Gaubatz J W, Flores S C
Department of Biochemistry, University of South Alabama, College of Medicine, Mobile 36688.
Mutat Res. 1990 Jan;237(1):29-36. doi: 10.1016/0921-8734(90)90029-q.
Extrachromosomal circular (ecc) DNA was isolated from mouse brain, liver, and heart tissues at different ages. To determine the abundance of repetitive sequences in eccDNAs, preparations were probed for short-interspersed (B1 and B2), long-interspersed (L1), endogenous retroviral-like (IAP), and tandemly repeated satellite sequences (SAT) of the mouse genome. Together these sequence families comprise approximately 15% of the mouse genome. The hybridization results showed that each tissue had a characteristic pattern of repetitive sequence elements in eccDNAs, and the abundance of repetitive sequences changed as a function of age. Repetitive sequences decreased in liver and brain eccDNAs from 1 month to 8 months of age but appeared to remain stable thereafter. In contrast, repetitive sequence families in heart eccDNAs were constant from 1 month to 16 months of age but declined in 24-month-old mice. The present studies indicate that extrachromosomal sequences exhibit greater flexibility than chromosomal sequences.
从不同年龄段的小鼠脑、肝和心脏组织中分离出染色体外环状（ecc）DNA。为了确定eccDNA中重复序列的丰度，用小鼠基因组的短散在（B1和B2）、长散在（L1）、内源性逆转录病毒样（IAP）和串联重复卫星序列（SAT）对样本进行检测。这些序列家族共同构成了小鼠基因组的约15%。杂交结果表明，每个组织的eccDNA中都有重复序列元件的特征模式，并且重复序列的丰度随年龄而变化。肝和脑eccDNA中的重复序列在1个月至8个月龄时减少，但此后似乎保持稳定。相比之下，心脏eccDNA中的重复序列家族在1个月至16个月龄时保持不变，但在24月龄小鼠中减少。目前的研究表明，染色体外序列比染色体序列具有更大的灵活性。
