Distinct differentiation trajectories leave lasting impacts on gene regulation and function of V2a interneurons.

During development, early regionalization segregates lineages and directs diverse cell fates. Sometimes, however, distinct progenitors produce analogous cell types. For example, V2a neurons, are excitatory interneurons that emerge from different anteroposterior progenitors.

Axial elongation of caudalized human organoids mimics aspects of neural tube development.

Axial elongation of the neural tube is crucial during mammalian embryogenesis for anterior-posterior body axis establishment and subsequent spinal cord development, but these processes cannot be interrogated directly in humans as they occur post-implantation. Here, we report an organoid model of neural tube extension derived from human pluripotent stem cell (hPSC) aggregates that have been caudalized with Wnt agonism, enabling them to recapitulate aspects of the morphological and temporal gene expression patterns of neural tube development. Elongating organoids consist largely of neuroepithelial compartments and contain TBXT+SOX2+ neuro-mesodermal progenitors in addition to PAX6+NES+ neural progenitors.

Cellular Plasticity of Defa4-Expressing Paneth Cells in Response to Notch Activation and Intestinal Injury.

Background & Aims: Loss of leucine-rich repeat-containing G-protein-coupled receptor 5-positive crypt base columnar cells provides permissive conditions for different facultative stem cell populations to dedifferentiate and repopulate the stem cell compartment. In this study, we used a defensin α4-Cre recombinase (Defa4Cre) line to define the potential of Paneth cells to dedifferentiate and contribute to intestinal stem cell (ISC) maintenance during normal homeostasis and after intestinal injury.

Methods: Small intestine and enteroids from Defa4;Rosa26 tandem dimer Tomato (tdTomato), a red fluoresent protein, (or Rosa26 Enhanced Yellow Fluorescent Protein (EYFP)) reporter, Notch gain-of-function (Defa4;Rosa26 Notch Intracellular Domain (NICD)-ires-nuclear Green Fluorescent Protein (nGFP) and Defa4;Rosa26 Enhanced Green Fluorescent Protein (EGFP);TetO), A Disintegrin and Metalloproteinase domain-containing protein 10 (ADAM10) loss-of-function (Defa4;ADAM10), and Adenomatous polyposis coli (APC) inactivation (Defa4;APC) mice were analyzed.