Iranian Biomedical Journal
مجله بیومدیکال ایران
IBJ
Basic Sciences
http://ibj.pasteur.ac.ir
1
admin
1028-852X
2008-823X
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10.61186/ibj
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8888
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en
jalali
1397
8
1
gregorian
2018
11
1
22
6
online
1
fulltext
other
Cell Timer/Cell Clock
Related Fields
Related Fields
Study Break
Study Break
<strong>Like the biological clock in the body, replication of each cell type (even different cells of the same organism) follows a timing program. Abnormal function of this </strong><strong>timer</strong><strong> could be an alarm for a disease like cancer.</strong><br>
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DNA replication starts from a specific point on the chromosome that is called the origin of replication. In contrast to prokaryotes in which DNA replication starts from a single origin, eukaryotic DNA replication starts from many origins scattered along the chromosomes. Budding yeast contains 300 origins, whereas fission yeast has 1,100, and the numbers of replication origins for human increase to over 20,000. These origins are fired in a coordinated manner, and there are spatial and temporal disciplines for this process, which happens in the S phase of the cell cycle. It was known that eukaryotic cells prepare all these potential origins during the G1 phase of the cell cycle but utilize only a portion of these origins during S phase. Furthermore, firing some of these origins are delayed until the mid and late phases of the S phase. Coordinated activation of these origins occurs under “Replication Timing Program”. The segments of the chromosome containing co-regulated origins that fire simultaneously are named “Replication Timing Domains”, ranging in size from 100 kb to 1 Mb. Replication timing is determined at a specific time in the early G1 phase that is called Timing Decision Point (TDP). Studies have shown that major chromosome repositioning occurs at TDP. Generally, replication timing domains are classified into three classes including Early, Mid and Late...
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361
http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-1-746&slc_lang=other&sid=1
Hamed
Ghadiri
100319475328460055021
100319475328460055021
No
Faculty of Biological Sciences, Tarbiat Modares University, Tehran 14115-175, Iran
Sana
Alavi
100319475328460055022
100319475328460055022
No
Faculty of Biological Sciences, Tarbiat Modares University, Tehran 14115-175, Iran
Bahareh
Dabirmanesh
100319475328460055023
100319475328460055023
No
Faculty of Biological Sciences, Tarbiat Modares University, Tehran 14115-175, Iran
Kenji
Moriyama
100319475328460055024
100319475328460055024
No
Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamkitazawa, Setagaya-ku, Tokyo 156-8506, Japan
Khosro
Khajeh
100319475328460055025
100319475328460055025
No
Faculty of Biological Sciences, Tarbiat Modares University, Tehran 14115-175, Iran
Hisao
Masai
100319475328460055026
100319475328460055026
Yes
Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamkitazawa, Setagaya-ku, Tokyo 156-8506, Japan