Phylogenomic analysis provides insights into and gene diversification and floral development of the Asteraceae, supported by genome and transcriptome sequences from dandelion ().

The Asteraceae is the largest angiosperm family with more than 25,000 species. Individual studies have shown that and transcription factors are regulators of the development and symmetry of flowers, contributing to their iconic flower-head (capitulum) and floret. However, a systematic study of and genes across the Asteraceae is lacking. We performed a comparative analysis of genome sequences of 33 angiosperm species including our assembly of diploid sexual dandelion () and 11 other Asteraceae to investigate the lineage-specific evolution of and genes in the Asteraceae. We compared the phylogenomic results of and genes with their expression in floral tissues at different developmental stages to demonstrate the regulation of genes with Asteraceae-specific attributes. Here, we show that and () genes have expanded in the Asteraceae. The phylogenomic analysis identified -like (-like: []-like), -like (3-like), and ()-like copies with lineage-specific genomic contexts in the Asteraceae, Cichorioideae, or dandelion. Different expression patterns of some of these gene copies suggest functional divergence. We also confirm the presence and revisit the evolutionary history of previously named " genes ()." Specifically, we identify non-Asteraceae homologs, indicating a more ancient origin of this gene clade. Syntenic relationships support that is paralogous to () as demonstrated by the shared ancient duplication of and 3.