Identification of a DNA fragment that increases mitotic stability of episomal linear DNAs in Leishmania major
Identification of a DNA fragment that increases mitotic stability of episomal linear DNAs in Leishmania major
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DOI：
10.1016/j.ijpara.2005.04.004
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发表时间：
2005-08-01
影响因子：
4
通讯作者：
Cruz, AK
中科院分区：
文献类型：
--
作者：
Casagrande, L;Ruiz, JC;Cruz, AK
着丝粒是真核生物染色体的一个特化区域，是有丝分裂和减数分裂过程中着丝粒形成、纺锤体附着和染色体分离调节的场所。为了鉴定在硕大利什曼原虫中增加有丝分裂稳定性和/或充当潜在着丝粒的序列，我们首先产生了带有随机选择的基因组DNA的30 kb插入物的利什曼原虫线性人工染色体（拉克）文库。将其引入寄生虫中，然后在不存在选择压力的情况下生长10代后评估其稳定性。108个被测转染子中约80%迅速失去了它们的拉克，只有20%的重组子被保留下来;其中6个表现出很强但部分的稳定性（在30-46%的细胞中保持）。一个克隆（cSC 10）的定位和测序（其赋予最高程度的维持）揭示了在另一个稳定附加体中发现的序列的存在，并且该序列分散在L.少校这些数据的可能机制的染色体维护的影响进行了讨论。(c)2005年澳大利亚寄生虫学会由爱思唯尔有限公司出版。保留所有权利。
The centromere is a specialized region of eukaryotic chromosomes, the site of kinetochore formation, spindle attachment and regulation of chromosome segregation during mitotic and meiotic cell divisions. To identify sequences which increase mitotic stability and/or act as potential centromeres in Leishmania major, we first generated libraries of Leishmania linear artificial chromosomes (LACs) bearing 30 kb inserts of randomly selected genomic DNAs. These were introduced into parasites, and then their stability was assessed following a period of 10 passages of growth in the absence of selective pressure. Approximately 80% of the 108 transfectants tested lost their LACs promptly and only 20% of the recombinants were retained; of these six showed strong but partial stability (maintained in 30-46% of cells). Mapping and sequencing of one clone (cSC10), which confers the highest degree of maintenance, revealed the presence of a sequence that was found within another stable episome, and which is dispersed in the genome of L. major. The implications of these data to the possible mechanisms of chromosomal maintenance are discussed. (c) 2005 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.