Evidence for a recent population bottleneck in an Apicomplexan parasite of caribou and reindeer, Besnoitia tarandi

• Published in: Infection, genetics and evolution genetics and evolution, 2012-12, Vol.12 (8), p.1605-1613
• Main Authors: Madubata, Chioma, Dunams-Morel, Detiger B., Elkin, Brett, Oksanen, Antti, Rosenthal, Benjamin M.
• Format: Article
• Language: English
• Subjects: Animals; Arctic; Besnoitia; Biological and medical sciences; Bottleneck; Canada; Caribou; Coccidiosis - parasitology; DNA, Protozoan - chemistry; DNA, Protozoan - genetics; DNA-directed RNA polymerase; epidemiology; Epidemiology. Vaccinations; Finland; General aspects; Genetic Variation; Genetics, Population; genotype; geographical distribution; Human protozoal diseases; Infectious diseases; intermediate hosts; internal transcribed spacers; intraspecific variation; loci; Medical sciences; Microsatellite Repeats; Muscles - parasitology; Mutation; parasites; Parasitic diseases; plastid DNA; population structure; Protozoal diseases; provenance; Rangifer tarandus; Reindeer; Reindeer - parasitology; ribosomal DNA; Sarcocystidae - genetics; Skin - parasitology; Toxoplasma gondii; Toxoplasmosis; transcription (genetics)
• ISSN: 1567-1348; 1567-7257
• DOI: 10.1016/j.meegid.2012.06.007

► Besnoitia tarandi parasites were genotyped in reindeer and caribou. ► Isolates in Canada and Finland were found to be identical at several markers. ► Nonetheless, other species of Besnoitia did vary at these loci. ► Parasites in the Arctic, therefore, have evidently undergone a recent bottleneck. The evolutionary history and epidemiology of parasites may be reflected in the extent and geographic distribution of their genetic variation. Among coccidian parasites, the population structure of only Toxoplasma gondii has been extensively examined. Intraspecific variation in other coccidia, for example, those assigned to the genus Besnoitia, remains poorly defined. Here, we characterize the extent of genetic variation among populations of Besnoitia tarandi, a parasite whose intermediate hosts include reindeer/caribou (Rangifer tarandus). Isolates from the Canadian Arctic and Finnish sub-Arctic were genotyped at six microsatellite loci, the first internal transcribed spacer region of nuclear rDNA, and the RNA polymerase β subunit (rpoB) encoded in the plastid genome. Remarkably, all isolates exhibited the same multilocus genotype, regardless of the isolate’s geographic origin. This absolute monomorphism occurred despite the capacity of these loci to vary, as established by evident differentiation between B. tarandi and two other species of Besnoitia, and variation among four isolates of B. besnoiti. The surprising lack of genetic variation across the sampled range suggests that B. tarandi may have experienced a recent population bottleneck.