Isolation and characterization of a rat amylase gene family.

Portions of at least nine distinct rat amylase genes or pseudogenes have been isolated. Cloned rat genomic DNA fragments containing complete or major portions of seven of these have been examined by heteroduplex analysis and fall within two separate groups based on their degree of homology. Four gene sequences comprising one of these groups are closely related to pancreatic amylase mRNA. The other group shows significant nonhomology to both pancreatic and parotid amylase cDNAs and may represent an additional gene type(s). All of the cloned amylase gene sequences are found in rat genomic DNA. Additional amylase sequences which have not yet been cloned are also detected. Comparison of DNA from individual Sprague-Dawley rats by Southern blotting techniques indicates allelic variation at multiple amylase loci.