Deep Insight Section

Eukaryote chromosomes usually condense during mitosis. Chromosome condensation is strictly regulated by cellular elaborated machinery but the details of the mechanism still remains to be elucidated. Occasionally, chromosomes condense at outside of mitosis under several circumstances (Gotoh et al., 1995; Gotoh and Durante, 2006). This phenomenon is known as premature chromosome condensation (PCC) or premature mitosis (PM); the resulted condensed chromosomes are called prematurely condensed chromosomes (PCCs). About a half century ago, the first description of PCC phenomenon was reported by several artisans from 1967 to 1969 by observing the chromosomes in virus infected mammalian cell (Kato and Sandberg, 1967; Kato and Sandberg, 1968). Then, PCC was introduced in cells fused with mitotic cells using fusogenic viruses such as Sendai virus or chemicals such as polyethylene glycol (fusionmediated PCC). Thereafter, PCC has been recognized and utilized as a useful tool for chromosome analysis in wide area of fields, such as radiation biology or chromosome science. The usefulness of PCC technique has been further advanced since the chemical mediated technique of PCC (drug-induced PCC) has been introduced (Gotoh et al., 1995), as the drug-induced PCC method is technically much simpler and easier. Utilized drug-induced PCC has explored much wider area in cytogenetic fields. In this chapter, history of PCC, molecular biological mechanism and application trial for cytogenetic approaches of PCC technique will be briefly summarized. I do not intend to describe the details of PCC but to introduce simply the usefulness of PCC technique in this chapter to many artisans in cytogenetic field.