ELIMINATION OF MICRONUCLEAR SPECIFIC DNA-SEQUENCES EARLY IN ANLAGEN DEVELOPMENT
ELIMINATION OF MICRONUCLEAR SPECIFIC DNA-SEQUENCES EARLY IN ANLAGEN DEVELOPMENT
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DOI：
10.1128/mcb.5.1.93
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发表时间：
1985-01-01
影响因子：
5.3
通讯作者：
CONOVER, RK
中科院分区：
文献类型：
--
作者：
BRUNK, CF;CONOVER, RK
嗜热四膜虫接合后，旧的大核退化，新的大核(Anlagen)发育。在抗原的发育过程中，在微核基因组中发现的一些DNA序列(微核受限序列)会从抗原中消除。使用重复微核限制序列的克隆拷贝来确定消除微核限制序列的发育阶段。对不同发育阶段的成骨细胞DNA进行Southern分析。微核限制性序列在4C胶原中存在，而在8C和16C胶原中基本不存在。这些序列在8C胶原中的急剧丢失排除了复制不足作为丢失的机制，并表明这些序列在胶原发育的早期被特异性地降解。
After conjugation in Tetrahymena thermophila, the old macronuclei degenerate, and new macronuclei (anlagen) develop. During anlagen development a number of DNA sequences found in the micronuclear genome (micronuclear limited sequences) are eliminated from the antigen. A cloned copy of a repetitive micronuclear limited sequence was used to determine the developmental stage at which micronuclear limited sequences are eliminated. DNA from anlagen of various developmental stages were examined by Southern analysis. Micronuclear limited sequences are present in 4C anlagen and essentially absent in 8C and 16C anlagen. The precipitous loss of these sequences in the 8C anlagen rules out under-replication as the mechanism for the loss and suggests that these sequences are specifically degraded early during anlagen development.