FUNCTIONAL-ANALYSIS OF A CENTROMERE FROM FISSION YEAST - A ROLE FOR CENTROMERE-SPECIFIC REPEATED DNA-SEQUENCES
FUNCTIONAL-ANALYSIS OF A CENTROMERE FROM FISSION YEAST - A ROLE FOR CENTROMERE-SPECIFIC REPEATED DNA-SEQUENCES
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DOI：
10.1128/mcb.10.5.1863
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发表时间：
1990-05-01
影响因子：
5.3
通讯作者：
BAUM, MP
中科院分区：
文献类型：
--
作者：
CLARKE, L;BAUM, MP
粟酒裂殖酵母II号染色体上的一个带有功能性着丝粒序列（cen2）的环状微染色体在粟酒裂殖酵母中表现为一个稳定的、独立的遗传连锁群。粟酒发现cen2区域被组织成四个大的串联重复序列单元，其跨越超过80个未转录DNA的DNA酶对（kb）。其中两个单位发生在一个31 kb的反向重复，侧翼的7 kb的中央核心的非同源性。反向重复区有着丝粒功能，但无论是中央核心单独或反向重复的一个臂是功能性的。缺失中央核心侧翼的一部分重复序列对有丝分裂分离功能或对小染色体向四个单倍体后代中的两个的减数分裂分离没有影响，但显著损害了减数分裂I中着丝粒介导的姐妹染色单体附着的维持。引入随机DNA序列无法满足对着丝粒特异性重复序列的这一要求。这些观察结果表明，高等真核生物的着丝粒区域中发现的异染色质重复DNA序列的功能。
A circular minichromosome carrying functional centromere sequences (cen2) from Schizosaccharomyces pombe chromosome II behaves as a stable, independent genetic linkage group in S. pombe. The cen2 region was found to be organized into four large tandemly repeated sequence units which span over 80 kilobase pairs (kb) of untranscribed DNA. Two of these units occurred in a 31-kb inverted repeat that flanked a 7-kb central core of nonhomology. The inverted repeat region had centromere function, but neither the central core alone nor one arm of the inverted repeat was functional. Deletion of a portion of the repeated sequences that flank the central core had no effect on mitotic segregation functions or on meiotic segregation of a minichromosome to two of the four haploid progeny, but drastically impaired centromere-mediated maintenance of sister chromatid attachment in meiosis I. This requirement for centromere-specific repeated sequences could not be satisfied by introduction of random DNA sequences. These observations suggest a function for the heterochromatic repeated DNA sequences found in the centromere regions of higher eucaryotes.