ANALYSIS OF THE CORE HISTONE GENE-CLUSTER OF THE ANNELID PLATYNEREIS-DUMERILII

The arrangement of the polychaete annelid Platynereis dumerilii core h istone gene cluster and nucleotide sequence has been reported (D. Sell os, S. A. Krawetz and C. H. Dixon, 1990). The H2B and H3 mRNAs are tra nscribed from one DNA strand, while the H2A and H4 histone mRNAs are t ranscribed from the other. The H1 gene is not contained as a member of this cluster. Computer assisted sequence analysis of this region was undertaken to define the organization and representation of the variou s sequence motifs embedded within this region. The analysis revealed t hat two large regions on opposite strands of the cluster were similar to one another. This organization is reminiscent of an ancient gene du plication event from which the various members independently evolved.