New Zealand Journal of Ecology (2016) 40(3): 351- 360

MHC genetic diversity and avian malaria prevalence in Mokoia Island saddlebacks

Research Article
Jolene T. Sutton 1,2,3*
Isabel Castro 4
Bruce C. Robertson 1,2
Daniel M. Tompkins 5
Jo-Ann L. Stanton 6
Ian G. Jamieson 1,2,7
  1. Allan Wilson Centre for Molecular Ecology and Evolution
  2. Department of Zoology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
  3. Department of Biology, University of Hawai‘i at Hilo, Hilo, USA
  4. Institute of Agriculture and the Environment, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand
  5. Landcare Research, Private Bag 1930, Dunedin 9054, New Zealand
  6. Department of Anatomy, University of Otago, Dunedin, New Zealand
  7. Died 2 February 2015
*  Corresponding author

Studies of wildlife populations have identified associations between disease resistance and diversity at genes of the major histocompatibility complex (MHC), which are involved with adaptive immunity. We compare MHC class II B (MHCIIB) and microsatellite genetic diversity in a population of New Zealand passerine birds, North Island saddlebacks on Mokoia Island, that was also tested for avian malaria. Prevalence of infection was low, and we found no conclusive evidence that infection status was linked to particular MHCIIB alleles. Individual-level MHCIIB nucleotide diversity, and the number of alleles per bird were both lower in infected compared with uninfected samples; however, neither trend was statistically significant. Genetic structure was observed in the MHCIIB dataset, suggesting that selective forces are shaping MHCIIB diversity in this population. Future research would benefit from long-term monitoring of allele frequencies and larger sample sizes where possible. Additionally, including disease intensity data (i.e. the degree of infection in an individual) alongside prevalence data (i.e. presence/absence of infection in an individual) may enhance the ability to detect phenotype-genotype associations in future research.