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The fine structure of trypanosomes after preservation by freezing
182
TRYPANOSOMIASIS SEMINAR
panosome from antibody. We envisage that the continuous production of filopodia, which in aggregates have a very large surface area (one filopodium has a surface area equivalent to 39% of the surface area of the trypanosome (WRIGHT, LUMSDEN and HALES, in press)) will carry away any attached antibody (escalator fashion) from the body of the trypanosome. Thus the trypanosome escapes a build-up of antibody molecules to the critical point at which they are sufficient to destroy it. REFERENCES
NJOGU, A. R. (1966). The nature of variable antigens of and antigenic variations in brucei subgroup (Trypanozoon) trypanosomes, llth meeting of I.S.C.T.R. WRIGHT, K. A. & LUMSDEN, W. H. R. (1969). Trans. R. Soc. trop. Med. Hyg., 63, 13. --, - & HALES, H. (In Press). The Formation of filopodium-like processes • by Trypanosoma (Trypanozoon) brucei. J. Cell. Sci.
The fine structure o f t r y p a n o s o m e s after preservation by freezing
R. F. MACADAM AND W. J. HERBERT Trypanosomes can be effectively preserved, at very low temperatures, by several methods (POLGE and SOLTYS, 1957; CUmqlNGHAM et al., 1963; HERBERT, et al., 1968). When such specimens are thawed their motility is regained immediately. However, their infectivity appears to be low at first and does not rise to a maximum until about 30 minutes later (LuMSDEN, GITATHAand LUTZ, 1968). We have carried out an electron microscopic examination of Trypanosoma (Trypanozoon) brucei stabilate T R E U 370, immediately after thawing, to see if the fine structure of the trypanosome had been disturbed by the preservation process, and whether any cytopathology could be detected which could account for the low immediate-post-thawing infectivity. So far, our results show that the fine structure is abnormal in only one respect, rig., there is gross dilatation of the mitochondrial envelope of the DNA core of the kinetoplast. Sequential studies, at multiple time intervals after thawing, are now being carried out to see if this abnormality resolves as the infective capacity of the trypanosomes increases.
CUNNINGHAM, M.
P.,
REFERENCES LUMSDEN, W. H. R. • WEBBER, W. A. F.
(1963). Exp. Parasit.,
14, 280. H~RBERT, W. J., LUMSDEN,W. H. R. & McK. FRENCH, A. (1968). Trans. R. Soc. trop. ivied. Hyg., 62, 209.. LUMSDEN, W. H. R., GITATI-~, S. K. & LUTZ, W. (1968). J. Protozool., 15, 129. POLGE, C., & SOLTYS,M. A. (1957). Trans. R. Soc. trop. _iVied. Hyg., 51, 519.
Studies on the biology o f t r y p a n o s o m e s with special reference to their surface properties
D. G. GODFREY, ANGELA E. R. TAYLOR AND SHEILA M. LANHAM Summary of recent and current research at the Lister Institute, September 1969 Surface charge : Trypanosoma percae was successfully concentrated from perch blood on DEAE-cellulose columns. The buffer of high ionic strength required to elute this highly negatively charged trypanosome also eluted some erythrocytes.
TRYPANOSOMIASIS SEMINAR
panosome from antibody. We envisage that the continuous production of filopodia, which in aggregates have a very large surface area (one filopodium has a surface area equivalent to 39% of the surface area of the trypanosome (WRIGHT, LUMSDEN and HALES, in press)) will carry away any attached antibody (escalator fashion) from the body of the trypanosome. Thus the trypanosome escapes a build-up of antibody molecules to the critical point at which they are sufficient to destroy it. REFERENCES
NJOGU, A. R. (1966). The nature of variable antigens of and antigenic variations in brucei subgroup (Trypanozoon) trypanosomes, llth meeting of I.S.C.T.R. WRIGHT, K. A. & LUMSDEN, W. H. R. (1969). Trans. R. Soc. trop. Med. Hyg., 63, 13. --, - & HALES, H. (In Press). The Formation of filopodium-like processes • by Trypanosoma (Trypanozoon) brucei. J. Cell. Sci.
The fine structure o f t r y p a n o s o m e s after preservation by freezing
R. F. MACADAM AND W. J. HERBERT Trypanosomes can be effectively preserved, at very low temperatures, by several methods (POLGE and SOLTYS, 1957; CUmqlNGHAM et al., 1963; HERBERT, et al., 1968). When such specimens are thawed their motility is regained immediately. However, their infectivity appears to be low at first and does not rise to a maximum until about 30 minutes later (LuMSDEN, GITATHAand LUTZ, 1968). We have carried out an electron microscopic examination of Trypanosoma (Trypanozoon) brucei stabilate T R E U 370, immediately after thawing, to see if the fine structure of the trypanosome had been disturbed by the preservation process, and whether any cytopathology could be detected which could account for the low immediate-post-thawing infectivity. So far, our results show that the fine structure is abnormal in only one respect, rig., there is gross dilatation of the mitochondrial envelope of the DNA core of the kinetoplast. Sequential studies, at multiple time intervals after thawing, are now being carried out to see if this abnormality resolves as the infective capacity of the trypanosomes increases.
CUNNINGHAM, M.
P.,
REFERENCES LUMSDEN, W. H. R. • WEBBER, W. A. F.
(1963). Exp. Parasit.,
14, 280. H~RBERT, W. J., LUMSDEN,W. H. R. & McK. FRENCH, A. (1968). Trans. R. Soc. trop. ivied. Hyg., 62, 209.. LUMSDEN, W. H. R., GITATI-~, S. K. & LUTZ, W. (1968). J. Protozool., 15, 129. POLGE, C., & SOLTYS,M. A. (1957). Trans. R. Soc. trop. _iVied. Hyg., 51, 519.
Studies on the biology o f t r y p a n o s o m e s with special reference to their surface properties
D. G. GODFREY, ANGELA E. R. TAYLOR AND SHEILA M. LANHAM Summary of recent and current research at the Lister Institute, September 1969 Surface charge : Trypanosoma percae was successfully concentrated from perch blood on DEAE-cellulose columns. The buffer of high ionic strength required to elute this highly negatively charged trypanosome also eluted some erythrocytes.