ALTERNATIVE MESSENGER-RNA FORMS AND OPEN READING FRAMES WITHIN AN ADDITIONAL CONSERVED REGION OF THE HUMAN PAX-2 GENE

PAX-2 is a member of a family of genes containing a highly conserved p aired box domain. The paired box domain encodes a DNA binding motif, i ndicating that PAX proteins may function as transcriptional regulators , participating in a hierarchical network of gene regulation during em bryogenesis. In this report, we provide evidence that there is an addi tional conserved region near the predicted COOH-terminus of PAX-2, PAX -5, and PAX-8. We also describe alternative splicing of a conserved 83 -nucleotide segment in the 3' coding sequence of the PAX-2 gene. PAX-2 transcripts that contain the 83-nucleotide insertion encode a putativ e protein with an alternative COOH-terminus. The presence of an additi onal conserved region and alternative splicing within the predicted CO OH-terminal region of several PAX genes has implications for the evolu tionary origins and for the DNA binding site specificity of PAX-2, PAX -5, and PAX-8.