[Serial deletions of tandem reverse CTCF sites reveal balanced regulatory landscape of enhancers].

The genome architectural protein CTCF (CCCTC-binding factor) not only mediates long-distance chromatin interactions between distal enhancers and target promoters, but also functions as an important insulator-binding factor to block improper enhancer activation of non-target promoters, and is thus of great significance to transcriptional regulation of developmental genes. The (Homeobox) gene family plays an important role in the development of the brain, bones, and limbs. The spatiotemporal colinear expression of the cluster along the proximal-distal axis of limbs is regulated by two clusters of enhancers known as super-enhancers located in the flanking regulatory regions.

[Combinatorial CRISPR inversions of CTCF sites in cluster reveal complex insulator function].

CTCF (CCCTC-binding factor) is a zinc-finger protein which plays a vital role in the three-dimensional (3D) genome architecture. A pair of forward-reverse convergent CTCF binding sites (CBS elements) mediates long-distance DNA interactions to form chromatin loops with the assistance of the cohesin complex, while CBS elements at the chromatin domain boundaries show reverse-forward divergent patterns and function as insulators to discriminate against DNA interaction between chromatin domains. However, there are still many unresolved problems regarding CTCF-mediated insulation function.

A new upper bound of geometric constant [Formula: see text].

A new constant [Formula: see text] is introduced into any real [Formula: see text]-dimensional symmetric normed space . By virtue of this constant, an upper bound of the geometric constant [Formula: see text], which is used to measure the difference between Birkhoff orthogonality and isosceles orthogonality, is obtained and further extended to an arbitrary -dimensional symmetric normed linear space ([Formula: see text]). As an application, the result is used to prove a special case for the reverse Hölder inequality.

DNA fragment editing of genomes by CRISPR/Cas9.

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated nuclease 9 (Cas9) system from bacteria and archaea emerged recently as a new powerful technology of genome editing in virtually any organism. Due to its simplicity and cost effectiveness, a revolutionary change of genetics has occurred. Here, we summarize the recent development of DNA fragment editing methods by CRISPR/Cas9 and describe targeted DNA fragment deletions, inversions, duplications, insertions, and translocations.

[Study on the interaction of cobalt (II) polyamidomine dendrimer with DNA by spectrometry techniques].

Cobalt (II) polyamidomine dendrimer was prepared by the reaction of cobalt chloride, glyoxal and polyamidomine dendrimer of 5.0 generation. The interaction of cobalt (II) polyamidomine dendrimer complex with herring sperm (hsDNA) was carried out using methylene blue (MB) as the probe molecule by absorption and fluorescence spectroscopy and synchronous fluorescence spectroscopy.