Conformational switching of Arp5 subunit regulates INO80 chromatin remodeling.

The INO80 chromatin remodeler is a versatile enzyme capable of several functions, including spacing nucleosomes equal distances apart, precise positioning of nucleosomes based on DNA shape/sequence and exchanging histone dimers. Within INO80, the Arp5 subunit plays a central role in INO80 remodeling, evidenced by its interactions with the histone octamer, nucleosomal and extranucleosomal DNA, and its necessity in linking INO80's ATPase activity to nucleosome movement. We find two distinct regions of Arp5 binding near the acidic pocket of nucleosomes.

Cas9/Nickase-induced allelic conversion by homologous chromosome-templated repair in somatic cells.

Repair of double-strand breaks (DSBs) in somatic cells is primarily accomplished by error-prone nonhomologous end joining and less frequently by precise homology-directed repair preferentially using the sister chromatid as a template. Here, a system performs efficient somatic repair of both DSBs and single-strand breaks (SSBs) using intact sequences from the homologous chromosome in a process we refer to as homologous chromosome-templated repair (HTR). Unexpectedly, HTR-mediated allelic conversion at the locus was more efficient (40 to 65%) in response to SSBs induced by Cas9-derived nickases D10A or H840A than to DSBs induced by fully active Cas9 (20 to 30%).

A nickase Cas9 gene-drive system promotes super-Mendelian inheritance in Drosophila.

CRISPR-based gene-drives have been proposed for managing insect populations, including disease-transmitting mosquitoes, due to their ability to bias their inheritance toward super-Mendelian rates (>50%). Current technologies use a Cas9 that introduces DNA double-strand breaks into the opposing wild-type allele to replace it with a copy of the gene-drive allele via DNA homology-directed repair. However, the use of different Cas9 versions is unexplored, and alternative approaches could increase the available toolkit for gene-drive designs.

Oral immunotherapy in severe cow's milk allergic patients treated with omalizumab: Real life survey from a Spanish registry.

Background: Oral immunotherapy is a frequent treatment for the management of food allergies, but adverse events (AE) are common. This study assessed the outcome of cow's milk oral immunotherapy (MOIT) in severe cow`s milk-allergic patients treated with omalizumab in a real-life setting.

Methods: OmaBASE was a national, multicenter, open, and observational registry that collected clinical, immunologic, and treatment from patients with food allergy receiving omalizumab.

Active Genetic Neutralizing Elements for Halting or Deleting Gene Drives.

CRISPR-Cas9-based gene drive systems possess the inherent capacity to spread progressively throughout target populations. Here we describe two self-copying (or active) guide RNA-only genetic elements, called e-CHACRs and ERACRs. These elements use Cas9 produced in trans by a gene drive either to inactivate the cas9 transgene (e-CHACRs) or to delete and replace the gene drive (ERACRs).