Differential subcellular localization of DNA topoisomerase-1 isoforms and their roles during Caenorhabditis elegans development

► TOP-1β is broadly expressed in the nuclei of cells and concentrated in nucleoli. ► TOP-1α is specifically localized to centrosomes, neuronal cells, excretory cells and chromosomes of germ cells. ► TOP-1 proteins are required for chromosomal segregation and germline development in Caenorhabditis elegans.