Stage-specific changes in <i>Leishmania</i> growth rates.

<p><b>A</b>. Schematic overview of ²H₂O labeling protocol. Parasite stages were cultivated axenically in the presence 5% ²H₂O, or isolated from infected macrophages or BALB/c lesion incubated or infused with ²H₂O (final concentration 5%). Parasite stages were harvested at multiple time points and extracts containing total DNA/RNA, or total proteins and lipids generated from purified parasite fraction. Levels of deuterium enrichment in constituent dRib/Rib, amino acids and fatty acids were subsequently quantitated by GC-MS. <b>B</b>. Kinetics of ²H-labeling of DNA dRib in cultured promastigotes (Pro^log, Pro^stat) and amastigotes (Ama^axenic), and in amastigotes isolated from macrophages (Ama^Mø) and murine lesions (Ama^lesion). The fraction of new cells (Y-axis) was calculated from the level of ²H-enrichment in dRib relative to maximum labeling observed in each parasite stage after long term (equilibrium) labeling. Calculated doubling times for each stage are shown in inset boxes. <b>C</b>. Comparative growth rates of different <i>Leishmania</i> stages, calculated from ²H-enrichment in dRib. <b>D</b>. Section of stained cutaneous lesion (with detail in insert) and calculated range of parasite numbers/phagolysosome. Abbreviations: dRib; deoxyribose, Rib; ribose.