Oral Paper

         Pteridology

Genetic Mechanisms of Sex Determination in Ceratopteris richardii

Presenting Author
Katelin Burow
Description
Ceratopteris richardii is an aquatic, homosporous fern that produces both male and hermaphrodite haploid gametophytes. Spores developing on their own will develop into hermaphrodites which produce a pheromone called Ceratopteris antheridiogen (ACE) that is secreted into its surroundings. Spores developing in the presence of ACE will develop as male. Previous work has identified 32 mutants of C. richardii that are defective in their sexual development, making it an ideal model for studying sex determination in plants. Ten of these mutants are hermaphroditic (her) mutants which all produce an identical phenotype that has been mapped to four separate loci. These her mutants are insensitive to the ACE pheromone. To identify the underlying mutations for this phenotype, three mutants were selected for bulk segregation analysis.  Using a SNP analysis, we identified regions of the genome on chromosomes 28 and 29 that are linked to the mutant phenotype. Ongoing work will identify the causal SNP and identify genes involved in the sex determination pathway of C. richardii and plants in general.