What happens to genes in duplicated genomes

摘要

Introductory textbooks tell us that humans (and other metazoa and all our agricultural plants) are diploid. They have two copies of each gene, one from each parent. Comparative genomic studies, however, suggest that we, along with yeast (Saccharomyces cer-evisiae) (1), maize (2, 3), and Arabidop-sis (4), may actually be ancient polyploids (5, 6) in which the chromosome complement doubled at some time in the past and then, through gene silencing, mutation, and loss, reverted to a diploid-like state.