Sex determination gene discovery in the fern Ceratopteris richardii

The fern Ceratopteris richardii (Ceratopteris) is a model species for studying sex determination, a vital developmental process in both plants and animals. In Ceratopteris, haploid gametophytes develop as either hermaphrodites or males. Sex type is determined by an as yet unidentified pheromone, antheridiogen (ACE), which is secreted by hermaphrodites and promotes male development in sexually undetermined gametophytes. In the late 20th century, Ceratopteris mutants in at least nine genes were isolated that have altered sex determination. However, the genes responsible for these mutant phenotypes remain unidentified. The recent release of a high-quality reference assembly of the Ceratopteris genome makes the molecular identification of sex-determining genes possible for the first time. Our goal in this project is to identify mutant genes responsible for sex determination in Ceratopteris.