Gene duplication in Mimulus underlies parallel floral evolution via independent trans-regulatory changes.

摘要: Summary Identifying the genetic basis of parallelism reveals means by which evolution repeats itself and shows what aspects—if any—may be predictable [1]. The recently tetraploid luteus group Mimulus [2] contains five species native to central Chile [3], three have evolved extensive red floral pigmentation using at least two distinct loci [4]. Here we show that parallel petal lobe anthocyanin (PLA) in M. cupreus M. luteus var. variegatus occurred via separate yet strikingly similar mechanisms. In each case, a dominant, single-locus gain [4] maps genomic region ( pla1 pla2 , respectively) containing adjacent, apparently duplicated paralogs MYB anthocyanin-regulating transcription factors. Interestingly, candidate genes are themselves related an older duplication. In both cases, pla genotype cosegregates with expression multiple biosynthetic pathway, revealing mechanism coordinated trans -regulatory changes across functionally enzyme-encoding genes. We conclude this instance, has repeated marked consistency. Duplication enabled repetition occur physically independent but loci, highlighting importance complexity evolutionary process.