| Phycomyces blakesleeanus | |
|---|---|
| Phycomyces blakesleeanus zygosporangia | |
| Scientific classification | |
| Kingdom: | Fungi |
| Order: | Mucorales |
| Family: | Phycomycetaceae |
| Genus: | Phycomyces |
| Species: | P. blakesleeanus |
| Binomial name | |
| Phycomyces blakesleeanus Burgeff, 1925 |
|
Phycomyces blakesleeanus (Algal fungi) is a filamentous fungus in the Order Mucorales of the phylum Zygomycota or subphylum Mucormycotina. The spore-bearing sporangiophores of Phycomyces are very sensitive to different environmental signals including light, gravity, wind, chemicals and adjacent objects. They exhibit phototropic growth, and most Phycomyces research has focused on sporangiophore photobiology, such as phototropism and photomecism ('light growth response'). Metabolic, developmental, and photoresponse mutants have been isolated, some of which have been genetically mapped. At least ten different genes (named madA through to madJ) are required for phototropism. The madA gene encodes a protein related to the White Collar 1 class of photoreceptors that are present in other fungi, while madB encodes a protein related to the White Collar 2 protein that physically bind to White collar 1 to participate in the responses to light [1].
Phycomyces also exhibits an avoidance response, in which the growing sporangiophore avoids solid objects in its path, bending away from them and then continuing to grow upward again. This is believed to result from an unidentified "avoidance gas" that is emitted by the growing zone of the sporangiophore. This gas would concentrate in the airspace between the Phycomyces and the object. This higher concentration would be detected by the side of the sporangiophore's growing zone, which would grow faster, causing the sporangiophore to bend away.
Phycomyces blakesleeanus became the primary organism of research by the Nobel laureate Max Delbrück starting in the 1950s, when Delbrück decide to switch from research on bacteriophage and bacteria to P. blakesleeanus.