Molecular programs guiding arealization of descending cortical pathways.

Layer 5 extratelencephalic (ET) neurons are present across neocortical areas and send axons to multiple subcortical targets. Two cardinal subtypes exist: (1) Slco2a1-expressing neurons (ET), which predominate in the motor cortex and project distally to the pons, medulla and spinal cord; and (2) Nprs1- or Hpgd-expressing neurons (ET), which predominate in the visual cortex and project more proximally to the pons and thalamus. An understanding of how area-specific ET and ET emerge during development is important because they are critical for fine motor skills and are susceptible to spinal cord injury and amyotrophic lateral sclerosis.

Small extracellular vesicles administered directly in the brain promote neuroprotection and decreased microglia reactivity in a stroke mouse model.

Herein, we investigate the bioactivity of small extracellular vesicles (sEVs), focusing on their local effect in the brain. sEVs from mononuclear cells (MNCs) showed superior effects to sEVs from mesenchymal stem cells (MSCs) and were able to promote neuroprotection and decrease microglia reactivity in a stroke mouse model.

Transcriptional linkage analysis with in vivo AAV-Perturb-seq.

The ever-growing compendium of genetic variants associated with human pathologies demands new methods to study genotype-phenotype relationships in complex tissues in a high-throughput manner. Here we introduce adeno-associated virus (AAV)-mediated direct in vivo single-cell CRISPR screening, termed AAV-Perturb-seq, a tuneable and broadly applicable method for transcriptional linkage analysis as well as high-throughput and high-resolution phenotyping of genetic perturbations in vivo. We applied AAV-Perturb-seq using gene editing and transcriptional inhibition to systematically dissect the phenotypic landscape underlying 22q11.

Multiplexed genome engineering by Cas12a and CRISPR arrays encoded on single transcripts.

The ability to modify multiple genetic elements simultaneously would help to elucidate and control the gene interactions and networks underlying complex cellular functions. However, current genome engineering technologies are limited in both the number and the type of perturbations that can be performed simultaneously. Here, we demonstrate that both Cas12a and a clustered regularly interspaced short palindromic repeat (CRISPR) array can be encoded in a single transcript by adding a stabilizer tertiary RNA structure.