Variable-Number Tandem Repeats as Molecular Markers for Biotypes of
            <i>Pasteuria ramosa</i>
            in
            <i>Daphnia</i>
            spp

Mouton, Laurence; Nong, Guangmin; Preston, James F.; Ebert, Dieter

doi:10.1128/aem.02398-06

Cited by 21 publications

(30 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Three primer sets were used (primers marked with a star in Table 2). We tested the reliability of this method by mixing different proportions of spores from the isolates P1 and P3 whose allele sizes had been previously determined for the different primer sets (Mouton et al 2007), and determined the relative proportion of each isolate after amplifying samples with five sets of primers ( (Fig. 1).…”

Section: Genetic Molecular Analysismentioning

confidence: 99%

“…• C for 2-3 h. Final elution volume was 100 l. PCR amplification and automatic genotyping are as described elsewhere (for details, see Mouton et al 2007). The relative quantification of the different P. ramosa isolates within a single host was determined by calculating the ratio of respective peak heights of the isolatespecific alleles on the electropherogram.…”

Section: Genetic Molecular Analysismentioning

confidence: 99%

See 1 more Smart Citation

THE EFFECTS OF MULTIPLE INFECTIONS ON THE EXPRESSION AND EVOLUTION OF VIRULENCE IN ADAPHNIA‐ENDOPARASITE SYSTEM

2008

Self Cite

View full text Add to dashboard Cite

Multiple infections of a host by different strains of the same microparasite are common in nature. Although numerous models have been developed in an attempt to predict the evolutionary effects of intrahost competition, tests of the assumptions of these models are rare and the outcome is diverse. In the present study we examined the outcome of mixed-isolate infections in individual hosts, using a single clone of the waterflea Daphnia magna and three isolates of its semelparous endoparasite Pasteuria ramosa.We exposed individual Daphnia to single-and mixed-isolate infection treatments, both simultaneously and sequentially. Virulence was assessed by monitoring host mortality and fecundity, and parasite spore production was used as a measure of parasite fitness.Consistent with most assumptions, in multiply infected hosts we found that the virulence of mixed infections resembled that of the more virulent competitor, both in simultaneous multiple infections and in sequential multiple infections in which the virulent isolate was first to infect. The more virulent competitor also produced the vast majority of transmission stages. Only when the less virulent isolate was first to infect, the intrahost contest resembled scramble competition, whereby both isolates suffered by producing fewer transmission stages. Surprisingly, mixed-isolate infections resulted in lower fecundity-costs for the hosts, suggesting that parasite competition comes with an advantage for the host relative to single infections. Finally, spore production correlated positively with time-to-host-death. Thus, early-killing of more competitive isolates produces less transmission stages than less virulent, inferior isolates. Our results are consistent with the idea that less virulent parasite lines may be replaced by more virulent strains under conditions with high rates of multiple infections.

show abstract

Section: Genetic Molecular Analysismentioning

confidence: 99%

Section: Genetic Molecular Analysismentioning

confidence: 99%

THE EFFECTS OF MULTIPLE INFECTIONS ON THE EXPRESSION AND EVOLUTION OF VIRULENCE IN ADAPHNIA‐ENDOPARASITE SYSTEM

2008

Self Cite

View full text Add to dashboard Cite

show abstract

“…First, we employ a clone of P. ramosa (single genotype), not field isolates. Field isolates may contain more than one parasite clone (Jensen et al, 2006;Mouton et al, 2007;Ben-Ami et al, 2008;Luijckx et al, 2011). The use of P. ramosa clones negates the complicating factors intrinsic to mixed infections and allows for a more definitive interpretation of experimental results .…”

Section: Introductionmentioning

confidence: 99%

Resistance to a bacterial parasite in the crustacean Daphnia magna shows Mendelian segregation with dominance

et al. 2011

View full text Add to dashboard Cite

The influence of host and parasite genetic background on infection outcome is a topic of great interest because of its pertinence to theoretical issues in evolutionary biology. In the present study, we use a classical genetics approach to examine the mode of inheritance of infection outcome in the crustacean Daphnia magna when exposed to the bacterial parasite Pasteuria ramosa. In contrast to previous studies in this system, we use a clone of P. ramosa, not field isolates, which allows for a more definitive interpretation of results. We test parental, F1, F2, backcross and selfed parental clones (total 284 genotypes) for susceptibility against a clone of P. ramosa using two different methods, infection trials and the recently developed attachment test. We find that D. magna clones reliably exhibit either complete resistance or complete susceptibility to P. ramosa clone C1 and that resistance is dominant, and inherited in a pattern consistent with Mendelian segregation of a single-locus with two alleles. The finding of a single host locus controlling susceptibility to P. ramosa suggests that the previously observed genotype-genotype interactions in this system have a simple genetic basis. This has important implications for the outcome of host-parasite coevolution. Our results add to the growing body of evidence that resistance to parasites in invertebrates is mostly coded by one or few loci with dominance.

show abstract

“…Thus far, few species-specific molecular markers have been developed for Daphnia parasites (33,38,39,41) and then used in experimental studies (3). In surveys of natural Daphnia populations, parasite identification has been based primarily on microscopic examination (4,5,29,52), with only one exception (32).…”

mentioning

confidence: 99%

Molecular Identification and Hidden Diversity of Novel Daphnia Parasites from European Lakes

Wolinska

Gießler

Koerner

2009

Appl Environ Microbiol

View full text Add to dashboard Cite

Parasites play important roles in local population dynamics and genetic structure. However, due to insufficient diagnostic tools, detailed host-parasite interactions may remain concealed by hidden parasite diversity in natural systems. Microscopic examination of 19 European lake Daphnia populations revealed the presence of three groups of parasites: fungi, microsporidia, and oomycetes. For most of these parasites no genetic markers have been described so far. Based on sequence similarities of the nuclear small-subunit and internal transcribed spacer (ITS) rRNA gene regions, one fungus, four microsporidian, and nine oomycete taxa were discovered in 147 infected Daphnia (and/or three other zooplankton crustaceans). Additionally, cloning of rRNA gene regions revealed parasite sequence variation within host individuals. This was most pronounced in the ITS region of one microsporidian taxon, where the within-host sequence variation ranged from 1.7% to 5.3% polymorphic sites for parasite isolates from 14 different geographical locations. Interestingly, the parasite isolates from close locations grouped together based on sequence similarities, suggesting that there was parasite dispersal. Taken together, the data obtained in this study revealed hidden diversity of parasite communities in Daphnia lake populations. Moreover, a higher level of resolution for identifying parasite strains makes it possible to test new hypotheses with respect to parasite dispersal, transmission routes, and coinfection.During the last decade, microparasites of Daphnia species, which are small zooplankton crustaceans, have become a popular study system in ecological and evolutionary research (for a review, see reference 15). It has been shown both in the field and under controlled laboratory conditions that parasites have a substantial impact on Daphnia fitness (7, 21, 52). Parasiteinduced reductions in Daphnia population density (11,12) or even population crashes (17) might result in disruptions of aquatic food webs, as daphnids play important roles as main phytoplankton grazers and as a major food of planktivorous fish (27). Moreover, as infections are often genotype specific (6, 8), they can lead to changes in the gene pool of a Daphnia population (7,14), sometimes significantly increasing the genetic diversity of the host population (12, 54). Thus, Daphnia parasites cause not only ecological but also evolutionary changes in aquatic systems.Conclusions regarding the importance of parasites in natural systems require powerful tools to detect and properly identify parasite taxa. Thus far, few species-specific molecular markers have been developed for Daphnia parasites (33, 38, 39, 41) and then used in experimental studies (3). In surveys of natural Daphnia populations, parasite identification has been based primarily on microscopic examination (4, 5, 29, 52), with only one exception (32). The parasites recorded in natural populations of Daphnia are thus considered members of certain taxa, or even species, without genetic confirmation. The fac...

show abstract

Variable-Number Tandem Repeats as Molecular Markers for Biotypes of Pasteuria ramosa in Daphnia spp

Cited by 21 publications

References 22 publications

THE EFFECTS OF MULTIPLE INFECTIONS ON THE EXPRESSION AND EVOLUTION OF VIRULENCE IN ADAPHNIA‐ENDOPARASITE SYSTEM

THE EFFECTS OF MULTIPLE INFECTIONS ON THE EXPRESSION AND EVOLUTION OF VIRULENCE IN ADAPHNIA‐ENDOPARASITE SYSTEM

Resistance to a bacterial parasite in the crustacean Daphnia magna shows Mendelian segregation with dominance

Molecular Identification and Hidden Diversity of Novel Daphnia Parasites from European Lakes

Contact Info

Product

Resources

About