MHC class IIB additive and non-additive effects on fitness measures in the guppy Poecilia reticulata

Fraser, B A and Neff, B D (2009) MHC class IIB additive and non-additive effects on fitness measures in the guppy Poecilia reticulata. Journal of Fish Biology, 75 (9). pp. 2299-2312. ISSN 0022-1112

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The genetic architecture of fitness at the class IIB gene of the major histocompatibility complex (MHC) in the guppy Poecilia reticulata was analysed. Diversity at the MHC is thought to be maintained by some form of balancing selection; heterozygote advantage, frequency-dependent selection or spatially and temporally fluctuating selection. Here these hypotheses are evaluated by using an algorithm that partitions the effect of specific MHC allele and genotypes on fitness measures. The effect of MHC genotype on surrogate measures of fitness was tested, including growth rate (at high and low bulk food diets), parasite load following a parasite challenge and survival. The number of copies of the Pore a132 MHC allele was inversely related to infection by Gyrodactylus flukes and it appeared to be positively related to faster growth. Also, genotypes combining the Pore a132 or other relatively common alleles paired with rare MHC alleles produced both advantageous and detrimental non-additive effects. Thus, the genetic architecture underlying fitness at the MHC is complex in the P. reticulata.

Item Type: Article
Keywords: fitness; genetic quality; growth rate; major histocompatibility complex; parasite; Poecilia reticulata.
Schools and Departments: School of Life Sciences > Evolution, Behaviour and Environment
Subjects: Q Science > QL Zoology
Depositing User: Bonnie Fraser
Date Deposited: 14 Sep 2016 14:47
Last Modified: 02 Jul 2019 21:34

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