Sequencing of the tammar wallaby (Macropus eugenii) genome has the potential to be an extremely valuable resource for investigating evolutionary and developmental aspects of the mammalian immune system. However, the tammar wallaby genome has only been sequenced to a 2-fold depth and consists of small contigs, leaving many sequence gaps, many putative orthologs unpredicted and the location of genes within the genome unknown. In the case of low sequenced genomes, physical maps of genes on chromosomes can help identify specific genes if they map to conserved regions. Genes corresponding to adaptive immunity have been mapped in the tammar wallaby; however, genes corresponding to the innate immune system have not been investigated. We predict 2 types of genes important to the innate immune system, mucins and lysozymes, in the tammar wallaby and compare the predicted peptide sequences and locations of the genes with the South American opossum (Monodelphis domestica) and human. We use fluorescence in situ hybridization to physically map the genes to tammar wallaby chromosomes, demonstrating the importance of identifying and mapping genes when genomes have low sequence coverage. As mucins and lysozymes play protective roles in young animals, we also propose that their immunological role in developing marsupials warrants further investigation.

Adamski FM, Demmer J: Two stages of increased IgA transfer during lactation in the marsupial, Trichosurus vulpecula (brushtail possum). J Immunol 162:6009–6015 (1999).
Adamski FM, Demmer J: Immunological protection of the vulnerable marsupial pouch young: two periods of immune transfer during lactation in Trichosurus vulpecula (brushtail possum). Dev Comp Immunol 24:491–502 (2000).
Alsop AE, Miethke P, Rofe R, Koina E, Sankovic N, et al: Characterizing the chromosomes of the Australian model marsupial Macropus eugenii (tammar wallaby). Chromosome Res 13:627–636 (2005).
Ambatipudi K, Joss J, Deane E: A comparative proteomic analysis of skin secretions of the tammar wallaby (Macropus eugenii) and the wombat (Vombatus ursinus). Comp Biochem Physiol Part D Genomics Proteomics 2:322–331 (2007).
Ambatipudi K, Joss J, Rafferty M, Deane E: A proteomic approach to analysis of antimicrobial activity in marsupial pouch secretions. Dev Comp Immunol 32:108–120 (2008).
Basden K, Cooper DW, Deane EM: Development of the lymphoid tissues of the tammar wallaby Macropus eugenii. Reprod Fert Develop 9:243–254 (1997).
Belov K, Sanderson CE, Deakin JE, Wong ES, Assange D, et al: Characterization of the opossum immune genome provides insights into the evolution of the mammalian immune system. Genome Res 17:982–991 (2007).
Bininda-Emonds OR, Cardillo M, Jones KE, MacPhee RD, Beck RM, et al: The delayed rise of present-day mammals. Nature 446:507–512 (2007).
Carman RL, Simonian MR, Old JM, Jacques NA, Deane EM: Immunohistochemistry using antibodies to the cathelicidin LL37/hCAP18 in the tammar wallaby, Macropus eugenii. Tissue Cell 40:459–466 (2008).
Carman RL, Old JM, Baker M, Jacques NA, Deane EM: Identification and expression of a novel marsupial cathelicidin from the tammar wallaby (Macropus eugenii). Vet Immunol Immunop 127:269–276 (2009).
Casey NP, Martinus R, Selwood L: Outer egg coats of the marsupial conceptus: Secretion and protein composition. Mol Reprod Dev 62:181–194 (2002).
Chhour KL, Hinds LA, Jacques NA, Deane EM: An observational study of the microbiome of the maternal pouch and saliva of the tammar wallaby, Macropus eugenii, and of the gastrointestinal tract of the pouch young. Microbiology 156:798–808 (2010).
Coutinho HB, Sewell HF, Tighe P, King G, Nogueira JC, et al: Immunocytochemical study of the ontogeny of the marsupial Didelphis albiventris immune system. J Anat 187:37–46 (1995).
Cutts JH, Krause WJ: Postnatal development of the spleen in Didelphis virginiana. J Anat 135:601–613 (1982).
Daly KA, Digby MR, Lefévre C, Nicholas KR, Deane EM, Williamson P: Identification, characterization and expression of cathelicidin in the pouch young of tammar wallaby (Macropus eugenii). Comp Biochem Physiol B Biochem Mol Biol 149:524–533 (2008).
Deakin JE, Cooper DW: Characterisation of and immunity to the aerobic bacteria found in the pouch of the brushtail possum Trichosurus vulpecula. Comp Immunol Microb 27:33–46 (2004).
Deakin JE, Siddle HV, Cross JG, Belov K, Graves JA: Class I genes have split from the MHC in the tammar wallaby. Cytogenet Genome Res 116:205–211 (2007).
Deakin JE, Koina E, Waters PD, Doherty R, Patel VS, et al: Physical map of two tammar wallaby chromosomes: A strategy for mapping in non-model mammals. Chromosome Res 16:1159–1175 (2008).
Dharmani P, Srivastava V, Kissoon-Singh V, Chadee K: Role of intestinal mucins in innate host defense mechanisms against pathogens. J Innate Immun 1:123–135 (2009).
Duraisamy S, Ramasamy S, Kharbanda S, Kufe D: Distinct evolution of the human carcinoma-associated transmembrane mucins, MUC1, MUC4 and MUC16. Gene 373:28–34 (2006).
Edwards CA, Rens W, Clarke O, Mungall AJ, Hore T, et al: The evolution of imprinting: Chromosomal mapping of orthologues of mammalian imprinted domains in monotreme and marsupial mammals. BMC Evol Biol 7:157 (2007).
Escande F, Porchet N, Bernigaud A, Petitprez D, Aubert JP, Buisine MP: The mouse secreted gel-forming mucin gene cluster. Biochim Biophys Acta 1676:240–250 (2004).
Finn RD, Mistry J, Tate J, Coggill P, Heger A, et al: The Pfam protein families database. Nucl Acids Res 38:D211–D222 (2010).
Flicek P, Aken BL, Ballester B, Beal K, Bragin E, et al: Ensembl’s 10th year. Nucl Acids Res 38:D557–D562 (2010).
Hattrup CL, Gendler SJ: Structure and function of the cell surface (tethered) mucins. Annu Rev of Physiol 70:431–457 (2008).
Irwin DM, Wilson AC: Multiple cDNA sequences and the evolution of bovine stomach lysozyme. J Biol Chem 264:11387–11393 (1989).
Jollés P, Jollés J: What’s new in lysozyme research? Always a model system, today as yesterday. Mol Cell Biochem 63:165–189 (1984).
Joss J, Molloy M, Hinds L, Deane E: Proteomic analysis of early lactation milk of the tammar wallaby (Macropus eugenii). Comp Biochem Physiol Part D Genomics Proteomics D 2:150–164 (2007).
Joss JL, Molloy MP, Hinds L, Deane E: A longitudinal study of the protein components of marsupial milk from birth to weaning in the tammar wallaby (Macropus eugenii). Dev Comp Immunol 33:152–161 (2009).
Kuy S, Kelly VC, Smit AM, Palmer DJ, Cooper GJ: Proteomic analysis of whey and casein proteins in early milk from the marsupial Trichosurus vulpecula, the common brushtail possum. Comp Biochem Physiol Part D Genomics Proteomics 2:112–120 (2007).
Kwek JH, De Iongh R, Digby MR, Renfree MB, Nicholas KR, Familari M: Cross-fostering of the tammar wallaby (Macropus eugenii) pouch young accelerates fore-stomach maturation. Mech Dev 126:449–463 (2009).
Lang T, Hansson GC, Samuelsson T: Gel-forming mucins appeared early in metazoan evolution. Proc Natl Acad Sci USA 104:16209–16214 (2007).
Nicholas K, Loughnan M, Messer M, Munks S, Griffiths M, Shaw D: Isolation, partial sequence and asynchronous appearance during lactation of lysozyme and α-lactalbumin in the milk of a marsupial, the common ringtail possum (Pseudocheirus peregrinus). Comp Biochem Physiol B 94:775–778 (1989).
Old JM, Deane EM: The effect of oestrus and the presence of pouch young on aerobic bacteria isolated from the pouch of the tammar wallaby, Macropus eugenii. Comp Immunol Microb 21:237–245 (1998).
Old JM, Deane EM: The detection of mature T- and B-cells during development of the lymphoid tissues of the tammar wallaby (Macropus eugenii). J Anat 203:123–131 (2003).
Old JM, Selwood L, Deane EM: The appearance and distribution of mature T and B cells in the developing immune tissues of the stripe-faced dunnart (Sminthopsis macroura). J Anat 205:25–33 (2004).
Osawa R, Blanshard WH, O’Callaghan PG: Microflora of the pouch of the koala (Phascolarctos cinereus). J Wildlife Dis 28:276–280 (1992).
Paris DB, Taggart DA, Shaw G, Temple-Smith PD, Renfree MB: Birth of pouch young after artificial insemination in the tammar wallaby (Macropus eugenii). Biol Reprod 72:451–459 (2005).
Piotte CP, Marshall CJ, Hubbard MJ, Collet C, Grigor MR: Lysozyme and α-lactalbumin from the milk of a marsupial, the common brush-tailed possum (Trichosurus vulpecula). Biochim Biophys Acta 1336:235–242 (1997).
Renfree MB, Lewis AM: Cleavage in vivo and in vitro in the marsupial Macropus eugenii. Reprod Fert Develop 8:725–742 (1996).
Rens W, O’Brien PC, Fairclough H, Harman L, Graves JA, Ferguson-Smith MA: Reversal and convergence in marsupial chromosome evolution. Cytogenet Genome Res 102:282–290 (2003).
Sanderson CE, Belov K, Deakin JE: Physical mapping of immune genes in the tammar wallaby (Macropus eugenii). Cytogenet Genome Res 127:21–25 (2009).
Schumacher U, Krause WJ: Molecular anatomy of an endodermal gland: investigations on mucus glycoproteins and cell turnover in Brunner’s glands of Didelphis virginiana using lectins and PCNA immunoreactivity. J Cell Biochem 58:56–64 (1995).
Siddle HV, Sanderson CE, Deakin JE, Belov K: Genetic architecture of the macropodid immune system, in Coulson G, Eldridge M (eds): Macropods: The Biology of Kangaroos, Wallabies and Rat-Kangaroos, pp 13–23 (CSIRO Publishing, Melbourne 2010).
Thornton DJ, Rousseau K, McGuckin MA: Structure and function of the polymeric mucins in airways mucus. Annu Rev Physiol 70:459–486 (2008).
Voynow JA, Rubin BK: Mucins, mucus, and sputum. Chest 135:505–512 (2009).
Yadav M, Stanley NF, Waring H: The thymus glands of a marsupial, Setonix brachyurus (quokka), and their role in immune responses: Structure and growth of thymus glands. Aust Exp Biol Med 50:347–356 (1972).
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