title: Evidence for a recent population bottleneck in an Apicomplexan parasite of caribou and reindeer, Besnoitia tarandi.
abstract: 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.
authors: Animal Parasitic Disease Laboratory, Agricultural Research Service, US Department of Agriculture, Henry A Wallace Agricultural Research Center, Beltsville, MD 20705, United States.
authors: Chioma
authors: C
authors: Madubata
authors: Detiger B
authors: DB
authors: Dunams-Morel
authors: Brett
authors: B
authors: Elkin
authors: Antti
authors: A
authors: Oksanen
authors: Benjamin M
authors: BM
authors: Rosenthal
mesh_terms: D000818:Animals; D002170:Canada; D003048:Coccidiosis / Q000469:parasitology*; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D005387:Finland; D014644:Genetic Variation; D005828:Genetics, Population; D018895:Microsatellite Repeats; D009132:Muscles / Q000469:parasitology; D009154:Mutation; D012053:Reindeer / Q000469:parasitology*; D021745:Sarcocystidae / Q000235:genetics*; D012867:Skin / Q000469:parasitology
chemical_list: D016054:DNA, Protozoan