Conidial anastomosis tubes

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Conidial anastomosis tubes (CATs) are cells formed from the conidia (a type of fungal asexual spores) of many filamentous fungi. These cells have a tubular shape and form an anastomosis (bridge) that allows fusion between conidia.

CATs and germ tubes (germination tubes) are some of the specialized hyphae (long cells formed by filamentous fungal species) that are formed by fungal conidia. CATs are morphologically and physiologically distinct from germ tubes and are under separate genetic control.

Germ tubes, produced during conidial germination, are different from CATs because: CATs are thinner, shorter, lack branches, exhibit determinate growth, and home toward each other.

CAT biology is not completely understood. Initially, conidia are induced to form CATs. Once they are formed, they grow homing toward each other, and eventually they fuse. Once fusion occurs, the respective nuclei can pass through the fused CATs from one conidium to the other. These are events of fungal vegetative growth (asexual reproduction) and not sexual reproduction. Part of the CAT fusion (cell fusion) have been shown to be a coordinated behaviour. [1]

The filamentous fungus Neurospora crassa (a bread mould and fungal model organism) produces CATs from conidia and conidial germ tubes. In contrast, the fungal plant pathogen, Colletotrichum lindemuthianum , only produces CATs from conidia and not from germ tubes.

Fusion between these cells seems to be important for some fungi during early stages of colony establishment. The production of these cells has been suggested to occur in 73 different species of fungi. [2]

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Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defining feature of this fungal group is the "ascus", a microscopic sexual structure in which nonmotile spores, called ascospores, are formed. However, some species of the Ascomycota are asexual, meaning that they do not have a sexual cycle and thus do not form asci or ascospores. Familiar examples of sac fungi include morels, truffles, brewers' and bakers' yeast, dead man's fingers, and cup fungi. The fungal symbionts in the majority of lichens such as Cladonia belong to the Ascomycota.

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<span class="mw-page-title-main">Zygomycota</span> Division or phylum of the kingdom Fungi

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This glossary of mycology is a list of definitions of terms and concepts relevant to mycology, the study of fungi. Terms in common with other fields, if repeated here, generally focus on their mycology-specific meaning. Related terms can be found in glossary of biology and glossary of botany, among others. List of Latin and Greek words commonly used in systematic names and Botanical Latin may also be relevant, although some prefixes and suffixes very common in mycology are repeated here for clarity.

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References

  1. Fleissner, A.; Leeder, A.; Roca M., M.G.; Read, N.D.; Glass, N.L. (2009). Oscillatory recruitment of signaling proteins to the cell tips promotes coordinated behaviour during cell fusion. PNAS. 106(46): 19387–19392.
  2. Roca, M.G., Read, N.D.; Wheals, A. E. (2005). Conidial anastomosis tubes in filamenotus fungi. FEMS Microbiol Lett. 249 (2): 191–198.