Posted by: Footler PJ19 FEB 2014
The amoeba Dictyostelium discoideum lives in the forest litter of temperate regions. It has a curious life cycle. As a single cell it feeds on bacteria and divides by splitting into two daughter cells. But if food is insufficient the cells aggregate to form a fruiting body of about 50,000 cells. This latter form gives the organism its other name, the social amoeba.
D discoideum can also be grown in the laboratory using a bacterial lawn as a food source.
D discoideum has proved to be an ideal model organism for studying a range of biomedical systems such as phagocytosis, signal transduction, chemotaxis, cellular differentiation, cell motility and cytokinesis.
The organism has helped us understand how drugs function on a molecular level and to identify genes controlling the action of medical treatments. Researchers have used its genetics for studies as varied as myosin mutations that cause cardiac myopathies, resistance to cisplatin used in chemotherapy and the mechanism of action of lithium.
Researchers at Royal Holloway, University of London, and the Institute of Psychiatry, King’s College London, are using D discoideum to study the cellular role of specific proteins. For example, mutations in presenilin proteins are carried by patients with inherited forms of Alzheimer’s disease and may play a major role in the age-related onset of the condition.
Understanding the role of these proteins has proved difficult since deletion of the proteins in experimental animal cells causes a loss of viability and blocks development. Using D discoideum allows researchers to better understand the roles of proteins and genes involved in Alzheimer’s disease and other forms of neurodegeneration without the need for such animal cell tests.
It is fascinating that so simple an organism lends itself to the study of such a complex disease.