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1.
Price JJ 《Animal behaviour》1999,57(2):483-492
Males of the cooperatively breeding stripe-backed wren Campylorhynchus nuchalis, learn repertoires of stereotyped calls (termed WAY calls) from older male relatives. As a result, these vocalizations are normally specific to patrilineal family groups but are sometimes shared by male relatives in different groups. To determine whether or not this species can recognize the calls of different family groups, I performed playback experiments with individual call types recorded from males of known social and genealogical relationships. Subjects discriminated between the calls of unrelated neighbouring groups and unfamiliar groups, and they discriminated both of these from calls of their own groups. However, subjects failed to distinguish calls of males in other groups from calls of their own groups when these males were members of the same patriline. These results indicate that stripe-backed wrens can discriminate between repertoires of these calls that match or differ from their own. Consequently, they can recognize members of their patriline, not just members of their immediate group. These vocalizations probably provide a useful mechanism for recognizing group membership in this species and might also provide a mechanism for recognizing unfamiliar relatives in other groups. Copyright 1999 The Association for the Study of Animal Behaviour.  相似文献   

2.
Yao Y  Shi L  Tao Y  Lin K  Liu S  Yu L  Yang Z  Yi W  Huang X  Sun H  Chu J  Shi L 《Immunogenetics》2011,63(8):475-483
Killer cell immunoglobulin-like receptors (KIRs) show extensive variation in terms of gene content and allelic polymorphisms among different populations. The aim of this study was to analyze the distribution of KIR genes in the Bulang, Nu, Yugu, and Zhuang ethnic groups, which belong to four different language families in China, and thus to provide basic KIR gene and genotype data for these Chinese ethnic groups. Genotyping of 16 KIR genes was performed in 425 unrelated individuals using the polymerase chain reaction-sequence-specific oligonucleotide probe method with the Luminex MultiAnalyte Profiling System. The four framework KIR genes were detected in all four ethnic groups. The activating KIR genes as well as the inhibitory KIR genes showed extreme diversity among these four populations. A total of 35 distinct KIR genotypes were identified, one of which was previously unknown. The four most common genotypes were identified in all four populations and comprised 66.1~91.1% of all the genotypes. The group A haplotype occurred more frequently than the group B haplotype in the Nu, Yugu, and Zhuang populations, as in other East Asian populations. In contrast, the group A and group B haplotypes occurred equally in the Bulang population. The results of the present study suggested that the KIR genes and genotypes are diverse in these four ethnic groups, and each ethnic group has its own characteristic KIR distribution. The findings with respect to KIR gene diversity in these four populations should provide relevant genomic diversity data for the future study of viral infections, autoimmune diseases, and reproductive fitness.  相似文献   

3.
Despite the large number of movement studies, the constraints that grouping imposes on movement decisions remain essentially unexplored, even for highly social species. Such constraints could be key, however, to understanding the dynamics and spatial organisation of species living in group fusion-fission systems. We investigated the winter movements (speed and diffusion coefficient) of groups of free-ranging roe deer (Capreolus capreolus), in an agricultural landscape characterised by a mosaic of food and foodless patches. Most groups were short-lived units that merged and split up frequently during the course of a day. Deer groups decreased their speed and diffusion rate in areas where food patches were abundant, as well as when travelling close to main roads and crest lines and far from forests. While accounting for these behavioural adjustments to habitat features, our study revealed some constraints imposed by group foraging: large groups reached the limit of their diffusion rate faster than small groups. The ability of individuals to move rapidly to new foraging locations following patch depression thus decreases with group size. Our results highlight the importance of considering both habitat heterogeneity and group dynamics when predicting the movements of individuals in group fusion-fission societies. Further, we provide empirical evidence that group cohesion can restrain movement and, therefore, the speed at which group members can explore their environment. When maintaining cohesion reduces foraging gains because of movement constraints, leaving the group may become a fitness-rewarding decision, especially when individuals can join other groups located nearby, which would tend to maintain highly dynamical group fusion-fission systems. Our findings also provide the basis for new hypotheses explaining a broad range of ecological patterns, such as the broader diet and longer residency time reported for larger herbivore groups.  相似文献   

4.
Guilds or functional groups: does it matter?   总被引:10,自引:0,他引:10  
Jacques Blondel 《Oikos》2003,100(2):223-231
Although most researchers use the terms "guild" and "functional group" more or less synonymously, these two concepts bear different meanings. The guild concept refers primarily to the mechanisms of resource sharing by species in a competitive context whereas the functional groups concept is concerned with how a resource or any other ecological component is processed by different species to provide a specific ecosystem service or function. In many cases but not necessarily all, the two concepts are the two "faces" or "sides" of the same coin: the sharing by species of a similar resource is the guild facet (structural), while the ecosystem processes these species eventually perform through resource exploitation is the functional group facet. The two concepts differ in that competitive relationships within groups of species are not the focus of the functional group approach, exactly as processes or functions are not the focus of the guild approach. A group of species can be considered either as a guild or a functional group depending on the question addressed. Guild and functional group membership is independent of phylogenetic relationships but because species tend to share similar life history traits and adaptations through common evolutionary history, guild and functional group associates are often closely related. The concept of guild has had broader application in animal studies than in plant studies, whereas the reverse is true for the concept of functional group. Recent methodological advances to objectively partition species into guilds and functional groups, taking into consideration the most relevant characters or traits for delineating them, provide the means to construct an operational framework for making in situ and ex situ experiments that are urgently needed for a better understanding of the role of species in ecosystem functioning, especially in relation to global change concerns.  相似文献   

5.
目的:探讨和研究血小板参数、超敏C反应蛋白(hs-CRP)与免疫球蛋白联合检测对肝炎患者的临床意义,为临床中肝炎患者的诊治提供参考。方法:收集各种病毒性肝炎患者共156例(急性肝炎组48例、慢性肝炎组56例、重型肝炎组24例和肝硬化组28例),选择40例健康体检者作为对照组,对5组研究对象的血小板参数((血小板计数(PLT)、平均血小板体积(MPC)、血小板压积(PCT)和血小板分布宽度(PDW))、血清超敏C反应蛋白和免疫球蛋白(IgA、IgG和IgM)水平进行检测和测定,并对这些指标的变化进行对比分析。结果:除重型肝炎组与肝硬化组的血小板计数(PLT),慢性肝炎组与重型肝炎组的PCT,急性肝炎组、肝硬化组与对照组3组间的PDW的差异无统计学意义外,任意两组之间的差异均有统计学意义(P0.05);各组肝炎患者的hs-CRP均比健康对照组显著升高(P0.01),且免疫球蛋白也较对照组差异有统计学意义。结论:肝炎患者的血小板参数、超敏C反应蛋白(hs-CRP)与免疫球蛋白水平可以提示肝炎病情的变化,三者的联合检测为指导肝炎患者的判断、治疗方案的选择和疗效评定提供有一定的参考依据。  相似文献   

6.
Flowering time in Arabidopsis is controlled by a large number of genes, identified by induced mutations. Forty-two double mutants involving 10 of these loci were obtained and analyzed for their flowering behavior under long-day conditions, with and without vernalization, and under short-day conditions. The genetic interactions between the various mutants proved to be complex, although a major epistatic group (called group A) could be identified corresponding to the mutants, which are relatively insensitive to vernalization and daylength. In contrast, the genetic behavior of the mutants much more responsive to these environmental factors (group B) is more complex. The vernalization responsiveness of the group B mutants did not compensate for the lateness of the group A mutants. This indicated that these genes do not control vernalization sensitivity as such, but provide a factor that becomes limiting in short days. The classification of these mutants in different physiological groups is discussed in relation to the detected genetic interactions, and based on these interactions a more detailed model of their role in flowering initiation is proposed.  相似文献   

7.
The comparative method is frequently employed to study primate behavior and evolution. The method is used to infer adaptations, and considerable improvements have been made with respect to its implementation. Despite these advances, scant attention has been given to the nature of the data that are used in comparative analyses. This creates a potential problem as data are often compiled from studies conducted by multiple researchers, whose methods may differ, resulting in variation in data quality. In this article, we investigate the quality of data employed in studies of primate group size. Several issues concerning data quality arise when assembling data on group size. For example, data quality may be compromised if group sizes are estimated from censuses, unhabituated groups, or groups with unrecognized individuals. To mitigate these and other data quality issues, we gathered data from the literature on 23 monkeys and apes using well-defined and biologically relevant criteria for inclusion. We compare our results with those of eight published compilations of group size. Most studies did not provide details regarding the criteria for including data. We found that our group size values were uncorrelated or weakly correlated with those from three other studies and differed in a consistent fashion from those of one other study. Because conclusions derived from comparative analyses are only as accurate as the data that they use, future studies should provide details regarding data collection to ensure their reliability.  相似文献   

8.
Numerous rodent cell lines exist that have defects in nucleotide excision repair of DNA caused by alterations in genes that fall into 10 different complementation groups. The precise roles in the repair of these genes are unknown. We report here that extracts from Chinese hamster ovary cells of excision repair-defective complementation groups 1 and 3 are defective in DNA excision repair in a cell-free system. In vitro complementation can be achieved by mixing extracts from the two groups with one another. In addition, extracts from a human cell line representing xeroderma pigmentosum complementation group B could complement rodent complementation group 1 extracts, but not group 3 extracts. This is consistent with an identity of the ERCC-3 and xeroderma pigmentosum group B genes. Cellular evidence points toward a defect in the incision of damaged DNA in group 1 and 3 mutants. Since the ERCC-1 and ERCC-3 proteins are required for the in vitro reaction, it appears that both gene products are directly involved in the enzymatic incision of damaged DNA, or in preincision reactions. The experiments reported here provide the biochemical basis of an approach to analyze the function of these nucleotide excision repair proteins.  相似文献   

9.
Optimal group size and composition are determined by both the costs and benefits of group living for the group's members. Verreaux's sifakas (Propithecus verreauxi), a diurnal lemur, form multimale multifemale groups with the tendency toward even adult sex ratios despite a small average number of females per group. The unexpected presence of multiple adult males may be explained by tolerance of other group members if subordinate males provide benefits to the group that outweigh the costs associated with their presence. Results based on both demographic data collected over a 13‐year period and behavioral observations suggest that subordinate males provide no benefits in terms of infant survival and defense against group takeover by outside males. Although groups with more males are more likely to win intergroup encounters, subordinate males do not participate in these encounters more often than expected. Subordinate males are not costly to other group members in terms of direct intragroup feeding competition, but aggression rates between dominant and immigrated subordinate males increase in the mating season. Even though subordinate males provide very few benefits to the group, they are not very costly either and thus may be tolerated by resident females and dominant males. This tolerance may help to partially explain the tendency towards their unusual adult sex ratio. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

10.
Leucocyte and plasma ascorbic acid values were measured in healthy students, adult factory employees, and old people not receiving supplementary vitamin C and in healthy old people receiving 500 mg of vitamin C daily. Significant positive correlations between leucocyte and plasma ascorbic acid were found in all the groups. The regression lines differed significantly between one another within the sexes, but the pooled lines for each sex did not differ significantly in the unsupplemented groups. The relationship between plasma and leucocyte ascorbic acid values in the supplemented group differed significantly from that in the pooled unsupplemented groups.There was a limited range of variation in leucocyte ascorbic acid values compared with the range in plasma values in the supplemented group, whereas there was a wider range of variation in the leucocyte values in the unsupplemented groups. Leucocytes can therefore achieve a saturation level of ascorbic acid. Measurement of leucocyte ascorbic acid concentrations alone does not provide a reliable guide for the estimation of tissue status of ascorbic acid in normal individuals. Leucocyte concentrations provide a measure of the availability of ascorbic acid for storage, and plasma levels give an indication of its metabolic turnover rate. When these values are related the regression lines provide information about the storage and metabolism of ascorbic acid in normal individuals.  相似文献   

11.
One commonly cited benefit to animals that forage in groups is an increase in the probability of detecting a predator, and a decrease in the time spent in predator detection. A mathematical model (Pulliam 1973) predicts a negative relationship between group size and vigilance rates. Over fifty studies of birds and mammals report that the relationship at least partly explains why individuals forage in groups. This review evaluates the strength of these conclusions based on their evidence. Those variables that may confound the relationship between vigilance and group size are outlined, and their control is assessed for each study. The variables I consider to be important include the density and type of food; competition between individuals; the proximity to both a safe place and the observer; the presence of predators; the visibility within the habitat; the composition of the group; the ambient temperature and the time of day. Based on these assessments, most of the studies fail to adequately demonstrate an unambiguous relationship between vigilance behavior and group size. Nevertheless, many studies reveal interesting features of the relationship between vigilance and group size that should provide fruitful avenues for future research.  相似文献   

12.
The treatment of brachial plexus avulsion lesions invariably involves the use of neurotization procedures. Although some of these therapeutic strategies have been used for the past 20 years to restore selective function to the injured extremity, the individual efficacy of these nerve transfers has not been measured objectively, thereby rendering the prognostication of outcomes for these techniques a major problem. Using a true global avulsion model, the present study compares outcomes of the various neurotization procedures for the first time. The strength of this experimental model is that each nerve transfer tested leads to a common terminal pathway involving a single target-namely, the biceps muscle. Thus, quantitative measurements of biceps restoration will provide strong clues to the power of axonal regrowth of that particular motor pool. This study also introduces the Terzis grooming test, a modified behavioral test that can be quantified and that can provide an overall functional scale in the assessment of outcome. Thirty-five Sprague-Dawley rats were divided into seven groups, with each group testing a different motor donor for biceps reinnervation. The ipsilateral brachial plexus was globally avulsed in all animals, with the exception of the ipsilateral C7 group, and the respective motor donor coapted in an end-to-end fashion to the musculocutaneous nerve. Functional outcomes were measured by the Terzis grooming test, electromyography, biceps muscle force measurements, motor end plate counts, and quantitative axonal morphometry. The values of the different parameters were expressed as a standard score on a common scale. The relative standings of each group on each parameter were compared. Superior outcome was observed in the phrenic, the hypoglossal, and the ipsilateral C7 groups.  相似文献   

13.
目的:探讨和研究血小板参数、超敏C 反应蛋白(hs-CRP)与免疫球蛋白联合检测对肝炎患者的临床意义,为临床中肝炎患者的诊治提供参考。方法:收集各种病毒性肝炎患者共156 例(急性肝炎组48 例、慢性肝炎组56 例、重型肝炎组24 例和肝硬化组28 例),选择40 例健康体检者作为对照组,对5 组研究对象的血小板参数((血小板计数(PLT)、平均血小板体积(MPC)、血小板压积(PCT)和血小板分布宽度(PDW))、血清超敏C 反应蛋白和免疫球蛋白(IgA、IgG 和IgM)水平进行检测和测定,并对这些指标的变化进行对比分析。结果:除重型肝炎组与肝硬化组的血小板计数(PLT),慢性肝炎组与重型肝炎组的PCT,急性肝炎组、肝硬化组与对照组3 组间的PDW 的差异无统计学意义外,任意两组之间的差异均有统计学意义(P<0.05);各组肝炎患者的hs-CRP 均比健康对照组显著升高(P〈0.01),且免疫球蛋白也较对照组差异有统计学意义。结论:肝炎患者的血小板参数、超敏C 反应蛋白(hs-CRP)与免疫球蛋白水平可以提示肝炎病情的变化,三者的联合检测为指导肝炎患者的判断、治疗方案的选择和疗效评定提供有一定的参考依据。  相似文献   

14.
Badgers ( Meles meles ) have been the focus for the development of a pervasive model of social grouping behaviour, relevant to a number of carnivore species and other taxonomic groups – the Resource Dispersion Hypothesis (RDH). The RDH hypothesises that the dispersion and richness of resources in the environment provide a passive mechanism for the formation of groups, even without any direct benefits of group living. However, few studies have tested the RDH in the field. The principal prediction is that, as opposed to enlargement of territory sizes to accommodate more members, territory size (TS) is independent of group size (GS). Instead, TS is determined by the spatial dispersion of resources, while GS is independently determined by the richness of those resources. However, these predictions provide only weak correlative tests, especially in non-experimental field studies. The first predicts an absence of correlation and is therefore prone to Type II error, especially given the small sample sizes and errors in estimating TS and GS of mammals in the field. We tested for independence of territory size and group size in all years with available data since the beginning of the long-term badger study in Wytham Woods in 1974. We used two methods of TS estimation, a sequential Bonferroni technique to adjust for multiple inference tests, a combined analysis and an analysis with pooled data. This prediction of the RDH could not be rejected on the basis of any of these analyses. Given this evidence that other processes are independently determining group size and territory size, further predictions of the RDH will be worth investigating in considerable detail.  相似文献   

15.
Enzymology of one-carbon metabolism in methanogenic pathways   总被引:1,自引:0,他引:1  
Methanoarchaea, the largest and most phylogenetically diverse group in the Archaea domain, have evolved energy-yielding pathways marked by one-carbon biochemistry featuring novel cofactors and enzymes. All of the pathways have in common the two-electron reduction of methyl-coenzyme M to methane catalyzed by methyl-coenzyme M reductase but deviate in the source of the methyl group transferred to coenzyme M. Most of the methane produced in nature derives from acetate in a pathway where the activated substrate is cleaved by CO dehydrogenase/acetyl-CoA synthase and the methyl group is transferred to coenzyme M via methyltetrahydromethanopterin or methyltetrahydrosarcinapterin. Electrons for reductive demethylation of the methyl-coenzyme M originate from oxidation of the carbonyl group of acetate to carbon dioxide by the synthase. In the other major pathway, formate or H2 is oxidized to provide electrons for reduction of carbon dioxide to the methyl level and reduction of methyl-coenzyme to methane. Methane is also produced from the methyl groups of methanol and methylamines. In these pathways specialized methyltransferases transfer the methyl groups to coenzyme M. Electrons for reduction of the methyl-coenzyme M are supplied by oxidation of the methyl groups to carbon dioxide by a reversal of the carbon dioxide reduction pathway. Recent progress on the enzymology of one-carbon reactions in these pathways has raised the level of understanding with regard to the physiology and molecular biology of methanogenesis. These advances have also provided a foundation for future studies on the structure/function of these novel enzymes and exploitation of the recently completed sequences for the genomes from the methanoarchaea Methanobacterium thermoautotrophicum and Methanococcus jannaschii.  相似文献   

16.
G- and C-banded karyotypes for two insular species of deer mice, Peromyscus slevini and P. sejugis, are described and analyzed relative to the evolutionary relationship of these species to and their inclusion within the P. maniculatus species group. The chromosomal phenotype of P. slevini is unique among all banded karyotypes reported for Peromyscus, and comparison with published karyotypes suggests that P. slevini has systematic affinities with either the P. boylii or P. mexicanus species groups. The karyotypic data for P. sejugis clearly align these mice with P. maniculatus and provide a diagnostic character that supports the specific distinction between these taxa.  相似文献   

17.
《Animal behaviour》1988,36(1):140-149
Current knowledge of stable social groups of different size and structure suffers from a paucity of data on processes of group formation and development. If, for stable groups of one species, fission, growth, or other features of development reflect a uniform process operating on all groups, one might expect any group at one point in time to represent a single stage in the developmental process. Thus, unless group development is synchronous, a population should contain groups at all stages. A simple way to provide information about group development is to describe a large number of groups in a uniform habitat and to arrange the data along a variable axis, such as group size, that is thought to vary directly with development. A study was conducted on the tropical marine fish Anthias squamipinnis. Groups ranged in size from 1 to 370 fish. Small groups were spatially unitary. Intermediate-sized groups were divided into two spatially separate subgroups, i.e. were bipartite. Large groups were divided into three subgroups, i.e. were tripartite. Subgroups within each group were classified by relative size as small, medium, or large. Unitary groups were statistically similar to the larger subgroups in bi- and tripartite groups, but differed from smaller subgroups in sex ratio, juvenile membership, and relation to the substrate. While subdivision of groups could, in theory, be explained by proximity among randomly dispersed aggregations or by discontinuity of underlying substrate or available food, existing evidence does not favour these hypotheses. Group subdivision is probably the consequence of successive fissions of a previously unitary group.  相似文献   

18.
In fission–fusion social systems with scramble competition between males, multiple males join mating groups while surrounding an oestrous female. If male decisions to join a mating group have been shaped by natural selection, then there should be an optimal group size resulting from the trade‐offs between the benefits of monopolizing a female in small groups and the energy lost in defending her from rivals in large groups. Male dusky dolphins (Lagenorhynchus obscurus) off Kaikoura, New Zealand, provide a unique opportunity to assess the optimum mating group size because they join transient mating groups not confounded by foraging or predator evasion. Within aggregations of up to 1000 individuals, males search for oestrous females, encountering choices of staying with a large mating group or leaving to find a smaller group. Mating groups typically involve multiple males mating with a single female. We conducted focal follows of mating groups (N = 44) by vessel from November 2011 through January 2012. We used video and a GPS to record group size, behaviour and movement. For each group, we measured potential costs (Swim Speed, Loss of Monopolization Potential) and benefits (Copulation Rate and Duration, Energy Savings). Only Loss of Monopolization Potential was positively correlated with group size, while Energy Savings was negatively correlated. Using these two factors as utility functions, we constructed an optimality model and predicted the optimal mating group size to be seven individuals with a range of 4–11 individuals due to variance. The observed modal mating group size was five dolphins, with a range of 2–15. We compare variation in mating group currencies and sizes to past studies. We discuss potential limitations of applying optimality models to predict mating group size for socially complex and behaviourally plastic species such as dolphins.  相似文献   

19.
In order to provide a profile of the plasmid gene pool in Salmonella prior to the clinical use of antibiotics, a molecular genetic analysis was made of plasmids in strains collected by E.D.G. Murray between 1917 and 1954. These pre-antibiotic era (PAE) salmonellae contain conjugative plasmids of the same incompatibility groups as contemporary enterobacterial plasmids. Upon analysis of total plasmid content, 42 plasmids, sized between 23 and 72 MDa, were found. We defined and investigated six groups of these PAE Salmonella plasmids in terms of three groups of genes; those involved in plasmid maintenance and incompatibility, DNA repair and virulence. Of the five groups, three were replicon-typed to groups IncI1, IncX and IncFII; one group exhibited no homology to contemporary Inc/Rep probes, and one group represented virulence plasmids containing a common plasmid-partitioning locus. The results indicated that most of the PAE groups were progenitors of contemporary R-plasmids, except for the virulence plasmids, which have generally not evolved as vectors of antibiotic resistance.  相似文献   

20.
Over 300 blood group specificities on red cells have been identified, many of which are polymorphic. The molecular mechanisms responsible for these polymorphisms are diverse, though many simply represent single nucleotide polymorphisms (SNPs). Other mechanisms include the following: gene deletion; single nucleotide deletion and sequence duplication, which introduce reading-frame shifts; nonsense mutation; intergenic recombination between closely linked genes, giving rise to hybrid genes and hybrid proteins; and a SNP in the promoter region of a blood group gene. Examples of these various genetic mechanisms are taken from the ABO, Rh, Kell, and Duffy blood group systems. Null phenotypes, in which no antigens of a blood group system are expressed, are not generally polymorphic, but provide good examples of the effect of inactivating mutations on blood group expression. As natural human ‘knock-outs’, null phenotypes provide useful clues to the functions of blood group antigens. Knowledge of the molecular backgrounds of blood group polymorphisms provides a means to predict blood group phenotypes from genomic DNA. This has two main applications in transfusion medicine: determination of foetal blood groups to assess whether the foetus is at risk from haemolytic disease and ascertainment of blood group phenotypes in multiply transfused, transfusion-dependent patients, where serological tests are precluded by the presence of donor red cells. Other applications are being developed for the future.  相似文献   

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