MHC class II genotype-by-pathogen genotype interaction for infection prevalence in a natural rodent-Borrelia system.

MHC genes are extraordinarily polymorphic in most taxa. Host-pathogen coevolution driven by negative frequency-dependent selection (NFDS) is one of the main hypotheses for the maintenance of such immunogenetic variation. Here, we test a critical but rarely tested assumption of this hypothesis-that MHC alleles affect resistance/susceptibility to a pathogen in a strain-specific way, that is, there is a host genotype-by-pathogen genotype interaction.

Effects of protein malnutrition on tolerance to helminth infection.

Infection tolerance is the ability of a host to limit the health effects of a given parasite load. A few recent studies have demonstrated genetic variation for tolerance, but little is known about how environmental factors affect tolerance. Here, we used the intestinal nematode Heligmosomoides polygyrus in laboratory mice to test for effects of protein malnutrition on tolerance.

Contrasting patterns of structural host specificity of two species of Heligmosomoides nematodes in sympatric rodents.

Host specificity is a fundamental property of parasites. Whereas most studies focus on measures of specificity on host range, only few studies have considered quantitative aspects such as infection intensity or prevalence. The relative importance of these quantitative aspects is still unclear, mainly because of methodological constraints, yet central to a precise assessment of host specificity.

Genetic regulation of parasite infection: empirical evidence of the functional significance of an IL4 gene SNP on nematode infections in wild primates.

Background: Susceptibility to parasite infection affects fitness-related processes, such as mate choice and survival, yet its genetic regulation remains poorly understood. Interleukin-4 (IL4) plays a central role in the humoral immune defence against nematode parasite infections, inducing IgE switch and regulation of worm expulsion from the intestines. The evolutionary and functional significance of single nucleotide polymorphisms (SNPs) in IL4-genes is known, yet empirical information on the effect of IL4 SNPs on gastro-intestinal infections is lacking.

Host intrinsic determinants and potential consequences of parasite infection in free-ranging red-fronted lemurs (Eulemur fulvus rufus).

Parasites and infectious diseases represent ecological forces shaping animal social evolution. Although empirical studies supporting this link abound in various vertebrate orders, both the study of the dynamics and impact of parasite infections and infectious diseases in strepsirrhine primates have received little empirical attention. We conducted a longitudinal parasitological study on four groups of wild red-fronted lemurs (Eulemur fulvus rufus) at Kirindy Forest, Madagascar, during two field seasons in consecutive years to investigate i) the degree of gastrointestinal parasite infection on population and individual levels and ii) factors potentially determining individual infection risk.

Gastro-intestinal parasites of red-fronted lemurs in Kirindy Forest, western Madagascar.

Although parasites are important regulatory factors in animal populations, basic knowledge on their fauna in many vertebrate taxa is lacking. In particular, parasite infections of primate species have gained little attention. Here, I present data on the gastro-intestinal fauna of a population of wild red-fronted lemurs ( Eulemur fulvus rufus; Primates: Lemuriformes) monitored over a total of 8 mo during 2 consecutive field seasons in 2006 and 2007 in Kirindy Forest, western Madagascar.

Individual Facial Coloration in Male Eulemur fulvus rufus: A Condition-dependent Ornament?

Researchers studying individual variation in conspicuous skin coloration in primates have suggested that color indicates male quality. Although primate fur color can also be flamboyant, the potential condition dependence and thus signaling function of fur remains poorly studied. We studied sources of variation in sexually dichromatic facial hair coloration in red-fronted lemurs (Eulemur fulvus rufus).