Massive ribonucleoprotein bodies in gametophyte vegetative cells of the moss Timmiella barbuloides (Brid.) Moenk.

Vegetative cells of the gametophyte phase of the moss Timmiella barbuloides (Pottiales) are characterized by large cytoplasmic bodies of spherical shape (SBs) whose ribonucleoprotein composition is cytochemically demonstrated. SBs seem to be derived from massive aggregation of cytoplasmic ribosomes, with possible participation by rough endoplasmic reticulum elements. SBs have been found in stereids, parenchymatous cells and young hydroids of the gametophyte stem, and in euricysts of the leaf nerve. The SBs develop early in the course of cell differentiation and, once formed, persist until advanced stages of cell senescence. [ABSTRACT FROM AUTHOR]