“Characterization of maize and teosinte using the variation in their knobs sequences”

GONZÁLEZ G., FOURASTIÉ M.F. AND POGGIO L.

Maize Genetics Cooperation Newsletter

Maize Genetics Cooperation Newsletter

Lugar: USA; Año: 2009 vol. 83 p. 7 - 7

1090-4573

In maize, the wide variation in nuclear DNA content is mainlycaused by differences in heterochromatin amounts (Tito et al.,Theor. App. Genet. 83:58-64, 1991; Poggio et al., Ann. J. Bot.82:115-117, 1998). Knob heterochromatin of maize and teosintediffers from all other classes of heterochromatin due to its cytologicalappearance and DNA sequence composition (Peacock et al., J.Mol. Evol. 20:341-350, 1981). It is a useful cytological markerbecause it is polymorphic and was found at 22 different positionswithin the maize karyotype (Kato, Mass. Agric. Exp. Stn. Bull.635:1-185, 1976). Knobs consist of thousands to millions of tandem180- and 350-bp (TR-1) repeats which are present in cytologicallydetectable knobs in different proportions relative to oneanother (Ananiev et al., Proc. Natl. Acad. Sci. 95:10785-10790,1998). Maize knob heterochromatin is also visible in interphase ornondividing somatic cells using a simple DAPI-banding method.