The DNA sequences for 17 plant genes for α-amylase (EC 126.96.36.199) were analyzed to determine their phylogenetic relationship. A phylogeny for these genes was obtained using two separate approaches, one based on molecular clock assumptions and the other based on a comparison of sequence polymorphisms (i.e., small and localized insertions) in the α-amylase genes. These polymorphisms are called "α-amylase signatures" because they are diagnostic of the gene subfamily to which a particular αamylase gene belongs. Results indicate that the cereal α-amylase genes fall into two major classes: AmyA and AmyB. The AmyA class is subdivided into the Amyl and Amy2 subfamilies previously used to classify α-amylase genes in barley and wheat. The AmyB class includes the Amy3 subfamily to which most of the α-amylase genes of rice belong. Using polymerase chain reaction and oligonucleotide primers that flank one of the two signature regions, we show that the AmyA and AmyB gene classes are present in approximately equal amounts in all grass species examined except barley. The AmyB (Amy3 subfamily) genes in the latter case are comparatively underrepresented. Additional evidence suggests that the AmyA genes appeared recently and may be confined to the grass family.
|Original language||English (US)|
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - 1992|
- Polymerase chain reaction
- Signature regions
ASJC Scopus subject areas