Gene duplication and dosage effects during the early emergence of C4 photosynthesis in the grass genus Alloteropsis.

摘要: The importance of gene duplication for evolutionary diversification has been mainly discussed in terms genetic redundancy allowing neofunctionalization. In the case C4 photosynthesis, which evolved via co-option multiple enzymes to boost carbon fixation tropical conditions, not consistently supported by genomic studies. Here, we test a different role early evolution dosage effects creating rapid step changes expression levels. Using genome-wide data accessions grass genus Alloteropsis that recently diversified into photosynthetic types, estimate copy numbers and demonstrate recurrent duplications two important families genes coincided with increases transcript abundance along phylogeny, some cases pure effect. While increased number during initial emergence photosynthesis probably offered route enhanced expression, also find losses duplicates following acquisition encoding better-suited isoforms. effect might therefore act as transient process biochemistry, rendered obsolete regulatory mutations increasing