Brief Communication | Published:

Discovery of tetraploidy in a mammal

Naturevolume 401page341 (1999) | Download Citation


The red viscacha rat is unaffected by having double the usual number of chromosomes.


Polyploidy, or having more than a pair of each type of chromosome, is considered to be unlikely in mammals because it would disrupt the mechanism of dosage compensation that normally inactivates one X chromosome in females1. Also, any imbalance in chromosome number should affect the normal developmental processes and therefore constitute an evolutionary end, as in triploid humans2.

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  1. Instituto de Ecología y Evolución, Universidad Austral de Chile, Casilla 567, Valdivia, Chile

    • Milton H. Gallardo
    •  & N. Köhler
  2. Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, Texas, 77843, USA

    • J. W. Bickham
    •  & R. L. Honeycutt
  3. Instituto Argentino de Investigación de Zonas Áridas, Cricyt, GIB Conicet Casilla de Correo 507, 5500, Mendoza, Argentina

    • R. A. Ojeda


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Correspondence to Milton H. Gallardo.

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