Caffeic acid O-methyltransferase allelic polymorphism characterization and analysis in different maize inbred lines

The caffeic acid O-methyltransferase (COMT) gene is a gene candidate forimproving silage maize digestibility. Before assessing possible functionalconsequences of COMT gene polymorphism, the nucleotide sequence variability atthe COMT locus in 6 normal maize inbred lines was characterized and analyzed.Inaddition, the COMT bm3-3 mutation characterization was specified. Even if theCOMT gene seemed to evolve according to the predictions of the neutral model,estimates of nucleotide diversity indicated that polymorphism distributionwithin the sequence was not uniform and that nonsynonymous sites were the leastvariable. Linkage disequilibrium calculation and estimates of recombinationshowed that polymorphism was a dimorphic segregating distribution caused by alot of recombination events.