platypus

Summary

Summary: A small aquatic oviparous mammal of the order Monotremata found in Australia and Tasmania.

Top Publications

  1. Daish T, Casey A, Grützner F. Platypus chain reaction: directional and ordered meiotic pairing of the multiple sex chromosome chain in Ornithorhynchus anatinus. Reprod Fertil Dev. 2009;21:976-84 pubmed publisher
    ..unique animals with an unusually complex sex chromosome system that is composed of ten chromosomes in platypus and nine in echidna. These chromosomes are alternately linked (X1Y1, X2Y2, .....
  2. Suzuki S, Ono R, Narita T, Pask A, Shaw G, Wang C, et al. Retrotransposon silencing by DNA methylation can drive mammalian genomic imprinting. PLoS Genet. 2007;3:e55 pubmed
    ..therian mammal, the marsupial tammar wallaby (Macropus eugenii), but not in a prototherian mammal, the egg-laying platypus (Ornithorhynchus anatinus), suggesting its close relationship to the origin of placentation in therian mammals...
  3. Ashwell K, Hardman C, Paxinos G. Cyto- and chemoarchitecture of the sensory trigeminal nuclei of the echidna, platypus and rat. J Chem Neuroanat. 2006;31:81-107 pubmed
    ..trigeminal nucleus and the oralis and interpolaris spinal trigeminal nuclei were substantially larger in the platypus than in either the echidna or rat, but the caudalis subnucleus was similar in size in both monotremes and the rat...
  4. Rens W, Wallduck M, Lovell F, Ferguson Smith M, Ferguson Smith A. Epigenetic modifications on X chromosomes in marsupial and monotreme mammals and implications for evolution of dosage compensation. Proc Natl Acad Sci U S A. 2010;107:17657-62 pubmed publisher
    ..immunofluorescence on somatic cells of the female Australian marsupial possum Trichosurus vulpecula, the female platypus Ornithorhynchus anatinus, and control mouse cells...
  5. McMillan D, Miethke P, Alsop A, Rens W, O Brien P, Trifonov V, et al. Characterizing the chromosomes of the platypus (Ornithorhynchus anatinus). Chromosome Res. 2007;15:961-74 pubmed publisher
    Like the unique platypus itself, the platypus genome is extraordinary because of its complex sex chromosome system, and is controversial because of difficulties in identification of small autosomes and sex chromosomes...
  6. Miska K, Harrison G, Hellman L, Miller R. The major histocompatibility complex in monotremes: an analysis of the evolution of Mhc class I genes across all three mammalian subclasses. Immunogenetics. 2002;54:381-93 pubmed
    ..major histocompatibility complex class-I ( Mhc-I) genes from two species of monotremes: the duck-billed platypus and the short-beaked echidna...
  7. Holmes R, Goldberg E. Computational analyses of mammalian lactate dehydrogenases: human, mouse, opossum and platypus LDHs. Comput Biol Chem. 2009;33:379-85 pubmed publisher
    ..The platypus genome contained at least 3 LDH genes encoding LDHA, LDHB and LDH6B subunits...
  8. Hore T, Koina E, Wakefield M, Marshall Graves J. The region homologous to the X-chromosome inactivation centre has been disrupted in marsupial and monotreme mammals. Chromosome Res. 2007;15:147-61 pubmed
    ..We found that these genes map to two distant locations on the opossum X, and also to different locations on a platypus autosome...
  9. Wallis M, Delbridge M, Pask A, Alsop A, Grutzner F, O Brien P, et al. Mapping platypus SOX genes; autosomal location of SOX9 excludes it from sex determining role. Cytogenet Genome Res. 2007;116:232-4 pubmed
    In the absence of an SRY orthologue the platypus sex determining gene is unknown, so genes in the human testis determining pathway are of particular interest as candidates...

More Information

Publications77

  1. Whittington C, Papenfuss A, Bansal P, Torres A, Wong E, Deakin J, et al. Defensins and the convergent evolution of platypus and reptile venom genes. Genome Res. 2008;18:986-94 pubmed publisher
    When the platypus (Ornithorhynchus anatinus) was first discovered, it was thought to be a taxidermist's hoax, as it has a blend of mammalian and reptilian features...
  2. Gambón Deza F, Sánchez Espinel C, Magadán Mompó S. The immunoglobulin heavy chain locus in the platypus (Ornithorhynchus anatinus). Mol Immunol. 2009;46:2515-23 pubmed publisher
    ..These data and the characterization of the IGH locus in platypus (Ornithorhynchus anatinus), allow us to elucidate the changes that took place in this genomic region during ..
  3. Veyrunes F, Waters P, Miethke P, Rens W, McMillan D, Alsop A, et al. Bird-like sex chromosomes of platypus imply recent origin of mammal sex chromosomes. Genome Res. 2008;18:965-73 pubmed publisher
    ..The platypus has an extraordinary sex chromosome complex, in which five X and five Y chromosomes pair in a translocation chain ..
  4. Kourie J. Characterization of a C-type natriuretic peptide (CNP-39)-formed cation-selective channel from platypus (Ornithorhynchus anatinus) venom. J Physiol. 1999;518 ( Pt 2):359-69 pubmed
    ..the biophysical and pharmacological properties of a novel, fast, cation-selective channel formed by incorporating platypus (Ornithorhynchus anatinus) venom (OaV) into lipid membranes. 2...
  5. van Rheede T, Bastiaans T, Boone D, Hedges S, de Jong W, Madsen O. The platypus is in its place: nuclear genes and indels confirm the sister group relation of monotremes and Therians. Mol Biol Evol. 2006;23:587-97 pubmed
    ..The morphological evidence for a basal position of Monotremata, well separated from Theria, is thus fully supported by the available molecular data from nuclear genes. ..
  6. Tsend Ayush E, Dodge N, Mohr J, Casey A, Himmelbauer H, Kremitzki C, et al. Higher-order genome organization in platypus and chicken sperm and repositioning of sex chromosomes during mammalian evolution. Chromosoma. 2009;118:53-69 pubmed publisher
    ..Monotremes (platypus and echidnas) are the most basal group of living mammals...
  7. Bansal P, Torres A, Crossett B, Wong K, Koh J, Geraghty D, et al. Substrate specificity of platypus venom L-to-D-peptide isomerase. J Biol Chem. 2008;283:8969-75 pubmed
    The L-to-D-peptide isomerase from the venom of the platypus (Ornithorhyncus anatinus) is the first such enzyme to be reported for a mammal...
  8. El Mogharbel N, Wakefield M, Deakin J, Tsend Ayush E, Grützner F, Alsop A, et al. DMRT gene cluster analysis in the platypus: new insights into genomic organization and regulatory regions. Genomics. 2007;89:10-21 pubmed
    We isolated and characterized a cluster of platypus DMRT genes and compared their arrangement, location, and sequence across vertebrates. The DMRT gene cluster on human 9p24...
  9. Rapkins R, Hore T, Smithwick M, Ager E, Pask A, Renfree M, et al. Recent assembly of an imprinted domain from non-imprinted components. PLoS Genet. 2006;2:e182 pubmed publisher
    ..Using comparisons of orthologous genes in humans, marsupials, and the platypus, we discovered that the Prader-Willi/Angelman syndrome region on human Chromosome 15q was assembled only recently ..
  10. Schmitz J, Zemann A, Churakov G, Kuhl H, Grützner F, Reinhardt R, et al. Retroposed SNOfall--a mammalian-wide comparison of platypus snoRNAs. Genome Res. 2008;18:1005-10 pubmed publisher
    ..The duck-billed platypus (Ornithorhynchus anatinus) and echidnas are the only potential contemporary witnesses of this period and, thereby,..
  11. de Plater G, Milburn P, Martin R. Venom from the platypus, Ornithorhynchus anatinus, induces a calcium-dependent current in cultured dorsal root ganglion cells. J Neurophysiol. 2001;85:1340-5 pubmed
    The platypus (Ornithorhynchus anatinus), a uniquely Australian species, is one of the few living venomous mammals...
  12. Wong E, Papenfuss A, Whittington C, Warren W, Belov K. A limited role for gene duplications in the evolution of platypus venom. Mol Biol Evol. 2012;29:167-77 pubmed publisher
    ..The availability of a sequenced genome and a venom gland transcriptome for the enigmatic platypus provides a unique opportunity to explore the role that gene duplication plays in venom evolution...
  13. Wrigley J, Graves J. Sex chromosome homology and incomplete, tissue-specific X-inactivation suggest that monotremes represent an intermediate stage of mammalian sex chromosome evolution. J Hered. 1988;79:115-8 pubmed
    ..This model involves a gradual reduction of the Y chromosome and an accompanying gradual recruitment of (newly unpaired) X-linked loci under the control of a single inactivation center...
  14. Hrdlicková R, Nehyba J, Lim S, Grützner F, Bose H. Insights into the evolution of mammalian telomerase: platypus TERT shares similarities with genes of birds and other reptiles and localizes on sex chromosomes. BMC Genomics. 2012;13:216 pubmed publisher
    ..The platypus occupies an important evolutionary position, providing unique insight into the evolution of mammalian genes...
  15. Schauer R, Srinivasan G, Coddeville B, Zanetta J, Guerardel Y. Low incidence of N-glycolylneuraminic acid in birds and reptiles and its absence in the platypus. Carbohydr Res. 2009;344:1494-500 pubmed publisher
    The sialic acids of the platypus, birds, and reptiles were investigated with regard to the occurrence of N-glycolylneuraminic (Neu5Gc) acid...
  16. Babin P. Conservation of a vitellogenin gene cluster in oviparous vertebrates and identification of its traces in the platypus genome. Gene. 2008;413:76-82 pubmed publisher
    ..Orthologs to chicken VtgI were found in similar locations in teleost fish, as well as in the platypus (Ornithorhynchus anatinus)...
  17. Wong E, Sanderson C, Deakin J, Whittington C, Papenfuss A, Belov K. Identification of natural killer cell receptor clusters in the platypus genome reveals an expansion of C-type lectin genes. Immunogenetics. 2009;61:565-79 pubmed publisher
    ..We identified 213 putative C-type lectin NK receptor homologs in the genome of the platypus. Many have arisen as the result of a lineage-specific expansion...
  18. Dohm J, Tsend Ayush E, Reinhardt R, Grützner F, Himmelbauer H. Disruption and pseudoautosomal localization of the major histocompatibility complex in monotremes. Genome Biol. 2007;8:R175 pubmed
    The monotremes, represented by the duck-billed platypus and the echidnas, are the most divergent species within mammals, featuring a flamboyant mix of reptilian, mammalian and specialized characteristics...
  19. Grafodatskaya D, Rens W, Wallis M, Trifonov V, O Brien P, Clarke O, et al. Search for the sex-determining switch in monotremes: mapping WT1, SF1, LHX1, LHX2, FGF9, WNT4, RSPO1 and GATA4 in platypus. Chromosome Res. 2007;15:777-85 pubmed
    The duck-billed platypus has five pairs of sex chromosomes, but there is no information about the primary sex-determining switch in this species...
  20. Grus W, Shi P, Zhang J. Largest vertebrate vomeronasal type 1 receptor gene repertoire in the semiaquatic platypus. Mol Biol Evol. 2007;24:2153-7 pubmed
    ..of reduced olfaction in aquatic and semiaquatic mammals, we here report the surprising finding that the platypus, a semiaquatic monotreme, has the largest V1R repertoire and nearly largest combined repertoire of V1Rs and V2Rs ..
  21. Zhao Y, Cui H, Whittington C, Wei Z, Zhang X, Zhang Z, et al. Ornithorhynchus anatinus (platypus) links the evolution of immunoglobulin genes in eutherian mammals and nonmammalian tetrapods. J Immunol. 2009;183:3285-93 pubmed publisher
    ..We report in this study that the platypus (Ornithorhynchus anatinus) Ig H chain constant region gene locus contains eight Ig encoding genes, which are ..
  22. Macgregor J, Holyoake C, Munks S, Robertson I, Warren K. Preliminary investigation into the prevalence of mucormycosis in the platypus (Ornithorhynchus anatinus) in three catchments in north-west Tasmania. Aust Vet J. 2010;88:190-6 pubmed publisher
    To investigate the distribution and prevalence of mucormycosis in platypus (Ornithorhynchus anatinus) from the Inglis, Emu and Black-Detention catchment areas in north-west Tasmania.
  23. Ferguson Smith M, Rens W. The unique sex chromosome system in platypus and echidna. Genetika. 2010;46:1314-9 pubmed
    A striking example of the power of chromosome painting has been the resolution of the male platypus karyotype and the pairing relationships of the chain often sex chromosomes...
  24. Wrigley J, Graves J. Karyotypic conservation in the mammalian order monotremata (subclass Prototheria). Chromosoma. 1988;96:231-47 pubmed
    The order Monotremata, comprising the platypus and two species of echidna (Australian and Nuigini) is the only extant representative of the mammalian subclass Prototheria, which diverged from subclass Theria (marsupials and placental ..
  25. Killian J, Nolan C, Stewart N, Munday B, Andersen N, Nicol S, et al. Monotreme IGF2 expression and ancestral origin of genomic imprinting. J Exp Zool. 2001;291:205-12 pubmed
    ..In this investigation, we have cloned IGF2 from two monotreme mammals, the platypus and echidna, to further investigate the origin of imprinting...
  26. Parra Z, Arnold T, Nowak M, Hellman L, Miller R. TCR gamma chain diversity in the spleen of the duckbill platypus (Ornithorhynchus anatinus). Dev Comp Immunol. 2006;30:699-710 pubmed
    ..diversity in splenic gammadelta T cells was determined for an egg-laying mammal (or monotreme), the duckbill platypus. Three distinct V subgroups were found in the expressed TRG chains and these three subgroups are members of a ..
  27. Kirsch J, Mayer G. The platypus is not a rodent: DNA hybridization, amniote phylogeny and the palimpsest theory. Philos Trans R Soc Lond B Biol Sci. 1998;353:1221-37 pubmed
  28. Grützner F, Rens W, Tsend Ayush E, El Mogharbel N, O Brien P, Jones R, et al. In the platypus a meiotic chain of ten sex chromosomes shares genes with the bird Z and mammal X chromosomes. Nature. 2004;432:913-7 pubmed
    Two centuries after the duck-billed platypus was discovered, monotreme chromosome systems remain deeply puzzling...
  29. Weidman J, Murphy S, Nolan C, Dietrich F, Jirtle R. Phylogenetic footprint analysis of IGF2 in extant mammals. Genome Res. 2004;14:1726-32 pubmed publisher
    ..We performed phylogenetic sequence and epigenetic comparisons of IGF2 between the nonimprinted platypus (Ornithorhynchus anatinus) and imprinted opossum (Didelphis virginiana), mouse (Mus musculus), and human (Homo ..
  30. Mitchell M, Wilcox S, Watson J, Lerner J, Woods D, Scheffler J, et al. The origin and loss of the ubiquitin activating enzyme gene on the mammalian Y chromosome. Hum Mol Genet. 1998;7:429-34 pubmed
    ..Here we describe a more extensive study of UBE1 homologues in primates and a prototherian mammal, the platypus. Our findings indicate that UBE1 lies within the X-Y pairing segment of the platypus but is absent from the human ..
  31. Manger P, Fahringer H, Pettigrew J, Siegel J. The distribution and morphological characteristics of cholinergic cells in the brain of monotremes as revealed by ChAT immunohistochemistry. Brain Behav Evol. 2002;60:275-97 pubmed
    ..Two of the three extant species of monotreme were studied: the platypus (Ornithorhynchus anatinus) and the short-beaked echidna (Tachyglossus aculeatus)...
  32. Belov K, Hellman L. Immunoglobulin genetics of Ornithorhynchus anatinus (platypus) and Tachyglossus aculeatus (short-beaked echidna). Comp Biochem Physiol A Mol Integr Physiol. 2003;136:811-9 pubmed
    ..Preliminary analysis of monotreme heavy chain variable region diversity suggests that the platypus primarily uses a single VH clan, while the short-beaked echidna utilises at least 4 distinct VH families which ..
  33. Killian J, Byrd J, Jirtle J, Munday B, Stoskopf M, MacDonald R, et al. M6P/IGF2R imprinting evolution in mammals. Mol Cell. 2000;5:707-16 pubmed
    ..Unless there was convergent evolution of M6P/ IGF2R imprinting and receptor IGF2 binding in marsupials and eutherians, our results also demonstrate that these two functions evolved in a mammalian clade exclusive of monotremes...
  34. Noyes H, Stevens J, Teixeira M, Phelan J, Holz P. A nested PCR for the ssrRNA gene detects Trypanosoma binneyi in the platypus and Trypanosoma sp. in wombats and kangaroos in Australia. Int J Parasitol. 1999;29:331-9 pubmed
    ..one in an eastern grey kangaroo (Macropus giganteus), one in a common wombat (Vombatus ursinus) and one in a platypus (Ornithorhynchus anatinus). The kangaroo and wombat are new host records for Trypanosoma sp...
  35. Torres A, Alewood D, Alewood P, Gallagher C, Kuchel P. Conformations of platypus venom C-type natriuretic peptide in aqueous solution and sodium dodecyl sulfate micelles. Toxicon. 2002;40:711-9 pubmed
    Nuclear magnetic resonance spectroscopy was used to investigate the conformations of the platypus venom C-type natriuretic peptide A (OvCNPa) in aqueous solutions and in solutions containing sodium dodecyl sulfate (SDS) micelles...
  36. Patel V, Cooper S, Deakin J, Fulton B, Graves T, Warren W, et al. Platypus globin genes and flanking loci suggest a new insertional model for beta-globin evolution in birds and mammals. BMC Biol. 2008;6:34 pubmed publisher
    ..Here we analyse genomic data from an egg-laying monotreme mammal, the platypus (Ornithorhynchus anatinus), to explore haemoglobin evolution at the stem of the mammalian radiation.
  37. Deakin J, Hore T, Koina E, Marshall Graves J. The status of dosage compensation in the multiple X chromosomes of the platypus. PLoS Genet. 2008;4:e1000140 pubmed publisher
    ..operates in the third mammal lineage, the egg-laying monotremes, is of considerable interest, since the platypus has a complex sex chromosome system in which five X and five Y chromosomes share considerable genetic homology ..
  38. Krause W. Morphological and histochemical observations on the crural gland-spur apparatus of the echidna (Tachyglossus aculeatus) together with comparative observations on the femoral gland-spur apparatus of the duckbilled platypus (Ornithorhyncus anatinus). Cells Tissues Organs. 2010;191:336-54 pubmed publisher
    The echidna and platypus have a crural/femoral gland that is linked by a large duct to a canalized, keratinous spur located on the medial side of the ankle...
  39. Miska K, Hellman L, Miller R. Characterization of beta(2)-microglobulin coding sequence from three non-placental mammals: the duckbill platypus, the short-beaked echidna, and the grey short-tailed opossum. Dev Comp Immunol. 2003;27:247-56 pubmed
    ..non-placental mammals, cDNAs encoding beta(2)-microglobulin (beta(2)m) were isolated from two prototherians, the platypus and an echidna, and one metatherian, a grey short-tailed opossum...
  40. Rowe T, Rich T, Vickers Rich P, Springer M, Woodburne M. The oldest platypus and its bearing on divergence timing of the platypus and echidna clades. Proc Natl Acad Sci U S A. 2008;105:1238-42 pubmed publisher
    ..mute during two decades of discussion about molecular clock estimates of the timing of divergence between the platypus and echidna clades...
  41. Grützner F, Deakin J, Rens W, El Mogharbel N, Marshall Graves J. The monotreme genome: a patchwork of reptile, mammal and unique features?. Comp Biochem Physiol A Mol Integr Physiol. 2003;136:867-81 pubmed
    The first specimen of platypus (Ornithorhynchus anatinus) that reached Britain in the late 18th century was regarded a scientific hoax...
  42. Grützner F, Graves J. A platypus' eye view of the mammalian genome. Curr Opin Genet Dev. 2004;14:642-9 pubmed
    ..important for studying the evolution and organization of the mammalian genome, and the proposal to sequence the platypus genome has been received enthusiastically by the genomics community...
  43. Watson J, Spencer J, Riggs A, Graves J. The X chromosome of monotremes shares a highly conserved region with the eutherian and marsupial X chromosomes despite the absence of X chromosome inactivation. Proc Natl Acad Sci U S A. 1990;87:7125-9 pubmed
    ..and present on the marsupial X chromosome, were mapped by in situ hybridization to the chromosomes of the platypus Ornithorhynchus anatinus, one of the three species of monotreme mammals. All were located on the X chromosome...
  44. Gruetzner F, Ashley T, Rowell D, Marshall Graves J. How did the platypus get its sex chromosome chain? A comparison of meiotic multiples and sex chromosomes in plants and animals. Chromosoma. 2006;115:75-88 pubmed
    The duck-billed platypus is an extraordinary mammal. Its chromosome complement is no less extraordinary, for it includes a system in which ten sex chromosomes form an extensive meiotic chain in males...
  45. Delbridge M, Wallis M, Kirby P, Alsop A, Grutzner F, Graves J. Assignment of SOX1 to platypus chromosome 20q by fluorescence in situ hybridization. Cytogenet Genome Res. 2006;112:342L pubmed
  46. Whittington C, Papenfuss A, Kuchel P, Belov K. Expression patterns of platypus defensin and related venom genes across a range of tissue types reveal the possibility of broader functions for OvDLPs than previously suspected. Toxicon. 2008;52:559-65 pubmed publisher
    The platypus, as an egg-laying mammal, displays an unusual mixture of reptilian and mammalian characteristics...
  47. Fjällbrant T, Manger P, Pettigrew J. Some related aspects of platypus electroreception: temporal integration behaviour, electroreceptive thresholds and directionality of the bill acting as an antenna. Philos Trans R Soc Lond B Biol Sci. 1998;353:1211-9 pubmed
    This paper focuses on how the electric field from the prey of the platypus is detected with respect to the questions of threshold determination and how the platypus might localize its prey...
  48. Dacheux J, Dacheux F, Labas V, Ecroyd H, Nixon B, Jones R. New proteins identified in epididymal fluid from the platypus (Ornithorhynchus anatinus). Reprod Fertil Dev. 2009;21:1002-7 pubmed publisher
    The platypus epididymal proteome is being studied because epididymal proteins are essential for male fertility in mammals and it is considered that knowledge of the epididymal proteome in an early mammal would be informative in assessing ..
  49. Fish F, Baudinette R, Frappell P, Sarre M. Energetics of swimming by the platypus Ornithorhynchus anatinus: metabolic effort associated with rowing. J Exp Biol. 1997;200:2647-52 pubmed
    The metabolism of swimming in the platypus Ornithorhynchus anatinus Shaw was studied by measurement of oxygen consumption in a recirculating water flume. Platypuses swam against a constant water current of 0.45-1.0 ms-1...
  50. Endoh R, Suzuki M, Okada G, Takeuchi Y, Futai K. Fungus symbionts colonizing the galleries of the ambrosia beetle Platypus quercivorus. Microb Ecol. 2011;62:106-20 pubmed publisher
    Isolations were made to determine the fungal symbionts colonizing Platypus quercivorus beetle galleries of dead or dying Quercus laurifolia, Castanopsis cuspidata, Quercus serrata, Quercus crispula, and Quercus robur...
  51. Janke A, Gemmell N, Feldmaier Fuchs G, von Haeseler A, P bo S. The mitochondrial genome of a monotreme--the platypus (Ornithorhynchus anatinus). J Mol Evol. 1996;42:153-9 pubmed
    The complete nucleotide sequence of the mitochondrial genome of a platypus (Ornithorhynchus anatinus) was determined. Its overall genomic organization is similar to that of placental mammals, Xenopus laevis, and fishes...
  52. Pask A, Papenfuss A, Ager E, McColl K, Speed T, Renfree M. Analysis of the platypus genome suggests a transposon origin for mammalian imprinting. Genome Biol. 2009;10:R1 pubmed publisher
    ..The recent release of the platypus genome has provided the first opportunity to perform comparisons between prototherian (monotreme; which appear to ..
  53. Johansson J, Salazar J, Aveskogh M, Munday B, Miller R, Hellman L. High variability in complementarity-determining regions compensates for a low number of V gene families in the lambda light chain locus of the platypus. Eur J Immunol. 2005;35:3008-19 pubmed
    Based on the analysis of a panel of variable (V) region sequences from the Australian duck-billed platypus and the Australian short beaked echidna, the monotremes were found to express a highly diversified Vlambda repertoire...
  54. Ordóñez G, Hillier L, Warren W, Grützner F, Lopez Otin C, Puente X. Loss of genes implicated in gastric function during platypus evolution. Genome Biol. 2008;9:R81 pubmed publisher
    The duck-billed platypus (Ornithorhynchus anatinus) belongs to the mammalian subclass Prototheria, which diverged from the Theria line early in mammalian evolution...
  55. Warren W, Hillier L, Marshall Graves J, Birney E, Ponting C, Grützner F, et al. Genome analysis of the platypus reveals unique signatures of evolution. Nature. 2008;453:175-83 pubmed publisher
    We present a draft genome sequence of the platypus, Ornithorhynchus anatinus. This monotreme exhibits a fascinating combination of reptilian and mammalian characters...
  56. Vernersson M, Aveskogh M, Munday B, Hellman L. Evidence for an early appearance of modern post-switch immunoglobulin isotypes in mammalian evolution (II); cloning of IgE, IgG1 and IgG2 from a monotreme, the duck-billed platypus, Ornithorhynchus anatinus. Eur J Immunol. 2002;32:2145-55 pubmed
    ..We here present an analysis of the Ig expression in an egg-laying mammal, a monotreme, the duck-billed platypus (Ornithorhynchus anatinus)...
  57. Murchison E, Kheradpour P, Sachidanandam R, Smith C, Hodges E, Xuan Z, et al. Conservation of small RNA pathways in platypus. Genome Res. 2008;18:995-1004 pubmed publisher
    ..The monotremes, with only platypus and four species of echidna as extant members, represent the basal branch of the mammalian lineage...
  58. Wong E, Morgenstern D, Mofiz E, Gombert S, Morris K, Temple Smith P, et al. Proteomics and deep sequencing comparison of seasonally active venom glands in the platypus reveals novel venom peptides and distinct expression profiles. Mol Cell Proteomics. 2012;11:1354-64 pubmed publisher
    The platypus is a venomous monotreme. Male platypuses possess a spur on their hind legs that is connected to glands in the pelvic region. They produce venom only during the breeding season, presumably to fight off conspecifics...
  59. Davies W, Carvalho L, Cowing J, Beazley L, Hunt D, Arrese C. Visual pigments of the platypus: a novel route to mammalian colour vision. Curr Biol. 2007;17:R161-3 pubmed publisher
  60. Lillie M, Woodward R, Sanderson C, Eldridge M, Belov K. Diversity at the major histocompatibility complex Class II in the platypus, Ornithorhynchus anatinus. J Hered. 2012;103:467-78 pubmed publisher
    The platypus (Ornithorhynchus anatinus) is the sole survivor of a previously widely distributed and diverse lineage of ornithorhynchid monotremes...
  61. Edwards C, Rens W, Clarke O, Mungall A, Hore T, Graves J, et al. The evolution of imprinting: chromosomal mapping of orthologues of mammalian imprinted domains in monotreme and marsupial mammals. BMC Evol Biol. 2007;7:157 pubmed
    ..There are several theories to account for how the mechanism evolved including the hypothesis that it was driven by the evolution of X-inactivation, or that it arose from an ancestrally imprinted chromosome...
  62. Rens W, O Brien P, Grützner F, Clarke O, Graphodatskaya D, Tsend Ayush E, et al. The multiple sex chromosomes of platypus and echidna are not completely identical and several share homology with the avian Z. Genome Biol. 2007;8:R243 pubmed
    ..Our previous studies showed that male platypus has five X and five Y chromosomes, no SRY, and DMRT1 on an X chromosome...
  63. Whittington C, Papenfuss A, Locke D, Mardis E, Wilson R, Abubucker S, et al. Novel venom gene discovery in the platypus. Genome Biol. 2010;11:R95 pubmed publisher
    To date, few peptides in the complex mixture of platypus venom have been identified and sequenced, in part due to the limited amounts of platypus venom available to study...
  64. Johansson J, Aveskogh M, Munday B, Hellman L. Heavy chain V region diversity in the duck-billed platypus (Ornithorhynchus anatinus): long and highly variable complementarity-determining region 3 compensates for limited germline diversity. J Immunol. 2002;168:5155-62 pubmed
    ..we present an analysis of 25 independent H chain V regions from a monotreme, the Australian duck-billed platypus, Ornithorhynchus anatinus...
  65. Torres A, Tsampazi M, Kennett E, Belov K, Geraghty D, Bansal P, et al. Characterization and isolation of L-to-D-amino-acid-residue isomerase from platypus venom. Amino Acids. 2007;32:63-8 pubmed
    b>Platypus venom contains an isomerase that reversibly interconverts the second amino-acid residue in some peptides between the L-form and the D-form...
  66. Renfree M, Papenfuss A, Shaw G, Pask A. Eggs, embryos and the evolution of imprinting: insights from the platypus genome. Reprod Fertil Dev. 2009;21:935-42 pubmed publisher
    ..The recent release of the platypus genome sequence has provided the first opportunity to make comparisons between prototherian (monotreme, which ..
  67. Whittington C, Koh J, Warren W, Papenfuss A, Torres A, Kuchel P, et al. Understanding and utilising mammalian venom via a platypus venom transcriptome. J Proteomics. 2009;72:155-64 pubmed publisher
    ..Here we describe the status of current research into the venom of the platypus, a semi-aquatic egg-laying Australian mammal, and discuss our approach to platypus venom transcriptomics...
  68. Fish F. Biomechanics and energetics in aquatic and semiaquatic mammals: platypus to whale. Physiol Biochem Zool. 2000;73:683-98 pubmed
    ..It is these intermediate animals that indicate which potential selection factors and mechanical constraints may have directed the evolution of more derived aquatic forms...