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Table 1 Variation in rates of apoptosis and temporal patterns observed in malaria parasites.

From: Investigating the evolution of apoptosis in malaria parasites: the importance of ecology

Species Life cycle stage ref condition Marker Detection method Proportion positive
P. berghei ookinetes   In vitro Condensed chromatin Acridine orange (Sigma) 18 hrs - 15.5 (±1.06)%
       18 hrs - 34.5 (±1.76)%
   [83] in PBS suspension    22 hrs - 55.8 (±13.68)%
       26 hrs - 49.01 (±5.51)%
     Fragmented DNA TUNEL (histochemical, Calbiochem, UK) 18 hrs - 48.55 (±6.01)%
    or    22 hrs - 64.19 (±6.09)%
       26 hrs - 69.89 (±2.81)%
    In RPMI Caspase-like activity CaspaTag (Chemicon international, USA) 18 hrs - 17.0 (±2.12)
       18 hrs - 30.15 (±2.14)%
       22 hrs - 43.8 (±1.53)%
       18 hrs - 47.72(±3.93)%
     Translocation of phosphatidylserine Annexin V- FITC apoptosis detection kit (Sigma, UK) 18 hrs - 19.57 (±1.88)%
       22 hrs - 28.33 (±5.61)%
       26 hrs - 30.12 (±2.75)%
     Mitochondrial membrane potential JC-1 assay kit (Molecular Probes, UK) 18 hrs - 34.38 (±2.95)%
  ookinetes [24] In vitro In RPMI Condensed chromatin Acridine orange (Sigma) 24 hrs - 31%
       36 hrs - 80%
  ookinetes & zygotes mix   In vivo Condensed chromatin Acridine orange (Sigma) 18, 20 & 24 hrs - all over 60%
  ookinetes [77] In vitro Translocation of phosphatidylserine Annexin-FITC Apoptosis Detection Kit (Sigma, UK) <3% (assay time not reported)
     Fragmented DNA ApopTag® Fluorescein In Situ Apoptosis Detection Kit (Chemicon International) No positive cells observed (assay time not reported)
     Condensed chromatin Acridine orange (Sigma) No positive cells observed (assay time not reported)
     Caspase-like activity CaspaTag (Chemicon international, USA) 21 hrs - 3.8 (±0.05)%
       24 hrs - 14 (±9.00)%
  ookinetes * In vitro In RPMI Caspase-like activity CaspaTag (Chemicon international, USA) 15 hrs - 13.70 (±12.20)%
       18 hrs - 13.06 (±6.42)%
       21 hrs - 45.90 (±11.00)%
       24 hrs - 67.94 (±4.83)%
  ookinetes   In vitro In RPMI Fragmented DNA In situ cell death detection kit, Flourescein (Roche) 15 hrs - 9.38 (±4.44)%
       18 hrs - 14.57 (±3.29)%
       21 hrs - 22.08(±8.96)%
       24 hrs - 9.24 (±3.09)%
  ookinetes $ In vitro In RPMI Caspase-like activity CaspaTag (Chemicon international, USA) 18 hrs - 20.06 (±3.50)%
P. yoellii ookinetes * In vitro In RPMI Caspase-like activity CaspaTag (Chemicon international, USA) 15 hrs - No positive cells observed
       18 hrs - 4.85 (±1.40)%
       21 hrs - 62.8 (±11.10)%
       24 hrs - 92.59 (±7.41)%
  ookinetes   In vitro In RPMI Fragmented DNA In situ cell death detection kit, Flourescein (Roche) 15 hrs - 7.29 (±3.84)%
       18 hrs - 7.41 (±4.90)%
       21 hrs - 6.09 (±2.92)%
       24 hrs - 9.70 (±0.36)%
P. falciparum ookinete [25] In vivo Fragmented DNA TUNEL (histochemical, Calbiochem, UK) 24 hrs - 67.8 (±2.82)%
  Asexual blood stages (trophozoites & schizonts) [23] In vivo after treatment with chloroquine Loss of mitochondrial transmembrane potential Carbocyanine dye JC-1 Timings and proportions positive not reported
     Fragmented DNA TUNEL (fluorescent, Roche)  
   [26] In vivo after treatment with chloroquine DNA laddering After electrophoresis, Southern blotting and autoradiography, a ladder pattern observed Timings and proportions positive not reported
P. falciparum Asexual blood stages [38] In vivo after treatment with chloroquine (CQ) or staurosporine (ST) Loss of mitochondrial transmembrane potential Cell-permeable lipophillic cation probe JC-1 (Molecular probes, Eugene, USA) 10% in untreated cultures increased to 31% (CQ) and 25% (ST)
     Caspase-like activity CaspaTag (Chemicon international, USA) 10% in untreated cultures increased to 34% (CQ) and 32% (ST)
     Fragmented DNA ApoDirect DNA fragmentation assay kit (Clontech, San Diego, USA) 10% in untreated cultures increased to 27% (CQ) and 56% (ST)
  1. Results organised by life-cycle stage and study. Although the majority of studies summarised here have focused on the ookinete parasite stage, there is still considerable variation in the proportion of cells judged to be apoptotic. This variation may be due to differences in experimental set up between labs, e.g. the nutrients available to parasites and the densities of cultures. Assays of apoptosis may also vary at specific time points in the proportions of positive cells depending on the time scale of the processes being assayed. When parasites are assayed over a time course there is a general trend for an increase in positive cells with time. * Pollitt et al. reported here (figure 2) $ Pollitt et al. reported here (figures 4 & 5)