PHYSICAL MAPPING OF POTASSIUM CHANNEL GENE CLUSTERS ON MOUSE CHROMOSOME-3 AND CHROMOSOME-6

Mammalian voltage-gated K channel genes have been divided into four su bfamilies (Shaker, Shab, Shal, and Shaw) based on their sequence ident ity and similarity to related genes in Drosophila. Genetic mapping of the voltage-gated K channel genes has shown that similar multigene clu sters exist on mouse Chr 3 and 6 and suggests that the clusters may ha ve arisen through chromosomal duplication. In this report, YAC-based p hysical maps of the clustered mouse Shaker-like K channel genes have b een constructed using restriction endonuclease and yeast chromosome fr agmentation approaches. These data define the physical spacing as 5'-K cna3-(60 kb)-Kcna2-(90 kb)-Kcna8-3' on Chr 3, and as 5'-Kcna6-(80 kb)- Kcna1-(110 kb)-Kcna5-3' on Chr 6, with all genes oriented in a head-to -tail manner within their respective clusters. These detailed physical maps of both K channel gene clusters provide additional support for t he idea of an ancient genome tetraploidization event. (C) 1997 Academi c Press.