cells at about 18 : 00 to 21 : 00 (estrus : II). At about 0 : 00 of day 2, however, nucleated epithelial cells were superseded suddenly by cornified epithelial cells, and this phase lasted for 9 to 12 hr (metestrus I : III). Towards the end of the cornified stage, nucleated cells appeared in short duration (metestrus II : IV). And then, in the evening of day 2, leucocytes gradually increased in number with degeneration of nucleated cells (diestrus I : V-1). On day 3, vaginal smear contained a large amount of mucus as well as degenerated nucleated cells and leucocytes (diestrus II : V-2). At about 21 : 000 of day 4, some cornified epithelial cells were seen and then proestrous stage was returned. The females were mated with 3 to 5 males in the evening of day 1, copulation was confirmed in 83.7% females in the next morning,thus the copulation in the Chinese hamster may be thought to occur during the vaginal smear stage of nucleated epithelial cells (estrous phase), i.e. about 18 : 00 to 24 : 00 of day 1.

Animals↗
PubMedDate not supplied

Existence of a sex pheromone in Triatoma infestans (Hemiptera: Reduviidae): II. Electrophysiological correlates.

The stimulus provided by a copulating pair of Triatoma infestans significantly affects the electrical activity of the nervous system of Triatoma infestans. Electrophysiological recordings were performed on stationary adult males presented with stimuli of an air current carrying odors from males, females, non-copulating pairs and mating pairs. The electrophysiological response was characterized by the low frequency occurrence of biphasic compound impulses. A significant increase in the frequency of the impulses occurred in stationary males when exposed to air currents of mating pairs, when compared to that evoked by a clean air stream. Analysis of the time course of the assays, showed that the electrophysiological activity during the copula was higher than prior to or after copula. The electrophysiological evidence presented here strongly supports the existence of pheromone(s) released by one or both sexes during mating and which is perceived by male chemoreceptors located on the antennae.

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↗
PubMed2004

Alterations to gonadal development and reproductive success in Japanese medaka (Oryzias latipes) exposed to 17alpha-ethinylestradiol.

The Japanese medaka (Oryzias latipes) was used as an in vivo model to evaluate the effects of exposure to the synthetic estrogen 17alpha-ethinylestradiol (EE2) on reproductive behavior and reproductive success in fish. Exposures to EE2 began within 2 to 5 d posthatch and continued until medaka were sexually mature, between four and six months of age. Among male and female medaka exposed to EE2 at nominal concentrations of 0.2 and 2 ng/L, mating behavior and reproductive success were normal in reproductive trials. However, reproductive behavior (i.e., copulations) was suppressed in the treatment with 10 ng/L EE2. Among 19 males exposed to 10 ng/L EE2 and placed with unexposed females in reproductive trials, 16 males did not copulate and reproductive success was very low. None of the females exposed to 10 ng/L of EE2 participated in reproductive behavior with unexposed males. The reproductive trials in combination with a histological survey indicated that male fish with gonadal intersex (i.e., testis-ova) were still capable of reproductive behavior and could fertilize eggs. Even though females exposed to 10 ng/L EE2 had poor reproductive success, their ovaries showed normal development and oogenesis. These data are relevant to observations of intersex in feral fish populations. Although intersex in male fish may be an indicator of exposure to estrogenic compounds, it appears that the presence of oocytes in testicular tissue may not directly impact the reproductive capability of the male fish. However, it is clear that concentrations of endocrine disrupting chemicals (EDCs) that cause gonadal intersex are sufficient to reduce reproductive performance.

Animals↗
PubMed1995

Effects of short-term administration of alpha-chlorohydrin on reproductive toxicity parameters in male Sprague-Dawley rats.

alpha-Chlorohydrin (alpha-CH) was administered orally at doses of 0, 2 or 8 mg/kg/day for 2 weeks to Sprague-Dawley male rats. At the end of the administration period or 2 weeks after withdrawal (one group also treated with 8 mg/kg for 4 weeks), males were mated (treatment with alpha-CH was continued throughout the mating period of 2 weeks) with untreated females, and underwent examination, including assessment of sperm, to determine fertility. No significant treatment-associated changes were observed in terms of body weight, food consumption, or weights of the testes, epididymides or prostate in either the 2 or the 8 mg/kg group. Although there were no significant differences in sperm number, viability or maturation rate between either of the treated groups and the control group, sperm motility in the 8 mg/kg group observed after 2 hours incubation and sperm activity in groups treated with 8 mg/kg observed immediately after collection or after 2 hours incubation, as well as in the 2 mg/kg observed after 2 hours of incubation were significantly decreased. Two weeks after withdrawal (8 mg/kg group only), sperm motility and activity were no longer decreased. Histopathological examination of the testes after 4 weeks of alpha-CH administration disclosed no abnormalities on staining with Hematoxylin-Eosin after fixation in Bouin's solution. All treated male rats copulated with untreated females, but no pregnancy resulted from mating in the 8 mg/kg continuous administration case. There were no significant differences between the control and 2 mg/kg groups in numbers of corpora lutea and implantations in animals becoming pregnant. Two weeks after withdrawal, male rats treated with 8 mg/kg copulated and impregnated females. These findings suggest that evaluation of male fertility is possible within or following a 2-week treatment period for compounds like alpha-CH which have no toxicological, histopathological or sperm morphological effects, and that the use of several parameters for sperm examination is important in determining male fertility.

Animals↗
PubMed1995

Male reproductive toxicity of ethinylestradiol associated with 4 weeks daily dosing prior to mating in rats.

Parameters of male reproductive toxicity of ethinylestradiol were assessed by conducting a mating test, sperm assay, organ weight determination and histopathological examination. Male Sprague Dawley rats were orally administered 0.1, 0.3, 3 or 10 mg/kg/day ethinylestradiol for 4 weeks prior to mating. Body weight gain and food consumption were suppressed in all treated groups. Reproductive ability of the 3 and 10 mg/kg/day males disappeared. Slightly low copulation indices were observed in the 0.1 and 0.3 mg/kg/day groups, although fertility indices were not affected. Sperm could hardly be found in the epididymis of 3 and 10 mg/kg/day males. Sperm counts were also decreased in the other treated groups, but sperm motility was not affected. Decreased absolute and/or relative weights of testes, epididymides, prostate and seminal vesicles were observed in all treated groups along with testis, epididymis, seminal vesicle and prostate atrophy, and degenerative changes of spermatocytes, spermatids, Sertoli cells and Leydig cells. These results suggest that sperm quantification and histopathological assessment are more appropriate for assessing male reproductive toxicity of ethinylestradiol than performance of copulation and fertility tests.

Animals↗
PubMed2001

Multiple paternity in Littorina obtusata (Gastropoda, Littorinidae) revealed by microsatellite analyses.

Parental identity for juvenile Littorina obtusata was determined from three egg masses by means of microsatellite DNA markers. Results confirm that the attendant adult female in each case was the dam of the offspring and that at least 4-6 males contributed to each brood. This correlates with our behavioral observations that indicated multiple copulations between the female and several males in each experimental aquarium. A significant number of offspring from each brood were sired by non-sampled males (males that had copulated with females before capture) whose sperm had been stored by the female. This is the first direct evidence of multiple paternity in the Littorinidae. Results are discussed in reference to current theories of sperm competition, male precedence, and cryptic female choice.

Animals↗
PubMed1996

Facially impaired man versus chimpanzee: a within-primate differentiation effect.

66 women, French students enrolled in a course, evaluated the presumed behavioural identity of a man whose face was severely deformed as observed in a photograph and evaluated the presumed behavioural identity of a chimpanzee whose face was also observed in a photograph. The behavioural targets referred to five areas of sexuality, to copulate, to masturbate, and to experience sexual pleasure with another; technology to garden, to prepare a meal, and to scavenge for plants; physiology to digest food to form hormones, and to perspire; social interactions: to converse with another, to do a favour for another, and to imitate; and cognition: to count up to ten, to remember recent events, and to use a stick as lever. The experiment had a 2 (entity: human's face versus chimpanzee's face) x 2 (presentation-order: man then chimpanzee versus the opposite order) experimental design with 33 subjects per cell. As predicted, the main effect of the presentation-order factor and the two-way interaction were significant for three target behaviors (to converse with another, to prepare a meal; and to copulate). The within-primate differentiation effect was explained in terms of motivation to preserve the identity of both the man and the chimpanzee.

Adult↗
PubMed2002

An evolutionary perspective on the interaction of age and sex differences in short-term sexual strategies.

Buss and Schmitt's sexual strategies theory (1993) suggests that short-term mating represents a larger component of men's than women's mating strategies. Assuming this sex difference there is potential for conflict. Symons argued that, because men are more interested in copulation than women, this gives women greater power in establishing conditions (short- vs long-term) under which copulation takes place. The result is that the conflict in sexual strategies is resolved in favor of women's relatively greater interest in long-term sexual strategies. This research tested the hypothesis that across ages men would decrease in desire to employ short-term mating strategies in favor of long-term mating strategies. Specifically, in Study I, men and women in their teens, twenties, and thirties or older were given a measure of desire for a committed relationship. It was predicted that women, regardless of age, would score high on desire for a committed relationship. In contrast, teenage boys would score low on desire for a committed relationship while men in their thirties or older would score as high as the women. In Study II both sexes in their teens, twenties, and thirties or older were given measures of desire for promiscuous sex. It was predicted that the women, regardless of age, would score low on desire for promiscuous sex. In contrast, teenage boys would score high on desire for promiscuous sex while men in their thirties or older would score as low as the women. Support was found for both predictions.

Adolescent↗
PubMed1999

Hormonal and behavioral correlates of emotional states in sexually trained boars.

Physiological and behavioral traits of sexually mature boars were compared between episodes of copulation and sexual frustration in order to determine reliable indicators of the differences in emotional states. Ten boars, approximately 6 mo of age, were trained to mount a stationary artificial sow (ArtSow) and to ejaculate when digital pressure was applied to the extended penis. This method of semen collection is the typical procedure of the industry. All 10 boars used in this study were fully trained to this procedure before the onset of the study. Each boar was subjected to trials in which one of the following two treatments was applied. In the control (CTRL) treatment, boars were treated the same as during their training (i.e., allowed to complete ejaculation). In the frustration (FRUS) treatment, boars were allowed to mount the ArtSow, but because no manual pressure was applied to the extended penis, ejaculation never occurred. Blood was collected via indwelling catheters before onset of the trial, during exposure to the ArtSow, and after returning to their home pen. Concentrations of testosterone, cortisol, and beta-endorphin were quantified. Behavior of the boars was recorded during exposure to the ArtSow and for 30 min after return to their home pen. Relative to preexposure levels, serum cortisol increased (P<.05) during CTRL exposure and after exposure to both treatments (CTRL; P<.04 and FRUS; P<.06). Serum testosterone did not change during and after either treatment. Serum concentrations of beta-endorphin did not change during or after CTRL trials, but serum beta-endorphin was greater (P<.05) during FRUS than during CTRL trials. Behavioral analysis revealed that boars spent less time lying down and more time moving about their home pen (P<.05) after a FRUS than after a CTRL trial. In summary, serum cortisol did not allow us to distinguish between the excitement of copulation and the negative affect associated with sexual frustration, whereas increases in serum beta-endorphin and motor activity seemed to be indicators of the negative emotional state of sexual frustration in trained boars.

Animals↗
PubMed1992

Environmental cues, endocrine factors, and reproductive diapause in male insects.

Environmental cues, mostly photoperiod and temperature, mediated by effects on the neuroendocrine system, control reproductive diapause in female insects. Arrest of oocyte development characterizes female reproductive diapause, which has two major adaptive functions: It improves chances of survival during unfavorable season(s), and/or it confines oviposition to that period of the year that is optimal for survival of the eggs and progeny. Although reproductive diapause is less well studied in male insects, there may be no sex-dependent differences in regard to the first of these functions. The second one, however, is not valid for the male; instead, selection pressure directs the male's reproductive strategy toward maximum chances of fertilization of the female's eggs with minimum waste of energy. Therefore, in species with female reproductive diapause, the males may or may not exhibit diapause, but if they do, their diapause must be adapted to that existing in conspecific females. Male reproductive diapause is defined as a reversible state of inability of the male to inseminate receptive females. In relation to reproductive diapause, there are several patterns of coadaptations between male reproductive strategy and timing of female receptivity. (a) In some insects, the females are receptive in the early part of their diapause; mating occurs during this period and there is no diapause in the male. The male dies shortly after copulation and the female stores the sperms to fertilize the eggs that develop after termination of the female's diapause. (b) In some species, as in the grasshopper Anacridium aegyptium, females are receptive during diapause; though oocyte development is arrested, copulation occurs and the stored sperms fertilize the eggs when the female's diapause ends. Males were claimed to have no diapause, but recent studies have revealed the presence of a reproductive diapause in a proportion of the males. This and other cases show that female receptivity during reproductive diapause may or may not be accompanied by male reproductive diapause. If there is a reproductive diapause in the male, it is controlled by the same endocrine mechanism, the corpora allata (CA), as in the females. (c) In many species females are refractory during their diapause. In these cases, males exhibit reproductive diapause, which may be light, as in the beetle Oulema melanopus, or well established, as in certain grasshoppers, butterflies, and beetles. In the latter cases, male diapause is controlled by similar environmental cues (photoperiod, temperature) and by the same intrinsic mechanism (neuroendocrine system, especially CA) as female diapause.(ABSTRACT TRUNCATED AT 400 WORDS)

Adaptation, Physiological↗
PubMed2000

Microbes in tree swallow semen.

A frequently hypothesized but poorly studied cost of multiple mating in birds is that exposure to pathogenic sexually transmitted microbes (STM's) can lower reproductive success. Conversely, female birds may benefit from high frequencies of copulation and multiple copulation partners if they receive cloacal inoculations of beneficial STM's that can either protect them against future encounters with pathogens and/or serve as therapy against present infection. We examined the semen of 30 male tree swallows (Tachycineta bicolor) in 1998 to determine the presence and prevalence of potential pathogenic and beneficial STM's. Semen was collected directly from males after applying gentle pressure to the cloaca and we used standard microbiological techniques to identify microbes. We found that 19 of 30 samples contained one or more types of microbes. In these 19 positive samples, we isolated both pathogenic and beneficial microbes from 11, only pathogenic microbes from seven, and only beneficial microbes from one. This variation among males suggests that females would benefit from considering a particular male's potential as a donor of either pathogenic or beneficial STM's as a criterion for mate choice. There were few significant differences between males with pathogen-infected semen and those without pathogens in their semen in measures of size, morphology, and ectoparasite score and feather damage. Likewise, there were few significant differences between males with beneficial Lactobacilli spp. in their semen and those without Lactobacilli spp. in their semen in measures of size, morphology, and ectoparasite score and feather damage. We were unable to determine if there was a relationship between microbe presence and prevalence on reproductive performance.

Animals↗
PubMed1999

Nitric oxide and penile erection in streptozotocin-diabetic rats.

The purpose of this investigation was to study the time course, response to insulin and characteristics of erectile dysfunction in streptozotocin (STZ)-diabetic Sprague-Dawley rats, and the function of the NO-generating system in these animals. Copulation-induced and reflex erection were quantified in conscious Sprague-Dawley rats at different times after injection of STZ. The corporal vasodilatation response to nerve stimulation was studied by measuring the rise in corporal pressure in pithed rats following electrical stimulation of sacral spinal nerve roots. The activity of NO synthase was determined in corporal tissue by measuring the generation of [3H]citrulline from [3H]arginine. Copulation-induced erection was inhibited at 1 and 2 months after STZ treatment, but this could be prevented by a short (2-week) pretreatment with insulin. Reflex erection was inhibited at 1, 4, 6 and 9 months after STZ; at 6 months, this inhibition was also reversible by insulin pretreatment. Following pithing, the basal corporal pressure was elevated in diabetic rats. At 4 months after STZ, this increase was normalized by a 2-week, but not by a 1-week, pretreatment with insulin; however, at 9 months after STZ, insulin pretreatment did not normalize corporal pressure. The increase in corporal pressure caused by stimulation of sacral nerve roots in pithed rats was enhanced in diabetic animals. This enhancement was also normalized at 4 months, but not at 9 months, by 2 weeks of insulin treatment. The inhibition of the stimulation-induced increase in corporal pressure by NG-nitro-L-arginine methyl ester (5 mg/kg) was less following 9 months of diabetes, although NO synthase activity was normal in cavernosal tissue following 6-8 months of diabetes. In conclusion, STZ-induced diabetes caused changes in the erectile system that were initially reversible by a short insulin treatment, but which with time (more than 6 months) became irreversible. NO synthase activity in cavernosal tissue was normal, but the response to NG-nitro-L-arginine methyl ester was inhibited in long-term diabetes (9 months).

Animals↗
PubMedDate not supplied

[Physical factors in the treatment and rehabilitation of patients with chronic prostatitis complicated by impotence].

103 patients with chronic prostatitis complicated by erectile impotence were given combined treatment including shock-wave massage, mud applications, local vacuum magnetotherapy. This combination was found to stimulate copulative function, urodynamics of the lower urinary tracts, to produce an antiinflammatory effect. These benefits allow to recommend the above physical factors for management of chronic prostatitis patients with copulative dysfunction.

Adult↗
PubMed1975

Ejaculatory disorders of the stallion.

Ejaculatory disorders of the stallion seem to occur more frequently than hitherto accepted. The condition is manifested differently in individual stallions from normal copulation without ejaculation to an abnormal pattern of copulation without or with occasional ejaculation. The condition is probably caused by a functional disturbance of the nervous mechanism which controls the ejaculatory process, and may be caused by environmental or other factors. Eleven cases of ejaculatory disorders in normal healthy stallions were investigated and three of these animals recovered after simple correction of environmental factors, including the number of mares served. Of the eight stallions which did not respond to environmental changes, one recovered after treatment with pilocarpine and one after treatment iwth ephedrine. Possible causes of failure of the nervous regulation of the reproductive tract are discussed.

Animals↗
PubMedDate not supplied

[The effect of the actoprotector preparation bromantane on the postnatal development of rat pups].

The purpose of this work was study of the late-term results of a course of the actoprotector bromantan on the formation and development of the rat progeny. Bromantan was given per os daily in doses of 30, 150, and 600 mg/kg once a day: females received the drug for 15 days (2.5 estrous cycles), males for 60 days (whole cycle of spermatogenesis). When the course of treatment with the drug ended, the females were put together with the males for two weeks. The experiments were subdivided into two series: in series I the progeny obtained from coupling of experimental males with intact females was studied, in series II the progeny of intact males and experimental females. According to the results of the investigation, bromantan produced a late-term effect on the formation and development of the offsprings. The number of females who gave birth in series I and II of the experiment, despite a low dose-dependent increase, did not differ significantly from the controls. In series I of the experiment the litter increased insignificantly depending on the dose (by 0.3, 14.9, and 23.4%, respectively). In distinction, in the case of experimental females given 30 and 600 mg/kg bromantan before copulation (series II) the number of young rats in the litter insignificantly reduced (by 34.9 and 44.2%), in the case of rats given 150 mg/kg bromantan the litter increased (by 45%, p < 0.05). Both in series I and series II the mean weight of the newborns in the first week was significantly higher than the weight of the controls. After that the growth in body weight was insignificantly slower. Evaluation of the functional condition of the nervous system and terms of physical development of the progeny in series I and II of copulation showed an insignificant increase in the rate of maturation of the sensorimotor reflexes and physical parameters of the young experimental rats. The "open-field" test conducted on the 40th day of life showed increase of motor (by 8.0-21.6%) and exploration activity (by 94.5-109.9%, p < 0.05) in the young experimental rats of series I and, at the same time, decrease of the grooming parameters (by 26.9-63.5%, p < 0.05) and emotionality. In all experimental groups of series II horizontal and vertical motor and searching activity was reduced. The authors believe that the actoprotector bromantan, possessing a dopaminergic effect in the mechanism of its action, may cause a late-term influence on prolactin secretion in lactating rats. The deficiency in this hormone in the early period of postnatal development affects the neurochemical organization of the hypothalamo-hypophyseal region and the brain areas connected with it, involving in this case also the mechanisms of sexual differentiation of the brain and, as a consequence, the somatic and sexual development of the progeny.

Amantadine↗
PubMed2001

Drosophila bipectinata species complex.

The Drosophila bipectinata species complex belongs to the ananassae subgroup of the melanogaster species group (Genus Drosophila, Subgenus Sophophora). The members of the complex are: D. bipectinata, D. parabipectinata, D. malerkotliana, and D. pseudoananassae. Of the four species, D. bipectinata is most widely distributed. Females are indistinguishable, but males are distinguishable by their sex-comb teeth number and pattern and by abdominal colouration. Chromosomal inversions have been detected in these species. In natural populations of D. bipectinata the frequency of inversions and the level of inversion heterozygosity were found to be very low but in laboratory stocks inversions persisted for more than 20 generations due to heterotic buffering. On an average 9.3 fixed interspecific inversions separate each species pair. Non-random association between linked inversions indicated epistatic interaction in natural populations of D. bipectinata. Certain spontaneous mutations were detected and mapped for the first time in D. bipectinata. Low frequency of spontaneous male recombination has also been reported in D. bipectinata. Sexual isolation study in the complex indicated strong preference for homogamic mating. The results also indicated incomplete sexual isolation among different members of this complex. The isolation estimate among six different geographic populations of D. bipectinata ranged from 0.54 - 0.92 representing positive assortative mating which is an evidence for incipient sexual isolation. Incipient sexual isolation was also found within D. malerkotliana and D. parabipectinata . Chromosomal, hybridization and allozyme studies revealed close phylogenetic relationship among the four species of the bipectinata complex. Mitochondrial DNA study revealed net nucleotide difference (delta) between these species to be very small (0.0002 +/- 0.0008) reflecting closeness. Evidence for genetic control of sexual activity and existence of sexual selection in D. bipectinata has been shown on the basis of mating propensity tests carried out on geographic strains, their hybrids and diallel crosses. Significant variation was found among the strains tested with respect to courtship time, duration of copulation and fertility. A positive correlation between duration of copulation and fertility in D. bipectinata was found. Evidence for rare-male mating advantage was also found in D. bipectinata. A positive response to selection for high and low mating activity provided evidence for polygenic control of this phenomenon in D. bipectinata. Bilateral outgrowths on thorax, a unique phenotype, reported for the first time in D. bipectinata has been shown to affect mate recognition ability. Results of the study on pupation site preference (larval behaviour) and oviposition site preference (non-sexual behaviour) have also been included.

Animals↗