• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of pnasPNASInfo for AuthorsSubscriptionsAboutThis Article
Proc Natl Acad Sci U S A. Dec 15, 1991; 88(24): 11256–11260.

Sex chromosome evolution: platypus gene mapping suggests that part of the human X chromosome was originally autosomal.


To investigate the evolution of the mammalian sex chromosomes, we have compared the gene content of the X chromosomes in the mammalian groups most distantly related to man (marsupials and monotremes). Previous work established that genes on the long arm of the human X chromosome are conserved on the X chromosomes in all mammals, revealing that this region was part of an ancient mammalian X chromosome. However, we now report that several genes located on the short arm of the human X chromosome are absent from the platypus X chromosome, as well as from the marsupial X chromosome. Because monotremes and marsupials diverged independently from eutherian mammals, this finding implies that the whole human X short arm region is a relatively recent addition to the X chromosome in eutherian mammals.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1023K), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Click on the image to see a larger version.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Richardson BJ, Czuppon AB, Sharman GB. Inheritance of glucose-6-phosphate dehydrogenase variation in kangaroos. Nat New Biol. 1971 Mar 31;230(13):154–155. [PubMed]
  • Donald JA, Hope RM. Mapping a marsupial X chromosome using kangaroo-mouse somatic cell hybrids. Cytogenet Cell Genet. 1981;29(3):127–137. [PubMed]
  • Dawson GW, Graves JA. Gene mapping in marsupials and monotremes. I. The chromosomes of rodent-marsupial (Macropus) cell hybrids, and gene assignments to the X chromosome of the grey kangaroo. Chromosoma. 1984;91(1):20–27. [PubMed]
  • Spencer JA, Watson JM, Graves JA. The X chromosome of marsupials shares a highly conserved region with eutherians. Genomics. 1991 Apr;9(4):598–604. [PubMed]
  • Sinclair AH, Wrigley JM, Marshall Graves JA. Autosomal assignment of OTC in marsupials and monotremes: implications for the evolution of sex chromosomes. Genet Res. 1987 Oct;50(2):131–136. [PubMed]
  • Sinclair AH, Foster JW, Spencer JA, Page DC, Palmer M, Goodfellow PN, Graves JA. Sequences homologous to ZFY, a candidate human sex-determining gene, are autosomal in marsupials. Nature. 1988 Dec 22;336(6201):780–783. [PubMed]
  • Spencer JA, Sinclair AH, Watson JM, Graves JA. Genes on the short arm of the human X chromosome are not shared with the marsupial X. Genomics. 1991 Oct;11(2):339–345. [PubMed]
  • Watson JM, Graves JA. Gene mapping in marsupials and monotremes, V. Synteny between hypoxanthine phosphoribosyltransferase and phosphoglycerate kinase in the platypus. Aust J Biol Sci. 1988;41(2):231–237. [PubMed]
  • Watson JM, Spencer JA, Riggs AD, Graves JA. 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 Sep;87(18):7125–7129. [PMC free article] [PubMed]
  • Wrigley JM, Graves JA. Two monotreme cell lines, derived from female platypuses (Ornithorhynchus anatinus; Monotremata, Mammalia). In Vitro. 1984 Apr;20(4):321–328. [PubMed]
  • Wang TS, Pearson BE, Suomalainen HA, Mohandas T, Shapiro LJ, Schröder J, Korn D. Assignment of the gene for human DNA polymerase alpha to the X chromosome. Proc Natl Acad Sci U S A. 1985 Aug;82(16):5270–5274. [PMC free article] [PubMed]
  • Davies KE, Pearson PL, Harper PS, Murray JM, O'Brien T, Sarfarazi M, Williamson R. Linkage analysis of two cloned DNA sequences flanking the Duchenne muscular dystrophy locus on the short arm of the human X chromosome. Nucleic Acids Res. 1983 Apr 25;11(8):2303–2312. [PMC free article] [PubMed]
  • Kilimann MW, DeGennaro LJ. Molecular cloning of cDNAs for the nerve-cell specific phosphoprotein, synapsin I. EMBO J. 1985 Aug;4(8):1997–2002. [PMC free article] [PubMed]
  • Baehner RL, Kunkel LM, Monaco AP, Haines JL, Conneally PM, Palmer C, Heerema N, Orkin SH. DNA linkage analysis of X chromosome-linked chronic granulomatous disease. Proc Natl Acad Sci U S A. 1986 May;83(10):3398–3401. [PMC free article] [PubMed]
  • Hsu YP, Weyler W, Chen S, Sims KB, Rinehart WB, Utterback MC, Powell JF, Breakefield XO. Structural features of human monoamine oxidase A elucidated from cDNA and peptide sequences. J Neurochem. 1988 Oct;51(4):1321–1324. [PubMed]
  • Ramesh V, Eddy R, Bruns GA, Shih VE, Shows TB, Gusella JF. Localization of the ornithine aminotransferase gene and related sequences on two human chromosomes. Hum Genet. 1987 Jun;76(2):121–126. [PubMed]
  • Reed KC, Mann DA. Rapid transfer of DNA from agarose gels to nylon membranes. Nucleic Acids Res. 1985 Oct 25;13(20):7207–7221. [PMC free article] [PubMed]
  • Wrigley JM, Graves JA. Karyotypic conservation in the mammalian order monotremata (subclass Prototheria). Chromosoma. 1988;96(3):231–247. [PubMed]
  • Lyon MF. The William Allan memorial award address: X-chromosome inactivation and the location and expression of X-linked genes. Am J Hum Genet. 1988 Jan;42(1):8–16. [PMC free article] [PubMed]
  • Adler DA, Bressler SL, Chapman VM, Page DC, Disteche CM. Inactivation of the Zfx gene on the mouse X chromosome. Proc Natl Acad Sci U S A. 1991 Jun 1;88(11):4592–4595. [PMC free article] [PubMed]
  • Migeon BR, Shapiro LJ, Norum RA, Mohandas T, Axelman J, Dabora RL. Differential expression of steroid sulphatase locus on active and inactive human X chromosome. Nature. 1982 Oct 28;299(5886):838–840. [PubMed]
  • Schneider-Gädicke A, Beer-Romero P, Brown LG, Nussbaum R, Page DC. ZFX has a gene structure similar to ZFY, the putative human sex determinant, and escapes X inactivation. Cell. 1989 Jun 30;57(7):1247–1258. [PubMed]
  • Lau EC, Mohandas TK, Shapiro LJ, Slavkin HC, Snead ML. Human and mouse amelogenin gene loci are on the sex chromosomes. Genomics. 1989 Feb;4(2):162–168. [PubMed]
  • Fisher EM, Beer-Romero P, Brown LG, Ridley A, McNeil JA, Lawrence JB, Willard HF, Bieber FR, Page DC. Homologous ribosomal protein genes on the human X and Y chromosomes: escape from X inactivation and possible implications for Turner syndrome. Cell. 1990 Dec 21;63(6):1205–1218. [PubMed]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences


Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


  • Compound
    PubChem Compound links
  • MedGen
    Related information in MedGen
  • OMIM
    OMIM record citing PubMed
  • PubMed
    PubMed citations for these articles
  • Substance
    PubChem Substance links