Extensive Genotypic Diversity in a Recombining Population of the Apicomplexan ParasiteTheileria parva
- 1 October 2006
- journal article
- Published by American Society for Microbiology in Infection and Immunity
- Vol. 74 (10), 5456-5464
- https://doi.org/10.1128/iai.00472-06
Abstract
We evaluated sexual recombination in the apicomplexan parasiteTheileria parvausing genome-wide marker analysis of haploid sporozoite populations obtained from infectedRhipicephalus appendiculatusticks. Analysis of 231 parasite clones derived by in vitro infection of bovine lymphocytes revealed 48 distinct combinations of 64 polymorphic marker loci. One genotype accounted for more than 75% of the clones, and the population was highly inbred with respect to this. The occurrence of frequent recombination was evident from reassortment of contiguous markers in blocks, with some recombination occurring within blocks. Analysis of four polymorphic loci encoding antigens targeted by protective cytotoxic-T-lymphocyte responses confirmed that these loci reassort, both within and between chromosomes, suggesting that recombination may influence immune recognition. Marker analysis of a panel of 142 clones derived from the population after an additional passage through a calf and the same tick colony revealed 18 genotypes, with the original dominant genotype accounting for 75% of the population and a higher level of inbreeding with respect to it in the remaining clones. Selected marker analysis of genomic DNA from these stabilates and the two preceding generations of the isolate, each derived from distinct tick colonies, revealed shifts in population structure with each generation, suggesting that the tick vector may impose nonrandom selective pressure on the parasite.Keywords
This publication has 29 references indexed in Scilit:
- A panel of microsatellite and minisatellite markers for the characterisation of field isolates of Theileria parvaInternational Journal for Parasitology, 2003
- Sex allocation and population structure in apicomplexan (protozoa) parasitesProceedings Of The Royal Society B-Biological Sciences, 2000
- Organisation and informational content of the Theileria parva genomeMolecular and Biochemical Parasitology, 1998
- Innate immunity of insectsCurrent Opinion in Immunology, 1995
- DNA measurements and ploidy determination of developmental stages in the life cycles ofTheileria annulata andT. parvaZeitschrift für Parasitenkunde, 1995
- Generation and characterization of clonedTheileria parvaparasitesParasitology, 1995
- How clonal are bacteria?Proceedings of the National Academy of Sciences, 1993
- Detection of polymorphisms amongTheileria parvastocks using repetitive, telomeric and ribosomal DNA probes and anti-schizont monoclonal antibodiesParasitology, 1993
- Cytotoxic T‐cells elicited in cattle challenged withTheileria parva(Muguga): evidence for restriction by class I MHC determinants and parasite strain specificityParasite Immunology, 1987
- Infection and Transformation of Bovine Lymphoid Cells in vitro by Infective Particles of Theileria parvaNature, 1973