CHARACTERIZATION OF HISTONE H2A AND H2B CDNA CLONES ISOLATED FROM A MAIZE OVULE CDNA LIBRARY

A cDNA library was made using RNA from unfertilized maize ovules. Diff erential screening against total RNA from leaf and ovule, resulted in the isolation of several ovule-preferential clones, which were partial ly sequenced. Two clones showed homology to histones H2A and H2B and c omputer alignments of the putative amino acid sequences of these two c lones showed that they represent expressed variants of histones H2A an d H2B. RNA blot analysis, using probes derived from each clone, showed hybridization of both clones to RNA from unfertilized ovules, fertili zed ovules, and root.