Amoeba proteus and ploidy cycles: From simple model to complex issues

Abstract

This short topical review/opinion paper is inspired by the recent study of Amoeba proteus cell cycle. These obligate agamic amoebae have a special type of cyclic polyploidy - an alternation of unproportional polyploidization and depolyploidization, with the latter provided by chromatin extrusion from the nucleus into the cytoplasm. Here we discuss possible significance and mechanisms of this phenomenon, reconsider similar strategies of life cycles in other unicellular eukaryotes, and debate provocatively the fundamental issues, which could be brought up during its study - from functions of meiotic genes to evolution of sexual process to survival strategy of cancer cells.