Rhizoplast and rootlet system of the flagellar apparatus of Chlamydomonas moewusii.

The ultrastructure of the flagellar apparatus of Chlamydomonas moewusii was examined in detail. Two rhizoplasts were found associated with the basal bodies of this biflagellate and were observed to extend to the central area of the cell. A segment of smooth endoplasmic reticulum ran parallel to each rhizoplast. These 2 segments anastomose beneath the basal bodies and the tubule proceeds over the top of the distal connecting fibre. A functional role for the smooth endoplasmic reticulum in these locations is discussed. Four sets of rootlet microtubules emanate from a region between the 2 basal bodies and the distal connecting fibre. Two sets have a three-over-one arrangement and the other 2 sets are doublets. Cytoplasmic microtubules were seen associated with possible nucleating sites on the rootlet microtubules. The association of the observed structures are discussed and compared to the flagellar apparatus of C. reinhardtii.