title: Characterization of MHC class IA in the endangered southern corroboree frog.
abstract: Southern corroboree frogs (Pseudophryne corroboree) have declined to near extinction in the wild after the emergence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in southeastern Australia in the 1980s. A major captive breeding and reintroduction program is underway to preserve this iconic species, but improving resistance to B. dendrobatidis would help the wild population to be self-sustaining. Using 3' and 5' rapid amplification of complementary DNA ends (RACE), we characterized the major histocompatibility complex (MHC) class IA locus in this species. We then used sequences generated from RACE to design primers to amplify the peptide-binding region (PBR) of this functional genetic marker. Finally, we analysed the diversity, phylogeny, and selection patterns of PBR sequences from four P. corroboree populations and compared this with other amphibian species. We found moderately high MHC class IA genetic diversity in this species and evidence of strong positive and purifying selection at sites that are associated with putative PBR pockets in other species, indicating that this gene region may be under selection for resistance to Bd. Future studies should focus on identifying alleles associated with Bd resistance in P. corroboree by performing a Bd laboratory challenge study to confirm the functional importance of our genetic findings and explore their use in artificial selection or genetic engineering to increase resistance to chytridiomycosis.
authors.affiliation: One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, 4811, Australia. tiffany.kosch@jcu.edu.au.|Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Victoria, 3010, Australia. tiffany.kosch@jcu.edu.au.
authors.forename: Tiffany A
authors.initials: TA
authors.lastname: Kosch
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
authors.forename: John A
authors.initials: JA
authors.lastname: Eimes
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
authors.forename: Chelsea
authors.initials: C
authors.lastname: Didinger
authors.affiliation: One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, 4811, Australia.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Brannelly
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
authors.forename: Bruce
authors.initials: B
authors.lastname: Waldman
authors.affiliation: One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, 4811, Australia.|Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Victoria, 3010, Australia.
authors.forename: Lee
authors.initials: L
authors.lastname: Berger
authors.affiliation: One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, 4811, Australia.|Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Victoria, 3010, Australia.
authors.forename: Lee F
authors.initials: LF
authors.lastname: Skerratt
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001001:Anura / Q000235:genetics*; D001315:Australia; D056727:Endangered Species; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D000949:Histocompatibility Antigens Class II
keywords: Amphibian declines; Batrachochytrium dendrobatidis; Chytrid fungus; Genetic variation; Major histocompatibility complex; Pseudophryne corroboree