Detection and quantification of coccidia in studies of wildlife can be challenging. Therefore, prevalence of coccidia is often not assessed at the parasite species level in non-livestock animals. Parasite species - specific prevalences are especially important when studying evolutionary questions in wild populations. We tested whether increased host population density increases prevalence of individual Eimeria species at the farm level, as predicted by epidemiological theory. We studied free-living commensal populations of the house mouse (Mus musculus) in Germany, and established a strategy to detect and quantify Eimeria infections. We show that a novel diagnostic primer targeting the apicoplast genome (Ap5) and coprological assessment after flotation provide complementary detection results increasing sensitivity. Genotyping PCRs confirm detection in a subset of samples and cross-validation of different PCR markers does not indicate bias towards a particular parasite species in genotyping. We were able to detect double infections and to determine the preferred niche of each parasite species along the distal-proximal axis of the intestine. Parasite genotyping from tissue samples provides additional indication for the absence of species bias in genotyping amplifications. Three Eimeria species were found infecting house mice at different prevalences: Eimeria ferrisi (16.7%; 95% CI 13.2-20.7), E. falciformis (4.2%; 95% CI 2.6-6.8) and E. vermiformis (1.9%; 95% CI 0.9-3.8). We also find that mice in dense populations are more likely to be infected with E. falciformis and E. ferrisi. We provide methods for the assessment of prevalences of coccidia at the species level in rodent systems. We show and discuss how such data can help to test hypotheses in ecology, evolution and epidemiology on a species level.

• Keywords
• Coccidia, Diagnostic PCR, Eimeria, House mice, Species-specific prevalence, qPCR,
• Publication type
• Journal Article MeSH

The CD94 receptor, expressed on natural killer (NK) and CD8+ T cells, is known as a relatively non-polymorphic receptor with orthologues in humans, other primates, cattle, and rodents. In the house mouse (Mus musculus), a single allele is highly conserved among laboratory strains, and reports of allelic variation in lab- or wild-living mice are lacking, except for deficiency in one lab strain (DBA/2J). The non-classical MHC-I molecule Qa-1b is the ligand for mouse CD94/NKG2A, presenting alternative non-americ fragment of leader peptides (Qa-1 determinant modifier (Qdm)) from classical MHC-I molecules. Here, we report a novel allele identified in free-living house mice captured in Norway, living among individuals carrying the canonical Cd94 allele. The novel Cd94LocA allele encodes 12 amino acid substitutions in the extracellular lectin-like domain. Flow cytometric analysis of primary NK cells and transfected cells indicates that the substitutions prevent binding of CD94 mAb and Qa-1b/Qdm tetramers. Our data further indicate correlation of Cd94 polymorphism with the two major subspecies of house mice in Europe. Together, these findings suggest that the Cd94LocA/NKG2A heterodimeric receptor is widely expressed among M. musculus subspecies musculus, with ligand-binding properties different from mice of subspecies domesticus, such as the C57BL/6 strain.

• Keywords
• Comparative immunology/evolution, Genomics, Inhibitory/activating receptors, MHC, NK cell,
• MeSH
• Alleles MeSH
• Killer Cells, Natural metabolism   MeSH
• CD8-Positive T-Lymphocytes metabolism   MeSH
• CHO Cells MeSH
• Cricetulus MeSH
• Species Specificity MeSH
• HEK293 Cells MeSH
• Cricetinae MeSH
• NK Cell Lectin-Like Receptor Subfamily C chemistry   genetics   metabolism   MeSH
• NK Cell Lectin-Like Receptor Subfamily D chemistry   genetics   metabolism   MeSH
• Humans MeSH
• Histocompatibility Antigens Class I chemistry   genetics   metabolism   MeSH
• Protein Multimerization MeSH
• Mice, Inbred C57BL MeSH
• Mice, Inbred DBA MeSH
• Peptides chemistry   genetics   metabolism   MeSH
• Polymorphism, Genetic * MeSH
• Amino Acid Sequence MeSH
• Sequence Homology, Amino Acid MeSH
• Protein Binding MeSH
• Animals MeSH
• Check Tag
• Cricetinae MeSH
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Norway MeSH
• Names of Substances
• NK Cell Lectin-Like Receptor Subfamily C MeSH
• NK Cell Lectin-Like Receptor Subfamily D MeSH
• Histocompatibility Antigens Class I MeSH
• Peptides MeSH
• Q surface antigens MeSH Browser
• Qdm protein, mouse MeSH Browser