Закономерности формирования угольных бассейнов Южно-Гобийской провинции Монголии и содержание в них редких элементов

Background— Ion channels are key determinants for the function of excitable cells, but little is known about their role and involvement during cardiac development. Earlier work identified Ca 2+ -activated potassium channels of small and intermediate conductance (SKCas) as important regulators of neural stem cell fate. Here we have investigated their impact on the differentiation of pluripotent cells toward the cardiac lineage. Methods and Results— We have applied the SKCa activator 1-ethyl-2-benzimidazolinone on embryonic stem cells and identified this particular ion channel family as a new critical target involved in the generation of cardiac pacemaker-like cells: SKCa activation led to rapid remodeling of the actin cytoskeleton, inhibition of proliferation, induction of differentiation, and diminished teratoma formation. Time-restricted SKCa activation induced cardiac mesoderm and commitment to the cardiac lineage as shown by gene regulation, protein, and functional electrophysiological studies. In addition, the differentiation into cardiomyocytes was modulated in a qualitative fashion, resulting in a strong enrichment of pacemaker-like cells. This was accompanied by induction of the sino-atrial gene program and in parallel by a loss of the chamber-specific myocardium. In addition, SKCa activity induced activation of the Ras-Mek-Erk signaling cascade, a signaling pathway involved in the 1-ethyl-2-benzimidazolinone–induced effects. Conclusions— SKCa activation drives the fate of pluripotent cells toward mesoderm commitment and cardiomyocyte specification, preferentially into nodal-like cardiomyocytes. This provides a novel strategy for the enrichment of cardiomyocytes and in particular, the generation of a specific subtype of cardiomyocytes, pacemaker-like cells, without genetic modification. </jats:sec

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead