Diversity and dynamics of the minichromosomal karyotype in Trypanosoma brucei.

The genome of African trypanosomes contains a large number of minichromosomes. Their only proposed role is in the expansion of the parasites' repertoire of telomeric variant surface glycoprotein (VSG) genes as minichromosomes carry silent VSG gene copies in telomeric locations. Despite their im...

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Main Authors: Alsford, S, Wickstead, B, Ersfeld, K, Gull, K
Format: Journal article
Language:English
Published: 2001
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author Alsford, S
Wickstead, B
Ersfeld, K
Gull, K
author_facet Alsford, S
Wickstead, B
Ersfeld, K
Gull, K
author_sort Alsford, S
collection OXFORD
description The genome of African trypanosomes contains a large number of minichromosomes. Their only proposed role is in the expansion of the parasites' repertoire of telomeric variant surface glycoprotein (VSG) genes as minichromosomes carry silent VSG gene copies in telomeric locations. Despite their importance as VSG gene donors, little is known about the actual composition of the minichromosomal karyotype and the stability of its inheritance. In this study we show, by using high-resolution pulsed-field electrophoresis, that a non-clonal trypanosome population contains an extremely diverse pattern of minichromosomes, which can be resolved into less complex clone-specific karyotypes by non-selective cloning. We show that the minichromosome patterns of such clones are stable over at least 360 generations. Furthermore, using DNA markers for specific minichromosomes, we demonstrate the mitotic stability of these minichromosomes within the population over a period of more than 5 years. Length variation is observed for an individual minichromosome and is most likely caused by a continuous telomeric growth of approximately 6 bp per telomere per cell division. This steady telomeric growth, counteracted by stochastic large losses of telomeric sequences is the most likely cause of minichromosome karyotype heterogeneity within a population.
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spelling oxford-uuid:e7808f09-7e8a-4186-90d2-b4e4ed949d432022-03-27T10:39:12ZDiversity and dynamics of the minichromosomal karyotype in Trypanosoma brucei.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:e7808f09-7e8a-4186-90d2-b4e4ed949d43EnglishSymplectic Elements at Oxford2001Alsford, SWickstead, BErsfeld, KGull, KThe genome of African trypanosomes contains a large number of minichromosomes. Their only proposed role is in the expansion of the parasites' repertoire of telomeric variant surface glycoprotein (VSG) genes as minichromosomes carry silent VSG gene copies in telomeric locations. Despite their importance as VSG gene donors, little is known about the actual composition of the minichromosomal karyotype and the stability of its inheritance. In this study we show, by using high-resolution pulsed-field electrophoresis, that a non-clonal trypanosome population contains an extremely diverse pattern of minichromosomes, which can be resolved into less complex clone-specific karyotypes by non-selective cloning. We show that the minichromosome patterns of such clones are stable over at least 360 generations. Furthermore, using DNA markers for specific minichromosomes, we demonstrate the mitotic stability of these minichromosomes within the population over a period of more than 5 years. Length variation is observed for an individual minichromosome and is most likely caused by a continuous telomeric growth of approximately 6 bp per telomere per cell division. This steady telomeric growth, counteracted by stochastic large losses of telomeric sequences is the most likely cause of minichromosome karyotype heterogeneity within a population.
spellingShingle Alsford, S
Wickstead, B
Ersfeld, K
Gull, K
Diversity and dynamics of the minichromosomal karyotype in Trypanosoma brucei.
title Diversity and dynamics of the minichromosomal karyotype in Trypanosoma brucei.
title_full Diversity and dynamics of the minichromosomal karyotype in Trypanosoma brucei.
title_fullStr Diversity and dynamics of the minichromosomal karyotype in Trypanosoma brucei.
title_full_unstemmed Diversity and dynamics of the minichromosomal karyotype in Trypanosoma brucei.
title_short Diversity and dynamics of the minichromosomal karyotype in Trypanosoma brucei.
title_sort diversity and dynamics of the minichromosomal karyotype in trypanosoma brucei
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