Centromere-associated repeat arrays on Trypanosoma brucei chromosomes are much more extensive than predicted.
Centromere-associated repeat arrays on Trypanosoma brucei chromosomes are much more extensive than predicted.
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DOI：
10.1186/1471-2164-13-29
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发表时间：
2012-01-18
期刊：
影响因子：
4.4
通讯作者：
Kelly JM
中科院分区：
文献类型：
--
作者：
Echeverry MC;Bot C;Obado SO;Taylor MC;Kelly JM
非洲锥虫属于真核谱系，表现出许多不寻常的遗传特征。人们对这些二倍体原生动物寄生虫的染色体分离机制知之甚少。布氏锥虫的着丝粒已定位于包含一系列约 147 bp 富含 AT 的串联重复序列的染色体区域。基因组测序项目的初步估计表明这些阵列的大小为 2 - 8 kb。在本文中，我们表明着丝粒重复区域要广泛得多。我们使用长程限制性内切核酸酶作图方法来更准确地定义 8 条布氏锥虫染色体上着丝粒重复阵列的大小，其中可以获得明确的组装数据。结果表明，不同染色体上的阵列大小从20到120 kb不等。此外，我们还发现了染色体同源物之间长度异质性的情况。例如，1 号染色体上的阵列值分别为 20 和 65 kb，5 号染色体上的阵列值分别为 50 和 75 kb。我们的结果表明，T. brucei 染色体上的着丝粒重复阵列的大小与高等真核生物的重复阵列的大小比之前怀疑的更为相似。这些信息为研究染色体分离的各个方面提供了更坚实的框架，并将允许更准确地绘制与该过程相关的表观遗传特征。
African trypanosomes belong to a eukaryotic lineage which displays many unusual genetic features. The mechanisms of chromosome segregation in these diploid protozoan parasites are poorly understood. Centromeres in Trypanosoma brucei have been localised to chromosomal regions that contain an array of ~147 bp AT-rich tandem repeats. Initial estimates from the genome sequencing project suggested that these arrays ranged from 2 - 8 kb. In this paper, we show that the centromeric repeat regions are much more extensive. We used a long-range restriction endonuclease mapping approach to more accurately define the sizes of the centromeric repeat arrays on the 8 T. brucei chromosomes where unambiguous assembly data were available. The results indicate that the sizes of the arrays on different chromosomes vary from 20 to 120 kb. In addition, we found instances of length heterogeneity between chromosome homologues. For example, values of 20 and 65 kb were obtained for the arrays on chromosome 1, and 50 and 75 kb for chromosome 5. Our results show that centromeric repeat arrays on T. brucei chromosomes are more similar in size to those of higher eukaryotes than previously suspected. This information provides a firmer framework for investigating aspects of chromosome segregation and will allow epigenetic features associated with the process to be more accurately mapped.
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影响因子：
12.3
作者：
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