Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Copulation”

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 1,729 records · Page 96Linked to original sources
PubMed1975

Individual odor differences and their social functions in insects.

The evolution of individual or subgroup differences in odors of halictine bees is suggested from possible widespread intraspecific variation in pheromones. An important result of such variation may be maintenance of genetic polymorphisms; in nesting Hymenoptera odor differences may also facilitate individual nest recognition. In Lasioglosum zephyrum males habituate to odors of different females and perhaps thus save time by not trying to copulate with nonreceptive individuals. Guards (females) at nest entrances distinguish their few nestmates (other females) from other conspecific individuals by odors, seemingly pheromones. Duration of the habituation in L. zephyrum is at least an hour (perhaps much more) for males in relation to females and 6 or 7 days for guards in relation to nestmates. Studies of pheromones should take into consideration the possibility of pheromonal polymorphism in any species and the likelihood that it may be significant from biological and practical viewpoints.

Animals↗
PubMed1980

Purification and primary structure of two neuroactive peptides that cause bag cell afterdischarge and egg-laying in Aplysia.

Two neuroactive peptides, A and B, have been isolated from the atrial gland in the reproductive tract of Aplysia. Each of the two peptides is able to induce egg-laying behavior in recipient animals. In vitro recordings from the abdominal ganglion show that both peptides also trigger longlasting discharges in the bag cell neurons at concentrations around 0.1 muM. The peptides were purified by a combination of ammonium sulfate precipitation, agarose gel filtration, and cation exchange chromatography. Each peptide has 34 amino acid residues. Microsequencing together with carboxypeptidase Y degradation and analysis of tryptic peptides revealed the following sequence for peptide A: H-Ala-Val-Lys-Leu-Ser-Ser-Asp-Gly-Asn-Tyr-Pro-Phe-Asp-Leu-Ser-Lys-Glu-Asp-Gly -Ala-Gln-Pro-Tyr-Phe-Met-Thr-Pro-Arg-Leu-Arg-Phe-Tyr-Pro-Ile. Peptide B differs from A in only four positions. The first nine residues of B are: Ala-Val-Lys-Ser-Ser-Ser-Tyr-Glu-Lys-, whereas residues 10-34 of B are identical to those of A. The calculated M(r) of A is 3924 and that of B is 4032. The pI of peptide A as determined by isoelectric focusing in polyacrylamide gels is 7.9-8.1 and that of peptide B is 9.0-9.2. It is estimated that each atrial gland contains at least 150 mug of peptide A and 50 mug of B. Neither peptide resembles the egg-laying hormone isolated from bag cell neurons. It is postulated that the atrial gland peptides are released during copulation, and then by interacting with neuronal receptors in the head ganglia and pleuroabdominal connectives they cause the bag cells to afterdischarge, thereby releasing egg-laying hormone.

Action Potentials↗
PubMed1983

Combination therapy of schistosomiasis by tubercidin and nitrobenzylthioinosine 5'-monophosphate.

Nitrobenzylthioinosine 5'-monophosphate (NBMPR-P) inhibits the transport of nucleosides, including tubercidin, in mammalian systems but not in Schistosoma mansoni. Administration of NBMPR-P with high doses of tubercidin (lethal doses if injected alone) by intraperitoneal injection into S. mansoni-infected mice was highly toxic to the parasite but not to the host. Combination therapy resulted in a striking decrease in the number and copulation of worms. The few worms that could be found were so stunted that it was difficult to identify their sex. Mice receiving the combination of tubercidin plus NBMPR-P appeared healthy and had normal-sized livers and spleens. Combination therapy also caused a drastic decrease in the number of eggs in the liver (from 32,500 to 1,800 eggs per liver) and in the intestine (from 1,295 to 2 eggs per cm2). All eggs found were dead, indicating the termination of oviposition. Very few granulomas were detected in livers of treated animals. Sections of these livers showed lesions containing dead worms and what appeared to be a process of regeneration of normal tissue around old granulomas. Thus, combination therapy reduced the number and the progress of the primary pathological lesions associated with schistosomiasis. These results demonstrate that through combination therapy, highly selective toxicity against a parasite can be achieved. The effectiveness, simplicity, and practicality of host protection afforded by this method may yield a promising chemotherapeutic approach for the treatment of schistosomiasis and other parasitic diseases.

Animals↗
PubMed1994

Large-male advantages associated with costs of sperm production in Drosophila hydei, a species with giant sperm.

Males of the fruit fly Drosophila hydei were found to produce 23.47 +/- 0.46-mm-long spermatozoa, the longest ever described. No relationship was found between male body size and sperm length. We predicted that if these giant gametes are costly for males to produce, then correlations should exist between male body size, rates of sperm production, and fitness attributes associated with the production of sperm. Smaller males were found to make a greater relative investment in testicular tissue growth, even though they have shorter and thinner testes. Smaller males were also found to (i) be maturing fewer sperm bundles within the testes at any point in time than larger males, (ii) require a longer period of time post-eclosion to become reproductively mature, (iii) mate with fewer females, (iv) transfer fewer sperm per copulation, and (v) produce fewer progeny. The significance of these findings for body size-related fitness and the question of sperm size evolution are discussed.

Animals↗
PubMed1995

The chemistry of sexual selection.

The moth Utetheisa ornatrix (Lepidoptera: Arctiidae) is protected against predation by pyrrolizidine alkaloids that it sequesters as a larva from its foodplants. At mating, the male transfers alkaloid to the female with the spermatophore, a gift that the female supplements with alkaloid of her own and transmits to the eggs. Eggs are protected as a result. The male produces a pheromone, hydroxydanaidal, that he derives from the alkaloid and emits from a pair of extrusible brushes (coremata) during precopulatory interaction with the female. Males rendered experimentally alkaloid-free fail to produce the pheromone and are less successful in courtship. The male produces the pheromone in proportion both to his alkaloid load and to the amount of alkaloid he transfers to the female. The pheromone could thus serve as an indication of male "worth" and provide a basis for female choice. Utetheisa females are promiscuous and therefore are able to accrue multiple nuptial gifts (alkaloid and nutrient, both transmitted with the spermatophore). They use sperm selectively, favoring those of larger males. Larger males in nature are also richer in alkaloid. Females therefore reinforce after copulation the choice mechanism they already exercise during courtship.

Alkaloids↗
PubMed1995

Reproductive cooperation between queens and their mated workers: the complex life history of an ant with a valuable nest.

The life history of Harpegnathos saltator is exceptional among ants because both queens and workers reproduce sexually. Recently mated queens start new colonies alone, but later some of the offspring workers also become inseminated and take over the egg-laying role. This alternation seems associated with the existence of very complex underground nests, which are designed to survive floods. Longevity of ponerine queens is low (a consequence of limited caste dimorphism in this "primitive" subfamily), and upon the death of an H. saltator foundress, the nest represents a substantial investment. The queen's progeny should thus be strongly selected to retain the valuable nests. Unlike the flying queens, the workers copulate with males from their own colonies, and, thus, their offspring are expected to be highly related to the foundress. Colony fission appears not to occur because a daughter fragment would lack an adequate nest for protection. Thus, the annual production of queens in colonies with reproductive workers remains essential for the establishment of new colonies. This contrasts with various other ponerine species in which the queens no longer exist.

Journal Article↗
PubMed1995

Dimensionless invariants from foraging theory's marginal value theorem.

Copula duration (t) decreases, and proportional rate of sperm transfer (c) increases, with larger male body size in dung flies, so their dimensionless product (c. t) is approximately constant (approximately 2.2). The most recent copulating male fertilizes about 89% of the eggs laid (= 1 - e(-c.t) = 1 - e(-2.2)), independent of his body size. The conditions under which natural selection favors this phenotypic invariance are studied with fitness optimization models. The dimensionless rules for optimal patch residence times are then generalized to cover phenotypic variation in other foraging cases.

Journal Article↗
PubMed1996

Sexual orientation in Drosophila is altered by the satori mutation in the sex-determination gene fruitless that encodes a zinc finger protein with a BTB domain.

We have isolated a new Drosophila mutant, satori (sat), the males of which do not court or copulate with female flies. The sat mutation comaps with fruitless (fru) at 91B and does not rescue the bisexual phenotype of fru, indicating that sat is allelic to fru (fru(sat)). The fru(sat) adult males lack a male-specific muscle, the muscle of Lawrence, as do adult males with other fru alleles. Molecular cloning and analyses of the genomic and complementary DNAs indicated that transcription of the fru locus yields several different transcripts. The sequence of fru cDNA clones revealed a long open reading frame that potentially encodes a putative transcription regulator with a BTB domain and two zinc finger motifs. In the 5' noncoding region, three putative transformer binding sites were identified in the female transcript but not in male transcripts. The fru gene is expressed in a population of brain cells, including those in the antennal lobe, that have been suggested to be involved in determination of male sexual orientation. We suggest that fru functions downstream of tra in the sex-determination cascade in some neural cells and that inappropriate sexual development of these cells in the fru mutants results in altered sexual orientation of the fly.

Alleles↗
PubMed1997

A genetic screen for mutations that disrupt an auditory response in Drosophila melanogaster.

Hearing is one of the last sensory modalities to be subjected to genetic analysis in Drosophila melanogaster. We describe a behavioral assay for auditory function involving courtship among groups of males triggered by the pulse component of the courtship song. In a mutagenesis screen for mutations that disrupt the auditory response, we have recovered 15 mutations that either reduce or abolish this response. Mutant audiograms indicate that seven mutants reduced the amplitude of the response at all intensities. Another seven abolished the response altogether. The other mutant, 5L3, responded only at high sound intensities, indicating that the threshold was shifted in this mutant. Six mutants were characterized in greater detail. 5L3 had a general courtship defect; courtship of females by 5L3 males also was affected strongly. 5P1 males courted females normally but had reduced success at copulation. 5P1 and 5N18 showed a significant decrement in olfactory response, indicating that the defects in these mutations are not specific to the auditory pathway. Two other mutants, 5M8 and 5N30, produced amotile sperm although in 5N30 this phenotype was genetically separable from the auditory phenotype. Finally, a new adult circling behavior phenotype, the pirouette phenotype, associated with massive neurodegeneration in the brain, was discovered in two mutants, 5G10 and 5N18. This study provides the basis for a genetic and molecular dissection of auditory mechanosensation and auditory behavior.

Animals↗
PubMed2001

Seasonal population dynamics of Neoechinorhynchus qinghaiensis in the carp, Gymnocypris przewalskii przewalskii, from Qinghai Lake, China.

Studies on the seasonal population dynamics of Neoechinorhynchus qinghaiensis (Acanthocephala: Neoechinorhynchidae) in its fish host Gymnocypris przewalskii przewalskii in the Qinghai Lake, China, were carried out with samples taken in May 1991, August 1992, November 1992 and February 1993. Prevalences were higher than 44% in all seasons. The mean intensity of infection was above 124 worms per fish. The maximum intensity of worms recovered from a single fish was 1402 in the autumn of 1992. Differences in the mean abundance, mean intensity and prevalence are not statistically significant relative to season and this is likely to be related to the stable temperatures recorded at the bottom of Qinghai Lake. Over-dispersed distributions of N. qinghaiensis in the host population, due to heterogeneity and feeding habits, were observed in all seasons. The size composition of both sexes of N. qinghaiensis showed males to be less than 3.5 mm and females between 0.5 and 4.25 mm, with the main recruitment phase in the worm populations occurring in the autumn, extending through winter and spring with the lowest recruitment occurring in the summer. The maturation and copulation of worms were mainly focused in the summer season. The sex ratio of female to male was both high in winter (1.51:1) and spring (1.48:1). The higher proportion of females and the change in the worm sex ratio in winter can be attributed to the reduced longevity of male worms. As immature male worms exhibit a higher proportion of the worm population than females in all seasons, further studies are needed to determine if such a situation compensates for the shorter life span of males.

Acanthocephala↗
PubMedDate not supplied

Hypoxia and induced mutations in Syrian (golden) hamsters. The origin and perpetuation of a species.

We were able to identify anomalous chromosome patterns-monosomy, trisomy, and polyploidy-in metaphase plates prepared from embryos of Syrian hamsters (Mesocricetus auratus) whose mothers had been exposed to low-pressure hypoxia during the hours after copulation. These females were exposed in a low-pressure chamber for 4 hours at pressures equivalent to 30,000 feet of altitude before (estimated) ovulation to create acid shifts of pH equilibrium in the milieu of newly released eggs during passage of sperm upward, during fertilization itself, and during early cleavage stages. The D group chromosomes were most frequently involved in both monosomy and hyperdiploidy. The easily identifiable X chromosome also appeared to be susceptible to aneuploid formation. Chromosomally abnormal patterns most frequently among sibling embryos conceived by aging mothers exposed to low-pressure hypoxia. The significance of induced mutations is discussed.

Animals↗
PubMed1997

Effects of male body weight, strain and dietary protein content on fertility and musculo-skeletal disease in naturally mated broiler breeder males.

1. The effects of male body weight at mating and different rates of gain on overall fertility were studied in two strains of broiler breeder males fed on a diet containing 160 or 120 g crude protein/kg. Sexual activity, musculo-skeletal disease and culling were also assessed. 2. There were no differences in early fertility between males weighing 3.0 or 3.5 kg at the start of the mating period, or between males gaining 1.0 or 1.5 kg body weight from mating to 60 weeks of age. 3. There were no differences in fertility between males fed on the two diets differing in crude protein content. 4. One strain of male had lower fertility than the other and this was associated with a greater weight of breast muscle, lower frequency of observed copulations and a higher number of incompleted matings. 5. Sexual activity declined and the number of spermatozoa trapped on the perivitelline membrane increased with age. 6. There were no differences among the treatments in the prevalence of musculo-skeletal lesions (destructive cartilage loss). As a proportion destructive cartilage loss occurred in 0.67 of the males at 66 weeks of age. Degeneration of the antitrochanter was present in 3 of 50 females examined and a cartilage flap in the medial condyle of the tibiotarsus occurred in 15 of these birds. 7. Beak lesions were the most important cause of male culling which averaged 0.24 as a proportion of the males at the start of the experiment.

Aging↗
PubMed2002

Ground scratching and preferred leg use in domestic chicks: changes in motor control in the first two weeks post-hatching.

Lateralisation of a variety of visual functions: food discrimination, fear response, copulation, and performance of topographical and other tasks, such as olfactory and auditory functions, have been described in the domestic chick, Gallus gallus domesticus. A bias to left hemisphere control on day 8 and to the right on day 11 has also been demonstrated in the domestic chick. In this study we show that motor control as to foot preference in initiating a scratching bout and a tape-removing task is lateralised in both adults and chicks. There was a preference for the right leg to initiate a bout of ground scratching in both male and female adult birds. Second, foot preference is also affected by the changes in shifts of bias on day 8 and day 11. The right leg preference in initiating a ground scratching bout observed on day 5 is reversed to a left leg preference on day 8. This then reverts to the right leg preference after day 11. Hence it is postulated that the hemisphere that is not activated due to the bias of age controls the first leg to be used in initiating routine movements such as ground scratching. For the tape-removing task the right leg was used to remove a tape adhered to the beak of the chick for the trained group on day 8; but there was no preference in the naive group. Similarly, on day 11 a left foot bias was observed for the trained group and right foot bias for the naive group. To remove a tape the activated hemisphere on days of bias is used; whereas in a novel situation the foot use is reversed. Thus, footedness is affected by age, type of task, and changing hemispheric dominance.

Journal Article↗
PubMed2004

Mechanism of antifertility in male rats treated with 3-monochloro-1,2-propanediol (3-MCPD).

3-Monochloro-1,2-propanediol (3-MCPD) is a food contaminant that is often found in foods containing acid-hydrolyzed (AH) protein, like seasonings and savory food products. The purpose of the present study was to investigate the effects of 3-MCPD on male fertility, sperm, and hormonal levels and its antifertility mechanism. In vivo male fertility testing was performed to observe the adverse effects of 3-MCPD on the functioning of the male reproductive system and pregnancy outcome. 3-MCPD (0.01-5 mg/kg) was administered daily by gavage to Sprague-Dawley (SD) male rats for 4 wk. At the end of the pretreatment period, male rats were mated overnight with untreated females. Males successfully inducing pregnancy were sacrificed to assess sperm parameters, reproductive organ histopathology, and spermatogenesis. The resulting pregnant females were sacrificed on 20 of gestation to evaluate pregnancy outcome. The paternal administration of 3-MCPD (5 mg/kg) was found to result in adverse effects on male fertility and pregnancy outcome without inducing remarkable histopathological changes in testes and epididymides. Additionally, 3-MCPD (5 mg/kg) significantly reduced sperm motility, copulation, fertility indices, and the number of live fetuses showed steep dose-response curves. 3-MCPD did not affect spermatogenesis or induce hormonal changes in the blood and testes of male rats. An in vitro hormone assay using primary isolated Leydig cells showed no significant changes in related hormone levels after 3-MCPD treatment. To evaluate the effects of 3-MCPD on apoptotic induction and H+-ATPase levels in the testis and epididymis, 10 or 100 mg/kg of 3-MCPD was administered by gavage to male rats and testes and epididymides were examined at 3, 6, 12, and 24 h later. Apoptosis was not detected in the testes of animals treated with 100 mg/kg 3-MCPD. However, the level of H+-ATPase in the cauda epididymis was reduced by 3-MCPD treatment. These results indicate that 3-MCPD induced a spermatotoxic effect, which was mediated by reduced H+-ATPase expression in the cauda epididymis, and suggest that an altered pH level in the cauda epididymis might lead to a disruption of sperm maturation and the acquisition of motility.

Animals↗
PubMed1988

Uptake, distribution, and metabolism of trivalent arsenic in the pregnant mouse.

To investigate the distribution of trivalent arsenic (arsenite) in the pregnant rodent, CD-1 mice were dosed with sodium arsenite by ip injection or by gavage on gestation d 18 (copulation plug day = d 1). Doses were 8 (ip) or 25 (po) mg/kg, and samples of maternal blood, liver, and kidneys, as well as fetuses and pooled placentas, were analyzed for total arsenic at intervals of up to 24 h. Fetal tissue was also analyzed for relative proportions of inorganic arsenic and methylated metabolites. Arsenic uptake was significantly greater in the injected mice and their fetuses (as a proportion of the administered dose), with levels highest at 10 min to 4 h in maternal tissues and 24 h in fetuses. Peak maternal arsenic levels (as microgram/g or microgram/ml) ranged from 2.36 (blood) to 26.15 (liver) for the ip injected and 1.25 (blood) to 17.64 (liver) for the gavaged treatment group. The rate of arsenic elimination from maternal samples was not significantly influenced by administration route, with first-order elimination rate constants (k) of 0.215 and 0.234 h-1 for the po and ip dosed mice, respectively. Fetal tissue arsenic peaks were 2.10 and 0.77 micrograms/g for the ip and po treatment groups, respectively. The proportion of methylated arsenic in fetuses increased to 79% in the ip treatment group and 88% in the po group by 24 h. Such results show that much of the arsenic reaching the mouse fetus has been methylated to less toxic metabolites. They also confirm that assumptions made regarding hazard to the fetus must reflect the likelihood that a portion of any maternal dose of inorganic arsenite reaching a fetus may have been methylated, and they support previous findings that arsenite is toxic to the conceptus at lower doses when given by injection than by gavage.

Animals↗
PubMed1989

Male fertility study on N,N-dimethylacetamide administered by the inhalation route to Sprague-Dawley rats.

Male Sprague-Dawley rats were exposed to N,N-dimethylacetamide (DMAC) and mated to untreated virgin females. Mean analytical exposure concentrations were 40, 116, and 386 ppm, respectively. A control group was exposed to air containing no DMAC. A total of 69 d of exposure to DMAC at these levels produced treatment-related effects of increased liver weights and liver/body weight ratios in the high- and medium-exposure groups of male rats. Reproductive data indicated no treatment-related effects on copulation efficiency or efficiency in effecting pregnancy, and there were no detectable treatment-related effects on preimplantation loss, postimplantation loss, embryotoxicity, or fetotoxicity in litters of females mated to males exposed to DMAC at the levels used in this study. The significance of these findings is discussed.

Acetamides↗
PubMed2000

Reproduction/developmental toxicity screening test in rats with orally-administered 1-hexene.

This study was conducted to provide screening information concerning the potential systemic, reproductive and developmental toxicity of 1-hexene when administered orally, by gavage, to male and female rats using a modified OECD 421 protocol. 1-Hexene was administered at doses of 100, 500, and 1000 mg/kg/day in corn oil; the control group received the vehicle at an equivalent volume. The males were treated for 28 days prior to mating and until euthanasia (44 days of dosing). The females were treated for 14 days prior to mating and during mating, gestation, and lactation until euthanasia (41-55 total days of dosing). Females were allowed to deliver and rear their offspring until lactation day 4. The parental rats were subject to a gross and microscopic examination. Viability and development of the pups were followed through lactation day 4. There was no mortality, and there were no clinical signs of toxicity or differences in body weights, weight gain, feed consumption or organ weights. Copulation and fertility indices, precoital intervals, gestation lengths and pregnancy rates were comparable among the groups, and no signs of prolonged delivery or unusual nesting behaviors were noted. Pup viability, body weights, external observations and necropsy data were comparable among the groups. Pitted kidneys were observed at necropsy for two parental males in the 500 mg/kg/day group and three males in the 1000 mg/kg/day group. Microscopic changes in the kidneys of some male rats from the 100, 500, and 1000 mg/kg/day groups consisted of dose-related accumulations of hyaline droplets in the epithelial cells of the proximal convoluted tubules of the kidneys. In summary, the only treatment-related effect noted in this study was hydrocarbon nephropathy in male rats, which is not considered relevant for human health. The NOAEL for systemic and reproductive toxicity was 1000 mg/kg/day, excluding the finding of male rat hydrocarbon nephropathy.

Administration, Oral↗
PubMed2001

Evaluation of the potential developmental toxicity of 3-aminopentanenitrile (3-APN) in the rat.

The potential developmental toxicity of 3-aminopentanenitrile (3-APN) was assessed in rats. Groups of 25 time-mated female Crl:CD(SD)IGS BR rats were orally gavaged at daily dose levels of 0, 5, 30, 100 or 300 mg/kg over days 6-20 of gestation (days 6-20G); the day of copulation plug detection was designated day 0G. The dams were euthanized on day 21G and their abdominal and thoracic viscera were examined grossly. The fetuses were weighed, sexed, and examined for external, visceral, and skeletal alterations. Evidence of maternal and developmental toxicity was seen at 100 and 300 mg/kg. Regarding maternal toxicity, there were compound-related, statistically significant reductions in maternal body weight and food consumption at 100 and 300 mg/kg. The incidence of alopecia was significantly increased at these levels as well. Regarding developmental toxicity, mean fetal weight was slightly but significantly reduced at 100 and 300 mg/kg. In addition, at 300 mg/kg, there were significant increases in several skeletal variations (wavy ribs and skull, rib, and vertebral ossification delays) consistent with developmental delay. There was no evidence of either maternal or developmental toxicity at 5 or 30 mg/kg. Thus, the maternal and developmental no-observed-effect level (NOEL) was 30 mg/kg. Because developmental toxicity was observed only after administration of doses that also produced signs of maternal toxicity, 3-APN is not considered to be a selective developmental toxicant in the rat.

Animals↗