• Introduction
• Background
• The team
• The barley collection
• Starch characterisation
• Gene discovery
• Fast-track barley breeding
• Our approach in wheat
• Contacts and funding

Gene discovery

We are using several different methods (summarised below) to discover the genes responsible for the interesting starch characteristics in our barley mutants. First we undertake rough mapping to find the chromosome and the chromosome arm on which the gene is located (the genetic map location). We can then use:

• Barley genome sequence. The full sequence is not yet available but the location of some of the genes involved in starch synthesis is known. We can therefore discover whether there are known starch genes in the same region as our mutant gene.
• Comparative genomics. To discover what genes may lie in our region of interest in the barley genome, we can compare the co-linearity of barley genes in the region with their orthologues in grasses with a full genome sequence (rice, Brachypodium, sorghum).
• Fine mapping. We can use the comparative genomics information to design gene-based markers for further mapping to obtain a more precise position for the mutant gene. This allows us to identify a region of ~100 genes likely to include our gene of interest.
• Candidate gene approaches. Using the above approaches, we may be able to identify a known starch gene in the region containing our mutant gene. If so, we can sequence this candidate gene in our mutant to see whether it contains a mutation.
• Transcript analysis. We can compare the transcriptomes of normal and mutant barley to identify whether any transcripts are missing in the mutant, and if so whether the genes fall within the map position defined for the mutation.