A model plant, Arabidopsis thaliana, duplicates its chromosomes without undergoing cellular division, in a process known as endoreplication. The primary objective of this study was to identify genes and proteins that specifically accumulate in endoreplicated nuclei in Arabidopsis thaliana. The secondary objective was to identify the biological function of unique domains found in Arabidopsis topoisomerase VI subunit B (AtTopVIB) that contributes to endoreplication. Using the AtTopVIB amino acid sequence and protein database search engine, I identified two unique domains to which I designated...