Scaling relationship between intra-nuclear DNA density and chromosomal condensation in metazoan and plant

Abstract

Across species, eukaryotic chromosomes share common features at the molecular level. However, common features at the cellular level are not well investigated. A correlation has been suggested between the linear packing ratio of mitotic chromosomes and the intra-nuclear DNA density, by comparing these values in the nematode Caenorhabditis elegans. In this study, these values were measured and compared among several metazoan and plant species. The obtained values corroborated the correlation proposed in the previous study, supporting the theory that intra-nuclear DNA density is a common regulator of chromosome condensation. Moreover, the comparison among different species suggested a correlation between the length of a mitotic chromosome and the nuclear volume to the power of 2/3. Given this observation, we speculate that: (i) a rate-limiting component defines the length of a mitotic chromosome that is proportional to the nuclear surface area, and (ii) such regulation of the mitotic chromosomal length may play a role in maintaining the ratio between the cell size and the metaphase plate.