Abstract

The DNA contents of 18 Trypanosoma brucei ssp. stocks were compared using flow cytometry, karyotype analysis and quantitation of repetitive DNA by Southern blotting and hybridisation. The DNA contents of Type I T. b. gambiense stocks were lower than those of non-gambiense stocks, but both groups showed a wide range of variation in DNA content. Amongst T. b. gambiense stocks, Mabia at the lower end of the range had 14% less DNA than Dal 972 at the top of the range. Similarly, amongst non-gambiense stocks, 117R at the lower end of the range had 14% less DNA than LM55 at the top of the range. The T. b. gambiense stock Mabia had 29% less DNA than non-gambiense stock LM55. The DNA content of Type II T. b. gambiense clearly fell within the non-gambiense range. Karyotype analysis showed that all T. b. gambiense stocks had minichromosomes, albeit fewer than non-gambiense stocks. This result was verified by hybridisation with probes for satellite DNA and a telomere-specific repeat. Hybridisation with a probe for the β-tubulin genes also revealed an apparent reduction of gene copy number in T. b. gambiense relative to non-gambiense stocks. In conclusion, there is a wide range of variation in genome size in T. brucei ssp., with T. b. gambiense stocks at the lower end of the range. The reduction in genome size correlates with loss of repeated genes and non-coding sequences in T. b. gambiense stocks, and is not confined to chromosomes of a particular size.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.