Micrurgical Studies with Large Free-Living Amebas

Abstract

Publisher Summary This chapter discusses the results of micrurgical studies on large, free-living amebas and describes the usefulness of the amebas as a model system for further micrurgical studies. The diverse experiments show that the micrurgical methods of transferring nuclei and cytoplasm have been effectively used in the studies of cells. These studies have joined with those using other methods in demonstrating the importance of the nuclear role both in simple cell activity, such as movement and in complicated cell functions including reproduction and inheritance. One of the valuable contributions of the nuclear transfer studies has been the direct demonstration of nuclear–cytoplasmic interactions at the macromolecular level. One interesting aspect of the nuclear–cytoplasmic interactions is the relation between heterologous nuclei and cytoplasm cells exhibit normal activities, such as phagocytosis, digestion of ingested food, growth, and cell division for several days before they decline and die. These functions are absent in anucleate amebas. In the case of a nuclear–cytoplasmic hybrid cell, the original cytoplasm is diluted by a factor of 2n as the cell multiplies, n being the number of cell divisions. Amebas have been shown to have DNA- and RNA-containing cytoplasmic particles that are capable of synthesizing nucleic acids and of reproducing cytoplasm.