Lipids in the classification of Nocardioides: Reclassification of Arthrobacter simplex (Jensen) lochhead in the genus Nocardioides (Prauser) emend. O'Donnell et al. as Nocardioides simplex comb. nov.

The tubulin proteins of Blastocladiella emersonii have been characterized, and the pool sizes of soluble tubulins measured to evaluate turnover during early development. The axonemal tubulins and soluble tubulin dimers were typical of tubulin proteins from other eukaryotes.³H]cholchicine binding assays were used to estimate the soluble tubulin pools of zoospores and during early development. The free colchicine-binding pool of tubulin in zoospores represents 1% of the soluble protein. It increases by 49% after encystment (at 30 min), decreases to 21% below the spore level by 50 min, and then increases slowly with growth. Neither deflagellation of zoospores prior to encystment, nor inhibition of axonemal disassembly, alter the postencystment pool increases. Disassembly of cytoskeletal microtubules occurs in either circumstance, but can account for only 54% of the pool increase. It was concluded that (1) the retracted axonemal tubulins are not returned to the soluble pool detected by cholchicine binding and are probably degraded; (2) new microtubules are supplied by the preexisting cytoplasmic pool that expands from disassembly of cytoplasmic microtubules; and (3) that the tubulins of the axonemes and soluble pools may be distinct.