Dictyostelium discoideum
The social amoeba Dictyostelium discoideum is increasingly being used as a simple model for the investigation of problems that are relevant to human health:
analysis of immune-cell disease and chemotaxis
centrosomal abnormalities and lissencephaly
bacterial intracellular pathogenesis
mechanisms of neuroprotective and anti-cancer drug action
A multicellular model
Dictyostelium discoideum grow unicellularly, but develop as multicellular organisms. At two stages of development, their underlying symmetrical pattern of cellular organization becomes disrupted.
During starvation-induced Dictyostelium development, up to several hundred thousand amoeboid cells aggregate, differentiate and form a fruiting body.
The chemotactic movement of the cells is guided by the rising phase of the outward propagating cAMP waves and results in directed periodic movement towards the aggregation centre.
In the mound and slug stages of development, cAMP waves continue to play a major role in the coordination of cell movement, cell-type-specific gene expression and morphogenesis; however, in these stages where cells are tightly packed, cell-cell adhesion/contact-dependent signalling mechanisms also play important roles in these processes.
Videos
Dictyostelium chemotaxis
References
Williams RS, Boeckeler K, Graf R, Muller-Taubenberger A, Li Z, Isberg RR, Wessels D, Soll DR, Alexander H, Alexander S. Towards a molecular understanding of human diseases using Dictyostelium discoideum. Trends Mol Med. 2006 Sep;12(9):415-24. PMID: 16890490
Williams JG, Noegel AA, Eichinger L. Manifestations of multicellularity: Dictyostelium reports in. Trends Genet. 2005 Jul;21(7):392-8. PMID: 15975432
Bozzaro S, Fisher PR, Loomis W, Satir P, Segall JE. Guenther Gerisch and Dictyostelium, the microbial model for ameboid motility and multicellular morphogenesis. Trends Cell Biol. 2004 Oct;14(10):585-8. PMID: 15450981
Kimmel AR, Firtel RA. Breaking symmetries: regulation of Dictyostelium development through chemoattractant and morphogen signal-response. Curr Opin Genet Dev. 2004 Oct;14(5):540-9. PMID: 15380246
Weijer CJ. Dictyostelium morphogenesis. Curr Opin Genet Dev. 2004 Aug;14(4):392-8. PMID: 15261655