{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:09:30Z","timestamp":1760144970598,"version":"build-2065373602"},"reference-count":43,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2024,6,6]],"date-time":"2024-06-06T00:00:00Z","timestamp":1717632000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Sydney School of Veterinary Science (SSVS)"},{"name":"Wildlife Information, Rescue and Education Service NSW (WIRES NSW)"},{"name":"NSW Government through the NSW Koala Research Strategy"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JoF"],"abstract":"<jats:p>Cryptococcus is a genus of fungal pathogens that can infect and cause disease in a range of host species and is particularly prominent in koalas (Phascolarctos cinerus). Like other host species, koalas display a range of outcomes upon exposure to environmental Cryptococcus, from external nasal colonization to asymptomatic invasive infection and, in rare cases, severe clinical disease resulting in death. Host factors contributing to these varied outcomes are poorly understood. Due to their close relationship with eucalypt trees (a key environmental niche for Cryptococcus gattii) and suspected continual exposure to the pathogen, koalas provide a unique opportunity to examine host susceptibility in natural infections. Caspase recruitment domain-containing protein 9 (CARD9) is a key intracellular signaling protein in the fungal innate immune response. Humans with mutations in CARD9 succumb to several different severe and chronic fungal infections. This study is the first to sequence and explore CARD9 variation in multiple koalas using Sanger sequencing. Four CARD9 exons were successfully sequenced in 22 koalas from a New South Wales, Australia population. We found minimal variation between koalas across all four exons, an observation that was also made when CARD9 sequences were compared between koalas and six other species, including humans and mice. Ten single-nucleotide polymorphisms (SNP) were identified in this study and explored in the context of cryptococcal exposure outcomes. While we did not find any significant association with variation in cryptococcal outcomes, we found a high degree of conservation between species at several SNP loci that requires further investigation. The findings from this study lay the groundwork for further investigations of CARD9 and Cryptococcus both in koalas and other species, and highlight several considerations for future studies.<\/jats:p>","DOI":"10.3390\/jof10060409","type":"journal-article","created":{"date-parts":[[2024,6,6]],"date-time":"2024-06-06T06:40:26Z","timestamp":1717656026000},"page":"409","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["The CARD9 Gene in Koalas (Phascolarctos cinereus): Does It Play a Role in the Cryptococcus\u2013Koala Interaction?"],"prefix":"10.3390","volume":"10","author":[{"given":"Hannah P.","family":"Newton","sequence":"first","affiliation":[{"name":"Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, NSW 2006, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Damien P.","family":"Higgins","sequence":"additional","affiliation":[{"name":"Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, NSW 2006, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrea","family":"Casteriano","sequence":"additional","affiliation":[{"name":"Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, NSW 2006, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Belinda R.","family":"Wright","sequence":"additional","affiliation":[{"name":"Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, NSW 2006, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8168-4795","authenticated-orcid":false,"given":"Mark B.","family":"Krockenberger","sequence":"additional","affiliation":[{"name":"Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, NSW 2006, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3689-4109","authenticated-orcid":false,"given":"Luisa H. M.","family":"Miranda","sequence":"additional","affiliation":[{"name":"Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, NSW 2006, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,6,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"a019760","DOI":"10.1101\/cshperspect.a019760","article-title":"Cryptococcus neoformans and Cryptococcus gattii, the etiologic agents of cryptococcosis","volume":"4","author":"Fraser","year":"2014","journal-title":"Cold Spring Harb. Perspect. Med."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Danesi, P., Falcaro, C., Schmertmann, L.J., de Miranda, L.H.M., Krockenberger, M., and Malik, R. (2021). Cryptococcus in Wildlife and Free-Living Mammals. J. 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