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One Male (one + male)
Selected AbstractsSocial context affects testosterone-induced singing and the volume of song control nuclei in male canaries (Serinus canaria)DEVELOPMENTAL NEUROBIOLOGY, Issue 10 2006Géraldine Boseret Abstract The contribution of social factors to seasonal plasticity in singing behavior and forebrain nuclei controlling song, and their interplay with gonadal steroid hormones are still poorly understood. In many songbird species, testosterone (T) enhances singing behavior but elevated plasma T concentrations are not absolutely required for singing to occur. Singing is generally produced either to defend a territory or to attract a mate and it is therefore not surprising that singing rate can be influenced by the sex and behavior of the social partner. We investigated, based on two independent experiments, the effect of the presence of a male or female partner on the rate of song produced by male canaries. In the first experiment, song rate was measured in dyads composed of one male and one female (M-F) or two males (M-M). Birds were implanted with T-filled Silastic capsules or with empty capsules as control. The number of complete song bouts produced by all males was recorded during 240 min on week 1, 2, 4, and 8 after implantation. On the day following each recording session, brains from approximately one-fourth of the birds were collected and the volumes of the song control nuclei HVC and RA were measured. T increased the singing rate and volume of HVC and RA but these effects were affected by the social context. Singing rates were higher in the M-M than in the M-F dyads. Also, in the M-M dyads a dominance-subordination relationship soon became established and dominant males sang at higher rates than subordinates in T-treated but not in control pairs. The differences in song production were not reflected in the size of the song control nuclei: HVC was larger in M-F than in M-M males and within the M-M dyads, no difference in HVC or RA size could be detected between dominant and subordinate males. At the individual level, the song rate with was positively correlated with RA and to a lower degree HVC volume, but this relationship was observed only in M-M dyads, specifically in dominant males. A second experiment, carried out with castrated males that were all treated with T and exposed either to another T-treated castrate or to an estradiol-implanted female, confirmed that song rate was higher in the M-M than in the M-F condition and that HVC volume was larger in heterosexual than in same-sex dyads. The effects of T on singing rate and on the volume of the song control nuclei are thus modulated by the social environment, including the presence/absence of a potential mate and dominance status among males. 2006 Wiley Periodicals, Inc. J Neurobiol, 2006 [source] Chronic copper toxicity in the estuarine copepod Acartia tonsa at different salinitiesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2010Mariana M. Lauer Abstract Chronic Cu toxicity was evaluated in the euryhaline copepod Acartia tonsa. Male and female copepods were exposed (6 d) separately to different combinations of Cu concentration and water salinity (5, 15, and 30 ppt) using different routes of exposure (waterborne, waterborne plus dietborne, and dietborne). After exposure, groups of one male and three female copepods were allowed to reproduce for 24,h. In control copepods, egg production augmented with increasing water salinity. However, egg hatching rate did not change. Copper exposure reduced egg production and hatching rate in all water salinities tested, but the reproductive response was dependent on the route of Cu exposure. Median effective concentration (EC50) values for egg production after waterborne exposure were 9.9, 36.8, and 48.8,µg/L dissolved Cu at water salinities of 5, 15, and 30 ppt, respectively. For waterborne plus dietborne exposure, they were significantly higher (40.1, 63.7, and 109.9,µg /L, respectively). After dietborne exposure, approximately 40% decrease in egg production was observed, independently of Cu concentration and water salinity tested. At water salinities of 5 and 30 ppt, egg hatching rate reduced after waterborne exposure, together or not with the dietborne exposure. At water salinity of 15 ppt, Cu toxicity was only observed after dietborne exposure. Data indicate that egg production is a more reliable reproductive endpoint to measure chronic Cu toxicity in copepods than egg hatching rate in a wide range of water salinities. They also suggest that both water salinity and route of Cu exposure should be taken into account in the development of a chronic biotic ligand model version for estuarine and marine environments. Environ. Toxicol. Chem. 2010;29:2297,2303. © 2010 SETAC [source] Pair Bonding and Multiple Paternity in the Polygamous Common Quail Coturnix coturnixETHOLOGY, Issue 4 2003J. D. Rodríguez-Teijeiro The common quail (Coturnix coturnix) is one of the few species in which mate-switching (when different pair bonds are established within a single breeding attempt), has been recorded. In this study, we report the characteristics of pair bonds (description, number of males per female and duration) by monitoring a wild population of common quail (28 females and 49 males) by radiotracking. 57% of the females studied (n = 14) showed mate-switching, whereas 22% of the males were serially polygynous, successively forming pairs with a series of females. The fitness of females with mate-switching, measured in terms of clutch size and hatching success, did not differ from that of females bonded with one male. The analysis of paternity in three families by multilocus DNA fingerprinting revealed genetic polygamy in two of the nests studied. A male sired offspring with two females, and we obtained genetic evidence for intraspecific brood parasitism. We discuss how these behavioural and ecological observations may relate to the particular mating system of the common quail. [source] EVOLUTIONARY REDUCTION IN TESTES SIZE AND COMPETITIVE FERTILIZATION SUCCESS IN RESPONSE TO THE EXPERIMENTAL REMOVAL OF SEXUAL SELECTION IN DUNG BEETLESEVOLUTION, Issue 10 2008Leigh W. Simmons Sexual selection is thought to favor the evolution of secondary sexual traits in males that contribute to mating success. In species where females mate with more than one male, sexual selection also continues after copulation in the form of sperm competition and cryptic female choice. Theory suggests that sperm competition should favor traits such as testes size and sperm production that increase a male's competitive fertilization success. Studies of experimental evolution offer a powerful approach for assessing evolutionary responses to variation in sexual selection pressures. Here we removed sexual selection by enforcing monogamy on replicate lines of a naturally polygamous horned beetle, Onthophagus taurus, and monitoring male investment in their testes for 21 generations. Testes size decreased in monogamous lines relative to lines in which sexual selection was allowed to continue. Differences in testes size were dependent on selection history and not breeding regime. Males from polygamous lines also had a competitive fertilization advantage when in sperm competition with males from monogamous lines. Females from polygamous lines produced sons in better condition, and those from monogamous lines increased their sons condition by mating polygamously. Rather than being costly for females, multiple mating appears to provide females with direct and/or indirect benefits. Neither body size nor horn size diverged between our monogamous and polygamous lines. Our data show that sperm competition does drive the evolution of testes size in onthophagine beetles, and provide general support for sperm competition theory. [source] INCREASED POSTCOPULATORY SEXUAL SELECTION REDUCES THE INTRAMALE VARIATION IN SPERM DESIGNEVOLUTION, Issue 6 2008Simone Immler Sperm competition is an important force driving the evolution of sperm design and function. Inter- and intraspecific variation in sperm design are strongly influenced by the risk of sperm competition in many taxa. In contrast, the variation among sperm of one male (intramale variation) is less well understood. We investigated intramale variation in sperm design in passerine birds and found that risk of sperm competition is negatively associated with intramale variation. This result is the first clear evidence that variation among sperm within an individual male is influenced by postcopulatory sexual selection. Our finding has important implications for male traits under pre- and postcopulatory sexual selection. [source] DO WOLBACHIA- ASSOCIATED INCOMPATIBILITIES PROMOTE POLYANDRY?EVOLUTION, Issue 1 2008Fleur E. Champion de Crespigny The genetic incompatibility avoidance hypothesis as an explanation for the polyandrous mating strategies (mating with more than one male) of females of many species has received significant attention in recent years. It has received support from both empirical studies and a meta-analysis, which concludes that polyandrous females enjoy increased reproductive success through improved offspring viability relative to monandrous females. In this study we investigate whether polyandrous female Drosophila simulans improve their fitness relative to monandrous females in the face of severe Wolbachia- associated reproductive incompatibilities. We use the results of this study to develop models that test the predictions that Wolbachia should promote polyandry, and that polyandry itself may constrain the spread of Wolbachia. Uniquely, our models allow biologically relevant rates of incompatibility to coevolve with a polyandry modifier allele, which allows us to evaluate the fate of the modifier and that of Wolbachia. Our empirical results reveal that polyandrous females significantly reduce the reproductive costs of Wolbachia, owing to infected males being poor sperm competitors. The models show that this disadvantage in sperm competition can inhibit or prevent the invasion of Wolbachia. However, despite the increased reproductive success obtained by polyandrous females, the spread of a polyandry modifier allele is constrained by any costs that might be associated with polyandry and the low frequency of incompatible matings when Wolbachia has reached a stable equilibrium. Therefore, although incompatibility avoidance may be a benefit of polyandry, our findings do not support the hypothesis that genetic incompatibilities caused by Wolbachia promote the evolution of polyandry. [source] Adult sex ratios in wild bird populationsIBIS, Issue 4 2007PAUL F. DONALD Offspring sex ratios in wild bird populations, and the extent to which they vary from the equality expected by random genotypic sex determination, have received much recent attention. Adult sex ratios (ASRs) in wild birds, on the other hand, remain very poorly described, and many of the questions about them posed by Ernst Mayr in 1939 remain unanswered. This review assesses population-level sex ratio patterns in wild bird populations, with an emphasis on the ASR. A quantitative assessment of over 200 published estimates of ASR, covering species from a wide range of taxa, regions and habitats, supported Mayr's assertion that skewed ASRs are common in wild bird populations. On average, males outnumbered females by around 33%, and 65% of published estimates differed significantly from equality. In contrast, population-level estimates of offspring sex ratio in birds did not generally differ from equality, and mean ASR across a range of wild mammal species was strongly female-skewed. ASR distortion in birds was significantly more severe in populations of globally threatened species than in non-threatened species, a previously undescribed pattern that has profound implications for their monitoring and conservation. Higher female mortality, rather than skewed offspring sex ratio, is the main driver of male-skewed ASRs in birds, and the causes and implications of this are reviewed. While estimates of ASR in wild bird populations may be subject to a number of biases, which are discussed, there is currently no quantitative evidence that an ASR of one male to one female represents the norm in birds. A better understanding and reporting of ASRs in wild bird populations could contribute greatly to our understanding of population processes and could contribute much to theoretical and applied research and conservation. [source] Pubic symphyseal face eburnation: an Egyptian sport story?INTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 3 2010M. A. Judd Abstract Strenuous physical activity leaves scars on bone that attest to the demands of occupation, sport, aggression and recreation. During the assessment of 74 C-Group Nubians from Hierakonpolis (Egypt) dated to the Egyptian Middle Kingdom,Second Intermediate Period (2080,1700 BC), robust muscle insertions along the ilia and ischia were observed among some adults. In addition, a disproportionate degeneration of the pubic symphyseal faces when compared to other age-related features was also noted. In the case of one male (Burial 32), the pubic symphyseal faces were completely flattened and polished so that they resembled the eburnation that is pathognomic of osteoarthritis. Differential diagnoses are discussed and osteitis pubis, an increasingly diagnosed injury among modern athletes who participate in intense activity that involves running, kicking, twisting or leaping, is proposed as the most likely etiology. The exaggerated muscle insertions and pubic symphyseal wear, epitomised by the individual interred in Burial 32, are unique features that may be linked to the unexplained presence of this Nubian group deep in Egyptian territory during a period of political instability. Artefactual, artistic and documentary evidence records how the Egyptian pharaohs and elites conscripted Nubian athletes to the royal courts for staged contests and entertainment, part of a propaganda program engineered to reinforce among the general populace the dogma of Egyptian supremacy over the enemy. This Nubian community, serviced by Cemetery HK27C, may have functioned as a source for individuals skilled in athletics or other activities that required exceptional physical dexterity. The extraordinary modification of these pubic symphyseal faces underscores the importance of recognising paleopathological conditions that may further confound current macroscopic methods used to ascertain the chronological age of an individual. Copyright © 2009 John Wiley & Sons, Ltd. [source] Effects of intensive harvesting on moose reproductionJOURNAL OF APPLIED ECOLOGY, Issue 3 2000Catherine Laurian Summary 1.,It has been hypothesized that a balanced adult sex ratio is necessary for the full participation of ungulate females in reproduction and therefore high productivity. We tested this general hypothesis by combining two complementary approaches. 2.,First, using telemetry (n = 60) and annual aerial censuses between 1995 and 1998, we compared two moose Alces alces populations in Quebec, Canada, one non-harvested and the other subject to intensive sport harvesting from the end of September to mid-October. We tested the following predictions for the harvested population: (i) females increase movements and home ranges during the mating period; (ii) the mating system is modified, with the appearance of groups of one male and many females; (iii) subadult males participate in reproduction; (iv) the mating period extends over two to three oestrus cycles; (v) the calving period extends over several months; and (vi) productivity declines. 3.,Daily movements and home range sizes during the mating period did not differ between harvested and non-harvested populations. Most groups observed were male,female pairs. Subadult males (1·5,2·5 years old) were only observed with females in the harvested population. Mating and calving periods did not differ between populations. The proportion of females that gave birth and the number of calves produced were also comparable in the two populations. 4.,Secondly, we also assessed the existence of a relationship between population productivity and percentage of males in various management units of the province of Quebec that were characterized by a wide range in sex ratios. Contrary to prediction (vi), the number of calves per 100 adult females was not related to the percentage of adult males in the population. 5.,The participation of young adult males (subadults) in reproduction in our harvested population may have compensated for the lower percentage of adult males, and thus productivity was unaffected. We therefore reject the hypothesis that intensive harvesting, at least at the level we observed, affects reproduction and population productivity. 6.,As there are some uncertainties regarding the long-term effects of high hunting pressure, however, managers should favour sex ratios close to levels observed in non-harvested populations. [source] Increasing distribution and damage to palms by the Neotropical whitefly, Aleurotrachelus atratus (Hemiptera: Aleyrodidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 6 2010N. Borowiec Abstract In recent years, the coconut whitefly, Aleurotrachelus atratus Hempel, has been recorded from various islands in the southwestern Indian Ocean. Field surveys in La Réunion, the Seychelles, the Comoros and glasshouses in Paris have allowed us to record this whitefly on 56 palm species, some of which are endemic and/or threatened species. Most of trees showed low infestation levels, except for the coconut palm that is its main host plant. Such a wide host range has facilitated the rapid geographical dissemination of this whitefly. A field study was conducted in 2006 in La Réunion, to gain a better understanding of the bioecology of A. atratus in a tropical insular ecosystem. The whitefly was found throughout the island, from sea level to 800-m altitude. Five parasitoid species (Hymenoptera: Aphelinidae) were found associated with the populations of this pest, with Eretmocerus cocois Delvare being the dominant one. A laboratory study showed that the pre-imaginal development of A. atratus is around 48 days at 25,27°C, which is relatively long compared to other whitefly species. With a sex ratio of one male per 1022 females collected in La Réunion, it appears that the whitefly reproduces by thelytoky. It represents a threat to ornamental and agricultural palms as well as to natural palm ecosystems in the absence of effective parasitoids. [source] Gonadal development and spawning cycle in the digynic hermaphrodite sharpsnout seabream Diplodus puntazzo (Sparidae) off the Canary Islands, northwest of AfricaJOURNAL OF APPLIED ICHTHYOLOGY, Issue 1 2008J. G. Pajuelo Summary Diplodus puntazzo is a species characterized by a rudimentary hermaphroditism, with a low level of protandry. The study found that the overall sex ratio was one male to 2.03 females, diverging significantly from 1 : 1, and that there was a ratio of one male to 0.11 transitional fish. The sex ratio varied with season: during the reproductive period the ratio was 1 : 1.86 (male : female), significantly lower than in the non-reproductive period in which the sex ratio was approximately 1 : 2.26. Both sexes had similar size distributions; however, females were predominant in all size intervals, especially in the larger ones. No significant difference in mean total length (TL) between females (330 mm), males (319 mm) or transitionals (321 mm) was found. The smallest functional female and male analysed were 159 and 157 mm TL, and the largest were 520 and 510 mm TL, respectively. No significant difference in length at first level of maturity, attained at the second year of life, was found between males (281 mm) and females (292 mm), respectively. A protracted spawning season was identified for the species: from September to February, with a peak in November. GSI values followed the same pattern for males and females, with values of females being similar to those of males; the highest values occurred between September and December, with a maximum in November. Occurrence of transitional fish was significantly higher during the month with highest values of GSI than in the resting period. The study found that vitellogenesis did not begin synchronously for all females, and the simultaneous presence of oocytes in all stages of development indicated an asynchronous mode of ovarian development. The presence of postovulatory, together with tertiary yolk vesicle oocytes, indicated that the species is a multiple spawner. [source] Sperm competition selects for increased testes mass in Australian frogsJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 3 2002P. G. Byrne Game theory predicts that investment in spermatogenesis will increase with the risk and intensity of sperm competition. Widespread support for this prediction has come from comparative studies of internal fertilizing species reporting positive associations between testes mass and the probability that females mate with more than one male. Data for external fertilizers have generated conflicting results. We investigated how risk of sperm competition affects testes size in two families of Australian frogs: the Myobatrachidae and the Hylidae. We also examined effects of clutch size, egg size and oviposition location as alternative factors that might influence sperm production. Species were ranked according to probability of group spawning, and hence risk of sperm competition. Controlling for body size and phylogenetic relationships, we demonstrated that within the Myobatrachidae, the risk of sperm competition explained a significant amount of variation in testes mass. Oviposition location had a weak influence, with species ovipositing into foam having smaller testes. No significant effects of clutch size or egg size were detected. In hylids, the relationship between testes mass and risk of sperm competition was positive but not significant, again with no predictable effects related to egg size or number. These data provide an important test of sperm competition theory for externally fertilizing taxa. [source] Adolescents coping with mood disorder: a grounded theory studyJOURNAL OF PSYCHIATRIC & MENTAL HEALTH NURSING, Issue 2 2007R. J. MEADUS phd rn A grounded theory methodology was used to explore the phenomenon of coping as experienced by adolescents with a mood disorder. Mood disorders among children and adolescents are more persistent than previously thought and have numerous negative associated features, including further episodes of depression, impaired social, academic and vocational relationships, use of alcohol and other drugs, and an increased risk of suicide. Current literature offered little awareness of how adolescents cope with a mood disorder, as well as their perspective of how such an illness impacts their lives. A substantive theory regarding the process of coping for adolescents with a mood disorder was generated from the data collected from one male and eight female adolescents. Using grounded theory coding procedures, a four-phase coping theory identified by the categories feeling different, cutting off connections, facing the challenge/reconnecting, and learning from the experience was developed. The core category identified in this research was An Unplanned Journey: Coping Through Connections. Implications identified for nursing practice, research and education included greater attention on the prevention of adolescent mood disorder, and the education of adolescents about the development and enhancement of healthy coping skills. [source] Spatial ecology of the European wildcat in a Mediterranean ecosystem: dealing with small radio-tracking datasets in species conservationJOURNAL OF ZOOLOGY, Issue 1 2009P. Monterroso Abstract Despite some populations of European wildcat Felis silvestris in central Europe are stable or increasing, the Iberian subpopulation is in decline and is listed as ,vulnerable'. In Portugal, little is known about wildcat populations, making conservation policies extremely difficult to define. Furthermore, the secretive behaviour of these mammals, along with low population densities, make data collection complicated. Thus, it is crucial to develop efficient analytical tools to interpret existing data for this species. In this study, we determine the home-range size and environmental factors related to wildcat spatial ecology in a Mediterranean ecosystem using a combined analysis of habitat selection and maximum entropy (Maxent) modelling. Simultaneously, we test the feasibility of using radio-tracking locations to construct an ecologically meaningful distribution model. Six wildcats were captured and tracked. The average home-range size (MCP95) was 2.28 km2 for females and 13.71 km2 for one male. The Maxent model built from radio-tracking locations indicated that the abundance of the European rabbit Oryctolagus cuniculus and limited human disturbance were the most important correlates of wildcat presence. Habitat selection analysis revealed that wildcats tend to use scrubland areas significantly more than expected by chance. A mosaic of scrublands and agricultural areas, with a higher proportion of the former, benefits wildcat presence in the study area; however, species distribution is mainly constrained by availability of prey and resting sites. The Maxent model validation with camera-trapping data indicated that highly adequate model performance. This technique may prove useful for recovering small radio-tracking datasets as it provides a new alternative for handling data and maximizing the ecological information on a target population, which can then be used for conservation planning. [source] Open-label pilot study of folic acid in patients with nonalcoholic steatohepatitisLIVER INTERNATIONAL, Issue 2 2007Phunchai Charatcharoenwitthaya Abstract: Background/Aims: Folate deficiency disturbs hepatic methionine metabolism and promotes the development of steatohepatitis in animal models. Our aims were (1) to determine the safety and efficacy of folic acid treatment in patients with nonalcoholic steatohepatitis (NASH) on changes in liver biochemistries, and (2) to investigate the presence of subclinical folate deficiency in this population. Methods: Patients with biopsy-proven NASH were treated with folic acid 1 mg/day for 6 months. Liver enzymes and adverse events were monitored every 3 months until completion. Results: Ten patients (one male and nine females) with a median age of 54 years were enrolled in this study. At baseline, the median steatosis grade was 2 (range 1,3), the median necroinflammatory grade was 1 (1,3), and the median fibrosis stage was 2 (0,4). The median level of red cell folate was 526 ng/ml (range 99,708); the normal level was 268,616 ng/ml. One compensated cirrhotic patient had folate deficiency. No serious adverse events occurred. After 6 months of therapy, no significant reductions in serum aspartate and alanine aminotransferase levels (60±25 vs. 54±29, P=0.5 and 86±29 vs. 83±42, P=0.6, respectively), were observed. Serum levels of bilirubin, alkaline phosphatase, albumin, and prothrombin time remained in the normal range during treatment in all patients. Conclusion: Six months of therapy with folic acid at a dose of 1 mg/day, although safe and well tolerated, does not lead to a significant biochemical improvement in patients with NASH. In a small number of patients, folate deficiency was present in only a cirrhotic patient. [source] Searching for sex-reversals to explain population demography and the evolution of sex chromosomesMOLECULAR ECOLOGY, Issue 9 2010CLAUS WEDEKIND Sex determination can be purely genetic (as in mammals and birds), purely environmental (as in many reptiles), or genetic but reversible by environmental factors during a sensitive period in life, as in many fish and amphibians (Wallace et al. 1999; Baroiller et al. 2009a; Stelkens & Wedekind 2010). Such environmental sex reversal (ESR) can be induced, for example, by temperature changes or by exposure to hormone-active substances. ESR has long been recognized as a means to produce more profitable single-sex cultures in fish farms (Cnaani & Levavi-Sivan 2009), but we know very little about its prevalence in the wild. Obviously, induced feminization or masculinization may immediately distort population sex ratios, and distorted sex ratios are indeed reported from some amphibian and fish populations (Olsen et al. 2006; Alho et al. 2008; Brykov et al. 2008). However, sex ratios can also be skewed by, for example, segregation distorters or sex-specific mortality. Demonstrating ESR in the wild therefore requires the identification of sex-linked genetic markers (in the absence of heteromorphic sex chromosomes) followed by comparison of genotypes and phenotypes, or experimental crosses with individuals who seem sex reversed, followed by sexing of offspring after rearing under non-ESR conditions and at low mortality. In this issue, Alho et al. (2010) investigate the role of ESR in the common frog (Rana temporaria) and a population that has a distorted adult sex ratio. They developed new sex-linked microsatellite markers and tested wild-caught male and female adults for potential mismatches between phenotype and genotype. They found a significant proportion of phenotypic males with a female genotype. This suggests environmental masculinization, here with a prevalence of 9%. The authors then tested whether XX males naturally reproduce with XX females. They collected egg clutches and found that some had indeed a primary sex ratio of 100% daughters. Other clutches seemed to result from multi-male fertilizations of which at least one male had the female genotype. These results suggest that sex-reversed individuals affect the sex ratio in the following generation. But how relevant is ESR if its prevalence is rather low, and what are the implications of successful reproduction of sex-reversed individuals in the wild? [source] Microsatellite analysis of female mating behaviour in lek-breeding sage grouseMOLECULAR ECOLOGY, Issue 8 2001K. Semple Abstract We used microsatellite DNA markers to genotype chicks in 10 broods of lek-breeding sage grouse, Centrocercus urophasianus, whose mothers' behaviour was studied by radio-tracking and observing leks. Previous behavioural studies suggested that almost all matings are performed by territorial males on leks and that multiple mating is rare. Two broods (20%) were sired by more than one male. Genetic analyses of the broods of eight females that visited an intensively studied lek were consistent with behavioural observations. Four females observed mating produced singly sired broods and males other than the individual observed copulating were excluded as sires for most or all of their chicks. Territorial males at the study lek were excluded as sires of broods of four other females that visited the lek but were not observed mating there. Radio-tracking suggested that two of these females mated at other leks. Our results confirm the reliability of mating observations at leks, but do not rule out a possible unseen component of the mating system. [source] Possible human chimera detected prenatally after in vitro fertilization: a case reportPRENATAL DIAGNOSIS, Issue 11 2003B. Simon-Bouy Abstract Background Chimerism is the coexistence of more than one cell line in an individual, due to the fusion of originally separate zygotes. It has been very rarely described in humans. Methods A 36-year-old woman who was referred for in vitro fertilization (IVF) for unexplained infertility had three embryos transferred. Results Four weeks and five days after the transfer, ultrasound examination detected a single fetus in the uterus. Ultrasound examination at 17 weeks for metrorrhagia showed severe intrauterine growth retardation. Amniocentesis revealed a mixture of 46,XY and 46,XX clones. Histopathologic examination showed a dysmorphic fetus with female phenotype and severe growth retardation. Conclusions Although demonstration by fingerprinting has not been possible, fusion of two of the three transferred embryos (one male and one female) seems to be the most probable mechanism that could explain both cytogenetic and histopathologic observations. No chimera has yet been described after IVF. It would be interesting to collect any such observations from other IVF centers. Copyright © 2003 John Wiley & Sons, Ltd. [source] The mating system of the Sichuan snub-nosed monkey (Rhinopithecus roxellana)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 1 2010Songtao Guo Abstract This article reports the first genetic study of the mating system of the Sichuan snub-nosed monkey (Rhinopithecus roxellana), an endemic and endangered species in China. The investigation was carried out in a population (WRT) in the Qinling Mountains using data from both field observation and paternity analysis through microsatellite DNA profiling. During a mating season, a male on an average copulated with 5.7 females. Approximately 18% of the females were observed to copulate with more than one male over the study period. The majority of copulations (94.5%) were initiated by females. Twenty-eight of 430 observed matings were extra-unit copulations. Eight polymorphic microsatellite loci were used for paternity analysis. The number of alleles at each locus ranged from 3 to 7 (mean=4.3). Observed heterozygosity ranged between 0.32 and 0.79. None of the loci showed significant deviation from Hardy,Weinberg equilibrium. Results from paternity exclusion showed that 12 of 21 (57.1%) immature individuals were sired by extra-unit males. Although the basic social unit of snub-nosed monkeys is consistent with a polygynous mating system, both field observation and genetic data suggests that their mating system is polygamous. Infanticide and inbreeding avoidance are the most likely explanations for the promiscuity of female snub-nosed monkeys. Am. J. Primatol. 72:25,32, 2010. © 2009 Wiley-Liss, Inc. [source] Prospective study of clinical symptoms and skin test reactions in medical students exposed to formaldehyde gasTHE JOURNAL OF DERMATOLOGY, Issue 5 2007Sachiko TAKAHASHI ABSTRACT Previous investigators have reported the occurrence of both allergic and non-allergic systemic complications due to exposure to formaldehyde gas. However, little is known about the pathogenic link between formaldehyde-induced clinical symptoms and patch test results, or about the long-term effects of formaldehyde exposure. In the present study, a questionnaire was administered to 143 medical students, and 60 of them were tested by patch test for formaldehyde at the beginning and end of a human anatomy laboratory course. Another group of 76 students who had finished the course 2,4 years previously were administered another questionnaire, and the patch test was carried out on 58 of them. The frequencies of skin irritation, eye soreness, lacrimation, eye fatigue, rhinorrhea, throat irritation, general fatigue and mood swings increased after repeated exposure. Two (3.3%) of 60 students became positive to 1% formaldehyde at the end of the anatomy course (one male with allergic hand dermatitis due to direct contact with formaldehyde, and one female with an atopic background with unbearable physical symptoms) while the remaining 58 showed a negative reaction throughout the study period. The vast majority of students complained of various non-allergic, physical symptoms, and recovered from such symptoms without subsequent complications. No progression to multiple chemical sensitivity was found. Students with an episode of atopic dermatitis and allergic rhinitis were susceptible to formaldehyde exposure, and developed mucocutaneous symptoms, probably due to the impaired barrier function and remodeling of the skin and mucosa. [source] Flow Cytometric Sorting of Fresh and Frozen-Thawed Spermatozoa in the Western Lowland Gorilla (Gorilla gorilla gorilla)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 4 2005J.K. O'Brien Abstract We adapted flow cytometry technology for high-purity sorting of X chromosome-bearing spermatozoa in the western lowland gorilla (Gorilla gorilla gorilla). Our objectives were to develop methodologies for liquid storage of semen prior to sorting, sorting of liquid-stored and frozen-thawed spermatozoa, and assessment of sorting accuracy. In study 1, the in vitro sperm characteristics of gorilla ejaculates from one male were unchanged (P>0.05) after 8 hr of liquid storage at 15°C in a non-egg yolk diluent (HEPES-buffered modified Tyrode's medium). In study 2, we examined the efficacy of sorting fresh and frozen-thawed spermatozoa using human spermatozoa as a model for gorilla spermatozoa. Ejaculates from one male were split into fresh and frozen aliquots. X-enriched samples derived from both fresh and frozen-thawed human semen were of high purity, as determined by fluorescence in situ hybridization (FISH; 90.7%±2.3%, overall), and contained a high proportion of morphologically normal spermatozoa (86.0%±1.0%, overall). In study 3, we processed liquid-stored semen from two gorillas for sorting using a modification of methods for human spermatozoa. The sort rate for enrichment of X-bearing spermatozoa was 7.3±2.5 spermatozoa per second. The X-enriched samples were of high purity (single-sperm PCR: 83.7%) and normal morphology (79.0%±3.9%). In study 4 we examined frozen-thawed gorilla semen, and the sort rate (8.3±2.9 X-bearing sperm/sec), purity (89.7%), and normal morphology (81.4%±3.4%) were comparable to those of liquid-stored semen. Depending on the male and the type of sample used (fresh or frozen-thawed), 0.8,2.2% of gorilla spermatozoa in the processed ejaculate were present in the X-enriched sample. These results demonstrate that fresh or frozen-thawed gorilla spermatozoa can be flow cytometrically sorted into samples enriched for X-bearing spermatozoa. Am. J. Primatol. 66:297,315, 2005. © 2005 Wiley-Liss, Inc. [source] Multiple paternity occurs with low frequency in the territorial roe deer, Capreolus capreolusBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009C. VANPÉ An explanation for female multiple mating when males offer no material benefits but sperm remains elusive, largely because of a lack of empirical support for the genetic benefits hypothesis. We used 21 microsatellite markers to test for multiple paternities among 88 litters of roe deer, Capreolus capreolus, and to investigate the inbreeding avoidance hypothesis as a potential mechanism for the evolution of female multiple mating. From paternity analyses, we found that 13.5% of polytocous litters were sired by more than one male. We also found that a half-sib relationship was more likely than a full-sib relationship for 20.5% of all litters. This is the first report of multiple paternities in a territorial ungulate species. In support of the inbreeding avoidance hypothesis, we found that parents who were strongly related produced offspring with lower individual heterozygosity that survived less well during their first summer than fawns with unrelated parents. In addition, fawns from multiple paternity litters survived their first summer better than fawns from single paternity litters. However, it remains unclear whether all female multiple paternity events in this species are provoked by an initial consanguineous mating. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society 2009, 97, 128,139. [source] The sexually-selected sperm hypothesis: sexbiased inheritance and sexual antagonismBIOLOGICAL REVIEWS, Issue 2 2002T. PIZZARI ABSTRACT When females are inseminated by more than one male (polyandry) sexual selection continues after insemination in the form of sperm competition and cryptic female choice. The sexually-selected sperm hypothesis proposes that, under the risk of sperm competition, additive variation in male traits determining fertilising effciency will select for female propensity to be polyandrous in order to increase the probability of producing sons with superior fertilising effciency. Two factors complicate this prediction: sex-biased transmission of male fertilising effciency traits and sexual antagonism of sex-limited traits, fostered by sexbiased inheritance. Here, we (i) review the evidence that male traits contributing towards fertilising effciency are heritable through sex-biased mechanisms, and (ii) explore the evolutionary implications for male and female reproductive strategies caused by both sex-biased transmission and sexual antagonism of fertilising effciency traits. Many male fertilising effciency traits are heritable through sex-biased mechanisms and may not necessarily increase female fitness. The predictions of the sexually-selected sperm hypothesis change dramatically under these different mechanisms of inheritance of fertilising effciency traits, and different fitness pay-offs derived by females from the expression of such traits. Both sex-biased control of fertilising effciency and sexual antagonism may also be important in explaining the maintenance of the genetic variance and selection potential of fertilising effciency. We propose that a useful approach to test the sexually-selected sperm hypothesis is to combine studies which identify behavioural and physiological mechanisms explaining variation in reproductive success with artificial selection experiments to infer the underlying evolutionary patterns. [source] Varying Ecological Quality Influences the Probability of Polyandry in White-handed Gibbons (Hylobates lar) in ThailandBIOTROPICA, Issue 4 2009Tommaso Savini ABSTRACT Although members of the family Hylobatidae are known to be monogamous, adult white-handed gibbons (Hylobates lar) at Khao Yai National Park, Thailand, also show multimale groups and polyandry. A need for more than one male to successfully raise offspring cannot explain the occurrence of polyandry in these territorial primates, because direct paternal care is absent in this species. We hypothesize that polyandry is primarily related to costs/benefits for males of cooperatively defending a female and/or resources; our prediction was that polyandry would become more frequent with increasing costs of female/resource defense. We measured the ecological quality of seven gibbon home ranges over a 3-yr period (2001,2003) to investigate how resource availability affected the probability of polyandry, and found a significant negative relationship between home range quality and home range size. Larger home ranges were of lower quality. As predicted, groups living on larger, poorer home ranges also experienced longer periods of polyandry. In forest areas of comparatively low quality, acquiring and maintaining a large home range that includes enough resources for a female to reproduce steadily may surpass a single male's capacity. Our model of cooperative male polyandry was supported by preliminary data of shared territorial defense and access to the female. However, interaction proportions were strongly skewed, and female's primary male partners monopolized grooming and mating. Nevertheless, a primary male on a large territory may benefit from the presence of a secondary male with aid in territorial/female defense, whereas a secondary male may gain by avoiding high dispersal costs. [source] A New Species of Dactylolabis (Eobothrophorus) from Baltic Amber (Diptera: Limoniidae)ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 4 2010Wieslaw KRZEMINSKI Abstract: A new species, Dactylolabis (Eobothrophorus) hoffeinsorum sp. nov. from the Baltic amber is described, based on one male. The distinctive characters are the shape of the discal cell in the wing and the shape of the process on tergite IX. The description of Dactylolabis (Eobothrophorus) lauryni Podenas, 2003 is amended, based on an additional specimen. With the new species added herein, the number of species of this subgenus totals four. The wing venation, antennae, and tergal processes of all four species of the subgenus described from the Baltic amber are compared. [source] Haemophagocytic lymphohistiocytosis: proposal of a diagnostic algorithm based on perforin expressionBRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2002Maurizio Aricň Summary. Haemophagocytic lymphohistiocytosis (HLH) is a rare, fatal disorder of early infancy. Mutations of the PRF1 gene have been identified in a subset of patients. However, the distinction between the different genetically determined and environmental subtypes of the disease remains a major issue to be solved. This may result in delayed or inappropriate application of bone marrow transplantation (BMT). We propose an algorithm that uses a combination of three rapid laboratory tests, i.e. perforin expression by peripheral lymphocytes, assessment of the behaviour of the 2B4 lymphocyte receptor and natural killer (NK) cell activity, to identify the different subgroups of HLH. In 19 patients diagnosed according to current criteria, we tested perforin expression, 2B4 receptor function and NK cell activity. PRF1 mutations were found in all seven patients showing absent perforin expression. In one male with abnormal behaviour of the 2B4 receptor, SH2D1A mutation confirmed the diagnosis of X-linked lymphoproliferative disease. Four patients with normal NK cell activity had evidence of associated infections. Of the seven with impaired NK cell activity, two had a probable genetically determined subtype of HLH and five appeared as sporadic, infection-associated cases. Improving the diagnostic approach may restrict the use of BMT, the only recognized curative treatment, to HLH patients with a documented poor prognosis while patients with milder disorders may be treated less intensively. Our flow chart could also lead to better selection of patients for specific gene analysis. [source] Lipid profiles in untreated severe congenital isolated growth hormone deficiency through the lifespanCLINICAL ENDOCRINOLOGY, Issue 1 2002Helena K. Gleeson Summary objective Growth hormone deficiency (GHD) is associated with adverse changes in lipid profile. However, changes in lipids through life in a homogeneous group of GHD subjects have not been defined. patients and measurements We examined lipid levels in a group of untreated severely GHD patients with a mutation in the GHRH receptor gene from a rural community in North-east Brazil. Lipid profiles in 15 GHD subjects [eight children and adolescents (one male), age (median [range]) 13·2 (5·4,19·9) years; seven adults (one male), age 47 (33,66) years] were compared with those in 29 indigenous controls from the same extended kindred [17 children and adolescents (six male), age 10·2 (5·3,18·4) years; 12 adults (eight male), age 54·5 (33,80) years]. All GHD subjects had a peak GH response of < 0·5 ng/ml in response to an insulin tolerance test and extremely reduced IGF-1 levels (median 5·5 ng/ml). Data were compared between cohorts and with an age- and sex-matched white American reference population. results Abnormalities were confined to plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels. More GHD children had levels of plasma TC and LDL-C above the 95th percentile for our reference population (3/8 and 4/7, respectively) compared to controls (0/17 and 1/15, respectively) (P < 0·05). In the adults, median TC and LDL-C levels were higher in the GHD than controls (P < 0·05) (6·3 vs. 4·1 mmol/l; 4·4 vs. 2·7 mmol/l, respectively). Median Z -scores, calculated using values from the reference population, were not different between GHD children and adults for both TC (+0·8 vs.+0·4) and LDL-C (+1·4 vs.+0·7). conclusions The lipid profile in children as well as in adults with very severe GHD is adversely modified. There would appear to be no significant worsening of the lipid abnormality with duration of GHD or achievement of adulthood. [source] | ||||||||||||||||