Both the DR and the DL extended toward the anterior side of the cell (Figures 7B-D) and supported the flagellar

pocket (Figures 7E-F). The DR occupied the dorsal left side of the flagellar pocket; the DL occupied the dorsal right side of the flagellar pocket and extended from the VR to the DR at the level of the transition zone (Figures 7E-F). A row of linked microtubules (LMt) originated in close association with the DL (above the VR) and supported the right side of the flagellar pocket (Figures 7F, 7H). The DL and LMt extended from the left side of the flagellar pocket to the right side near the posterior boundary of the vestibulum (Figures 8A-E). The LMt supported the inner lining of the vestibulum, turned find more posteriorly along the curve formed by the ventral opening (Figure 3E) and ultimately became the sheet of microtubules located beneath the plasma membrane of the entire cell (Figures 4A, 4C-D). The IR was APO866 supplier positioned between the two basal bodies, originated from the right dorsal side of the VB, and consisted

of four microtubules near the proximal boundary (Figures 7B-C, 7G). The left side of the IR was tightly associated with the IL and two fibrous roots: the DAPT mouse LF and the IF (Figure 7B). The LF extended laterally and was about 500 nm long; the IF extended to the left ventral side of the cell and was about 1.5 μm long (Figures 7B-C). The IL was associated with the left side of the IR along its entire length, and the IR and IL became more closely associated as they extended anteriorly along the left side of the flagellar pocket (Figures 7I-K). The microtubules from the IR eventually merged BCKDHA with the left side of the LMt-DL and likely contributed to the sheet of microtubules located beneath the plasma

membrane of the entire cell (Figures 8A-C). The VR originated from the ventral side of the VB and consisted of nine microtubules that were closely associated with the RF (Figures 7A, 7G). The RF extended toward the right-ventral side of the cell and was about 1 μm long (Figures 7A-C). The microtubules from the VR supported the right side of the flagellar pocket and joined the right side of the LMt and the DL (Figures 7D-F, 7L). The microtubules from the VR ultimately became one of the elements that reinforced the feeding apparatus (Figures 8, 9). Feeding Apparatus The feeding apparatus was positioned on the right side of the flagellar pocket and is described here along the posterior to anterior axis. This apparatus consisted of four main elements or spaces: a feeding pocket, a VR embedded within six electron-dense fibers, a compact “”oblique striated fiber”" (OSF) and a “”congregated globule structure”" (CGS) (Figures 8, 9C). The OSF was approximately 1.5 μm long, 800 nm wide and 500 nm high and was positioned between the feeding apparatus and the right side of the flagellar pocket (Figures 8A, J). The CGS attached to the anterior side of the OSF (Figures 8B-E, 8J).