Characterisation of four major histocompatibility complex class II genes of the koala (Phascolarctos cinereus)
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Major histocompatibility complex (MHC) class II molecules have an integral role in the adaptive immune response, as they bind and present antigenic peptides to T helper lymphocytes. In this study of koalas, species-specific primers were designed to amplify exon 2 of the MHC class II DA and DB genes, which contain much of the peptide-binding regions of the α and β chains. A total of two DA α1 domain variants and eight DA β1 (DAB), three DB α1 and five DB β1 variants were amplified from 20 koalas from two free-living populations from South East Queensland and the Port Macquarie region in northern New South Wales. We detected greater variation in the β1 than in the α1 domains as well as evidence of positive selection in DAB. The present study provides a springboard to future investigation of the role of MHC in disease susceptibility in koalas.
KeywordsKoala Phascolarctos cinereus MHC class II Marsupial Diversity
This research was funded by the Hermon Slade Foundation. All procedures were approved by the University of Sydney Animal Ethics Committee (AEC N00/4-2005/3/4088, AEC N00/5-2009/1/4829).We acknowledge Weerachai Jaratlerdsiri and Simon Ho for their help with analyses, Jaime Gongora for guidance on the manuscript and Joanna Griffith and all staff at the koala hospitals for sample collection.
- Belov K, Deakin JE, Papenfuss AT, Baker ML, Melman SD, Siddle HV, Gouin N, Goode DL, Sargeant TJ, Robinson MD, Wakefield MJ, Mahony S, Cross JG, Benos PV, Samollow PB, Speed TP, Graves JA, Miller RD (2006) Reconstructing an ancestral mammalian immune supercomplex from a marsupial major histocompatibility complex. PLoS Biol 4(3):e46. doi: 10.1371/journal.pbio.0040046 PubMedCrossRefGoogle Scholar
- Browning TL (2009) Inbreeding, the MHC and infectious disease susceptibility in the tammar wallaby, Macropus eugenii. Macquarie University, SydneyGoogle Scholar
- Lee A, Martin R (1988) The koala a natural history. New South Wales University Press, KensingtonGoogle Scholar
- Lunney D, Gresser S, O’Neill L, Matthews A, Rhodes JR (2007) The impact of fire and dogs on koalas at Port Stephens, New South Wales, using population viability analysis. Pac Conserv Biol 13(3):189–201Google Scholar
- Mitchell P (1990) Social behaviour and communication of koalas. In: Lee AK, Handasyde KA, Sanson GD (eds) Biology of the koala. Surrey Beatty, Chipping Norton, (Australia), pp 151-170Google Scholar
- Obendorf DL, Handasyde KA (1990) Pathology of chlamydial infection in the reproductive tract of the female koala. In: Lee AJ, Handasyde KA, Sanson GD (eds) Biology of the koala. Surrey and Beatty and Sons, Sydney, pp 255–259Google Scholar
- Rambaut A (2009) FigTree 1.3.1 ednGoogle Scholar