Project description:We examined genome-wide patterns of DNA methylation from whole genome DNA methylation maps of five tissues (brain, kidney, lung, skeletal muscle, and pancreas) from one male koala and one female koala (Phascolarctos cinereus), and present the first whole genome, multi-tissue “methylome atlas” with information on tissue- and sex-specific variation of DNA methylation for a marsupial.
Project description:The aims of this study were to investigate the proteome of koala (Phascolarctos cinereus) spermatozoa and that of the prostatic bodies with which they form intimate contact at the moment of ejaculation. For this purpose, spermatozoa and prostatic bodies were obtained from four adult male koala by electroejaculation and analysed by high performance liquid chromatography coupled to a mass spectrometer. This strategy successfully identified and 744 koala sperm and 1,297 prostatic body proteins, which were subsequently attributed to 482 and 776 unique gene products, respectively. Gene ontology curation of the koala sperm proteome revealed an abundance of proteins mapping to the canonical sirtuin and 14-3-3 signalling pathways. By contrast, protein ubiquitination and unfolding protein response pathways dominated the equivalent analysis of proteins uniquely identified in koala prostatic bodies. In terms of functional annotation, koala sperm proteins commonly mapped to the categories of cellular compromise/inflammatory response, whilst those of the prostatic body revealed an over-representation of molecular chaperone and stress-related proteins associated with cell survival. Cross-species comparisons demonstrated that the koala sperm proteome displays greater conservation with that of eutherians (human; 93%) as opposed to reptile (crocodile; 39%) and avian (rooster; 27%) spermatozoa. Similarly, koala prostatic body proteins also presented a relatively high degree of overlap (70%) with those identified in sub-populations of large human seminal plasma extracellular vesicles. Together, this work contributes our overall understanding of the core sperm proteome and has identified candidate markers that may contribute to the exceptional longevity of koala spermatozoa during ex vivo storage.
Project description:Bifidobacteria dominate the composition of the neonatal gut microbiota in the first number of weeks following birth. A number of species in particular are found with a significantly higher frequency in the microbiome of breastfed infants, owing to their ability to rely on Human Milk Oligosacchraides (HMOs) as their sole carbohydrate substrate; namely B. bifidum, B. longum spp. infantis and B. breve. Bifidobacterium kashiwanohense is a species that has been isolated previously only from the faeces of infants, but extremely infrequently at that. Relatively little is currently known about the species itself, let alone the metabolic pathways that allow it to successfully establish a population in the infant gut. We have isolated a novel strain of B. kashiwanohense from the faeces of a breastfed infant on the basis of its ability to utilise the HMO component fucosyllactose as its sole carbohydrate source. In this study, we read and annotate the full genome sequence of this novel strain, and use the data obtained to direct our further experimental analysis of fucosyllactose metabolism in B. kashiwanohense. Using transcriptomic and growth analysis results, we identify the genes responsible for B. kashiwanohense to utilise fucosyllactose, and employ a combination of cloning, in vitro hydrolysis assays, and further, recombinant transcriptomic and growth assays to elucidate the pathway for fucosyllactose metabolism in B. kashiwanohense, as well as revealing insight into fucosyllactose and fucose metabolism in Bifidobacteria as whole.
Project description:Production of milk is a key characteristic of mammals, but the features of lactation vary greatly between monotreme, marsupial and eutherian mammals. Marsupials have a short gestation followed by a long lactation period, and the milk constituents vary greatly across lactation to meet the changing needs of the developing young. Marsupials are born immunologically naïve and rely on their mother’s milk for immunological protection. The koala is an iconic Australian species and many are increasingly threatened by disease. Here we use a mammary transcriptome, two milk proteomes and the koala genome to comprehensively characterise the protein components of the milk of the koala, with a key focus on the immune constituents during early and late lactation. We have characterised the most abundant peptides present in milk, examined key differences between early and late lactation, and determined differences between the koala and other marsupial species. The most abundant proteins were well characterised mammalian and marsupial-specific milk proteins including β-lactoglobulin, lactotransferrin, caseins and early lactation protein. We have generated a list of 851 immune compounds identified in the mammary transcriptome and examined a range of immune proteins that were highly abundant in the milk proteomes. These include immunoglobulins, complement components and immune receptors. A host of antimicrobial peptides were identified including cathelicidins, lysozyme, WAP four-disulfide core domain protein 2, Mucin-1 and Peptidoglycan recognition protein. We discovered that the previously described marsupial milk protein Very Early Lactation Protein is an ortholog of the eutherian gene Glycam1 (PP3) and likely has an antimicrobial role in milk. We also identified highly abundant koala endogenous retrovirus sequences in the mammary and milk transcriptome and proteomes, identifying a potential route for retroviral transmission from mother to young. Identifying and characterising the immune components of milk is key to understanding how marsupial young are protected throughout lactation and the novel immune compounds identified may have applications in clinical research.