These proteins are concentrated along the axis of the chromatid. Only a few key non-histone proteins and protein complexes are required to form the chromosome: topoisomerase IIα, cohesin, condensin I and condensin II, and the chromokinesin KIF4A. It is now well established that each mitotic chromatid consists of a central organizing region containing a so-called “chromosome scaffold” from which loops of DNA project radially.
We also discuss some of the remaining questions.
In this chapter, we start with the early history of chromosome studies and then describe the path that led to our current understanding of the formation and structure of mitotic chromosomes.
Our understanding of the structure and function of mitotic chromosomes has come a long way since these iconic objects were first recognized more than 140 years ago, though many details remain to be elucidated.
