title: Linkage between nuclear and mitochondrial DNA sequences in avian malaria parasites: multiple cases of cryptic speciation?
abstract: Analyses of mitochondrial cytochrome b diversity among avian blood parasites of the genera Haemoproteus and Plasmodium suggest that there might be as many lineages of parasites as there are species of birds. This is in sharp contrast to the approximately 175 parasite species described by traditional methods based on morphology using light microscopy. Until now it has not been clear to what extent parasite mitochondrial DNA lineage diversity reflects intra- or interspecific variation. We have sequenced part of a fast-evolving nuclear gene, dihydrofolate reductase-thymidylate synthase (DHFR-TS), and demonstrate that most of the parasite mitochondrial DNA lineages are associated with unique gene copies at this locus. Although these parasite lineages sometimes coexist in the same host individual, they apparently do not recombine and could therefore be considered as functionally distinct evolutionary entities, with independent evolutionary potential. Studies examining parasite virulence and host immune systems must consider this remarkable diversity of avian malaria parasites.
authors.affiliation: Department of Animal Ecology, Ecology Building, S-223 62 Lund, Sweden. staffan.bensch@zooekol.lu.se
authors.forename: Staffan
authors.initials: S
authors.lastname: Bensch
authors.forename: Javier
authors.initials: J
authors.lastname: Pérez-Tris
authors.forename: Jonas
authors.initials: J
authors.lastname: Waldenström
authors.forename: Olof
authors.initials: O
authors.lastname: Hellgren
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics; D014644:Genetic Variation; D016787:Haemosporida / Q000235:genetics*; D006790:Host-Parasite Interactions; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000235:genetics; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D020308:Songbirds / Q000469:parasitology*; D013030:Spain; D013045:Species Specificity; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics; D013940:Thymidylate Synthase / Q000235:genetics
chemical_list: D017931:DNA Primers; D004272:DNA, Mitochondrial; D009097:Multienzyme Complexes; C056930:thymidylate synthase-dihydrofolate reductase; D013762:Tetrahydrofolate Dehydrogenase; D013940:Thymidylate Synthase