Author Identifier (ORCID)
Manujaya W. Jayamanna Mohottige: https://orcid.org/0009-0009-8818-4054
Angéla Juhász: https://orcid.org/0000-0002-4317-2027
Mitchell G. Nye-Wood: https://orcid.org/0000-0001-9560-9916
Tawfeek Khedr: https://orcid.org/0000-0003-4628-0768
Michelle L. Colgrave: https://orcid.org/0000-0001-8463-805X
Abstract
AbstractKoalas (Phascolarctos cinereus) give birth to highly altricial young that rely on maternal milk for nutritional support and immune protection in the first year of life. This study applied proteomics to analyse stage-specific shifts in the koala milk proteome across early-, mid-, and late-lactation. Proteins were extracted from seven samples and analysed using liquid chromatography-tandem mass spectrometry. Quantitative profiling identified 874, 1220, and 498 proteins in early-, mid- and late-lactation stages, respectively. The most abundant proteins—including β-lactoglobulin, caseins, clusterin, trichosurin, albumin and lactotransferrin—were consistently detected across all stages, reflecting crucial roles in nutrition, immune function, and detoxification. Protein–protein interaction analyses revealed functionally important protein clusters associated with energy metabolism, translation, protein transportation, and these clusters exhibited shifts in abundance that align with the developmental and metabolic demands of the joey. Gene set variation analysis revealed stage-dependent regulation of immune pathway proteins, supporting foundational immune development in early-lactation, heightened neuroimmune protection in mid-lactation, and increased immune competence in late-lactation. These findings provide comprehensive insight into the dynamic adaptation of koala milk composition to joey development and may inform the design of nutritionally and immunologically optimised milk replacers for koala conservation and rehabilitation.
Keywords
Lactation, Liquid chromatography-tandem mass spectrometry, Phascolarctos cinereus, Protein
Document Type
Journal Article
Date of Publication
4-1-2026
Volume
358
PubMed ID
41887423
Publication Title
International Journal of Biological Macromolecules
Publisher
Elsevier
School
Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science / Centre of Crops and Horticultural Analytics for Nutrition and Climate Excellence / School of Science
Funders
Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science
Grant Number
ARC Number : CE200100012
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Comments
Mohottige, M. W. J., Juhász, A., Peel, E., Nye-Wood, M. G., Farquharson, K. A., Khedr, T., Belov, K., Hogg, C. J., & Colgrave, M. L. (2026). Lactation-stage specific protein shifts in koala milk mirror the joey’s growth needs. International Journal of Biological Macromolecules, 358, 151640. https://doi.org/10.1016/j.ijbiomac.2026.151640