|a children's mummer's parade, as on the Fourth of July, with
prizes for the best costumes.| |the offspring of a zebra and a
donkey.| microtubule mi·cro·tu·bule
(mī'krō-t&oomacr;'by&oomacr;l, -ty&oomacr;-) Any of the
proteinaceous cylindrical hollow structures that are distributed
throughout the cytoplasm of eukaryotic cells, providing
structural support and assisting in cellular locomotion and
transport. |microtubule (mī'krō-t'byl) Pronunciation Key Any of
the tube-shaped protein structures that help eukaryotic cells
maintain their shape and assist in forming the cell spindle
during cell division. Microtubules and actin filaments are the
main components of the cell's supporting matrix or cytoskeleton.