Genetic Structure of Midwestern Ascaris suum Populations: A Comparison of Isoenzyme and RAPD Markers

Nadler, Steven A.; Lindquist, Rachel L.; Near, Thomas J.

doi:10.2307/3283820

Cited by 59 publications

(36 citation statements)

References 52 publications

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“…In view of this it was unsurprising that no genetic isolation by distance could be detected. This pattern of genetic variation is similar to that found for parasites of domesticated animals sampled from across the USA (Blouin et al 1995), although populations of Ascaris have more genetic structure than found in this study (Nadler et al 1995;Anderson et al 1995). The absence of any subdivision between S. ratti from di¡erent sample sites suggests that the e¡ective rate of parasite transfer between sample sites, and hence between rats, is su¤cient to prevent the generation of genetic subdivision.…”

Section: C Fisher and M Eviney Population Genetics Of Strongylosupporting

confidence: 88%

The population genetic structure of the facultatively sexual parasitic nematode Strongyloides ratti in wild rats

Fisher

Viney

1998

Proc. R. Soc. Lond. B

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We have investigated the population genetic structure of the parasitic nematode Strongyloides ratti in wild rats. In the UK, S. ratti reproduces predominantly by mitotic parthenogenesis, with sexual forms present at a rate of less than 1%. S. ratti was found to be a prevalent parasite and substantial genetic diversity was detected. Most rats were infected with a genotypic mixture of parasites. A hierarchical analysis of the genetic variation found in S. ratti sampled across Britain and Germany showed that 73.3% was explained by variation between parasites within individual hosts and 25.3% by variation between rats within sample sites. Only a small proportion (1.4%) of the total genetic variation was attributable to genetic subdivision between sample sites, suggesting that there is substantial gene £ow between these sites. Most parasites sampled were found to exist in Hardy^Weinberg equilibrium and this population genetic structure is discussed in view of the virtual absence of sexual reproduction.

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Section: C Fisher and M Eviney Population Genetics Of Strongylosupporting

confidence: 88%

The population genetic structure of the facultatively sexual parasitic nematode Strongyloides ratti in wild rats

Fisher

Viney

1998

Proc. R. Soc. Lond. B

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“…High levels of within-infrapopulation structure (the Wahlund effect [60]), as have been detected in Ascaris suum, could occur through the infection of a single host with multiple genetically distinct groups of larvae [58]. However, this effect requires the prior existence of interinfrapopulation structure, which we have shown to be absent in T. tenuis.…”

Section: Discussionmentioning

confidence: 50%

“…This scenario contrasts with Ascaris spp., where small infrapopulations, frequent autoinfection and recruitment of groups of siblings appear to have caused strong partitioning of genetic variance between infrapopulations [15,[57][58][59].…”

Section: Discussionmentioning

confidence: 99%

Abundant variation in microsatellites of the parasitic nematode Trichostrongylus tenuis and linkage to a tandem repeat

Johnson

Webster

Adam

et al. 2006

Molecular and Biochemical Parasitology

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“…DNA techniques provide useful tools to study the epidemiology and population genetics of Ascaris [9][10][11][24][25][26][27][28][29][30]. For instance, PCR-based restriction fragment length poly-morphism (RFLP) analyses of mitochondrial DNA and of a nuclear ribosomal DNA region spanning the first (ITS-1) and second (ITS-2) internal transcribed spacers (= ITS) and the intervening 5.8S gene were utilized to investigate the population genetics of Ascaris [9,10,24,28], but there was no unequivocal genetic differentiation between the Ascaris populations from each of the two species of host [12].…”

Section: Introductionmentioning

confidence: 99%

Mutation scanning-coupled analysis of haplotypic variability in mitochondrial DNA regions reveals low gene flow between human and porcineAscaris in endemic regions of China

Peng

Yuan

et al. 2005

Electrophoresis

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Haplotypic variation within and among the Ascaris populations representing six provinces in China was investigated. Mitochondrial DNA regions in the cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes were amplified by PCR from total genomic DNA samples (n > 720) from Ascaris individuals from humans and pigs, and subjected to mutation scanning and subsequent selective sequencing. For the cox1, ten different electrophoretic profiles were recorded for human Ascaris, and the same number for pig Ascaris, one of them being common to both host species. For the nad1, 11 different profiles were detected for human Ascaris, and 15 for pig Ascaris. Having defined all haplotypes (20 for pcox1 and 26 for pnad1) by sequencing, their frequencies were estimated in each of the two host species and each of the six provinces. For each mitochondrial region, the frequency of the different haplotypes varied considerably, depending on host species and geographical origin. Analysis of the sequence data (representing all haplotypes for each mitochondrial locus) by F-statistics indicated restricted gene flow between human Ascaris and pig Ascaris, and supported the conclusions from previous molecular epidemiological investigations that pigs are not a significant source of Ascaris infection in humans in endemic regions.

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Genetic Structure of Midwestern Ascaris suum Populations: A Comparison of Isoenzyme and RAPD Markers

Cited by 59 publications

References 52 publications

The population genetic structure of the facultatively sexual parasitic nematode Strongyloides ratti in wild rats

The population genetic structure of the facultatively sexual parasitic nematode Strongyloides ratti in wild rats

Abundant variation in microsatellites of the parasitic nematode Trichostrongylus tenuis and linkage to a tandem repeat

Mutation scanning-coupled analysis of haplotypic variability in mitochondrial DNA regions reveals low gene flow between human and porcineAscaris in endemic regions of China

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