Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Previous studies of gene diversity in the homeobox superclass have shown that the Florida amphioxus Branchiostoma floridae has undergone remarkably little gene family loss. Here we use a combined BLAST and HMM search strategy to assess the family level diversity of four other transcription factor superclasses: the Paired/Pax genes, Tbx genes, Fox genes and Sox genes. We apply this across genomes from five chordate taxa, including B. floridae and Ciona intestinalis, plus two outgroup taxa. Our results show scattered gene family loss. However, as also found for homeobox genes, B. floridae has retained all ancient Pax, Tbx, Fox and Sox gene families that were present in the common ancestor of living chordates. We conclude that, at least in terms of transcription factor gene complexity, the genome of amphioxus has experienced remarkable stasis compared to the genomes of other chordates.

Original publication




Journal article


Brief Funct Genomics

Publication Date





177 - 186


Animals, Biological Evolution, Chordata, Genetic Variation, Genome, Homeodomain Proteins, Transcription Factors