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Cytological Evidence for Crossing-Over in vitro in Human Lymphoid Cells
New Series, Vol. 144, No. 3616 (Apr. 17, 1964), pp. 298-301
Published by: American Association for the Advancement of Science
Stable URL: http://www.jstor.org/stable/1713346
Page Count: 4
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In human blood cells dividing in vitro two chromosomes are occasionally found intimately associated in a quadriradial configuration (Qr). A Qr by traditional interpretation is the result of chromatid interchange. Since the configurations in blood cells often are equal and symmetrical and are composed of homologous chromosomes, they are considered cytological evidence that somatic crossing-over may occur in mammalian cells.
Science © 1964 American Association for the Advancement of Science