Chromosomal heterozygosity of knob-associated sequences in maize inbred line Zi330

Abstract

Two classes of knob-associated sequences, 180-bp repeat unit and TR-1 element, were located on chromosomes of maize (Zea mays) inbred line Zi330 by fluorescence in situ hybridization (FISH). In Zi330, knob-associated sequences were just present in one chromosome 1 but absent in another homologous chromosome 1. And in this line we also observed the positional change of these knob-associated sequences on homologous chromosomes 2, which revealed the inversion of these two knob-associated sequences. This genetic behavior was akin to the characteristic of retroelements. These variations of distribution and heterozygosity were discussed in this paper. © 2012 Springer-Verlag GmbH.