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. 2024 Dec 28;14(1):31074.
doi: 10.1038/s41598-024-82217-w.

Koala MHCII association with chlamydia infertility remains equivocal: a need for new research approaches

Alana Kidd  1 , Andrea Casteriano  1 , Mark B Krockenberger  1 , Damien P Higgins  1 , Belinda R Wright  2
Affiliations

Koala MHCII association with chlamydia infertility remains equivocal: a need for new research approaches

Alana Kidd et al. Sci Rep. .

Abstract

Chlamydiosis is a common infectious disease impacting koalas and is a major cause of population decline due to resulting mortality and infertility. Polymorphisms of major histocompatibility complex (MHC) genes influence chlamydial disease outcomes in several species but koala studies have produced variable results. We aimed to identify the MHC II DAB and DBB repertoire of koalas from Liverpool Plains, NSW, a population heavily impacted by chlamydiosis. We compared variants between two studies, age cohorts and chlamydial infertility groups. Four DBB and eight DAB alleles were identified. The mean number of DAB alleles per individual increased and allele frequencies differed relative to a previous study, however the mean number of DBB alleles per individual decreased generationally, between age cohorts. DAB allele frequencies differed among fertility groups but contributing alleles could not be identified. While there is a likely role of MHCII in the complex pathogenesis of chlamydiosis, this study suggests that single gene association studies are not appropriate for understanding the impact of host genetics on koala chlamydiosis. A shift to larger multivariate studies is required to yield functional information on complex immunological interactions, and to inform targeted koala conservation across its diverse range and host-pathogen-environment contexts.

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Conflict of interest statement

Declarations. Competing interests: The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Allele frequencies of DBB (a) and DAB (b) in individuals sampled from Gunnedah NSW from the current study.
Fig. 2
Fig. 2
DBB (a) and DAB (b) allele frequency between Lau et al. 2014 study and current findings.
Fig. 3
Fig. 3
DBB (a) and DAB (b) allele frequency between “adult” and “juvenile” age groups.
Fig. 4
Fig. 4
DBB (a) and DAB (b) allele frequency between “infertile” and “fertile” groups.
See this image and copyright information in PMC

References

    1. Rhodes, J. R. et al. Using integrated population modelling to quantify the implications of multiple threatening processes for a rapidly declining population. Biol. Conserv.144, 1081–1088. 10.1016/j.biocon.2010.12.027 (2011).
    1. Dique, D. S. et al. Koala mortality on roads in south-east Queensland: the koala speed-zone trial. Wildl. Res.30, 419–426. 10.1071/WR02029 (2003).
    1. Gonzalez-Astudillo, V., Allavena, R., McKinnon, A., Larkin, R. & Henning, J. Decline causes of Koalas in South East Queensland, Australia: a 17-year retrospective study of mortality and morbidity. Sci. Rep.7, 42587. 10.1038/srep42587 (2017). - PMC - PubMed
    1. Lunney, D., Gresser, S., O’Neill, L. E., Matthews, A. & Rhodes, J. The impact of fire and dogs on Koalas at Port Stephens, New South Wales, using population viability analysis. Pac. Conserv. Biol.13, 189–201. 10.1071/PC070189 (2007).
    1. Melzer, A., Carrick, F., Menkhorst, P., Lunney, D. & John, B. S. Overview, critical assessment, and conservation implications of Koala Distribution and abundance. Conserv. Biol.14, 619–628. 10.1046/j.1523-1739.2000.99383.x (2000).

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