Sphaeroforma arctica
Species of protist
From Wikipedia, the free encyclopedia
Sphaeroforma arctica is a unicellular eukaryote with a pivotal position in the tree of life. It was first isolated from the arctic marine amphipod Gammarus setosus.[2][1] Like other Ichthyosporeans such as Creolimax and Abeoforma, Sphaeroforma arctica are spherical cells characterized with their capacity to grow into multi-nucleated coenocytes (multi-nucleates cell). However, a unique feature of S. arctica, is that no obvious budding, hyphal, amoeboid, sporal or flagellated growth stages have been observed in laboratory growth conditions.
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| Sphaeroforma arctica | |
|---|---|
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| Sphaeroforma arctica stained with phalloidin and DAPI | |
Scientific classification  | |
| Domain: | Eukaryota |
| Clade: | Obazoa |
| Clade: | Opisthokonta |
| Class: | Ichthyosporea |
| Order: | Ichthyophonida |
| Family: | Creolimacidae |
| Genus: | Sphaeroforma |
| Species: | S. arctica |
| Binomial name | |
| Sphaeroforma arctica | |
Taxonomy
Sphaeroforma is a member of the Ichthyosporea clade, which is the earliest branching holozoan lineage. It is a key organism to understand the origin of animals.
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Applications
Sphaeroforma arctica grows easily in marine broth, with the particularity of growing synchronously.[3][4] From a cell with 1 single nucleus (although newborn cells have been shown to contain 2 or even 4 nuclei, too[4]), it can grow to reach a 128 nuclei cell before undergoing cellularization (the process by which the coenocytes split up to give new-born cells). Cellularization involves coordinated inward plasma membrane invaginations dependent on an actomyosin network that leads to the formation of a polarized layer of cells resembling an epithelium. This process is associated with tightly regulated transcriptional activation of genes involved in cell adhesion.[5]
Moreover, it has been recently shown that S. arctica contains miRNA as well as the complex miRNA processing machinery. Taken together, Sphaeroforma arctica is a great model organism from both evolutionary and cell biology perspectives.[6]