Chromosome Research

, Volume 19, Issue 5, pp 635–644 | Cite as

Additional copies of CBX2 in the genomes of males of mammals lacking SRY, the Amami spiny rat (Tokudaia osimensis) and the Tokunoshima spiny rat (Tokudaia tokunoshimensis)

  • Asato Kuroiwa
  • Sanae Handa
  • Chigusa Nishiyama
  • Eriko Chiba
  • Fumio Yamada
  • Shintaro Abe
  • Yoichi Matsuda
Article

Abstract

Tokudaia osimensis (the Amami spiny rat) and Tokudaia tokunoshimensis (the Tokunoshima spiny rat) have a sex chromosome composition of XO/XO, no Y chromosome. The mammalian sex-determining gene, SRY, is also absent in these species, which indicates that these spiny rats exhibit a novel sex-determining mechanism that is independent of SRY. To identify a candidate gene that controls this mechanism, the copy numbers and chromosomal locations of 10 genes with important functions in gonadal differentiation were determined: ATRX, CBX2 (M33), DMRT1, FGF9, NR0B1 (DAX1), NR5A1 (Ad4BP/SF1), RSPO1, SOX9, WNT4, and WT1. Multiple bands were detected for NR0B1 in Southern blot analysis, which suggested the presence of multiple copies of the gene in the genomes of these two species. CBX2 was localized to two loci in both sexes of the two species by fluorescence in situ hybridization mapping: 3q24 and 6p11.2 in T. osimensis and 10q25–q26 and 14q12–q13.1 in T. tokunoshimensis. Quantification of copy numbers in the two species by quantitative real-time PCR indicated that there were two or three more copies of CBX2 per haploid genome in males (T. osimensis, n = 3; T. tokunoshimensis, n = 2) than in females (T. osimensis, n = 4; T. tokunoshimensis, n = 2), whereas NR0B1 was present as a single copy in both. The results suggest that additional copies of CBX2 in males might be involved in a novel sex-determining mechanism in species that lack SRY.

Keywords

sex determination sex differentiation XO Y chromosome 

Abbreviations

AP

Alkaline phosphatase

ASA

American Standards Association

BSA

Bovine serum albumin

BrdU

Bromodeoxyuridine

cDNA

Complementary DNA

CDP

Cytidine diphosphate

DIG

Digoxygenine

dUTP

Deoxyuridine 5-triphosphate

FISH

Fluorescence in situ hybridization

IgG

Immunoglobulin G

IUCN

International Union for Conservation of Nature

kb

Kilo base pairs

KO

Knockout

MEM

Minimal essential medium

qRT-PCR

Quantitative real-time PCR

RACE

Rapid amplification of cDNA ends

SD

Standard deviation

SDS

Sodium dodecyl sulfate

SSC

Saline sodium citrate

UTR

Untranslated region

UV

Ultraviolet

References

  1. Arakawa Y, Nishida-Umehara C, Matsuda Y, Sutou S, Suzuki H (2002) X-chromosomal localization of mammalian Y-linked genes in two XO species of the Ryukyu spiny rat. Cytogenet Genome Res 99:303–309PubMedCrossRefGoogle Scholar
  2. Biason-Lauber A, Konrad D, Meyer M, DeBeaufort C, Schoenle EJ (2009) Ovaries and female phenotype in a girl with 46,XY karyotype and mutations in the CBX2 gene. Am J Hum Genet 84:658–663PubMedCrossRefGoogle Scholar
  3. Brown CJ, Hendrich BD, Rupert JL, Lafrenière RG, Xing Y, Lawrence J, Willard HF (1992) The human XIST gene: analysis of a 17 kb inactive X-specific RNA that contains conserved repeats and is highly localized within the nucleus. Cell 71:527–542PubMedCrossRefGoogle Scholar
  4. Graham P, Penn JKM, Schedl P (2002) Masters change, slaves remain. BioEssays 25:1–4CrossRefGoogle Scholar
  5. Honda T, Suzuki H, Itoh M (1977) An unusual sex chromosome constitution found in the Amami spinous country-rat, Tokudaia osimensis osimensis. Jpn J Genet 52:247–249CrossRefGoogle Scholar
  6. Honda T, Suzuki H, Itoh M, Hayashi K (1978) Karyotypical differences of the Amami spinous country-rats, Tokudaia osimensis osimensis obtained from two neighbouring islands. Jpn J Genet 53:297–299CrossRefGoogle Scholar
  7. Katoh-Fukui Y, Tsuchiya R, Shiroishi T, Nakahara Y, Hashimoto N, Noguchi K, Higashinakagawa T (1998) Male-to-female sex reversal in M33 mutant mice. Nature 393:688–692PubMedCrossRefGoogle Scholar
  8. Kobayashi T, Yamada F, Hashimoto T et al (2007) Exceptional minute sex-specific region in the X0 mammal, Ryukyu spiny rat. Chromosome Res 15:175–187PubMedCrossRefGoogle Scholar
  9. Koopman P (2001a) The genetics and biology of vertebrate sex determination. Cell 105:843–847PubMedCrossRefGoogle Scholar
  10. Koopman P (2001b) Sry, Sox9 and mammalian sex determination. In: Scherer G, Schmid M (eds) Genes and mechanism in vertebrate sex determination. Birkhauser Verlag, BaselGoogle Scholar
  11. Koopman P, Gubbay J, Vivian N, Goodfellow P, Lovell-Badge R (1991) Male development of chromosomally female mice transgenic for Sry. Nature 351:117–121PubMedCrossRefGoogle Scholar
  12. Kuroiwa A, Ishiguchi Y, Yamada F, Shintaro A, Matsuda Y (2010) The process of a Y-loss event in an XO/XO mammal, the Ryukyu spiny rat. Chromosoma 119:519–526PubMedCrossRefGoogle Scholar
  13. Ludbrook LM, Harley VR (2004) Sex determination: a ‘window’ of DAX1 activity. Trends Endcrinol Metab 15:116–121CrossRefGoogle Scholar
  14. Marahrens Y, Panning B, Dausman J, Strauss W, Jaenisch R (1997) Xist-deficient mice are defective in dosage compensation but not spermatogenesis. Genes Dev 11:156–166PubMedCrossRefGoogle Scholar
  15. Marahrens Y, Loring J, Jaenisch R (1998) Role of the XIST gene in X chromosome choosing. Cell 92:657–664PubMedCrossRefGoogle Scholar
  16. Matsuda Y, Chapman VM (1995) Application of fluorescence in situ hybridization in genome analysis of the mouse. Electrophoresis 16:261–272PubMedCrossRefGoogle Scholar
  17. Matsuda Y, Harada Y-N, Natsuume-Sakai S et al (1992) Location of the mouse complement factor H gene (cfh) by FISH analysis and replication R-banding. Cytogenet Cell Genet 61:282–285PubMedCrossRefGoogle Scholar
  18. Matsuda M, Nagahama Y, Shinomiya A, Sato T, Matsuda C, Kobayashi T, Morrey CE, Shibata N, Asakawa S, Shimizu N, Hori H, Hamaguchi S, Sakaizumi M (2002) DMY is a Y-specific DM-domain gene required for male development in the medaka fish. Nature 417:559–563PubMedCrossRefGoogle Scholar
  19. Murata C, Yamada F, Kawauchi N, Matsuda Y, Kuroiwa A (2010) Multiple copies of SRY on the large Y chromosome of the Okinawa spiny rat, Tokudaia muenninki. Chromosome Res 18:623–634PubMedCrossRefGoogle Scholar
  20. Nanda I, Kondo M, Hornung U, Asakawa S, Winkler C, Shimizu A, Shan Z, Haaf T, Shimizu N, Shima A, Schmid M, Schartl M (2002) A duplicated copy of DMRT1 in the sex-determining region of the Y chromosome of the medaka, Oryzias latipes. Proc Natl Acad Sci U S A 99:11778–11783PubMedCrossRefGoogle Scholar
  21. Parma P, Radi O, Vidal V et al (2006) R-spondin1 is essential in sex determination, skin differentiation and malignancy. Nat Genet 38:1304–1309PubMedCrossRefGoogle Scholar
  22. Paro R, Hogness DS (1991) The Polycomb protein shares a homologous domain with a heterochromatin-associated protein of Drosophila. Proc Natl Acad Sci U S A 88:263–267PubMedCrossRefGoogle Scholar
  23. Pearce JJ, Singh PB, Graunt SJ (1992) The mouse has a Polycomb-like chromobox gene. Development 114:921–929PubMedGoogle Scholar
  24. Penny GD, Kay GF, Sheardown SA, Rasten S, Brockdorff N (1996) Requirement for XIST in X chromosome inactivation. Nature 379:131–137PubMedCrossRefGoogle Scholar
  25. Pirrotta V (1997) Chromatin-silencing mechanisms in Drosophila maintain patterns of gene expression. Trends Genet 13:314–318PubMedCrossRefGoogle Scholar
  26. Schartl M (2004) Sex chromosome evolution in non-mammalian vertebrates. Curr Opin Genet Dev 14:634–641PubMedCrossRefGoogle Scholar
  27. Sinclair AH, Berta P, Palmer MS, Hawkins JR, Griffiths BL, Smith MJ, Foster JW, Frischauf AM, Lovell-Badge R, Goodfellow PN (1990) A gene from the human sex-determining region encodes a protein with homology to a conserved DNA-binding motif. Nature 346:240–244PubMedCrossRefGoogle Scholar
  28. Soullier S, Hanni C, Catzeflis F, Berta P, Laudet V (1998) Male sex determination in the spiny rat Tokudaia osimensis (Rodentia: Muridae) is not Sry dependent. Mamm Genome 9:590–592PubMedCrossRefGoogle Scholar
  29. Sutou S, Mitsui Y, Tsuchiya K (2001) Sex determination without the Y chromosome in two Japanese rodents Tokudaia osimensis osimensis and Tokudaia osimensis spp. Mamm Genome 12:17–21PubMedCrossRefGoogle Scholar
  30. Swain A, Narvaez V, Burgoyne P, Camerino G, Lovell-Badge R (1998) Dax1 antagonizes Sry action in mammalian sex determination. Nature 391:761–767PubMedCrossRefGoogle Scholar
  31. Wilkins AS (1995) Moving up the hierarchy: a hypothesis on the evolution of a genetic sex determination pathway. BioEssays 17:71–77PubMedCrossRefGoogle Scholar
  32. Zanaria E, Muscatelli F, Bardoni B, Strom TM, Guioli S, Guo W, Lalli E, Moser C, Walker AP, McCabe ER, Meitinger T, Monaco AP, Sassone-Corsi P, Camerino G (1994) An unusual member of the nuclear hormone receptor superfamily responsible for X-linked adrenal hypoplasia congenita. Nature 372:635–641PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Asato Kuroiwa
    • 1
    • 5
  • Sanae Handa
    • 1
  • Chigusa Nishiyama
    • 1
  • Eriko Chiba
    • 1
  • Fumio Yamada
    • 2
  • Shintaro Abe
    • 3
  • Yoichi Matsuda
    • 4
  1. 1.Graduate School of Life ScienceHokkaido UniversitySapporoJapan
  2. 2.Forestry and Forest Products Research InstituteTsukubaJapan
  3. 3.Naha Nature Conservation Office, Ministry of the EnvironmentNahaJapan
  4. 4.Laboratory of Animal Genetics, Department of Applied Molecular Biosciences, Graduate School of Bioagricultural SciencesNagoya UniversityNagoyaJapan
  5. 5.Laboratory of Animal Cytogenetics, Faculty of ScienceHokkaido UniversitySapporoJapan

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