MHC‐linked susceptibility to a bacterial infection, but no MHC‐linked cryptic female choice in whitefish

• Published in: Journal of evolutionary biology Vol. 17; no. 1; pp. 11 - 18
• Main Authors: Wedekind, C., Walker, M., Portmann, J., Cenni, B., Müller, R., Binz, T.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.01.2004
• Subjects: Animals; Base Sequence; Coregonus; Crosses, Genetic; cryptic female choice; DNA Primers; egg disease; Embryo, Nonmammalian - microbiology; Female; fish; Fishes - genetics; Fishes - microbiology; Fishes - physiology; gamete fusion; Germ Cells - physiology; Major Histocompatibility Complex - genetics; Marine; MHC class II; Molecular Sequence Data; Polymorphism, Single-Stranded Conformational; Pseudomonas fluorescens; Reproduction - physiology; second meiotic division; Sequence Analysis, DNA; sperm‐egg interaction; within‐family comparison
• ISSN: 1010-061X; 1420-9101
• DOI: 10.1046/j.1420-9101.2004.00669.x

Non‐random gamete fusion is one of several potential cryptic female choice mechanisms that have been postulated and that may enhance the survival probability of the offspring. Previous studies have found that gamete fusion in mice is influenced by genes of the major histocompatibility complex (MHC) region. Here we test (i) whether there is MHC‐dependent gamete fusion in whitefish (Coregonus sp.) and (ii) whether there is a link between the MHC and embryo susceptibility to an infection by the bacterium Pseudomonas fluorescens. We experimentally bred whitefish and reared sibships in several batches that either experienced or did not experience strong selection by P. fluorescens. We then determined the MHC class II B1 genotype of 1016 surviving larvae of several full sibships. We found no evidence for MHC‐linked gamete fusion. However, in one of seven sibships we found a strong connection between the MHC class II genotype and embryo susceptibility to P. fluorescens. This connection was still significant after correcting for multiple testing. Hence, the MHC class II genotype can considerably influence embryo survival in whitefish, but gamete fusion seems to be random with respect to the MHC.