题目:Pause-melting misalignment: a novel model for the birth and motif indel of tandem repeats in the mitochondrial genome 

作者:Wei Shi, Xiaoyu Kong*, Zhongming Wang, Yu SS, Chen HX, De Stasio EA 

刊物:BMC Genomics,（IF=4.697，II区）

刊号:2013,14(1):103 

摘要:

BACKGROUND: 

Tandem repeats (TRs) in the mitochondrial (mt) genome control region have been documented in a wide variety of vertebrate species. The mechanism by which repeated tracts originate and undergo duplication and deletion, however, remains unclear. 

RESULTS: 

We analyzed DNA sequences of mt genome TRs (mtTRs) in the ridged-eye flounder (Pleuronichthys cornutus), and characterized DNA sequences of mtTRs from other vertebrates using the data available in GenBank. Tandem repeats are concentrated in the control regions; however, we found approximately 16.6% of the TRs elsewhere in the mt genome. The flounder mtTRs possess three motif types with hypervariable characteristics at the 3' end of the control region (CR). 

CONCLUSION: 

        Based on our analysis of this larger dataset of mtTR sequences, we propose a novel model of Pause MeltingMisalignment (PMM) to describe the birth and motif indel of tandem repeats. PMM is activated during a pause event inmitochondrial replication in which a dynamic competition between the nascent (N) heavy strand and the displaced (D) heavy strand may lead to the melting of the N-strand from the template (T) light strand. When mispairing occurs during rebinding of the N-strand, one or several motifs can be inserted or deleted in both strands during the next round of mt-replication or repair. This model can explain the characteristics of TRs in available vertebrate mt genomes.