Setosphaeria turcica,an essential phytopathogenic fungus,is the primary cause of serious yield losses in corn; however,its pathogenic mechanism is poorly understood.We cloned STK2,a newly discovered mitogen-activated ...Setosphaeria turcica,an essential phytopathogenic fungus,is the primary cause of serious yield losses in corn; however,its pathogenic mechanism is poorly understood.We cloned STK2,a newly discovered mitogen-activated protein kinase gene with a deduced amino acid sequence that is 96% identical to MAK2 from Phaeosphaeria nodorum,56% identical to KSS1 and 57% identical to FUS3 from Saccharomyces cerevisiae.To deduce Stk2 function in S.turcica and to identify the genetic relationship between STK2 and KSS1/FUS3 from S.cerevisiae,a restructured vector containing the open reading frame of STK2 was transformed into a fus3/kss1 double deletion mutant of S.cerevisiae.The results show that the STK2 complementary strain clearly formed pseudohyphae and ascospores,and the strain grew on the surface of the medium after rinsing with sterile water and the characteristics of the complementary strain was the same as the wild-type strain.Moreover,STK2 complemented the function of KSS1 in filamentation and invasive growth,as well as the mating behavior of FUS3 in S.cerevisiae,however,its exact functions in S.turcica will be studied in the future research.展开更多
Sexual selection by female mating preference for male nuptial coloration has been suggested as a driving force in the rapid speciation of Lake Victoria cichlid fish. This process could have been facilitated or acceler...Sexual selection by female mating preference for male nuptial coloration has been suggested as a driving force in the rapid speciation of Lake Victoria cichlid fish. This process could have been facilitated or accelerated by genetic associations between female preference loci and male coloration loci. Preferences, as well as coloration, are heritable traits and are probably determined by more than one gene. However, little is known about potential genetic associations between these traits. In turbid water, we found a population that is variable in male nuptial coloration from blue to yellow to red. Males at the extreme ends of the phenotype distribution resemble a reproductively isolated species pair in clear water that has diverged into one species with blue-grey males and one species with bright red males. Females of the turbid water population vary in mating preference coinciding with the male phenotype distribution. For the current study, these females were mated to blue males. We measured the coloration of the sires and male offspring. Parents-offspring regression showed that the sires did not affect male offspring coloration, which confirms earlier findings that the blue species breeds true. In contrast, male offspring coloration was determined by the identity of the dams, which suggests that there is heritable variation in male color genes between females. However, we found that mating preferences of the dams were not correlated with male offspring coloration. Thus, there is no evidence for strong genetic linkage between mating preference and the preferred trait in this population [Current Zoology 56 （1）： 57-64 2010].展开更多
Sexual size dimorphism(SSD) plays a significant role in understanding the evolution of life history and mating behavior. In this study,we analyzed the morphological data from a treefrog,Hyla ussuriensis,in northeaster...Sexual size dimorphism(SSD) plays a significant role in understanding the evolution of life history and mating behavior. In this study,we analyzed the morphological data from a treefrog,Hyla ussuriensis,in northeastern China and found that there are significant differences between males and females. Females that are larger in body size increase fecundity as the total number of eggs is positively correlated to female body size. Males are smaller in body size due to the mate choice by females based on the size dimorphism index(SVL mean of female divided by that of male) for the population,which may be an evolutionary stable strategy(ESS). SSD can be influenced not only through mate choice,but also reproductive behavior by analyzing the female reproduction output in the field. Our data are consistent with many previous studies,indicating that fecundity selection and sexual selection may be the common cause for sexual dimorphism in this species. Furthermore,there are no significant morphological differences between mated and unmated frogs of both sexes,which suggests that any frog can obtain a breeding chance when it matures. It further indicates that males may not affect female choice except by their snout-vent length(SVL) and body mass. It is,of course,possible that females adopt a mating strategy to mate with males whose SVL and body mass are smaller than paired females. Our research provides unequivocal evidence for effective female choice and information on the evolution of SSD in the production of anuran pairing patterns.展开更多
Sex differences in plumage color are common in bird species.Some bird species are regarded as sexually monochromatic in human visual systems,and in recent years,some species are found to be of cryptic(to human)sexual ...Sex differences in plumage color are common in bird species.Some bird species are regarded as sexually monochromatic in human visual systems,and in recent years,some species are found to be of cryptic(to human)sexual dichromatism by spectrophotometric techniques.However,the functions of plumage color are still less understood in these species.Here,we focused on plumage color traits in the Chestnut Thrush(Turdus rubrocanus),which is considered as a sexually monochromatic bird by human observers.We used spectrometer analyses and avian visual modeling to investigate the color traits of males and females,and whether these color traits are involved in assortative mating.We found that Chestnut Thrush showed sexual dichromatism in bill,throat and wing,and pairs mated assortatively with colorations of throat,chest,crown and wing.We also found that color of tarsus was different between two consecutive years.These results revealed that Chestnut Thrush is sexually dichromatic in the avian visual system,and plumage color traits play important roles in mate choice.展开更多
Sexual selection via female mate choice is thought to have played a key role in the speciation ofhaplochromine cichlids, but a dominant role for visual signals in such processes has lately been called into question. I...Sexual selection via female mate choice is thought to have played a key role in the speciation ofhaplochromine cichlids, but a dominant role for visual signals in such processes has lately been called into question. In addition, the possible role of male mating preferences in haplochromine speciation has been little studied. We studied patterns of both female and male mate choice, based exclusively on visual signals, in order to evaluate potential reproductive isolation between two populations of the Lake Malawi haplochromine Labeotropheus fuelleborni. In the first experiment, females were allowed to choose between two males, one from the same population and the other allopatric with respect to the female. Females in this experiment responded more frequently to males from their own population. Similarly, the males in these trials displayed more frequently when presented with females of their own population. In the second experiment, a female was allowed to choose between two males, either both from her own population or both allopatric. In these trials, both males and females from the Katale population interacted significantly more frequently in settings in which all three individuals were from the same population （＂same-population trios＂）, and those from the Chipoka population showed a similar trend. Thus, patterns in both male and female courtship behavior suggest that visual signals contribute to at least incipient reproductive isolation between populations of L. fuelleborni [Current Zoology 56 （ 1 ）： 65-72 2010].展开更多
Wolbachia are a group of intracellular bacteria, ma-ternally transmitted from infected females to their offspring, which affect a wide range of arthropods. Their presence is associated with Cytoplasmic Incompatibility...Wolbachia are a group of intracellular bacteria, ma-ternally transmitted from infected females to their offspring, which affect a wide range of arthropods. Their presence is associated with Cytoplasmic Incompatibility (CI) in crosses between infected males and uninfected females and between populations carrying different strains of Wolbachia. The negative influence of Wolbachia a infection on progeny fitness in incompatible crosses can be considered a first step in the appearance of reproductive isolation between infected and uninfected individuals. In this work, we examined the possibility of assortative mating in response to Wolbachia infection, a response that evolved as an incipient mechanism of sexual isolation in the species D. melanogaster and D. simulans. We found that the females of each species could detect the presence of the bacterium in the other sex and chose to mate with males who had the same state of infection, whereas the males randomly attempted to mate with both infected and uninfected females. Thus, Wolbachia may act as an additive factor influencing sexual isolation in Drosophila populations and may play a role in speciation events.展开更多
Five hundred and twenty-two isolates of Magnaporthe grisea isolated from rice in 5 Asian countries were characterized for their mating type by crossing them with 4 hermaphroditic isolates(KA3 and TH12: MAT1.1; Guy11 a...Five hundred and twenty-two isolates of Magnaporthe grisea isolated from rice in 5 Asian countries were characterized for their mating type by crossing them with 4 hermaphroditic isolates(KA3 and TH12: MAT1.1; Guy11 and TH16: MAT1. 2). Among them, 41% were MAT1.1 and 25% were MAT1. 2. The remaining 34% did not produce perithecia with any of the 4 hermaphroditic testers. In Bangladesh, India, Nepal, Vietnam and in most provinces of China, both mating types were present. Only one mating type was found in 3 provinces and 1 city of China. Almost all the isolates had very low fertility, as they were in general female sterile and sometimes also male sterile. Hermaphroditic isolates were recovered from the 5 countries. In these countries, they represented between 13% and 75% of the isolates. In Zhejiang, Guizhou, Guangdong, Hunan, Yunnan and Hubei provinces of China, hermaphroditic isolates represented between 6% and 67%. The genetic diversity of 143 isolates from these countries and provinces, where hermaphroditic isolates had been collected, was analyzed using SCAR markers. Genetic diversity was high and population structure did not resemble classical clonal structure described in most rice growing regions. The existence of sexual reproduction in the field, localization of a center of diversity in China, and migration between countries were discussed in this paper.展开更多
Sexual dimorphism in size and shape is common in many organisms, and is a key evolutionary feature. In this study, we analyzed morphometric data of the Jilin clawed salamander Onychodactylus zhangyapingi, an endemic C...Sexual dimorphism in size and shape is common in many organisms, and is a key evolutionary feature. In this study, we analyzed morphometric data of the Jilin clawed salamander Onychodactylus zhangyapingi, an endemic Chinese salamander, to examine sexual size and shape dimorphism. The morphometric data included 14 characteristics of 13 females and 11 males and was analyzed using univariate and multivariate methods. Our results showed that sexual dimorphism occurs not only in body size, but also in body shape. Males have a longer snout-vent length than females, a rarely reported pattern of male-biased sexual size dimorphism. Females have a larger space between the axilla and groin than males, while males have longer and larger tails compared to females. The sexual dimorphism in body size and shape can be explained by existing theories, but there is little data for the mating system, behavior, reproduction, or ecology of O. zhangyapingi, so further studies are required.展开更多
Sexual size dimorphism（SSD） is a widespread phenomenon among animals, and whose evolution and maintenance has been a central topic in evolutionary biology since Darwin＇s time. SSD varies in direction among the majo...Sexual size dimorphism（SSD） is a widespread phenomenon among animals, and whose evolution and maintenance has been a central topic in evolutionary biology since Darwin＇s time. SSD varies in direction among the major taxonomic groups of animals and even within the same groups. In anurans, female biased SSD is the rule in many lineages, whereas male biased SSD is a rare phenomenon. In this paper, we analyze whether SSD exists inLeptobrachium leishanensis by comparing morphological characteristics between the sexes. Our results show that all six morphological characteristics measured are significantly different between the sexes. Males are significantly larger than females, indicating that the male biased SSD of this species is apparent. The size of the nuptial spines, a special secondary sex trait of males, is significantly and positively correlated with body size. We suggest that the resource defense polygyny mating system and parental care behavior may be explanations for the evolution of male biased SSD and nuptial spine development in this species.展开更多
Theory suggests that males that are larger than their competitors may have increased mating success, due to both greater competitive ability and increased attractiveness to females. We examined how male mating suceess...Theory suggests that males that are larger than their competitors may have increased mating success, due to both greater competitive ability and increased attractiveness to females. We examined how male mating suceess varies with male size in the tessellated darter Etheostoma olmstedi. Previous work has shown that large males tend to move around and breed in vacant breeding sites, and consequently provide less care for their eggs, while smaller individuals can be allopaternal, caring for the eggs of other males as well as for their own. We studied female egg deposition in a natural breeding population using artificial breeding sites and in the laboratory, where female choice of spawning site was restricted to two breeding sites tended by two males of different sizes. In both the field and the laboratory, nests tended by larger males were more likely to receive new eggs. Additionally, the mean size of males associated with a nest was positively correlated with both the maximum coverage of eggs at the nest and the number of times new eggs were deposited. We discuss how the increased mating success of larger males, despite their decreased parental care, may help explain aUopaternal care in this species [Current Zoology 56 （1）： 1-5, 2010].展开更多
Background:As one of the most elaborate and diverse sexual signals,bird songs are prominent among mate choice criteria.Females generally prefer mates with larger repertoire size,which promotes the evolution of song co...Background:As one of the most elaborate and diverse sexual signals,bird songs are prominent among mate choice criteria.Females generally prefer mates with larger repertoire size,which promotes the evolution of song complex?ity.However,there are also some songbirds that have far simpler and less diverse vocalizations,which have not been the focus of scientific scrutiny.Most Phylloscopus warblers are accomplished singers with complex songs.In contrast,Hume's Warbler(P.humei) has extremely simple songs.In order to explore the song's function,its evolutionary sig?nificance and particularly to assess its possible relationship with parental investment,we studied mate choice of the subspecies P.h.mandellii in Lianhuashan National Nature Reserve,Gansu,China.Methods:We recorded body measurements and songs of breeding males and then explored their relationships with the date of clutch initiation,reasoning that the characteristics of males that are involved with early nesting activities reflect female mate preferences.We also recorded egg size and body measurements of nestlings to assess the rela?tionship between parental investment and mate choice.Results:We found that male wing and tail lengths were positively correlated with early clutch initiation as were songs characterized by short duration and rapid rise to maximum amplitude.We also found that early?breeding females did not lay large eggs,but produced more surviving young,which grew up faster.Conclusions:Female mate choice criteria in this bird include both visual signals and song characteristics.Our study supports the hypothesis that females may judge male quality from quite subtle differences.In order to reduce the risk of predation,a preference for such inconspicuous male characteristics may be partially driven by high vulnerability of this warbler to predators as a ground?nesting species.展开更多
Theory predicts that males and females of dioecious species typically engage in an evolutionary sexual conflict over the frequency and choice of mating partner.Female sexual cannibalism,a particularly dramatic illustr...Theory predicts that males and females of dioecious species typically engage in an evolutionary sexual conflict over the frequency and choice of mating partner.Female sexual cannibalism,a particularly dramatic illustration of this conflict,is widespread in certain animal taxa including spiders.Nevertheless,females of some funnel weaving spiders that are generally aggressive to conspecifics enter a cataleptic state after male courtship,ensuring the males can mate without risk of attack.In this study,we demonstrated that the physical posture and duration,metabo-lites,and central neurotransmitters of females of Aterigena aculeata in sexual catalepsy closely resemble females in thanatosis but are distinct from those in anesthesia,indicating that the courted females feign death to eliminate the risk of potentially aggressive responses and thereby allow preferred males to mate.Unlike the taxonomically widespread thanatosis,which generally represents a deceptive visual signal that acts against the interest of the receivers,sexual catalepsy of females in the funnel weaving spiders may deliver a sexual-receptive signal to the courting males and thereby benefit both the signal senders and receivers.Therefore,sexual catalepsy in A.aculeata may not reflect a conflict butrather a confluence of interest betweenthe sexes.展开更多
灵长类交配模式是灵长类社群结构和婚配制度的重要表征之一,其研究有助于了解灵长类社群结构和两性交配策略。2013年11月至2014年10月,我们对云南白马雪山国家级自然保护区一人工辅助投食滇金丝猴群进行了观察研究,采用焦点动物取样法...灵长类交配模式是灵长类社群结构和婚配制度的重要表征之一,其研究有助于了解灵长类社群结构和两性交配策略。2013年11月至2014年10月,我们对云南白马雪山国家级自然保护区一人工辅助投食滇金丝猴群进行了观察研究,采用焦点动物取样法和全事件记录法收集了雌雄个体交配相关的行为数据,主要包括邀配对象、交配过程、持续时间和回合数,以及参与交配的雌雄对在交配结束后的相互理毛的持续时间和回合数。研究结果表明:研究群滇金丝猴全年均有交配行为,交配高峰期在7-9月,两性参与交配的积极性和对季节变化的响应不同;交配主要由雌性通过邀配发动(76%),交配高峰期也是雌性邀配的高峰期;雄性爬跨频次(年均0.43次/月,n=5)和射精爬跨比(年均19%,n=5)在全年无显著变化。交配行为发生的典型表现为:雌性通过小跑或跳跃进入雄性视线范围内,爬伏呈臀向雄性邀配;雌猴爬伏时离雄猴的远近距离不同(<1 m vs.2-5 m:69%vs.31%)会影响其邀配成功率(<1 m vs.2-5 m:68%vs.40%);若一次邀配失败,雌猴可能会连续爬伏邀配(最多4次),连续多次邀配的成功率显著高于单次邀配(79%vs.52%)。交配结束后雌性会主动为雄性理毛,但雌性主动理毛与交配是否射精无关。展开更多
基金supported by the National Natural Science Foundation of China(30471126 and 31171805)
文摘Setosphaeria turcica,an essential phytopathogenic fungus,is the primary cause of serious yield losses in corn; however,its pathogenic mechanism is poorly understood.We cloned STK2,a newly discovered mitogen-activated protein kinase gene with a deduced amino acid sequence that is 96% identical to MAK2 from Phaeosphaeria nodorum,56% identical to KSS1 and 57% identical to FUS3 from Saccharomyces cerevisiae.To deduce Stk2 function in S.turcica and to identify the genetic relationship between STK2 and KSS1/FUS3 from S.cerevisiae,a restructured vector containing the open reading frame of STK2 was transformed into a fus3/kss1 double deletion mutant of S.cerevisiae.The results show that the STK2 complementary strain clearly formed pseudohyphae and ascospores,and the strain grew on the surface of the medium after rinsing with sterile water and the characteristics of the complementary strain was the same as the wild-type strain.Moreover,STK2 complemented the function of KSS1 in filamentation and invasive growth,as well as the mating behavior of FUS3 in S.cerevisiae,however,its exact functions in S.turcica will be studied in the future research.
基金supported by the Netherlands Science Fotmdation (NWO-ALW 810.64.011)research grants from Leiden University Fundthe Schure-Beijerinck-Popping Foundation
文摘Sexual selection by female mating preference for male nuptial coloration has been suggested as a driving force in the rapid speciation of Lake Victoria cichlid fish. This process could have been facilitated or accelerated by genetic associations between female preference loci and male coloration loci. Preferences, as well as coloration, are heritable traits and are probably determined by more than one gene. However, little is known about potential genetic associations between these traits. In turbid water, we found a population that is variable in male nuptial coloration from blue to yellow to red. Males at the extreme ends of the phenotype distribution resemble a reproductively isolated species pair in clear water that has diverged into one species with blue-grey males and one species with bright red males. Females of the turbid water population vary in mating preference coinciding with the male phenotype distribution. For the current study, these females were mated to blue males. We measured the coloration of the sires and male offspring. Parents-offspring regression showed that the sires did not affect male offspring coloration, which confirms earlier findings that the blue species breeds true. In contrast, male offspring coloration was determined by the identity of the dams, which suggests that there is heritable variation in male color genes between females. However, we found that mating preferences of the dams were not correlated with male offspring coloration. Thus, there is no evidence for strong genetic linkage between mating preference and the preferred trait in this population [Current Zoology 56 （1）： 57-64 2010].
基金supported by the National Natural Science Foundation of China (Project No. 31172079)the Natural Science Foundation of Heilongjiang, China (Project No. QC2010035)the Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Heilongjiang and Harbin Normal University (KJTD2011-2)
文摘Sexual size dimorphism(SSD) plays a significant role in understanding the evolution of life history and mating behavior. In this study,we analyzed the morphological data from a treefrog,Hyla ussuriensis,in northeastern China and found that there are significant differences between males and females. Females that are larger in body size increase fecundity as the total number of eggs is positively correlated to female body size. Males are smaller in body size due to the mate choice by females based on the size dimorphism index(SVL mean of female divided by that of male) for the population,which may be an evolutionary stable strategy(ESS). SSD can be influenced not only through mate choice,but also reproductive behavior by analyzing the female reproduction output in the field. Our data are consistent with many previous studies,indicating that fecundity selection and sexual selection may be the common cause for sexual dimorphism in this species. Furthermore,there are no significant morphological differences between mated and unmated frogs of both sexes,which suggests that any frog can obtain a breeding chance when it matures. It further indicates that males may not affect female choice except by their snout-vent length(SVL) and body mass. It is,of course,possible that females adopt a mating strategy to mate with males whose SVL and body mass are smaller than paired females. Our research provides unequivocal evidence for effective female choice and information on the evolution of SSD in the production of anuran pairing patterns.
基金supported by the National Natural Science Foundation of China(No.32070452to YS)。
文摘Sex differences in plumage color are common in bird species.Some bird species are regarded as sexually monochromatic in human visual systems,and in recent years,some species are found to be of cryptic(to human)sexual dichromatism by spectrophotometric techniques.However,the functions of plumage color are still less understood in these species.Here,we focused on plumage color traits in the Chestnut Thrush(Turdus rubrocanus),which is considered as a sexually monochromatic bird by human observers.We used spectrometer analyses and avian visual modeling to investigate the color traits of males and females,and whether these color traits are involved in assortative mating.We found that Chestnut Thrush showed sexual dichromatism in bill,throat and wing,and pairs mated assortatively with colorations of throat,chest,crown and wing.We also found that color of tarsus was different between two consecutive years.These results revealed that Chestnut Thrush is sexually dichromatic in the avian visual system,and plumage color traits play important roles in mate choice.
基金supported by the Milwaukee County Zoological Societythe American Cichlid Association Guy D. Jordan Endowment+1 种基金Clifford Mortimer Awardsupported in part by NSF RUI and REU grants
文摘Sexual selection via female mate choice is thought to have played a key role in the speciation ofhaplochromine cichlids, but a dominant role for visual signals in such processes has lately been called into question. In addition, the possible role of male mating preferences in haplochromine speciation has been little studied. We studied patterns of both female and male mate choice, based exclusively on visual signals, in order to evaluate potential reproductive isolation between two populations of the Lake Malawi haplochromine Labeotropheus fuelleborni. In the first experiment, females were allowed to choose between two males, one from the same population and the other allopatric with respect to the female. Females in this experiment responded more frequently to males from their own population. Similarly, the males in these trials displayed more frequently when presented with females of their own population. In the second experiment, a female was allowed to choose between two males, either both from her own population or both allopatric. In these trials, both males and females from the Katale population interacted significantly more frequently in settings in which all three individuals were from the same population （＂same-population trios＂）, and those from the Chipoka population showed a similar trend. Thus, patterns in both male and female courtship behavior suggest that visual signals contribute to at least incipient reproductive isolation between populations of L. fuelleborni [Current Zoology 56 （ 1 ）： 65-72 2010].
文摘Wolbachia are a group of intracellular bacteria, ma-ternally transmitted from infected females to their offspring, which affect a wide range of arthropods. Their presence is associated with Cytoplasmic Incompatibility (CI) in crosses between infected males and uninfected females and between populations carrying different strains of Wolbachia. The negative influence of Wolbachia a infection on progeny fitness in incompatible crosses can be considered a first step in the appearance of reproductive isolation between infected and uninfected individuals. In this work, we examined the possibility of assortative mating in response to Wolbachia infection, a response that evolved as an incipient mechanism of sexual isolation in the species D. melanogaster and D. simulans. We found that the females of each species could detect the presence of the bacterium in the other sex and chose to mate with males who had the same state of infection, whereas the males randomly attempted to mate with both infected and uninfected females. Thus, Wolbachia may act as an additive factor influencing sexual isolation in Drosophila populations and may play a role in speciation events.
文摘Five hundred and twenty-two isolates of Magnaporthe grisea isolated from rice in 5 Asian countries were characterized for their mating type by crossing them with 4 hermaphroditic isolates(KA3 and TH12: MAT1.1; Guy11 and TH16: MAT1. 2). Among them, 41% were MAT1.1 and 25% were MAT1. 2. The remaining 34% did not produce perithecia with any of the 4 hermaphroditic testers. In Bangladesh, India, Nepal, Vietnam and in most provinces of China, both mating types were present. Only one mating type was found in 3 provinces and 1 city of China. Almost all the isolates had very low fertility, as they were in general female sterile and sometimes also male sterile. Hermaphroditic isolates were recovered from the 5 countries. In these countries, they represented between 13% and 75% of the isolates. In Zhejiang, Guizhou, Guangdong, Hunan, Yunnan and Hubei provinces of China, hermaphroditic isolates represented between 6% and 67%. The genetic diversity of 143 isolates from these countries and provinces, where hermaphroditic isolates had been collected, was analyzed using SCAR markers. Genetic diversity was high and population structure did not resemble classical clonal structure described in most rice growing regions. The existence of sexual reproduction in the field, localization of a center of diversity in China, and migration between countries were discussed in this paper.
基金supported by grants from the National Natural Science Foundation of China (NSFC 30900138, 31471971)
文摘Sexual dimorphism in size and shape is common in many organisms, and is a key evolutionary feature. In this study, we analyzed morphometric data of the Jilin clawed salamander Onychodactylus zhangyapingi, an endemic Chinese salamander, to examine sexual size and shape dimorphism. The morphometric data included 14 characteristics of 13 females and 11 males and was analyzed using univariate and multivariate methods. Our results showed that sexual dimorphism occurs not only in body size, but also in body shape. Males have a longer snout-vent length than females, a rarely reported pattern of male-biased sexual size dimorphism. Females have a larger space between the axilla and groin than males, while males have longer and larger tails compared to females. The sexual dimorphism in body size and shape can be explained by existing theories, but there is little data for the mating system, behavior, reproduction, or ecology of O. zhangyapingi, so further studies are required.
基金supported by National Natural Science Foundation of China(No.31270425,No.31470442)
文摘Sexual size dimorphism（SSD） is a widespread phenomenon among animals, and whose evolution and maintenance has been a central topic in evolutionary biology since Darwin＇s time. SSD varies in direction among the major taxonomic groups of animals and even within the same groups. In anurans, female biased SSD is the rule in many lineages, whereas male biased SSD is a rare phenomenon. In this paper, we analyze whether SSD exists inLeptobrachium leishanensis by comparing morphological characteristics between the sexes. Our results show that all six morphological characteristics measured are significantly different between the sexes. Males are significantly larger than females, indicating that the male biased SSD of this species is apparent. The size of the nuptial spines, a special secondary sex trait of males, is significantly and positively correlated with body size. We suggest that the resource defense polygyny mating system and parental care behavior may be explanations for the evolution of male biased SSD and nuptial spine development in this species.
基金funded by a grant from the National Science Foundation (IOB-0450807) to S.H.A.by a Natural Sciences and Engineering Research Council (NSERC) of Canada Postdoctoral Fellowship to K.A.S.by Yale University
文摘Theory suggests that males that are larger than their competitors may have increased mating success, due to both greater competitive ability and increased attractiveness to females. We examined how male mating suceess varies with male size in the tessellated darter Etheostoma olmstedi. Previous work has shown that large males tend to move around and breed in vacant breeding sites, and consequently provide less care for their eggs, while smaller individuals can be allopaternal, caring for the eggs of other males as well as for their own. We studied female egg deposition in a natural breeding population using artificial breeding sites and in the laboratory, where female choice of spawning site was restricted to two breeding sites tended by two males of different sizes. In both the field and the laboratory, nests tended by larger males were more likely to receive new eggs. Additionally, the mean size of males associated with a nest was positively correlated with both the maximum coverage of eggs at the nest and the number of times new eggs were deposited. We discuss how the increased mating success of larger males, despite their decreased parental care, may help explain aUopaternal care in this species [Current Zoology 56 （1）： 1-5, 2010].
基金supported by the National Natural Sciences Foundation of China(Grant Nos.31301886,31272286)
文摘Background:As one of the most elaborate and diverse sexual signals,bird songs are prominent among mate choice criteria.Females generally prefer mates with larger repertoire size,which promotes the evolution of song complex?ity.However,there are also some songbirds that have far simpler and less diverse vocalizations,which have not been the focus of scientific scrutiny.Most Phylloscopus warblers are accomplished singers with complex songs.In contrast,Hume's Warbler(P.humei) has extremely simple songs.In order to explore the song's function,its evolutionary sig?nificance and particularly to assess its possible relationship with parental investment,we studied mate choice of the subspecies P.h.mandellii in Lianhuashan National Nature Reserve,Gansu,China.Methods:We recorded body measurements and songs of breeding males and then explored their relationships with the date of clutch initiation,reasoning that the characteristics of males that are involved with early nesting activities reflect female mate preferences.We also recorded egg size and body measurements of nestlings to assess the rela?tionship between parental investment and mate choice.Results:We found that male wing and tail lengths were positively correlated with early clutch initiation as were songs characterized by short duration and rapid rise to maximum amplitude.We also found that early?breeding females did not lay large eggs,but produced more surviving young,which grew up faster.Conclusions:Female mate choice criteria in this bird include both visual signals and song characteristics.Our study supports the hypothesis that females may judge male quality from quite subtle differences.In order to reduce the risk of predation,a preference for such inconspicuous male characteristics may be partially driven by high vulnerability of this warbler to predators as a ground?nesting species.
基金supported by Natural Science Foundation of China(no.32160243,no.32000301,no.32070429,no.31772423,no.82173799)the Science and Technology Foundation of Jiangxi Provincial Department of Education(no.GJJ190543).
文摘Theory predicts that males and females of dioecious species typically engage in an evolutionary sexual conflict over the frequency and choice of mating partner.Female sexual cannibalism,a particularly dramatic illustration of this conflict,is widespread in certain animal taxa including spiders.Nevertheless,females of some funnel weaving spiders that are generally aggressive to conspecifics enter a cataleptic state after male courtship,ensuring the males can mate without risk of attack.In this study,we demonstrated that the physical posture and duration,metabo-lites,and central neurotransmitters of females of Aterigena aculeata in sexual catalepsy closely resemble females in thanatosis but are distinct from those in anesthesia,indicating that the courted females feign death to eliminate the risk of potentially aggressive responses and thereby allow preferred males to mate.Unlike the taxonomically widespread thanatosis,which generally represents a deceptive visual signal that acts against the interest of the receivers,sexual catalepsy of females in the funnel weaving spiders may deliver a sexual-receptive signal to the courting males and thereby benefit both the signal senders and receivers.Therefore,sexual catalepsy in A.aculeata may not reflect a conflict butrather a confluence of interest betweenthe sexes.
文摘灵长类交配模式是灵长类社群结构和婚配制度的重要表征之一,其研究有助于了解灵长类社群结构和两性交配策略。2013年11月至2014年10月,我们对云南白马雪山国家级自然保护区一人工辅助投食滇金丝猴群进行了观察研究,采用焦点动物取样法和全事件记录法收集了雌雄个体交配相关的行为数据,主要包括邀配对象、交配过程、持续时间和回合数,以及参与交配的雌雄对在交配结束后的相互理毛的持续时间和回合数。研究结果表明:研究群滇金丝猴全年均有交配行为,交配高峰期在7-9月,两性参与交配的积极性和对季节变化的响应不同;交配主要由雌性通过邀配发动(76%),交配高峰期也是雌性邀配的高峰期;雄性爬跨频次(年均0.43次/月,n=5)和射精爬跨比(年均19%,n=5)在全年无显著变化。交配行为发生的典型表现为:雌性通过小跑或跳跃进入雄性视线范围内,爬伏呈臀向雄性邀配;雌猴爬伏时离雄猴的远近距离不同(<1 m vs.2-5 m:69%vs.31%)会影响其邀配成功率(<1 m vs.2-5 m:68%vs.40%);若一次邀配失败,雌猴可能会连续爬伏邀配(最多4次),连续多次邀配的成功率显著高于单次邀配(79%vs.52%)。交配结束后雌性会主动为雄性理毛,但雌性主动理毛与交配是否射精无关。
