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PubMedDate not supplied

Influence of experimental illumination and seasonal variation on crossbreeding mating in the snail Biomphalaria glabrata.

The crossbreeding activities of the Schistosoma mansoni vector snail Biomphalaria glabrata were counted in a laboratory aquarium throughout the year under two regimes of 12h light: 12h dark from 7 A. M. to 10 P. M. Mating increased significantly in Autumn and Winter and just missed a significant inverse correlation with temperature and a direct one with locomotion. Other similar experiments were carried out to compare mating under various illumination conditions in complete daily cycle measurements. Mating counts decreased under the regimes which submitted snail to a total exposure of 12h light and 12h dark during a daily cycle in the following sequence: 12h light:12h dark alternating hourly with light gradient, 12h light:12h dark, 1h light:1h dark and 12h dark:12h light. Under two constant illuminations, the mating scored less than under the previous conditions, except under 12h dark:12h light. Under darkness the mating count was lower than under light conditions. There was no way to differentiate the night and day rhythms of mating on different days in each regime, except for mating under 12h light:12h dark alternating with light gradient, constant dark and 12h dark:12h light conditions. Mating increased in certain light and temperature conditions, in which the intensities should have an optimum value.

Animals↗

PubMed2001

Exposure to ginger root oil enhances mating success of irradiated, mass-reared males of Mediterranean fruit fly (Diptera: Tephritidae).

Previous research revealed that exposure to ginger root oil, Zingiber officinale Roscoe, containing the known male attractant (a-copaene) increased the mating success of male Mediterranean fruit flies, Ceratitis capitata (Wiedemann), from a newly established laboratory colony. The goal of the current study was to determine whether exposure to ginger root oil likewise enhanced the mating competitiveness of irradiated C. capitata males from a 5-yr-old mass-reared strain. Mating tests were conducted in field cages containing guava trees (Psidium guajava L.) to monitor the mating frequency of irradiated, mass-reared and wild males competing for wild females. In the absence of chemical exposure, wild males outcompeted the mass-reared males and obtained 74% of all matings. However, following exposure to ginger root oil (20 microl for 6 h), the mating frequencies were reversed. Whether exposed as mature (3-d-old) or immature (1-d-old) adults, mass-reared males achieved approximately 75% of all matings in tests conducted 2 or 4 d following exposure, respectively. Irradiated, mass-reared males prevented from contacting the oil directly (i.e., exposed to the odor only for 6 h) still exhibited a mating advantage over wild males. In an additional study, signaling levels and female arrivals were compared between males exposed to ginger root oil and nonexposed males, but no significant differences were detected. The implications of these findings for the sterile insect technique are discussed.

Animals↗

PubMed2006

Mobility of mass-reared diapaused and nondiapaused Cydia pomonella (Lepidoptera: Tortricidae): effect of mating status and treatment with gamma radiation.

Mass-reared insects may differ in their behavioral traits depending on whether they have undergone diapause. We studied the mobility of mass-reared diapaused and nondiapaused Cydia pomonella (L.) with a focus on understanding the effect of mating status and treatment with gamma radiation as these insects are destined for use in an areawide program that uses the sterile insect technique (SIT). Actograph-measured mobility was assessed one gender at a time for 4 h during which the photoperiod transitioned from day to night. We tested 20-30 individuals per treatment. For experiments on the effect of mating status, we used 24-48-h-old adults (diapause [D]-virgin, D-mated, standard [N]-virgin, and N-mated), which is the typical age class that is released in the SIT program. Diapaused females were significantly more mobile than females reared through standard production, whereas no differences were detected in male mobility because of rearing strategy. Mated females were significantly more mobile than virgin females, whereas no difference in mobility because of mating status was detected for males. Mated females were significantly more mobile than mated males. In contrast, virgin females were significantly less mobile than virgin males. For experiments on the effect of treatment with gamma radiation, adults from all rearing strategies and treatments (D-0Gy, D-100Gy, D-250Gy, N-0Gy, N-100Gy, and N-250Gy), were tested simultaneously. Adult males were tested at two different constant temperatures (25 and 20 degrees C), whereas adult females were tested only at 25 degrees C. For standard-reared adults, we found a significant linear decrease in mobility as the radiation dose increased from 0 to 250 Gy. In contrast, the relationship between mobility and dose of radiation was quadratic for diapaused males and absent for diapaused females.

Animal Husbandry↗

PubMed1981

Effects of mating on levels of oxytocin and prolactin in the plasma of male and female rabbits.

The effects of mating on plasma levels of oxytocin and prolactin in male and females rabbits have been investigated. Blood was collected through indwelling cardiac catheters at intervals of 1, 2, 4, 6, 12, 24, 36 and 60 min after mating. In female rabbits additional samples were taken 5h after mating, as well as daily during the ensuing pregnancy or pseudopregnancy. They were also fitted with intrauterine balloons for recording uterine activity. Copulation induced a rapid, transient rise in plasma oxytocin in female rabbits at the same time as a fall in plasma prolactin. Mating or sexual excitement had no significant effect on plasma concentrations of oxytocin or prolactin in bucks. Relatively large fluctuations of plasma oxytocin were seen in male rabbits under normal conditions and after mating, suggesting episodic release of oxytocin in a random fashion. The uterine recordings indicated that, in spite of the modest release of oxytocin, a strong sympathetic adrenal activation occurred in response to mating and this provided the overriding influence on uterine activity. During pregnancy plasma levels of prolactin rose significantly on day 4, and remained raised throughout most of gestation. Plasma prolactin fluctuated widely during the first half of pregnancy but the mean levels were higher than those found during the second half of gestation. When pseudopregnancy was induced with injection of an ovulating dose of LH, plasma prolactin rose in a similar manner as during early gestation or mating-induced pseudopregnancy. Thus, in contrast to rats, stimuli associated with mating have no direct influence on the subsequent release of prolactin in rabbits. The secretion of prolactin during gestation seems to be controlled entirely by ovarian steroids, probably progesterone.

Animals↗

PubMed1985

Selecting mating pairs with linear programming techniques.

Mate selection can increase progency merit if overall merit is nonlinear for one or more component traits. An index of expected progeny merit could be calculated for all possible mating pairs, and the set of pairs with the highest progeny mean could be selected. There are serious computational problems for more than a few males and females. To select and mate f, females, and m, males, from n of each, with k0 females per male, would require (nf)(nm)f!/(k0!)m evaluations. Linear programming algorithms can determine the optimal strategy efficiently by considering only a subset of these possibilities. Let pi ij be the index of progency merit of the ith sire mated to the jth dam and Xij be the decision variable for that mating (restricted to 0 or 1). Then the problem of selecting mating pairs can be stated as: maximize sigma i sigma j pi ij Xij, subject to sigma i Xij less than or equal to 1, sigma j Xij less than or equal to k0, sigma i sigma j Xij = f, and Xij = 0 or 1. By including an artificial sire and an artificial dam and choosing appropriate merit values for the artificial matings, this problem can be solved by efficient "transportation" algorithms. These algorithms could be used to develop rational mating packages for dairy artificial insemination studs provided that an objective evaluation of progeny merit could be formulated, provided that merit is not simply additively inherited.

Animal Husbandry↗

PubMed1987

Influence of genetic differences in merit of mates on sire evaluation.

Effect of nonrandomness of bulls' mates on daughter milk yield was examined from first lactation records of cows with birth dates in 1965 and later. Results were based on 67,081 Ayrshire, 77,633 Brown Swiss, 241,486 Guernsey, 1,433,761 Holstein, 291,201 Jersey, and 10,465 Milking Shorthorn records. Extent of assortative mating was examined. Correlations between sire Predicted Difference and dam (mate) Cow Index for individual years ranged from -.08 to .20. Correlations for all records within herd-year (.00 to .02) indicated essentially no assortative mating for milk yield for any breed except Ayrshire. For Ayrshires, negative assortative mating was indicated by a correlation of -.07. Within-sire regressions of daughter milk yield deviated from contemporary average (which had been adjusted for average Predicted Difference of contemporaries' sires) on dam Cow Index (merit of mates) by breed were .84 to 1.08. Expected regression was 1.00. Effect of merit of mates on sire evaluation was determined by comparing evaluations from standardized yield with those from standardized yield minus dam Cow Index. Correlations between evaluations for 4233 Ayrshire, 5275 Brown Swiss, 13,742 Guernsey, 32,572 Holstein, 13,688 Jersey, and 1240 Milking Shorthorn bulls rounded to 1.00 except for Milking Shorthorns (.99); average absolute differences in evaluations were 9 to 16 kg, and maximum differences were 49 to 118 kg. Adding an adjustment to Sire Summaries to account for nonrandomness of mates would do little to increase accuracy.

Animals↗

PubMed2003

The epidemiology and mating behavior of Arthroderma benhamiae var. erinacei in household four-toed hedgehogs (Atelerix albiventris) in Japan.

An epidemiological survey of Trichophyton mentagrophytes var. erinacei in the household hedgehog and other rodents was made between January 17, 2002 and February 28, 2002 in Japan. Quills and hairs were collected from sources identified via the internet. The fungus was isolated only from the quills of four-toed hedgehogs (7/18; 39%) from Kanto to Kyushu regions. Isolates were examined morphologically, physiologically and genetically, and identified as T. mentagrophytes var. erinacei anamorph. The isolates were also genetically compared with European hedgehog (Erinaceus europeus)-borne T. mentagrophytes var. erinacei and Kenyan hedgehog (Aterelix albiventris)-borne Arthroderma benhamiae, and their genotypes of the ITS1-5.8S-ITS2 rDNA were all identical. The isolates were crossed with A. benhamiae Americano-European race and African race, A. vanbreuseghemii and A. simii, with the result that they mated only with African race (+) or (-). Mating types of the isolates were (+) in 6 isolates and (-) in one. An intra-isolate mating between one of the 6 plus isolates and the minus one formed abundant mature gymnothesia, the mating type ratio of the F1 progeny was approximately 1:1, and the sib crossings of F1 progeny produced abundant fertile gymnothesia. The present study revealed that the intra-Japanese hedgehog-borne isolate crossing showed complete fertility and that the sexual degeneration pointed out by Takashio (Mycologia 71: 968-976, 1979) did not exist. Two pairs of mating, (+) and (-) mating types of Japanese isolates with (-) and (+) tester strains of A. benhamiae African race formed less gymnothesia, mating type ratios were unbalanced, and sib crossings of F1 progeny produced small gymnothesia containing a low number of asci, pseudogymothesia, or none, respectively. These results show that A. benhamiae var. erinacei, the teleomorph of T. mentagrophytes var. erinacei, belongs to a different mating group (e.g. hedgehog race) than the Americano-European and African races in A. benhamiae.

Animals↗

PubMed2001

Central forebrain Fos responses to familiar male odours are attenuated in recently mated female mice.

Exposure of recently mated female mice to the urinary odours of an unfamiliar male blocks pregnancy (the Bruce effect). The absence of a pregnancy block in response to the stud male's familiar odours depends on an olfactory memory that is formed in the accessory olfactory bulb (AOB) in response to vomeronasal organ (VNO) inputs during mating. Sexually naive Balb/c female mice in pro-oestrus/oestrus were either placed onto soiled bedding ('bedding-only' females) from, or allowed to mate with, a Balb/c male ('recently mated' females). After 42 h, females were placed for 90 min onto clean bedding (controls) or onto soiled bedding from either a C57BL/6 male (unfamiliar bedding) or a Balb/c male (familiar bedding). Significant increases in Fos-immunoreactivity (Fos-IR, a marker of neuronal activation) occurred in the medial amygdala and the medial preoptic area (MPA) of 'bedding only' females exposed to either unfamiliar or familiar bedding and in 'recently mated' females exposed to unfamiliar bedding but not to familiar bedding. This suggests that a mating-induced memory prevents the later activation by the familiar stud male's odours of neurons in forebrain regions that receive inputs from the VNO--AOB. 'Bedding-only' females later exposed to either familiar or unfamiliar bedding had increased Fos-IR in the G alpha(o) protein-expressing basal zone of the VNO whereas no such effect occurred in 'recently mated' females. Familiar, as well as unfamiliar, male odours augmented Fos-IR in significantly more rostral than caudal AOB granule cells in all groups, with the effect being strongest in 'recently mated' females exposed to familiar male bedding. This outcome is consistent with the absence of odour-induced Fos-IR in forebrain regions of these females and, presumably, the absence of a pregnancy block.

Animals↗

PubMed2001

[The optimal mating time in the bitch based on the progesterone concentration in peripheral blood. A comparison of reliability between three ELISA test kits and a 125-iodine radioimmunoassay].

During oestrus the plasma progesterone concentration can be used to determine the optimal time for mating in the dog. In this study, the optimal time for mating for 26 bitches was determined by measuring progesterone concentrations with three ELISA test kits and a 125I-radioimmunoassay (125I-RIA). Two observers evaluated the ELISA results simultaneously. They graded the results independently and did not know which dog was being tested. For both observers, the optimal time for mating, based on progesterone concentrations measured with the Progesterone Small Rapid ELISA test and the Status-Pro test, differed significantly from that based on progesterone concentrations measured by 125I-RIA. Although the optimal time for mating based on the Ovucheck Premate test did not differ significantly from that based on the 125I-RIA, three out of 14 dogs (21%) for observer one and four out of 14 dogs (29%) for observer two would have been mated on a different day than that determined on the basis of results obtained with the 125I-RIA. The results did not change when the advised period for mating based on the RIA results was extended by two days. It is concluded that the progesterone concentrations measured with the ELISA test kits are too inaccurate for clinical use to determine the optimal time for mating. The only reliable results for determining the optimal mating period are obtained when plasma progesterone concentrations are measured with a RIA.

Animals↗

PubMed2000

[Mating behavioral ecology of Ancylis sativa adult].

The study shows that the mating peak of the overwintering generation adults of Ancylis sativa appeared at 6.0-8.0 hours in their scotophase and the mating activity was more intensive during 2-3 days after eclosion. The higher the temperature was, the later the adults began to mate. For most adults, the duration of mating was 3-4 hours, with a mean frequency of 3.3 times for males and 1.59 for females. The mating behavior of 2-days old adults shifted from photoperiod 14L:10D to continuous dark was similar to that at 14L:10D, all showing an obvious rhythm. When the adults were shifted to continuous light, their mating became inacitive and irregular. The sex pheromone titer of virgin female decreased significantly after mating 1 hour, and remained low until 48 hours after mating.

Animals↗

PubMedDate not supplied

[Macronuclear DNA and total protein contents of mating types I and II of Paramecium primaurelia, during the phase of maturity and the transition to senescence. Preliminary observations].

Concerning the studies on mating type differentiation and life cycle development in Paramecium primaurelia stock 90, both macronuclear DNA and total protein contents have been measured cytofluorometrically in mating type I and mating type II isogenic cell lines growing in logarithmic phase, throughout their maturity period and transition to senescence. The target was to investigate whether the two mating types undergo clonal decline in different times, as the previous studies suggested. The results indicate that, throughout the maturity period, macronuclear DNA and total protein contents vary both in mating type I and mating type II cell lines; moreover, aged phenotypes as the dramatic decrease of both contents, firstly occur in mating type II which, therefore, appears to be submitted to clonal decline before mating type I.

Aging↗

PubMed2005

[Intratetrad mating and its genetic and evolutionary consequences].

Genetic characteristics of intratetrad mating, i.e., fusion of haploid products of one meiotic division, are considered. Upon intratetrad mating, the probability of homozygotization is lower than that upon self-fertilization, while heterozygosity at genes linked to the mating-type locus, which determines the possibility of cell fusion, is preserved. If the mating-type locus is linked to the centromere, the genome regions adjoining the centromeres of all chromosomes remain heterozygous. Intratetrad mating is characteristic of a number of fungi (Saccharomyces cerevisiae, Saccharomycodes ludwigii, Neurospora tetrasperma, Agaricus bisporus, Microbotrium violaceum, and others). Parthenogenetic reproduction in some insects also involves this type of fusion of nuclei. Intratetrad mating leads to the accumulation of haplolethals (i.e., lethals manifesting in haploid cells but not hindering their mating) in pericentric chromosome regions. Since heterozygosity increases viability of an organism, recombination has been suppressed during evolution in fungi characterized by intratetrad mating, which ensures heterozygosity of the most part of the genome.

Biological Evolution↗

PubMed1990

Pseudo-random mating systems for 3-allele loci.

A random mating population attains equilibrium by the Hardy-Weinberg law. By demonstrating some simple examples for 2-allele loci, Li (1988) showed that a nonrandom mating population of certain mating patterns may also attain equilibrium. He called such a type of population a pseudo-random mating population. Tai (1990), then, gave a generalized representation of these pseudo-random mating systems. In this paper the clear patterns of pseudo-random mating behavior for a 3-allele locus are derived. Both autosomal and sex-linked systems are discussed. The study of these mating patterns provides a way to understand the complicated mating system of a population, which usually is only with difficulty realized through sampled individuals from that population.

Alleles↗

PubMed1990

Kinship and mate choice in a historic eastern Blue Ridge community, Madison County, Virginia.

Potential mates analysis is difficult to apply to small historic populations that lack clear boundaries or regular vital event registration. Here I analyze the actual mate pool as an alternative way to identify causes of nonrandom mating when unmarried members are unknown. Factors influencing mate choice within a historic eastern Blue Ridge community in Madison County, Virginia, are examined for four marriage cohorts: 1850-1879, 1880-1899, 1900-1919, and 1920-1939. These factors include nuclear kin avoidance, preferred age differences between mates, and preferences for more distant kin. A simulation is used to recombine members of the cohort-specific pools of married individuals to generate the probabilities of various types of kin marriages. The pedigree and vital statistics data are derived from first-time marriage licenses filled by community members in Madison County from 1794 to 1939. The numbers of marriages examined for each cohort are 88, 120, 132, and 132, respectively; the mate pools constructed from the samples are viewed from the female perspective. The results generated by simulation on the actual mate pools consist of mean kinship coefficients, numbers of marriages between "allowed" kin types, and probabilities of these values when marriage is random with respect to kinship. The results indicate significantly high levels of inbreeding in all four marriage cohorts, primarily because of high levels of first-cousin marriages in the first three cohorts and of first-cousin once-removed marriages in the 1920 cohort. The observed mating patterns are discussed in terms of the social history of the Blue Ridge community and restrictions of the data.

Appalachian Region↗

PubMed1981

Accumulation and proliferation of lymphocytes in the lymph nodes of the female rat following first mating.

Iliac and popliteal lymph nodes were removed from Sprague-Dawley female rats killed at 12-13 weeks of age in groups of 10 animals: one group of virgin controls and 10 groups at intervals of two days until the tenth day after either 'inbred' or outbred mating. The iliac lymph nodes on the second post-coital day after outbred mating were significantly heavier than those of virgin animals and on the fourth postcoital day were significantly heavier after outbred mating than 'inbred' mating. The total lymphocyte counts in the iliac and popliteal lymph nodes were significantly less in the virgin animals than those made on ;the second post-coital day after both 'inbred' and outbred mating. These increased counts were sustained until the tenth post-coital day and were associated with significantly increased lymphocyte cell densities in the nodes. Such lymphocyte accumulation probably results from an endogenous or exogenous hormonal stimulus. The proportions of proliferating cells in the lymphocyte population of the iliac and popliteal lymph nodes from the fourth until the tenth post-coital day were significantly greater after outbred mating than after 'inbred' mating. These observations indicate that after outbred mating the female animal mounts an immune response to the allogeneic spermatozoa and semiallogeneic products of conception within her reproductive tract.

Animals↗

PubMed1994

Sex-ratio and mating propensity in Drosophila biarmipes.

Mating success between purple eye colour mutant and wild type D. biarmipes was observed in Elens-Wattiaux mating chamber. Multiple-, female-, male- and no-choice techniques were used. The values of isolation estimate in different experiments are above one which provides no evidence for preferential mating between females and males of the same type. The comparison of sexual behaviour of mutant and wild flies clearly indicates that wild type males are more successful in mating than mutant males, and mutant females are more receptive than wild type females. Thus purple eye colour mutation affects mating propensity of both sexes in D. biarmipes. However, the difference in the number of matings of wild and mutant flies is highly significant in multipe- and no-choice experiments in which sex-ratio was 1:1 (equal number of males and females). But the difference is not significant when mating success was scored by female- and male-choice methods in which sex-ratio was 1:2 (one female and two males; one male:two females). Thus it is suggested that mating propensity in D. biarmipes is influenced by sex-ratio.

Animals↗

PubMed1990

Neurospora crassa A mating-type region.

The mating-type locus of the haploid filamentous fungus Neurospora crassa is a regulatory region that controls entry into the sexual cycle and prevents formation of mixed mating-type heterokaryons in the vegetative phase. The locus consists of alternative sequences called A and a. The A mating-type DNA sequence of Neurospora crassa is composed of a region of 5301 base pairs that has little similarity to the sequence present at the mating-type locus in an a mating-type strain. However, the sequences flanking the mating-type locus in the A haploid and a haploid genome are essentially identical. The region of the A mating-type sequence required for expression of the heterokaryon incompatibility and sexual functions has been localized to a single open reading frame (ORF) encoding a polypeptide of 288 amino acids. Sequence analysis of sterile, heterokaryon-compatible mutants reveals frameshift mutations in this same ORF. The putative 288-amino acid product has a region of similarity to the MAT alpha 1 polypeptide of Saccharomyces cerevisiae.

Amino Acid Sequence↗

PubMed2003

The adhesin Hwp1 and the first daughter cell localize to the a/a portion of the conjugation bridge during Candida albicans mating.

The cell wall protein Hwp1 was originally demonstrated to be expressed exclusively in hyphae of Candida albicans and cross-linked to human epithelium by mammalian transglutaminase. Hwp1 is expressed on the walls of hyphae formed by a/alpha, a/a, and alpha/alpha cells. Hence, it is expressed on hyphae independently of mating type. However, Hwp1 is selectively expressed on the wall of conjugation tubes formed by a/a cells, but not alpha/alpha cells, in the mating process. This was demonstrated in all possible crosses between four unrelated natural a/a strains and four unrelated alpha/alpha strains. In zygotes, Hwp1 is restricted to that portion of the wall of the conjugation bridge contributed by the a/a parent cell. Hwp1 staining further revealed that the first daughter bud that emerges from the conjugation bridge does so from the a/a-contributed portion. Hwp1 expression and localization during the mating process is, therefore, mating type specific, opaque phase specific, and alpha-pheromone induced. These results indicate that the mating type-specific contributions to the conjugation bridge during the mating process in C. albicans are qualitatively and functionally distinct and that the a/a portion of the bridge, which selectively contains Hwp1, bears the first daughter cell in the mating process.

Blotting, Northern↗