Cloning of human U6 small nuclear RNA genes

Vertebrate small nuclear RNA genes are present in multiple copies. The sequence of the 5' flanking region of the human U6 gene in our possession is not highly conserved as is the case for the many "true" U1 and U2 snRNA genes. Therefore, we are screening human genomic DNA in order to isolate other copies of the U6 gene. This task is complicated because U6 pseudogenes outnumber "true" genes, and both are selected by usual hybridization procedures. As we clone other U6 genes we will compare their proximal and distal region sequences, and subject them to comparative transcriptional assays.