Trends in Parasitology
Research FocusPopulation genetics of Cryptosporidium parvum
Section snippets
The population biology of C. parvum
During the past 10 years, much effort has focused on the taxonomy of the genus Cryptosporidium, but a consensus of what constitutes a valid or named species [2] remains elusive. New species are still being described 3, 4 and the subdivision of C. parvum into two species, C. parvum and Cryptosporidium hominis, has recently been proposed to replace the Type 1 and Type 2 subspecies designation, respectively [5]. These newly defined species are being adopted rapidly. However, although suggested by
Differences in population structure
The study by Mallon et al. [12] demonstrates that genetic recombination occurs in nature, and that out-crossing is common among C. parvum Type 2 parasites. Together with evidence showing genetic recombination in experimental mouse infections [19], this study emphasizes the importance of this process for the epidemiology of cryptosporidiosis. The results highlight the differences in the population structure of Type 1 and Type 2 C. parvum, and uncover what appear to be human-specific Type 2
Future implications
The presence of different population structures in C. parvum originating from a restricted geographical area represents a new insight into the epidemiology of cryptosporidiosis. Future studies from different geographical locations, in particular from those with high prevalence of human cryptosporidiosis, will reveal whether the differences in Type 1 and Type 2 populations are maintained, and will expand our understanding of the population biology of C. parvum.
In contrast to malaria, which has
Glossary
Glossary
- Linkage disequilibrium (LD):
- The non-random association between alleles at different genetic loci. LD is a measure of association between alleles at any two loci. LD is low in randomly mating populations and high in clonal populations.
- Microsatellite:
- Repeat of a long (>5 bp) sequence motif in a given DNA sequence. Microsatellites are useful markers for genotyping because of their frequent length polymorphism originating from a variable number of repeat units.
- Minisatellite:
- Repeat of a short (1–5
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Cited by (11)
Improving the genotyping resolution of Cryptosporidium hominis subtype IbA10G2 using one step PCR-based amplicon sequencing
2017, Infection, Genetics and EvolutionCitation Excerpt :A multi-locus approach would potentially give a higher discriminatory power than the single locus used today, partial sequencing of the gp60 gene. Similarly to other apicomplexan parasites, Cryptosporidium spp. have a life cycle including sexual reproduction where sexual recombination can occur (Widmer, 2004). Both the zoonotic species C. parvum, and the host specific C. hominis show genetic heterogeneity, although some studies suggest that there are regional differences (Li et al., 2013; Tanriverdi et al., 2008).
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