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 are morphologically and physiologically distinct from germ tubes and are under separate genetic control.
[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.