AbstractA typical cell cycle is characterized by a growth phase followed by DNA replication and then finally cell division, which produces genetically identical cells. Alternatively, in the process known as endoreduplication, cells grow, and DNA replication occurs, but the cell does not divide. In plants, CDC20 and CCS52 proteins control when a cell undergoes either mitosis or endoreduplication, respectively, via activating the anaphase promoting complex (APC). The APC then targets specific proteins called cyclins for degradation. This research project focuses on a potential third type of APC activator in soybean (Glycine max), Glyma.10G117000.1 or GLYMA10. GLYMA10 shares sequence similarities with CDC20 and CCS52 proteins such as a conserved C- box, MAD2-binding motif, IR tail, RVL motif, and WD40 domain, which indicates that the protein is capable of interacting with the APC, but there are also distinct differences between the proteins. To confirm that GLYMA10 is expressed, polymerase chain reaction (PCR) was used to amplify GLYMA10 from flower cDNA. The PCR product was cloned into a sequencing vector, which was then transformed into E. coli. The plasmid was sequenced confirming that GLYMA10 is expressed in flowers. Quantitative PCR (qPCR) was then used to analyze expression levels of GLYMA10 not only in flowers, but also in apical meristems, trifoliate leaves, unifoliate leaves, stems, roots, seeds, and new and old seed pods. Overall, GLYMA10 was not expressed in trifoliate leaves, unifoliate leaves, roots, or stem tissues and was only very weakly expressed in seeds, flowers and apical meristems. It was, however, very strongly expressed in new and old seed pods, with old seed pods showing the highest expression levels of GLYMA10. In the future, we will continue to study seed pods in an effort to understand the function of this protein.
