Figure 9-33. Karyotypes of the Reeves muntjac (a) and the Indian muntjac (b), two species of small deer that are quite similar but do not interbreed.

Figure 9-33Karyotypes of the Reeves muntjac (a) and the Indian muntjac (b), two species of small deer that are quite similar but do not interbreed

Despite the difference in the number of chromosomes in these animals, the two genomes contain about the same total amount of DNA. (The chromosomes from both deer are shown at the same magnification.) A karyotype is obtained by treating a metaphase cell with a DNA-staining reagent and then “squashing” the cell on a microscope slide. The homologous chromosomes identified in photographs of the specimen are cut out and remounted in pairs. Each number indicates a homologous pair, and the entire set constitutes the karyotype. [Part (a) (left) courtesy of K. W. Fink/Photo Researchers, Inc.; part (b) (left) courtesy of J. P. Ferrero/Jacana/Photo Researchers, Inc.; both karyotype photographs courtesy of R. Church.]

From: Section 9.6, Morphology and Functional Elements of Eukaryotic Chromosomes

Cover of Molecular Cell Biology
Molecular Cell Biology. 4th edition.
Lodish H, Berk A, Zipursky SL, et al.
New York: W. H. Freeman; 2000.
Copyright © 2000, W. H. Freeman and Company.

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