DNA synthesis in malaria parasites during sexual and erythrocytic asexual development : proefschrift ... / door Christoffel Jan Janse.

  • Janse, Chris J.
Date:
1987
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Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: DNA synthesis in malaria parasites during sexual and erythrocytic asexual development : proefschrift ... / door Christoffel Jan Janse. Source: Wellcome Collection.

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    6 during gamete formation, fertilization and zygote development (chapter VII, VIII, X). Besides microscopic microfluorometry of individual cells on slides, cell by cell measurements of DNA contents can also be performed by flow cytometry, a simple and rapid method if cells can be obtained in sufficient number. Results of DNA measurements in malaria parasites, obtained with this method, are shown in chapter XI. 2. The DNA of malaria parasites Genome size The total amount of DNA of the haploid genome, expressed in picograms (pg) or in base pairs ''bp), is a characteristic of each living species, known as genome size, genome complexity or С-value. Table 1 shows estimates of genome sizes of different Plasmodium species. The estimates vary widely, even for a single species, and range from 1 x 10^ to 3.8 X 10^ bp. 7 The genome size of 2.5 x 10 bp, established for berghei by comparison of sporozoites with human chromosome 21 using highly standardized meth¬ ods, is probably the most accurate estimation (CorneLissen et al., 1984). It is about 6 times the genome size of Escherichia coli, twice that of yeast, and less than one hundredth of the human haploid genome. Base composition of DNA Base composition of the nuclear DNA differs between the various mammalian parasites. The guanine - cytosine (G+C) content of falciparum (Goman et al., 1982; Pollack et ^., 1982; McCutchan et al., 1984; WilUamson et al., 1985), P^ berghei, P. vinckei and P^ chabaudi (McCutchan et al., 1984) has been reported to be around 18% which is considerably lower than the G+C content of host DNA (37%). The slightly higher values (23-24%) for P^ berghei and P^ vinckei found in earlier investigations (Gutteridge