Supplementary MaterialsFigure 1source data 1: Quantification of apical NPCs (RGs). (coding for LIS1) leads to the disruption of neurogenesis and neuronal migration via dysregulation of microtubule (MT) stability and dynein motor function/localization that alters mitotic spindle orientation, chromosomal segregation, and nuclear migration. Recently, human- induced pluripotent stem cell (iPSC) models revealed an important role for LIS1 in controlling the length of terminal cell divisions of outer radial glial (oRG) progenitors, suggesting cellular functions of LIS1 in regulating neural progenitor cell (NPC) daughter cell separation. Here, we examined the late mitotic stages NPCs in vivo and mouse DM1-Sme embryonic fibroblasts (MEFs) in vitro from mouse mutant studies suggest additional cellular functions of LIS1 in neocortical neural progenitor cell (NPC) division by regulating mitotic spindle orientation and cell fate (Yingling et al., 2008; Youn et al., 2009; Hippenmeyer et al., 2010; Bershteyn et al., 2017; Moon et al., 2014). The mitotic phenotypes of mutants are closely related and consistent with those of other mutants of MT/dynein-associated proteins such as LGN, NDE1, and NDEL1 (Bradshaw and Hayashi, 2017; Doobin et al., 2016; Wynne and Vallee, 2018). However, unlike these other mouse mutants of LIS1-interacting proteins, mutants displayed a significant decrease in neuroepithelial stem cells in the neocortex and subsequent neonatal death compared with a less catastrophic phenotype seen in radial glial (RG) progenitors (Yingling et al., 2008). Our recent studies with human-induced pluripotent stem cells (iPSCs) of Miller-Dieker syndrome, a severe form of lissencephaly caused by heterozygosity of more than 20 genes including mutant neocortical neural progenitor cells (NPCs) To elucidate molecular mechanisms underlying LIS1-dependent NPC regulation during neocortical development, mitotic phenotypes of is located on DM1-Sme chromosome 11 away from the centromere. To deplete sparsely Cd247 in neocortical NPCs during early embryonic development, we first generated (TG: tdTomato-GFP fusion) mice co-expressing the heterozygous knock-out (KO) allele. These mice were mated with (GT: GFP-tdTomato fusion) to generate the experimental mosaic animals which carry sparsely labeled NPCs with different expression levels of LIS1 ((red, labeled with tdTomato, 100% LIS1 wild-type (WT) levels), (yellow, double positive for GFP and tdTomato, 50% LIS1 WT levels), and (green, labeled with GFP, 0% LIS1) NPCs in an unlabeled heterozygous background. The fluorescence of each cell enabled us to distinguish the genotype of each cell. The same mating scheme was used DM1-Sme to generate WT control animals (and embryos.(A) Wild-type (WT) NPCs displayed recruitment of Anillin to the basal equatorial cortex and ultimately the Anillin-ring moved to the apical surface of the ventricular zone, forming a U-like shape. (B) Schematic representation of mating scheme and three types of neocortical NPCs with different LIS1 expression amounts. Immunoreactivity (IR) from immunohistochemistry test out anti-GFP and anti-tdT-c-Myc antibodies was indicated. (C) (e) Midbody-associated Anillin localization in WT (heterozygous (((insufficiency in neocortical DM1-Sme NPCs leads to displacement from the mitotic cleavage airplane with unusual distribution of contractile elements, we evaluated Anillin distribution in neocortices weighed against those of WTat E14.5. In the WTneocortex, Anillin was accumulated at the midzone during metaphase-to-anaphase (Physique 1ACa,b) and was enriched by forming a U shape (basal-to-apical ingression) at the midbody of NPCs, consistent with previous observations of normal NPC cleavage in WT mice (Kosodo et al., 2008;?Physique 1ACc,d). In the neocortices, the tdTomato-positive WT NPCs (reddish, heterozygous NPCs (yellow, (Physique 1BCC) neocortex displayed a profound decrease in GFP-positive homozygous KO apical NPCs located at the ventricular zone (green, NPCs were mostly found at prometaphase or metaphase and located at the ventricular surface with no obvious cell membrane-associated Anillin with dispersed patterns (Physique 1CCh), probably due to mitotic arrest after total loss of LIS1 (Yingling et al., 2008). Abnormal distribution of Anillin in mutant NPCs (neocortex (neocortex (heterozygous NPCs (yellow, KO NPCs (green, mutant neocortical NPCs (heterozygous neocortex We next asked whether heterozygosity prospects to changes in cytoarchitecture of the apical NPC niche at the ventricular surface of the neocortex. We deleted one copy of in neocortical NPCs by mating conditional knock-out (CKO) collection with the collection (Zhuo et al., 2001). In control neocortex (without Cre, hc: hypomorphic conditional), NPCs undergoing vertical divisions (with.