Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “COURTSHIP”

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 829 records · Page 46Linked to original sources
PubMed1987

Exogenous GnRH overrides the endogenous annual reproductive rhythm in green iguanas, Iguana iguana.

Female green iguanas, Iguana iguana, were caught in Belize, Central America (17 degrees N), in December, at the onset of seasonal gonadal activity. The animals were immediately transferred to San Diego (32 degrees N). Ovarian follicular development continued, with peak plasma hormone levels measured in January and February; 200 pg/ml for progesterone (P) and 800 pg/ml for total estrogens (Et = estradiol [E2] + estrone [E1]). E2 was the predominant estrogen throughout the cycle. Follicular atrophy was indicated in April with circulating progesterone and estrogen levels decreasing to baseline (refractory phase) levels (P = 20 pg/ml; Et = 50 pg/ml). Approximately midway through the refractory phase of their annual reproductive cycle (late May), either the D-Arg6 analog of Chicken II or mammalian GnRH was administered via intraperitoneal osmotic pumps for 14 days to nine females. The analog of chicken II induced a fivefold increase in total circulating estrogens within 3-4 days after implantation. Both continuous and pulsatile delivery of the chicken II analog produced a similar pattern of steroidogenic response. A radical sham control animal showed no increase in steroidogenesis. Mammalian GnRH produced a pattern of similar duration, although the magnitude of the steroidogenic response was only half that produced by the chicken II analog. Estrogen titers approached baseline levels in all treatment groups two days after treatment ceased. Progesterone levels increased in all treatment groups during the delivery of exogenous GnRH, although the increases were not consistent. Untreated male cagemates housed with treated females exhibited increased territoriality, courtship behavior, and mating, which began on day 4 or 5 of the treatment period. The control female was not courted by its male cagemate.

Animals↗
PubMed2002

Specialized mucous glands and their possible adaptive role in the males of some species of Rana (Amphibia, Anura).

A structural and ultrastructural study was carried out on the cutaneous glands in some species of Rana (R. dalmatina, R. iberica, R. italica, R. "esculenta," and R. perezi), giving particular attention to the mucous secretory units. Two different types of mucous glands occur in R. dalmatina, R. iberica, and R. italica. Besides the ordinary mucous units, which are randomly distributed over the body surface in both males and females, a further population of mucous glands was observed on the male dorsal skin. The latter is recognizable by the peculiar morphology of the epithelial cells and some characteristics of the secretory product. Specialized mucous glands are absent in both sexes of R. "esculenta" and R. perezi. The possible adaptive role of the specialized mucous glands is discussed in light of the absence of vocal sacs in males of R. dalmatina, R. iberica, and R. italica. Chemosignals released by sexually dimorphic mucous units may replace vocal communication during the breeding season and so play an important role in female attraction and/or territorial announcement. The morphology and possible function of the specialized mucous glands in the three species of Rana are compared with the breeding glands of other frogs and with the hedonic glands of some urodeles (Salamandridae and Plethodontidae), which are known to produce pheromonal substances during courtship.

Adaptation, Physiological↗
PubMed2005

Genital structures in the entelegyne widow spider Latrodectus revivensis (Arachnida; Araneae; Theridiidae) indicate a low ability for cryptic female choice by sperm manipulation.

The female genital structures of the entelegyne spider Latrodectus revivensis are described using semithin sections and scanning electron microscopy. Apart from the tactile hairs overhanging the opening of the atrium, the contact zones of the female epigynum are devoid of any sensilla, indicating that the female does not discriminate in favor or against males due to their genital size or stimulation through copulatory courtship. The dumb-bell shape and the spatial separation of the entrance and the exit of the paired spermathecae suggest that they are functionally of the conduit type. Not described for other entelegyne spiders so far, the small fertilization ducts originating from the spermathecae of each side lead to a common fertilization duct that connects the spermathecae to the uterus externus. During oviposition, it is most likely that spermatozoa are indiscriminately sucked out of the spermathecal lumina by the low pressure produced by the contraction of the muscle extending from the epigynal plate to the common fertilization duct. As no greater amounts of secretion are produced by the female during oviposition, and no activated sperm are present within the female genital tract, the secretion produced by the spermathecal epithelium does not serve in displacement or (selective) activation of spermatozoa. These findings suggest that female L. revivensis are not able to exert cryptic female choice by selectively choosing spermatozoa of certain males.

Animals↗
PubMed1977

Tergal modifications associated with abdominal glandular cells in the Blattaria.

Tergal abdominal modifications of 30 species of Blattaria (Dictyoptera) were studied by means of histological scanning electron microscopy techniques. Despite marked anatomical diversity of the glands, only a few basic types of cells are present. Male tergal glands which are involved in sexual behavior generally have glandular cells filled with electron transparent vacuoles (type 3a) and those with dense myeloid secretion (type 3b); in addition some have large cells without ducts, not in contact with the cuticle and surrounded by other cells (type 2). External setae, usually associated with these structures, are mechano-receptors or mechano-chemoreceptors. Glands not involved in courtship (e.g., defensive glands) usually have large glandular cells with a ductule that reaches the end apparatus secreted by the glandular cell itself (Type 3) but lack types 2, 3a, and 3b. Species which do not have distinctive tergal modifications may have concentrations of microscopic pores or openings associated with glandular cells on certain segments. The chemistry of the secretions produced by tergal glands is unknown for most species. This paper emphasizes the need for behavioral and biochemical studies to elucidate the biological significance of cockroach tergal glands.

Animals↗
PubMed1986

Transport of sperm within the cloaca of the female red-spotted newt.

The transport of sperm in the cloaca and adjacent regions of the female red-spotted newt was examined. It was found that within 1 min after sperm were introduced into the vent, they progressed in a random pattern past the apertures of the spermatheca (the glandular, sperm storage organ that opens from the anterior roof of the cloaca) forward to the anterior end of the cloaca and on into the posterior regions of the hindgut and bladder. Sperm did not enter the dorsal recess of the cloaca into which the oviducts and ureters open. After 1 day, few sperm remained within the cloaca lumen. Sperm were not transported into the cloacae of artificially inseminated, anesthetized females without prior administration of norepinephrine to their cloacal mounds. Treatment of the cloacal mounds of naturally inseminated females with an antagonist of neuromuscular transmission (lidocaine) decreased the numbers of sperm in the anterior cloaca relative to those of saline-injected control specimens. Neither dead newt sperm nor live rabbit sperm entered the spermatheca. Rabbit sperm, however, entered the oviduct. It is argued that passive and active mechanisms of sperm transport work in concert. Contractions of smooth muscle, which may be initiated during courtship, probably serve to draw sperm passively into the cloaca and up to and beyond the apertures of spermathecal tubules, but sperm, once in the vicinity of those apertures, probably swim actively into them.

Animals↗
PubMed1992

Comparative anatomy and phylogeny of the cloacae of salamanders (Amphibia: Caudata). VI. Ambystomatidae and Dicamptodontidae.

Histology of the cloacae of Rhyacotriton olympicus and representative species from the genera Ambystoma and Dicamptodon was examined by light microscopy. Females of Ambystoma possess sperm storage glands, the spermathecae, as well as ventral glands and dorsal glands, both of uncertain function. Females of Ambystoma examined from the subgenus Linguaelapsus differ from those in the subgenus Ambystoma by possessing more extensive ventral gland clusters and a shorter cloacal tube. Females of Dicamptodon possess spermathecae and ventral glands, but differ in cloacal conformation from females of Ambystoma and lack the dorsal glands. Females of R. olympicus possess more extensive epidermal lining in the cloaca than that found in females of Ambystoma and Dicamptodon, and the only glands present are spermathecae, which cluster around a tube in the dorsal roof. Males of Ambystoma, Dicamptodon, and R. olympicus possess five types of cloacal glands (dorsal pelvic glands, lateral pelvic glands, anterior ventral glands, posterior ventral glands, and Kingsbury's glands) that function in spermatophore formation, and vent glands that may produce a courtship pheromone. In Ambystoma and Dicamptodon, vent glands secrete along the medial borders of the cloacal orifice. Males of A. opacum and A. talpoideum differ from males of other species examined from the two genera by possessing more extensive vent glands. Males of R. olympicus possess unique vent glands in which tubules secrete onto the surface of vent lobes lateral to the posterior end of the cloacal orifice, and distal ends of the glands pass anteriorly, superficial to the fascia enclosing the other cloacal glands. The results from analysis of cloacal anatomy support other data indicating that Ambystoma and Dicamptodon are sister groups, and that Rhyacotriton olympicus is not closely related to either of the other two genera and merits placement in a separate family.

Ambystomatidae↗
PubMed2002

Recovery of song preferences after excitotoxic HVC lesion in female canaries.

The courtship solicitation display (CSD) of the female canary is a model to study estrogen dependent auditory preferences for male songs. The forebrain auditory-vocal nucleus, HVC, is part of the circuit that determines such preferences. To further develop this model we show that bilateral excitotoxic lesions of the medial part of HVC involving between 18-60% of the bilateral nucleus are behaviorally effective while complete unilateral lesions are not. Further, we show that animals recover their song preferences over a period of several months after the lesion. This functional recovery does not involve anatomical recovery of the HVC. Even 9 months after the lesion, the HVC size of these females was similar to that of females sacrificed 2 days after the lesion and thus was 40 +/- 8% smaller compared to normal females. Further, ipsilaterally, the lesion procedure transiently disturbed the neurochemistry, such as GAD-mRNA expression, in the part of HVC that did not undergo cell death. These results suggest that the integrity of the lateral part of at least one HVC is required to perform CSD in response to relevant auditory stimuli.

Animals↗
PubMed2003

Genetic basis of male sexual behavior.

Male sexual behavior is increasingly the focus of genetic study in a variety of animals. Genetic analysis in the soil roundworm Caenorhabditis elegans and the fruit fly Drosophila melanogaster has lead to identification of genes and circuits that govern behaviors ranging from motivation and mate-searching to courtship and copulation. Some worm and fly genes have counterparts with related functions in higher animals and many more such correspondences can be expected. Analysis of mutations in mammals can potentially lead to insights into such issues as monogamous versus promiscuous sexual behavior and sexual orientation. Genetic analysis of sexual behavior has implications for understanding how the nervous system generates and controls a complex behavior. It can also help us to gain an appreciation of how behavior is encoded by genes and their regulatory sequences.

Animals↗
PubMed2001

Dopamine and sensory tissue development in Drosophila melanogaster.

Dopamine is an important signaling molecule in the nervous system; it also plays a vital role in the development of diverse non-neuronal tissues in the fruit fly Drosophila melanogaster. The current study demonstrates that males depleted of dopamine as third instar larvae (via inhibition of the biosynthetic enzyme tyrosine hydroxylase) demonstrated abnormalities in courtship behavior as adults. These defects were suggestive of abnormalities in sensory perception and/or processing. Electroretinograms (ERGs) of eyes from adults depleted of dopamine for 1 day as third instar larvae revealed diminished or absent on- and off-transients. These sensory defects were rescued by the addition of L-DOPA in conjunction with tyrosine hydroxylase inhibition during the larval stage. Depletion of dopamine in the first or second larval instar was lethal, but this was not due to a general inhibition of proliferative cells. To establish that dopamine was synthesized in tissues destined to become part of the adult sensory apparatus, transgenic lines were generated containing 1 or 4 kb of 5' upstream sequences from the Drosophila tyrosine hydroxylase gene (DTH) fused to the E. coli beta-galactosidase reporter. The DTH promoters directed expression of the reporter gene in discrete and consistent patterns within the imaginal discs, in addition to the expected expression in gonadal, brain, and cuticular tissues. The beta-galactosidase expression colocalized with tyrosine hydroxylase protein. These results are consistent with a developmental requirement for dopamine in the normal physiology of adult sensory tissues.

Animals↗
PubMed1986

Neuroeffectors for vocalization in Xenopus laevis: hormonal regulation of sexual dimorphism.

South African clawed frogs use sex-specific vocalizations during courtship. In the male, vocalizations are under the control of gonadal androgen. Though females have moderate levels of circulating androgen, they do not give male-typical mate calls. Both muscles of the vocal organ and neurons of the central nervous system (CNS) vocal pathway are sexually dimorphic and androgen-sensitive. Recent studies suggest that the failure of androgen to masculinize adult females results from a male-specific, androgen-regulated developmental program. At metamorphosis the larynx is sexually monomorphic and feminine in morphology, muscle fiber number and androgen receptor content. During the next six months, under the influence of increasing androgen titers and high receptor levels, myoblasts proliferate in the male and muscle fibers increase at an average rate of 100/day. Females have much lower hormone levels, receptor values decline and they display no net addition of fibers. At metamorphosis, both males and females have approximately 4000 muscle fibers. By adulthood, males have eight times the female fiber number. In the CNS, adult laryngeal motor neurons are more numerous with larger somata and dendritic trees in males than in females. Certain connections of neurons in the vocal pathway are also less robust in females. Unlike the periphery, motor neuron number does not appear to be established by androgen-induced proliferation. Our current hypothesis is that androgen acts at the level of laryngeal muscle to produce more muscle fibers and thus provide more target for motor neurons in the male. This process could regulate cell number by ontogenetic cell death. In the CNS, androgen-target neurons become capable of accumulating hormone shortly before metamorphosis. Androgen receptor in laryngeal motor neurons may permit the dendritic growth characteristic of males by increasing sensitivity to afferent stimuli. Such a process could account for the observed differences in CNS vocal "circuitry" in X. laevis and thus behavioral differences between the sexes.

Afferent Pathways↗
PubMed1991

Testosterone and the incidence of hormone target cells in song-control nuclei of adult canaries.

Adult male canaries learn to produce high-amplitude complex courtship songs each breeding season, whereas females do not, and brain nuclei involved with the production of song behavior are much larger in breeding males than in nonbreeding males or females (Nottebohm, 1980, 1981). However, treatment of adult females with testosterone (T) causes them to produce male-like song and stimulates pronounced growth of some song-control brain nuclei such as the caudal nucleus of the ventral hyperstriatum (HVc). We reexamined the effects of T on song-control nuclei in deafened birds. In order to examine whether the pattern of hormone accumulation varies as a function of circulating testosterone levels we described the distribution of testosterone-concentrating cells in HVc and the magnocellular nucleus of the anterior neostriatum (MAN) in hearing adult male, female, and T-treated female canaries, as well as in deaf T-treated and untreated females. In contrast to our previous findings (Bottjer, Schoonmaker, and Arnold, 1986a), we observed no tendency in this study for testosterone-induced growth of HVc to be attenuated in deafened birds. There was no difference between deaf and hearing birds in the incidence of labeled cells within HVc. We also observed no sex or hormone-induced differences in the percentage of hormone-concentrating cells in HVc: normal females have approximately the same proportion of hormone target cells as do males and T-treated females. However, males normally have many more neurons in HVc than do control females, and systemic exposure to testosterone induces a pronounced increase in the number of HVc neurons of adult females. Therefore, the absolute number of hormone target cells in HVc is likely to be much greater in males and T-treated females than in normal females. As in HVc, there were no differences among groups in the proportion of labeled cells within lateral MAN (IMAN), a nucleus that has been implicated in song learning (Bottjer, Miesner and Arnold, 1984). In contrast, the incidence of hormone target cells in medial MAN (mMAN) did vary as a function of hormonal condition: although mMAN of normal females is rarely visible in Nissl-stained sections and cells in this region are not hormone labeled, mMAN is clearly visible in Nissl-stained sections of males and T-treated females and contains many hormone-labeled cells. This testosterone-induced change in the phenotype of mMAN cells suggests a possible role for mMAN in learned song behavior.

Animals↗
PubMed1993

Laryngeal muscle and motor neuron plasticity in Xenopus laevis: testicular masculinization of a developing neuromuscular system.

In Xenopus laevis, the sexual differentiation of the neuromuscular system responsible for courtship song is controlled by testicular androgen secretion. To explore the sensitivity of this system to androgenic stimulation, male and female frogs were gonadectomized and given testis transplants at seven different developmental stages between the end of metamorphosis and adulthood, grown to sexual maturity, and the laryngeal muscle fibers and motor axons were counted. Muscle fiber and axon numbers in males were not affected by the testicular transplant at any stage. In females, testicular transplants at all developmental stages increased muscle fiber numbers in adulthood. Values attained were, however, significantly less than those of adult intact or testis-transplanted males. Testis transplantation increased laryngeal axon numbers in females to levels equivalent to those of intact males; this effect was obtained at every stage of postmetamorphic development including adulthood. To further explore androgen regulation in adults, males and females were gonadectomized and implanted with silicone tubes containing testosterone propionate for 1.5-3 years and laryngeal muscle fibers and axon numbers compared to those of gonadectomized or sham-operated adult controls. Neither treatment with exogenous androgen nor gonadectomy had any effect on laryngeal muscle fiber or axon number in either males or females; values did not differ from those of sham-operated controls. We conclude that testicular secretions can induce laryngeal muscle fiber and axon addition in females throughout postmetamorphic life. This degree of plasticity, exhibited after the period when adult values are normally attained, stands in contrast to the effects of administration of synthetic androgen and suggests that the degree of plasticity in adult females may be underestimated if exogenous hormones rather than testicular transplants are provided.

Animals↗
PubMed1997

Differential effects of mate competition and mate choice on eastern tiger salamanders

Male tiger salamanders, Ambystoma tigrinum tigrinumare slightly larger in body size and have considerably higher and longer tails than females. To determine how these dimorphic traits affected reproductive performance and success, we conducted breeding trials using 12 males and six females per trial and monitored male-female and male-male interactions. Larger males had an advantage in most aspects of mate competition investigated. Males with higher tails had no advantage in either mate competition or mate choice. Males with longer tails also had no advantage in mate competition but were preferred as mates by females. Larger males interrupted courting males more often than smaller males did. The form of male-male interference was conditional on body size and not on either tail dimension. If the intruder was larger than the courting male, it would shove the female away from the courting male and initiate courtship; if the intruder was smaller, it adopted a female mimicry tactic in which it positioned itself between the courting male and female and performed female behaviours to the courting male while simultaneously courting the female. Our trials indicated that the two components of sexual selection may influence the evolution of different male morphological traits in tiger salamanders. Mate competition may favour increased male body length; mate choice may select for greater male tail length.

Journal Article↗
PubMed1997

Size-assortative mating in Drosophila malerkotliana

The relationships between wing size, locomotor activity, mating latency, courtship pattern and mating success (total number of pairs mated in a given time unit) were studied in pairs of Drosophila malerkotlianaMating latency was negatively correlated with wing length and with locomotor activity while wing length and locomotor activity were positively related. In trios of a female and a long-winged and a short-winged male, long-winged males mated more successfully than short-winged males. In trios of a male and a long-winged and a short-winged female, long-winged males mated with long-winged females, and short-winged males with short-winged females. In addition, in pairs of long-winged/short-winged flies, long-winged flies courted and mated more successfully than short-winged flies.

Journal Article↗
PubMed1997

Definitive evidence for cuticular pheromones in a cricket

The Orthoptera include many species established as important model systems in the study of animal behaviour, particularly in relation to communication and mating systems. Although most interest has focused on auditory communication, increasing circumstantial evidence suggests that there may be a widespread additional communication channel in the form of cuticular contact pheromones. Using the field cricket, Gryllus bimaculatuswe conducted a behavioural assay which demonstrated that males can distinguish the sex of conspecifics using such a channel. Male response to females (courtship song) was completely abolished by using an organic solvent to remove cuticular hydrocarbons and associated compounds from a stimulus female. It was subsequently restored by painting the washed female with the dissolved extract. This technique controls for the possibility, inherent in previous tests, that the lack of response to washed body parts might be due to the washing process itself. The composition of the cuticles of males and females was analysed using gas chromatography. This revealed that the two sexes differ markedly in the quantities of the majority of the compounds found in the cuticular extract that had previously been shown to be used in mate recognition. This suggests that mate recognition is likely to be due to the relative concentrations of several cuticular compounds, rather than a single 'sex pheromone'. It supports previous assertions of the existence of contact pheromones in the Orthoptera, suggesting that they may be widespread in this group.Copyright 1997 The Association for the Study of Animal Behaviour1997The Association for the Study of Animal Behaviour

Journal Article↗
PubMed1997

Territorial intrusions and copulation behaviour in the great skua, Catharacta skua

Birds of many species intrude on to territories in order to obtain extra-pair copulations, and frequent within-pair copulations are thought to be a response to cuckoldry where mate guarding is not possible. Great skuas are colonial birds in which females are left alone in the breeding territory while males forage for the pair. Opportunities for cuckoldry are therefore numerous, and it could be predicted that sperm competition should be intense in this species. We tested several hypotheses that attempt to explain territorial intrusions by female great skuas. Few intrusions coincided with the main fertile period and extra-pair copulations were almost never solicited, and therefore the sperm competition hypothesis was rejected. Only 0.9% of the copulations observed (N=339) were extra-pair. Thus opportunity for cuckoldry is a very poor predictor of the intensity of sperm competition, in spite of the relevance given to this factor in the literature. Of three extra-pair copulations observed, two involved unpaired territorial males. This suggests that genetic benefits were not the aim of unfaithful females. All three were preceded by courtship feeding, while only 26% of within-pair copulations followed successful food begging. This statistically significant difference constitutes evidence for a trade of copulations for food in a monogamous bird. Evidence is presented supporting hypotheses that females intrude on to territories in order to induce males to give away some food, and to become familiarized with potential partners for future breeding seasons.Copyright 1997 The Association for the Study of Animal Behaviour1997The Association for the Study of Animal Behaviour

Journal Article↗
PubMed1998

Female swordtail fish prefer symmetrical sexual signal

It has been proposed that females use the symmetry of secondary sexual traits to differentiate between potential mates. The vertical bars on male swordtail fish function as a signal that attracts females and deters rival males in one swordtail species. In addition, male courtship behaviour of most Xiphophorus species incorporates serial lateral presentations, which provide females with a clear opportunity to assess males for bilateral symmetry. We tested the hypothesis that X. cortezi females prefer males with a symmetrical bar number by determining whether females switched their preference between two males when we switched which male had a symmetrical number of bars. The ability to manipulate the bars without influencing other male traits allowed us to control for male characters correlated with bar symmetry that females might prefer. The degree of asymmetry in bar number we used was within the degree of asymmetry found for this trait in nature. Females switched their preference between a pair of males when we switched which male was symmetrical for bar number. We discuss the possibility that females prefer a symmetrical bar number as well as an alternative hypothesis. Copyright 1998 The Association for the Study of Animal Behaviour.

Journal Article↗
PubMed1998

Multi-male mating and female choice increase offspring growth in the spider Neriene litigiosa (Linyphiidae)

The purpose of this controlled-breeding study was to investigate the viability consequences of female choice and sequential polyandry for offspring in a way that would separate the influences of these two aspects of female sexual behaviour. Female sierra dome spiders, Neriene litigiosa (=Linyphia litigiosa) typically mate two to three times before production of their first batch of eggs, although some females (ca 16%) mate only once. Strong fighters are preferred as first mates and principal sires. Large males that give a vigorous performance during copulatory courtship are preferred as sires among a female's secondary mates. In this study, the number of matings by free-living females was experimentally controlled and the size and copulatory vigour of all the females' mates were recorded. At the end of the breeding season, the females were collected and their broods were obtained in captivity. Randomly chosen subsets of 28 female's offspring were reared under standard conditions during the following spring. The spiderlings were reared for 27 days in the company of siblings under conditions that would encourage the expression of genetic variation in viability, and growth and survivorship were monitored. After controlling for maternal effects (i.e. female size and oviposition date) and variance in feeding opportunities among rearing groups, both mate number and mate size were positively and independently related to offspring growth rates and the size of offspring attained after emergence from the natal cocoon. The results support the hypotheses that the preference for large males yields viability benefits to offspring and that polyandry can augment the benefits of selective mating. Copyright 1998 The Association for the Study of Animal Behaviour.

Journal Article↗