monotremata

Summary

Summary: An order of egg-laying mammals that includes the PLATYPUS and ECHIDNA.

Top Publications

  1. Janke A, Xu X, Arnason U. The complete mitochondrial genome of the wallaroo (Macropus robustus) and the phylogenetic relationship among Monotremata, Marsupialia, and Eutheria. Proc Natl Acad Sci U S A. 1997;94:1276-81 pubmed
    ..Theria hypothesis, according to which Marsupialia and Eutheria are grouped together to the exclusion of Monotremata. The region harboring the gene for lysine tRNA (tRNA-Lys) in the mtDNA of other vertebrates is in the wallaroo ..
  2. Margulies E, Maduro V, Thomas P, Tomkins J, Amemiya C, Luo M, et al. Comparative sequencing provides insights about the structure and conservation of marsupial and monotreme genomes. Proc Natl Acad Sci U S A. 2005;102:3354-9 pubmed
    ..Our results confirm that genomic sequence from noneutherian mammals can contribute uniquely to unraveling the functional and evolutionary histories of the mammalian genome...
  3. Gilbert N, Labuda D. Evolutionary inventions and continuity of CORE-SINEs in mammals. J Mol Biol. 2000;298:365-77 pubmed
    ..The proposed mechanism suggests that such an adaptation to the changing amplification machinery facilitated the survival and prosperity of CORE-elements over long evolutionary periods in different lineages...
  4. Hore T, Rapkins R, Graves J. Construction and evolution of imprinted loci in mammals. Trends Genet. 2007;23:440-8 pubmed
    ..Here, we use comparisons between different mammalian groups to chart the course of evolution of two related epigenetic regulatory systems in mammals: genomic imprinting and X-chromosome inactivation...
  5. 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 ..
  6. Proske U, Gregory J, Iggo A. Sensory receptors in monotremes. Philos Trans R Soc Lond B Biol Sci. 1998;353:1187-98 pubmed
    ..Perhaps the electric sense is used to detect moving prey in moist soil. ..
  7. Graves J. Mammals that break the rules: genetics of marsupials and monotremes. Annu Rev Genet. 1996;30:233-60 pubmed
    ..In many features, it appears that humans and, particularly, mice are the weird mammals that break more general mammalian, or even vertebrate rules. ..
  8. Haynes J. Parathyroids and ultimobranchial bodies in monotremes. Anat Rec. 1999;254:269-80 pubmed
    ..Identification of the ultimobranchial bodies was confirmed by immunostaining. The monotreme parathyroid gland, ultimobranchial bodies and thyroid show reptilian as well as mammalian features...
  9. Rowe M. Multiple representation of sensory system input in the cerebral cortex:the new phrenology?. Neurosci Lett. 2004;361:98-101 pubmed

More Information

Publications85

  1. Wakefield M, Graves J. Marsupials and monotremes sort genome treasures from junk. Genome Biol. 2005;6:218 pubmed
    ..A recent landmark paper demonstrates the unique contribution of marsupials and monotremes to comparative genome analysis, filling an evolutionary gap between the eutherian mammals (including humans) and more distant vertebrate species. ..
  2. Rougier G, Forasiepi A, Martinelli A. Comment on "Independent origins of middle ear bones in monotremes and therians" (II). Science. 2005;309:1492; author reply 1492 pubmed
  3. 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 lack imprinting) and therian (marsupial and eutherian; which have imprinting) mammals...
  4. Pask A, Graves J. Sex chromosomes and sex-determining genes: insights from marsupials and monotremes. Cell Mol Life Sci. 1999;55:864-75 pubmed
    ..Here we review comparisons between genes in the sex-determining pathway in different vertebrates, and ask how these comparisons affect our views on the role of each gene in vertebrate sex determination. ..
  5. Frankenberg S, Schneider N, Fletcher T, Shaw G, Renfree M. Identification of two distinct genes at the vertebrate TRPC2 locus and their characterisation in a marsupial and a monotreme. BMC Mol Biol. 2011;12:39 pubmed publisher
    ..The former is widely expressed with a putative role in DNA repair, while the latter shows VNO-specific expression under the probable regulation of NHLH1...
  6. Pask A. Insights on imprinting from beyond mice and men. Methods Mol Biol. 2012;925:263-75 pubmed publisher
    ..Examining imprinting across the three mammal groups enables us to test hypotheses on the origin of this phenomenon in mammals and also to investigate changes in the genome coincident with its evolution. ..
  7. Parkinson A, Whittington A, Spencer P, Grigg G, Hinds L, Gallagher C, et al. Comparative erythrocyte metabolism in marsupials and monotremes. Comp Biochem Physiol C Pharmacol Toxicol Endocrinol. 1995;110:261-5 pubmed
    ..There were wide variations in the glycolytic rate among the species examined. ..
  8. Rode Margono J, Nekaris K. Cabinet of Curiosities: Venom Systems and Their Ecological Function in Mammals, with a Focus on Primates. Toxins (Basel). 2015;7:2639-58 pubmed publisher
    ..of venom allow us to reconsider its diversity amongst mammals by reviewing the VDS of Chiroptera, Eulipotyphla, Monotremata, and Primates...
  9. Hughes R. Monotreme development with particular reference to the extraembryonic membranes. J Exp Zool. 1993;266:480-94 pubmed
  10. Opazo J, Hoffmann F, Storz J. Genomic evidence for independent origins of beta-like globin genes in monotremes and therian mammals. Proc Natl Acad Sci U S A. 2008;105:1590-5 pubmed publisher
  11. Schneider N. The development of the olfactory organs in newly hatched monotremes and neonate marsupials. J Anat. 2011;219:229-42 pubmed publisher
    ..It is therefore likely that neonate marsupials and newly hatched monotremes find their way to the milk source using olfactory cues, as has been previously suggested for the marsupial tammar wallaby, rabbits, rats and other eutherians. ..
  12. Rowe M, Mahns D, Bohringer R, Ashwell K, Sahai V. Tactile neural mechanisms in monotremes. Comp Biochem Physiol A Mol Integr Physiol. 2003;136:883-93 pubmed
  13. Macrini T, Rowe T, Archer M. Description of a cranial endocast from a fossil platypus, Obdurodon dicksoni (Monotremata, Ornithorhynchidae), and the relevance of endocranial characters to monotreme monophyly. J Morphol. 2006;267:1000-15 pubmed
    ..member of either extant monotreme lineage and is therefore important for inferring character support for Monotremata, a clade that is not well diagnosed...
  14. Tanaka Y, Eishi Y, Morris B. Splenic hemopoiesis of the platypus (Ornithorhynchus anatinus): evidence of primary hemopoiesis in the spleen of a primitive mammal. Am J Anat. 1988;181:401-5 pubmed
    ..Since the platypus is one of two species representing the most primitive existing mammals, it seems likely that the spleen may be the primary hemopoietic organ in mammalian evolution. ..
  15. Li G, Luo Z. A Cretaceous symmetrodont therian with some monotreme-like postcranial features. Nature. 2006;439:195-200 pubmed
  16. 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...
  17. Ferner K, Zeller U, Renfree M. Lung development of monotremes: evidence for the mammalian morphotype. Anat Rec (Hoboken). 2009;292:190-201 pubmed publisher
    ..and the extent of development of neonates differ markedly between the three extant mammalian groups: the Monotremata, Marsupialia, and Eutheria...
  18. Rich T, Hopson J, Musser A, Flannery T, Vickers Rich P. Independent origins of middle ear bones in monotremes and therians. Science. 2005;307:910-4 pubmed
  19. Divac I, Holst M, Nelson J, McKenzie J. Afferents of the frontal cortex in the echidna (Tachyglossus aculeatus). Indication of an outstandingly large prefrontal area. Brain Behav Evol. 1987;30:303-20 pubmed
    ..If this conclusion is correct, the echidna is the only species studied to date that has a proportionally larger prefrontal cortex than humans. ..
  20. Stokstad E. Society of Vertebrate Paleontology meeting. Jaw shows platypus goes way back. Science. 2007;318:1237 pubmed
  21. Rooney A, Zhang J, Nei M. An unusual form of purifying selection in a sperm protein. Mol Biol Evol. 2000;17:278-83 pubmed
    ..The driving force for arginine-rich selection appears to be the DNA-binding function of protamine P1 and an interaction with a protein kinase in the fertilized egg...
  22. Alibardi L, Maderson P. Distribution of keratin and associated proteins in the epidermis of monotreme, marsupial, and placental mammals. J Morphol. 2003;258:49-66 pubmed
    ..Nevertheless, the mechanism of redistribution of such proteins during maturation of monotreme keratinocytes is different from, perhaps more primitive, or less specialized, than that in the epidermis of eutherian mammals...
  23. Pupko T, Galtier N. A covarion-based method for detecting molecular adaptation: application to the evolution of primate mitochondrial genomes. Proc Biol Sci. 2002;269:1313-6 pubmed
    ..e. highly constrained) in primates, and some show the opposite pattern. Our results indicate that the mitochondrial genome of primates reached a new peak of the adaptive landscape through positive selection...
  24. Behringer R, Eakin G, Renfree M. Mammalian diversity: gametes, embryos and reproduction. Reprod Fertil Dev. 2006;18:99-107 pubmed
    ..This diversity creates challenges and opportunities for gamete and embryo collection, culture and transfer technologies...
  25. Lefèvre C, Sharp J, Nicholas K. Characterisation of monotreme caseins reveals lineage-specific expansion of an ancestral casein locus in mammals. Reprod Fertil Dev. 2009;21:1015-27 pubmed publisher
    ..The monotremes therefore provide insight into the ancestral drivers for lactation and how these have adapted in different lineages...
  26. Deakin J, Graves J, Rens W. The evolution of marsupial and monotreme chromosomes. Cytogenet Genome Res. 2012;137:113-29 pubmed publisher
  27. Divac I, Pettigrew J, Holst M, McKenzie J. Efferent connections of the prefrontal cortex of echidna (Tachyglossus aculeatus). Brain Behav Evol. 1987;30:321-7 pubmed
    ..The present material, albeit limited, shows some remarkable similarities between prefrontal efferents in the echidna and the placental mammals, including Old World monkeys...
  28. Siegel J, Manger P, Nienhuis R, Fahringer H, Pettigrew J. Monotremes and the evolution of rapid eye movement sleep. Philos Trans R Soc Lond B Biol Sci. 1998;353:1147-57 pubmed
  29. Zeller U. The lamina cribrosa of Ornithorhynchus (Monotremata, Mammalia). Anat Embryol (Berl). 1988;178:513-9 pubmed
    ..The lamina cribrosa developed only once in the phylogeny of mammals. Its lack in the adult Ornithorhynchus is not a "reptilian" character...
  30. Grigg G, Beard L, Augee M. Hibernation in a monotreme, the echidna (Tachyglossus aculeatus). Comp Biochem Physiol A Comp Physiol. 1989;92:609-12 pubmed
  31. Schreiber G, Pettersson T, Southwell B, Aldred A, Harms P, Richardson S, et al. Transthyretin expression evolved more recently in liver than in brain. Comp Biochem Physiol B. 1993;105:317-25 pubmed
    ..4. It is proposed that transthyretin gene expression in mammalian liver appeared about 200 million years later than its first occurrence in the choroid plexus of the stem reptiles...
  32. Novacek M, Rougier G, Wible J, McKenna M, Dashzeveg D, Horovitz I. Epipubic bones in eutherian mammals from the late Cretaceous of Mongolia. Nature. 1997;389:483-6 pubmed
    ..Thus the occurrence of epipubic bones in two Cretaceous eutherians suggests that the dramatic modifications connected with typical placental reproduction may have been later events in the evolution of the Eutheria...
  33. Weiss M, Oddie C, McCance I. The effects of ACTH on adrenal steroidogenesis and blood corticosteroid levels in the echidna (Tachyglossus aculeatus). Comp Biochem Physiol B. 1979;64:65-70 pubmed
    ..T. had no effect. 6. In control echidnas the Km and V for 11 beta-hydroxylation of 11-deoxycorticosterone were 20 microM and 2.8 rho mol/min/mg respectively. After L.T. V increased to 10 rho mol/min/mg...
  34. Wong E, Papenfuss A, Belov K. Immunome database for marsupials and monotremes. BMC Immunol. 2011;12:48 pubmed publisher
    ..This was required as many genes involved in immunity evolve rapidly and fail to be detected by automated gene annotation pipelines...
  35. Daish T, Grützner F. Location, location, location! Monotremes provide unique insights into the evolution of sex chromosome silencing in mammals. DNA Cell Biol. 2009;28:91-100 pubmed publisher
    ..We summarize recent research on monotreme and chicken sex chromosomes and discuss possible mechanisms that may contribute to sex chromosome silencing in monotremes...
  36. Selwood L, Johnson M. Trophoblast and hypoblast in the monotreme, marsupial and eutherian mammal: evolution and origins. Bioessays. 2006;28:128-45 pubmed
    ..These changes result in the conversion of a unilaminar blastocyst to a morula form composed of blastomeres with increased regulatory capacity...
  37. Menkhorst E, Nation A, Cui S, Selwood L. Evolution of the shell coat and yolk in amniotes: a marsupial perspective. J Exp Zool B Mol Dev Evol. 2009;312:625-38 pubmed publisher
  38. Shaffer J, Gillis T. Evolution of the regulatory control of vertebrate striated muscle: the roles of troponin I and myosin binding protein-C. Physiol Genomics. 2010;42:406-19 pubmed publisher
    ..This suggests that the replacement of these residues with alternative residues coincides with the evolution of endothermy in the mammalian lineage...
  39. Osborne P, Campbell G, Evans B. Distribution of substance P in the enteric plexuses of the small intestine of the platypus, Ornithorhynchus anatinus. Cell Tissue Res. 1989;255:663-7 pubmed
    ..Although applied substance P (10(-9) M-3 x 10(-8) M) caused contraction of the longitudinal muscle, neither mesenteric nerve stimulation nor application of capsaicin caused contractions...
  40. Brawand D, Wahli W, Kaessmann H. Loss of egg yolk genes in mammals and the origin of lactation and placentation. PLoS Biol. 2008;6:e63 pubmed publisher
  41. Heesy C, Hall M. The nocturnal bottleneck and the evolution of mammalian vision. Brain Behav Evol. 2010;75:195-203 pubmed publisher
    ..Only anthropoid primates notably differ from general mammalian patterns, and possibly have evolved an eye shape more typical of the ancestral amniote condition...
  42. Fong J, Fujita M. Evaluating phylogenetic informativeness and data-type usage for new protein-coding genes across Vertebrata. Mol Phylogenet Evol. 2011;61:300-7 pubmed publisher
    ..Our phylogenetic inference supports the Theria hypothesis of mammalian relationships, with marsupials and placentals being sister groups...
  43. Watson J, Spencer J, Graves J, Snead M, Lau E. Autosomal localization of the amelogenin gene in monotremes and marsupials: implications for mammalian sex chromosome evolution. Genomics. 1992;14:785-9 pubmed
  44. Krubitzer L. What can monotremes tell us about brain evolution?. Philos Trans R Soc Lond B Biol Sci. 1998;353:1127-46 pubmed
    ..This, in turn, allows us to appreciate how normal circuits function, and to pose very specific questions regarding the development of the neocortex...
  45. Martin T, Luo Z. Paleontology. Homoplasy in the mammalian ear. Science. 2005;307:861-2 pubmed
  46. Cui S, Hope R, Rathjen J, Voyle R, Rathjen P. Structure, sequence and function of a marsupial LIF gene: conservation of IL-6 family cytokines. Cytogenet Cell Genet. 2001;92:271-8 pubmed
    ..The availability of marsupial LIF probes provides an opportunity to investigate conservation of expression and function in these mammals...
  47. Jurd R. "Not proper mammals": immunity in monotremes and marsupials. Comp Immunol Microbiol Infect Dis. 1994;17:41-52 pubmed
    Immune systems and responses in Monotremata and Marsupialia are reviewed. The Monotremata (Prototheria) are egg-laying mammals. Few studies have been carried out on monotremes...
  48. Hinds D, Baudinette R, MacMillen R, Halpern E. Maximum metabolism and the aerobic factorial scope of endotherms. J Exp Biol. 1993;182:41-56 pubmed
    ..Aerobic scope during cold is significantly higher in marsupials (8.3) than in eutherians (5.1), birds (5.4) and monotremes (5.4). Aerobic scope during locomotion in all groups is almost twice that observed in cold conditions...
  49. Ligabue Braun R, Verli H, Carlini C. Venomous mammals: a review. Toxicon. 2012;59:680-95 pubmed publisher
    ..having different compositions and modes of action and are present in three classes of mammals, Insectivora, Monotremata, and Chiroptera. A fourth order, Primates, is proposed to have venomous representatives...
  50. Watson J, Graves J. Gene mapping in marsupials and monotremes, V. Synteny between hypoxanthine phosphoribosyltransferase and phosphoglycerate kinase in the platypus. Aust J Biol Sci. 1988;41:231-7 pubmed
    ..The implications of the chromosomal location of this ancient synteny group for the evolution of the mammalian X chromosome are discussed...
  51. Kullander K, Carlson B, Hallbook F. Molecular phylogeny and evolution of the neurotrophins from monotremes and marsupials. J Mol Evol. 1997;45:311-21 pubmed
    ..These studies show that sequence data from neurotrophins are well suited for phylogenetic analysis of mammals and that neurotrophins can resolve basal relationships in the evolutionary tree...
  52. Glusman G, Bahar A, Sharon D, Pilpel Y, White J, Lancet D. The olfactory receptor gene superfamily: data mining, classification, and nomenclature. Mamm Genome. 2000;11:1016-23 pubmed
    ..The symbol is to be preceded by a species indicator. We have assigned the proposed nomenclature symbols for all 330 human OR genes in the database. A WWW tool for automated name assignment is provided...
  53. Ecroyd H, Nixon B, Dacheux J, Jones R. Testicular descent, sperm maturation and capacitation. Lessons from our most distant relatives, the monotremes. Reprod Fertil Dev. 2009;21:992-1001 pubmed publisher
    ..It is suggested that this represents an early form of capacitation...
  54. Waters P, Marshall Graves J. Monotreme sex chromosomes--implications for the evolution of amniote sex chromosomes. Reprod Fertil Dev. 2009;21:943-51 pubmed publisher
  55. Renfree M. Monotreme and marsupial reproduction. Reprod Fertil Dev. 1995;7:1003-20 pubmed
    ..There is no doubt that future research will strengthen this contribution, but we are faced with serious conservation questions that must be solved if we are to maintain these wonderful animals as a resource for future generations...
  56. Renfree M, Hore T, Shaw G, Graves J, Pask A. Evolution of genomic imprinting: insights from marsupials and monotremes. Annu Rev Genomics Hum Genet. 2009;10:241-62 pubmed publisher
    ..Here we review the recent analyses of imprinted gene clusters in marsupials and monotremes, which have served to shed light on the origin and evolution of imprinting mechanisms in mammals...
  57. Tanaka Y. "Intermediate zone" of mammalian spleens: light and electron microscopic study of three primitive mammalian species (platypus, shrew, and mole) with special reference to intrasplenic arteriovenous communication. Am J Anat. 1990;187:313-37 pubmed
    ..The marginal sinus reported in some mammalian spleens is probably a modified AN formed during this process. Possible morphological alterations of the spleen in vertebrate phylogeny are discussed...
  58. Dobrovic A, Marshall Graves J. Gene mapping in marsupials and monotremes. II. Assignments to the X chromosome of dasyurid marsupials. Cytogenet Cell Genet. 1986;41:9-13 pubmed
    ..Counterselection confirmed the synteny of PGK and GLA with HPRT, whereas G6PD showed decreased concordance...
  59. Ashwell K, Hardman C, Paxinos G. The claustrum is not missing from all monotreme brains. Brain Behav Evol. 2004;64:223-41 pubmed
    ..Our findings indicate that presence of the claustrum cannot be considered a feature confined to therian mammals and lend weight to arguments that this structure was present in the ancestral mammalian brain...
  60. Gregory J, Iggo A, McIntyre A, Proske U. Responses of electroreceptors in the snout of the echidna. J Physiol. 1989;414:521-38 pubmed
    ..It remains to be determined what kinds of sources of electric fields the animal encounters in its normal habitat...
  61. Gregory J, Iggo A, McIntyre A, Proske U. Responses of electroreceptors in the platypus bill to steady and alternating potentials. J Physiol. 1989;408:391-404 pubmed
    ..Furthermore, they are able to respond to both steady and rapidly changing voltage gradients.(ABSTRACT TRUNCATED AT 400 WORDS)..
  62. Whittington R, Spratt D. Lesions associated with metazoan parasites of wild platypuses (Ornithorhynchus anatinus). J Wildl Dis. 1989;25:521-6 pubmed
    ..The digenean Mehlisia ornithorhynchi was present in the small intestine of one animal and was associated with mild catarrhal enteritis...
  63. Edwards J. Comparative genome mapping in mammals. Curr Opin Genet Dev. 1994;4:861-7 pubmed
    ..This allows the genome mapping of the main laboratory and farmyard species to help, and to be helped by, mapping of the human genome...
  64. Gregory J, Iggo A, McIntyre A, Proske U. Receptors in the bill of the platypus. J Physiol. 1988;400:349-66 pubmed
    ..This in turn emphasizes that monotremes are a highly evolved group which split off from the main mammalian stem a long time ago...
  65. Ashwell K, Shulruf B. Quantitative comparison of cerebral artery development in metatherians and monotremes with non-human eutherians. J Anat. 2016;228:384-95 pubmed publisher
    ..The findings have implications for nutritional sourcing of the developing brain in the three infraclasses of mammals...
  66. Ramírez Chaves H, Wroe S, Selwood L, Hinds L, Leigh C, Koyabu D, et al. Mammalian development does not recapitulate suspected key transformations in the evolutionary detachment of the mammalian middle ear. Proc Biol Sci. 2016;283: pubmed publisher
  67. Hamilton M, Davidson A, Sibly R, Brown J. Universal scaling of production rates across mammalian lineages. Proc Biol Sci. 2011;278:560-6 pubmed publisher
    ..Apparently all mammals are subject to the same fundamental metabolic constraints on productivity, because they share similar body designs, vascular systems and costs of producing new tissue...
  68. Deakin J, Chaumeil J, Hore T, Marshall Graves J. Unravelling the evolutionary origins of X chromosome inactivation in mammals: insights from marsupials and monotremes. Chromosome Res. 2009;17:671-85 pubmed publisher
    ..Availability of sequence data, and new techniques for studying expression and chromatin modification, now make rapid advance possible...
  69. Grutzner F, Nixon B, Jones R. Reproductive biology in egg-laying mammals. Sex Dev. 2008;2:115-27 pubmed publisher
    ..In addition we discuss works on the evolution of the complex sex chromosome system in platypus and echidna, which has also significant impact on our general understanding of mammalian sex chromosomes and sex determination...
  70. Nicol S. Monotreme biology. Comp Biochem Physiol A Mol Integr Physiol. 2003;136:795-8 pubmed
  71. Harrison G, Young L, Watson C, Miska K, Miller R, Deane E. A survey of type I interferons from a marsupial and monotreme: implications for the evolution of the type I interferon gene family in mammals. Cytokine. 2003;21:105-19 pubmed
    ..For example, this expansion in complexity may have, at least partially, facilitated the evolution of viviparity in marsupials and eutherians. Other evolutionary aspects of these sequences are also discussed...
  72. Allard M, McNiff B, Miyamoto M. Support for interordinal eutherian relationships with an emphasis on primates and their archontan relatives. Mol Phylogenet Evol. 1996;5:78-88 pubmed
    ..In reviewing relationships among the mammals, we have focused on collating all of the available evidence so that one could know where each of the specific data sets is in support of the various relationships...
  73. Watson J, Frost C, Spencer J, Graves J. Sequences homologous to the human X- and Y-borne zinc finger protein genes (ZFX/Y) are autosomal in monotreme mammals. Genomics. 1993;15:317-22 pubmed
    ..These results support the hypothesis that many of the genes located on the short arm of the human X were originally autosomal and have been translocated to the X chromosome since the eutherian-metatherian divergence...
  74. Whittington A, Parkinson A, Spencer P, Grigg G, Hinds L, Gallagher C, et al. Comparative study of the antioxidant defence systems in the erythrocytes of Australian marsupials and monotremes. Comp Biochem Physiol C Pharmacol Toxicol Endocrinol. 1995;110:267-72 pubmed
    ..Since both these enzymes "detoxify" H2O2, there appears to be a reciprocal relationship between the activities of these enzymes in marsupial RBC...
  75. 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
  76. Whittington R, Bell I, Searson J. A viral infection causing cytomegalic inclusion disease in the renal epithelium of the platypus (Ornithorhynchus anatinus). J Wildl Dis. 1990;26:55-61 pubmed
    ..Although the identity of the virus was not confirmed, it was probably an adenovirus based on morphological grounds. The infection appeared to have little effect on the host...