FPsc: A New, Plant-Based Model System for Integrated Education in Genetic and Genomic Sciences

FPsc (“Fast Plants, self-compatible”) is a self-fertile analog of the self-incompatible Wisconsin Fast Plants (WFP) variety of rapid-cycling Brassica rapa. Like WFP, the FPsc variety progresses rapidly through the plant life cycle, flowering ~18 DAP and yielding mature progeny seeds 7-8 weeks after planting. Unlike the WFP variety, in which heterozygosity exists throughout the genome, FPsc is homozygous at >99% of all loci due to imposition of inbreeding (selfing with single seed descent) during our selective breeding program. We have exploited the properties of self-compatibility and homozygosity in FPsc to create an integrated suite of resources useful for hands-on education in genetic and genomic sciences.

Mutagenesis screens were used to identify a collection of both dominant and recessive FPsc mutant alleles whose phenotypes are engaging and clear. Concurrently, our students developed a complementary collection of PCR-based genetic marker assays that have been used to map and then sequence candidate FPsc loci to identify causative mutations. Genomic resources based on the FPsc model system will be described, including a de novo genome sequence assembly, RNA-Seq datasets obtained by study of several FPsc mutants, and Advanced Intercross RIL populations with proven utility to map QTL that condition quantitative traits in B. rapa.

This student-friendly suite of resources allows educators to realize the Holy Grail of genetics education: To enable students to connect observable phenotypic differences with the underlying, DNA sequence-based, genotypes.