, Volume 46, Issue 5, pp 506–508 | Cite as

The largest known chromosome number for a mammal, in a South American desert rodent

  • L. C. Contreras
  • J. C. Torres-Mura
  • A. E. Spotorno
Research Articles


Tympanoctomys barrerae, a desert specialist member of the family Octodontidae, until now thought to be conservative, and ancestral to South American hystricognath rodents, presents the highest diploid chromosome number (2n=102) known in a mammal. Unexpectedly, its karyotype was found to be composed mainly of metacentric to sub-metacentric chromosomes. Mechanisms by which such a karyotype may have been derived are discussed.

Key words

Rodent hystricognath octodontid chromosome karyology heterochromatin 


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Copyright information

© Birkhäuser Verlag 1990

Authors and Affiliations

  • L. C. Contreras
    • 1
  • J. C. Torres-Mura
    • 2
  • A. E. Spotorno
    • 3
  1. 1.Departamento de BiologíaUniversidad de La SerenaLa SerenaChile
  2. 2.Sección ZoologíaMuseo Nacional de Historia NaturalSantiagoChile
  3. 3.Departamento de Biología Celular y Genética, Facultad de MedicinaUniversidad de ChileSantiago 7Chile

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