Linkage mapping of starch branching enzyme III in rice (Oryza sativa L) and prediction of location of orthologous genes in other grasses

The chromosomal position of Starch Branching Enzyme III (SBEIII) was determined via linkage to RFLP markers on an existing molecular map of rice (Oryza sativa L.). A cDNA of 890 bp was generated using specific PCR primers designed from available SBEIII sequence data and used as a probe in Southern analysis. The SBEIII cDNA hybridized to multiple restriction fragments, but these fragments mapped to a single locus on rice chromosome 2, flanked by CD0718 and RG157. The detection of a multiple-copy hybridization pattern suggested the possibility of a tandemly duplicated gene at this locus. The map location of orthologous SEE genes in maize, wheat, and oat were predicted based on previously published genetic studies and comparative maps of the grass family.