part of part of axonemal microtubule axonemal central pair C2 axonemal microtubule krc GO:1990720 2015-03-27T22:58:40Z C2 tubule One of two microtubules present in the axonemal central pair. It is distinguishable from the C1 axonemal microtubule (also called C1 tubule) by the presence of differing protein components of the projections. cellular_component