Dictyostelium

Dictyostelium
Dictyostelium fruiting bodies
Scientific classification
Domain:	Eukaryota
Phylum:	Amoebozoa
Class:	Dictyostelia
Order:	Dictyosteliida
Family:	Dictyosteliidae
Genus:	Dictyostelium Bref.
Type species
Dictyostelium mucoroides Brefeld 1869
Synonyms
Heterosphondylium Traub 1977 nom. nud. non Nägeli 1862 Hyalostilbum Oudemans 1885

Dictyostelium is a genus of single- and multi-celled eukaryotic, phagotrophic bacterivores. Though they are Protista and in no way fungal, they traditionally are known as "slime molds". They are present in most terrestrial ecosystems as a normal and often abundant component of the soil microflora, and play an important role in the maintenance of balanced bacterial populations in soils.^[1][2]

The genus Dictyostelium is in the order Dictyosteliida, the so-called cellular slime molds or social amoebae. In turn the order is in the infraphylum Mycetozoa. Members of the order are Protista of great theoretical interest in biology because they have aspects of both unicellularity and multicellularity. The individual cells in their independent phase are common on organic detritus or in damp soils and caves. In this phase they are amoebae. Typically, the amoebal cells grow separately and wander independently, feeding mainly on bacteria. However, they interact to form multi-cellular structures following starvation. Groups of up to about 100,000 cells signal each other by releasing chemoattractants such as cyclic AMP (cAMP) or glorin. They then coalesce by chemotaxis to form an aggregate that becomes surrounded by an extracellular matrix. The aggregate forms a fruiting body, with cells differentiating individually into different components of the final structure.^[3] In some species, the whole aggregate may move collectively – forming a structure known as a grex or "slug" – before finally forming a fruiting body. Basic processes of development such as differential cell sorting, pattern formation, stimulus-induced gene expression, and cell-type regulation are common to Dictyostelium and metazoans. For further detail see family Dictyostelid.