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1.
We studied patterns of parentage in 85 broods (332 cygnets) of black swans during three breeding seasons, using a set of eight polymorphic microsatellite markers. We detected both intraspecific brood parasitism (IBP; < 5% of cygnets per year) and extra-pair paternity (EPP). In these years, 10-17% (mean = 15.1%) of cygnets resulted from EPP, and 27-40% (mean 37.6%) of broods contained at least one extra-pair cygnet. Compared with levels of EPP in closely related species with similar life histories, these values are unexpectedly high. EPP in black swans appears unrelated to ecological factors (breeding density and synchrony) or genetic factors (genetic similarity between pair members or genetic quality of the offspring). We found no evidence that a mutual sexual feather ornament known to play a role in social mate choice in black swans (curled wing feathers) is involved in extra-pair mate choice. EPP does not lead to greater variance in reproductive success in males, relative to females in this species. We therefore suggest that EPP does not result in differential sexual selection on males and females, explaining why they are ornamented to the same degree.  相似文献   

2.
Primers for 16 microsatellite loci were developed for the trumpeter swan (Cygnus buccinator), a species recovering from a recent population bottleneck. In a screen of 158 individuals, the 16 loci were found to have levels of variability ranging from two to seven alleles. No loci were found to be linked, although two loci repeatedly revealed significant departures from Hardy–Weinberg equilibrium. Amplification in the closely related tundra swan (Cygnus columbianus) was successful for all except one locus. These microsatellite loci will be applicable for population genetic analyses and ultimately aid in management efforts.  相似文献   

3.
Nine polymorphic microsatellite loci from the Madagascar paradise flycatcher Terpsiphone mutata were isolated using nonradioactive polymerase chain reaction (PCR)‐based techniques to screen an enriched genomic library. Seven polymorphic loci showed no evidence of null alleles and exhibited high levels of variation in 18 unrelated individuals (mean diversity = 0.80, mean number of alleles = 13.6). These loci are therefore suitable for analysis of population structure and paternity (exclusion probability for six unlinked loci = 0.9998).  相似文献   

4.
McKinnon  Sally L.  Mitchell  S. F. 《Hydrobiologia》1994,279(1):163-170
In an earlier study, regression models were developed which related black swan populations to macrophyte biomass and to phytoplankton productivity in Tomahawk Lagoon No 2, a small South Island, New Zealand, lake in which phytoplankton and macrophytes vary widely from year to year, in an irregular inverse cycle. Two years of further study confirmed that winter swan populations are directly correlated with macrophytes, for samples taken on a single day in winter each year. They also confirmed that winter maximum swan populations can be predicted from measurements of phytoplankton productivity in the previous summer. This relationship is inverse. For 6 other lakes, 9 of the 11 data points lay within the 95% confidence intervals of the macrophyte-swan relationship, with the only outlier being a lake in which the macrophytic vegetation is dominated by filamentous algae. Further analysis, giving equal weight to each of the 7 lakes in the sample, confirmed that there is a significant correlation in winter between swan populations and macrophyte biomass for these lakes which show a wide range of size and trophic status. There was no such significant correlation in summer. All of the 8 data points from 7 other lakes lay within the rather broad 95% confidence intervals of the phytoplankton- swan relationship. The 4 lakes which fitted most closely to the predictions of this relationship have silty sediment. The other 3, which all had lower swan populations than predicted, have sediment predominantly of sand or fine clay, and macrophyte biomass and swan populations may be constrained by the nature of the sediment, rather than by shading effects from phytoplankton.  相似文献   

5.
We isolated and characterized six novel microsatellite markers for paternity analysis in the golden whistler Pachycephala pectoralis, by screening an enriched genomic library using nonradioactive PCR techniques. The six loci exhibited little or no evidence of null alleles and showed high levels of polymorphism (mean HE = 0.85, mean number of alleles = 15.2), making them suitable for paternity assessment in this species (exclusion probability of six unlinked loci = 0.9997).  相似文献   

6.
We describe seven polymorphic microsatellite loci for the mallard (Anas platyrhynchos). The microsatellites presented here are highly polymorphic, with on average 12 alleles in a sample of 15 presumably unrelated individuals. Therefore, they enable detailed parentage analysis in wild mallard populations, and can be used to answer many intriguing questions in behavioural ecology and evolutionary biology.  相似文献   

7.
A species of Actinobacillus was isolated in pure culture from the carcass of a captive Australian black swan (Cygnus atratus) dying of acute septicemia. The gross and microscopic findings are described and the significance of the isolate is discussed.  相似文献   

8.
Many recent studies have employed molecular markers to uncover important aspects of mating systems in teleost fishes. The fathead minnow (Pimephales promelas) is a nest‐building North American cyprinid that spawns multiply and exhibits exclusive male parental care. A battery of microsatellite markers was developed to analyse paternity in this species. The seven characterized loci possess four to 31 alleles and expected heterozygosities of 0.455–0.974. In combination, they elicit an exclusion probability of 0.999, a desirable level for paternity analysis. In addition, cross‐amplifications were conducted to test primer efficacy in 13 other taxa, including two congeners.  相似文献   

9.
We investigated the adaptive significance of a sexually monomorphicornament in the black swan Cygnus atratus. Both sexes grow curledfeathers on their wings (range 7–22 curled feathers perwing), which are displayed prominently in a range of socialinteractions. The number of curled feathers increased untilthe birds reached sexual maturity (at 2 years of age) but didnot vary with age thereafter. We found evidence for both sexualand social functions of the ornament. Paired, mature individualsof both sexes had higher numbers of curled feathers than unpaired,mature birds, and individuals paired assortatively with respectto curled feather number, suggesting the feathers may be involvedin mutual sexual selection. More ornamented individuals weredominant in agonistic interactions with birds of the same sexand pairing status. Highly ornamented pairs were also more likelyto maintain extended tenancy of preferred cygnet feeding areas,which resulted in improved offspring survival. The curled feathersthus appear to function as a signal of social dominance, whichis highly correlated with reproductive success and is thereforea reliable signal of parental quality in mate choice.  相似文献   

10.
Abstract. Octopodids are a globally distributed group of marine molluscs. Despite this, our knowledge of their reproductive biology rests heavily on inference, as all phases of copulation, beginning with sperm transfer, occur within the mantle cavity. Male octopuses insert a spermatophore into the female's oviduct, which is predicted to release a sperm-filled sac that either bursts to release sperm for storage or to itself be stored in a gland in the middle of the oviduct. To test whether female octopuses use sperm from multiple males to fertilize their eggs, as may be predicted from anatomy and anecdotal accounts, we apply microsatellite analysis to a partial clutch of Graneledone boreopacifica collected at 1600-m depth to test for multiple paternity. At least two genetically distinct sires contributed sperm to the hatchlings analyzed, demonstrating for the first time multiple paternity in octopodids.  相似文献   

11.
Ten polymorphic microsatellite loci were isolated from the cooperatively breeding and sexually dichromatic Eclectus parrot (Eclectus roratus). Nine loci were in Hardy–Weinberg equilibrium and unlinked. One locus, Ero1, was presumed to be sex‐linked since females, the heterogametic sex, were all homozygous, whereas 72% of males were heterozygous. A DNA database search revealed that Ero8 is probably an independent isolation of the microsatellite locus AgGT83 of the parrot Amozona guildingii. With high heterozygosity (0.41–0.89) and number of alleles (two to 13), these loci should prove useful for investigating the mating system of these unusual Australasian parrots.  相似文献   

12.
13.
Forty-three microsatellite loci originally isolated in Grus americana and G. japonensis were tested for polymorphism in the blue crane (G. paradisea). Amplified products were sequenced in the blue crane to aid in the design of blue crane-specific primers. When characterized in 20 unrelated blue crane individuals from South Africa, 14 loci were polymorphic, with each locus displaying between 2 and 7 alleles. Eight polymorphic loci were characterized in the grey-crowned crane (Balearica regulorum) and ten in the wattled crane (G. carunculatus).  相似文献   

14.
A set of polymorphic microsatellite loci was identified for population and behavioural studies of the rainbow bee‐eater (Merops ornatus). Eight loci were newly isolated from a rainbow bee‐eater genomic library enriched for GA‐containing repeats, and six loci from those previously reported for the European bee‐eater (Merops apiaster). From these two sources, the seven most variable loci that amplified reliably were unlinked and in Hardy–Weinberg equilibrium, had five to 13 alleles (mean 7.7) and an expected heterozygosity of 0.60–0.86 (mean 0.73).  相似文献   

15.
Ten polymorphic di‐ and trinucleotide microsatellite loci were developed in the fen raft spider Dolomedes plantarius from a partial phagemid genomic library enriched for microsatellite inserts. The expected heterozygosity at these loci ranges from 0.62 to 0.9, with the observed allele numbers varying from four to 15 in the 22 individuals tested. Average paternity exclusion probabilities ranged between 0.290 and 0.686. In combination, the 10 polymorphic loci elicit an exclusion probability of 0.999. The high level of polymorphism of these microsatellite loci makes them ideal genetic markers for paternity and population genetics analysis in this endangered species.  相似文献   

16.
We characterize 15 microsatellite loci from two microsatellite libraries developed from the Australian agamid lizards Amphibolurus muricatus and Ctenophorus pictus. All loci were tested for amplification in four other agamids: Ctenophorus fordi, Ctenophorus decresii, Chlamydosaurus kingii, and Physignathus lesueurii. These loci were highly polymorphic within and across species, with nine to 12 loci amplifying for each species tested.  相似文献   

17.
Sixteen polymorphic microsatellite loci were isolated in the cooperatively breeding grey‐crowned babbler (Pomatostomus temporalis). The number of alleles per locus ranged from two to eight, and observed heterozygosity from 0.07 to 0.88. Two loci showed a significant heterozygote deficiency, one of which appears to be sex‐linked. The exclusion probability for eight unlinked loci was 0.9996 with the other parent known. These loci will be used to analyse population genetic structure and the mating system of this vulnerable species.  相似文献   

18.
We used an enrichment technique to isolate 60 microsatellite loci in Ardea herodias. We developed primers for 17 loci, screened for variation in A. herodias and attempted to amplify these loci in three closely related species (A. alba, A. cinerea and A. cocoi). Fifteen loci were polymorphic in A. herodias. Observed heterozygosities ranged from 0.10 to 0.81. Two loci appeared to be monomorphic in A. herodias, but exhibited variation in product size among species within the genus. Our ability to amplify polymorphic products in closely related species suggests that these markers may be useful in other herons.  相似文献   

19.
The mute swan (Cygnus olor Gmelin) is one of the largest herbivorous waterbirds in the world. Its population increased dramatically over the last decades in Western Europe, leading to concerns about its potential impact on aquatic ecosystems. Indeed, swan consequences on fishponds remain poorly investigated, although fishpond animal communities and economic value both largely depend on aquatic macrophytes. We carried out an experiment in the Dombes region (Eastern France) with 96 exclosures on 24 fishponds. Our aim was to assess the impact of swan grazing on aquatic macrophyte presence, abundance and community structure (diversity and evenness) during the growing season (April to July). We also considered the potential effect of swan stay (i.e. number of swan days ha−1) and nutrient availability on macrophyte depletion. Swan grazing negatively affected the presence and abundance (% cover) of macrophyte beds, particularly at high swan density. No significant effect on dry biomass was found. Furthermore, swan grazing negatively affected community structure, suggesting that mute swan promoted the dominance of a few species in macrophyte communities. Whatever the macrophyte variable considered, nutrient availability in fishponds did not affect macrophyte depletion rate. It is speculated that both the repeated use of the same fishponds by birds and their expansion within the landscape may lead to more acute and broader consequences for macrophyte beds over the longer term.  相似文献   

20.
Eight polymorphic microsatellite loci were identified for Horsfield's bronze‐cuckoo (Chalcites basalis). These include seven newly isolated loci from cuckoo genomic libraries enriched for GA and GAAA repeat‐containing clones. These loci have a mean expected heterozygosity of 0.71, a mean number of alleles of 13.8 and a combined exclusion probability (one parent known) of 0.9999. Two loci (Cba01 and Cba07) showed a significant deficiency of heterozygotes and may therefore have null alleles, although this effect could be the result of nonrandom population sampling.  相似文献   

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