TABLE 1:
Comparison of flagellar phenotypes in Chlamydomonas retrograde motor mutant strains.
| Strain | DHC1b (%) | Percentage aflagellate | Flagellar length (% WT) | Swimming velocity (% WT) | Phototaxis | Gliding | Mating | IFT velocity (%) (A, R) | IFT frequency (%) (A, R) |
|---|---|---|---|---|---|---|---|---|---|
| WT | 100 | ∼5 | 100 | 100 | Normal | Normal | WT | 100, 100 | 100, 100 |
| DHC1b related | |||||||||
| dhc1b-2 (ts) | ND | 35 | 86 | ND | ND | ND | ND | 150, 68 | 49, 12 |
| dhc1b-3 (ts) | |||||||||
| 21°C | 52 | ∼12 | 100 | 100 | Normal | ND | WT | 100, 75 | 94, 75 |
| 34°C | ND | ∼15 (12–30 h) | 100 (12–30 h) | 50 (12 h) | Change in sign | Reduced | ND | 90, 48 (6 h) | 63, 35 (6 h) |
| ∼55 (36 h) | 95 (36 h) | 89, 40 (12 h) | 58, 20 (12 h) | ||||||
| fla24 (ts) | |||||||||
| 21°C | 86 | ∼35 | 100 | 100 | Normal | ND | WT | 99, 40 | 83, 46 |
| 32°C | ND | ∼95 (5 h) | ∼22 (3.5 h) | ND | Normal (6 h) | ND | ND | ND | ND |
| D1bLIC related | |||||||||
| d1blic mt+ | 13 | ∼30 | ∼14 | Immotile | NA | ND | ND | 105, 47 | 65, 24 |
| d1blic mt− | 13 | ∼30 | ∼22 | 50 | ND | ND | ND | ND | ND |
| RNAi-B | 54 | ∼5 | ∼91 | 100 | Normal | Reduced | WT | 100, 72 | 80, 72 |
| RNAi-A | 23 | ∼11 | ∼49 | 50 | Reduced | NA | Reduced | 85, 44 | 50, 20 |
| LC related | |||||||||
| fla14-1 | ND | ND | 36 | Immotile | NA | ND | ND | 99, 57 | 74, 17 |
| tctex2b | 40–60 | ND | 100 | 70 | ND | ND | ND | 95, ∼50 | 84, <25 |
A, anterograde; R, retrograde. NA, not applicable; ND, not described.
The data used to calculate the values in this table were taken from the following references: dhc1b-2 (Lechtreck et al., 2013a); dhc1b-3 (Engel et al., 2012; Shih et al., 2013); fla24 (Iomini et al., 2001; Lin et al., 2013; this study); d1blic mt+ (T8D9 or TBD9) and d1blic mt− (YH43) (Hou et al., 2004; this study); RNAi-A and RNAi-B (this study); fla14-1 (Pazour et al., 1998; Yang et al., 2009; this study); and tctex2b (Dibella et al., 2004; Schmidts et al., 2015). Flagella of dhc1b-null strains (stf1-1, stf1-2, dhc1b-1) were too short (<1–2 mm) for most assays (Porter et al., 1999; Pazour et al., 1999). The relative concentration of DHC1b present in cell extracts was determined by Western blots as shown in Figure 1A. Samples with ≥30% aflagellate cells are highlighted in bold, as are samples whose flagellar lengths are <50% of WT length. Phototaxis was measured by monitoring photoaccumulation in dishes. Mating tests were performed the absence of added 3-isobutyl-1-methylxanthine (IBMX) or papaverine and dibutyryl-cAMP. Changes in anterograde and retrograde IFT >50% are highlighted in bold. Most mutations had a greater effect on retrograde IFT frequency than retrograde IFT velocity, but reducing retrograde frequency by 50% had only minor effects on flagellar length or assembly. However, larger reductions in retrograde IFT typically resulted in shorter flagella and/or more aflagellate cells.