title: Intermediate number of major histocompatibility complex class IIB length variants relates to enlarged perivisceral fat deposits in the blunt-head cichlid Tropheus moorii.
abstract: Studying the genetic basis of host-parasite interactions represents an outstanding opportunity to observe eco-evolutionary processes. Established candidates for such studies in vertebrates are immunogenes of the major histocompatibility complex (MHC). The MHC has been reported to reach high intra- and interindividual diversity, and a diverse MHC might be advantageous when facing infections from multiple parasites. However, other studies indicated that individuals with an intermediate number of MHC alleles are less infected with parasites or have other fitness advantages. In this study, we assessed the optimal number of MHC alleles in the blunt-head cichlid Tropheus moorii from Lake Tanganyika. We investigated the influence of the interindividual variation in number of MHC length variants on parasite infection and body condition, measured by the amount of perivisceral fat reserves. Surprisingly, there was no correlation between parasite infection and number of MHC length variants or perivisceral fat deposits. However, the individual number of MHC length variants significantly correlated with the amount of perivisceral fat deposits in males, suggesting that male individuals with an intermediate number of alleles might be able to use their fat reserves more efficiently.
authors.affiliation: Laboratory of Biodiversity and Evolutionary Genomics, University of Leuven, Leuven, Belgium.
authors.forename: P I
authors.initials: PI
authors.lastname: Hablützel
authors.forename: M P M
authors.initials: MP
authors.lastname: Vanhove
authors.forename: A F
authors.initials: AF
authors.lastname: Grégoir
authors.forename: B
authors.initials: B
authors.lastname: Hellemans
authors.forename: F A M
authors.initials: FA
authors.lastname: Volckaert
authors.forename: J A M
authors.initials: JA
authors.lastname: Raeymaekers
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology*; D000818:Animals; D049628:Body Size; D023681:Cichlids / Q000033:anatomy & histology* / Q000235:genetics* / Q000469:parasitology*; D005260:Female; D005802:Genes, MHC Class II; D005838:Genotype; D016014:Linear Models; D008297:Male; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D059208:Parasite Load
keywords: Tropheus moorii; cichlids; diversity; evolution; fish; major histocompatibility complex; parasites; perivisceral fat