Interplay between DNA sequence and negative superhelicity drives R-loop structures

Geometry and mechanics of DNA superhelicity.

Interplay between changing climate and species' ecology drives macroevolutionary dynamics.

Ecological change provokes speciation and extinction, but our knowledge of the interplay among the biotic and abiotic drivers of macroevolution remains limited. Using the unparalleled fossil record of Cenozoic macroperforate planktonic foraminifera, we demonstrate that macroevolutionary dynamics depend on the interaction between species' ecology and the changing climate. This interplay drives d...

Termination Factor-Mediated DNA Loop between Termination and Initiation Sites Drives Mitochondrial rRNA Synthesis

The human mitochondrial transcription termination factor mTERF plays a central role in the control of heavy-strand rDNA transcription by promoting initiation, besides termination, of this transcription. However, until now, the mechanism underlying this stimulation of transcription by mTERF was not understood. In the present work, addition of mTERF to a HeLa cell mitochondrial lysate-based react...

Interplay between DNA supercoiling and transcription elongation.

Transcription-coupled DNA supercoiling has been shown to be an important regulator of transcription that is broadly present in the cell. Here we review experimental work which shows that RNA polymerase is a powerful torsional motor that can alter DNA topology and structure, and DNA supercoiling in turn directly affects transcription elongation.

Sequence Variations of Mitochondrial DNA Displacement-Loop in Iranian Indigenous Sheep Breeds

Mitochondrial DNA (mtDNA) has been used extensively to study population genetics because it has the unique features of maternal inheritance, a relatively fast rate of evolution and lack of recombination. A total of 82 unrelated sheep from 10 Iranian indigenous sheep breeds were investigated to determinate the maternal genetic diversity using a sequence of a 685 bp segment of the displacement lo...