Preprint Highlight: Dodecaploid Xenopus longipes provides insight into the emergence of size scaling relationships during development.

Abstract

Although the relationship between genome and cell size is well defined in developed tissues, it remains unclear when in development nuclear-cytoplasmic scaling is established. Here the authors analyzed multiple Xenopus species with varying genome and cell sizes to investigate scaling relationships during development. Imaging of cells, nuclei, and embryos shows that in early development, nuclear size correlates with genome size across species and cell size is predicted by egg size. Mitotic spindle size during cell division was determined by cell size, not genome size. These findings indicate that nuclear-cytoplasmic scaling mechanisms have evolved to support development despite dramatic variations in genome size. This work also suggests that maternal components in the egg drive cell size scaling in early development.