Genome editing in the mouse brain with minimally immunogenic Cas9 RNPs.

Transient delivery of CRISPR-Cas9 ribonucleoproteins (RNPs) into the central nervous system (CNS) for therapeutic genome editing could avoid limitations of viral vector-based delivery including cargo capacity, immunogenicity, and cost. Here, we tested the ability of cell-penetrant Cas9 RNPs to edit the mouse striatum when introduced using a convection-enhanced delivery system. These transient Cas9 RNPs showed comparable editing of neurons and reduced adaptive immune responses relative to one formulation of Cas9 delivered using AAV serotype 9.

Enteric glia express proteolipid protein 1 and are a transcriptionally unique population of glia in the mammalian nervous system.

In the enteric nervous system (ENS), glia outnumber neurons by 4-fold and form an extensive network throughout the gastrointestinal tract. Growing evidence for the essential role of enteric glia in bowel function makes it imperative to understand better their molecular marker expression and how they relate to glia in the rest of the nervous system. We analyzed expression of markers of astrocytes and oligodendrocytes in the ENS and found, unexpectedly, that proteolipid protein 1 (PLP1) is specifically expressed by glia in adult mouse intestine.

DNA slip-outs cause RNA polymerase II arrest in vitro: potential implications for genetic instability.

The abnormal number of repeats found in triplet repeat diseases arises from 'repeat instability', in which the repetitive section of DNA is subject to a change in copy number. Recent studies implicate transcription in a mechanism for repeat instability proposed to involve RNA polymerase II (RNAPII) arrest caused by a CTG slip-out, triggering transcription-coupled repair (TCR), futile cycles of which may lead to repeat expansion or contraction. In the present study, we use defined DNA constructs to directly test whether the structures formed by CAG and CTG repeat slip-outs can cause transcription arrest in vitro.