Journal: PLoS Biology
Article Title: Olig2 and Hes regulatory dynamics during motor neuron differentiation revealed by single cell transcriptomics
doi: 10.1371/journal.pbio.2003127
Figure Lengend Snippet: (A, B) Co-electroporation of CMV/β-actin::nLacZ and Hes5(e1) reporter plasmids into chick spinal cord. Although electroporation (revealed by β-Gal antibody staining, magenta in [A]) is uniform along the dorsal-ventral axis, expression of the EGFP reporter is confined to intermediate parts of the neural tube (A, B), and little coexpression of Olig2 and EGFP was detected (B). (C) Design of Hes5(e1) and Hes5(e1ΔE) reporters. The Hes5(e1) element was cloned in front of β-globin minimal promoter to drive EGFP reporter gene expression. To test the importance of the E-box in the Hes5(e1) element, critical base pairs for Olig2 binding were mutated (red). (D, E) Co-electroporation of CMV/β-actin::-nLacZ and Hes5(e1ΔE) reporter plasmids into chick spinal cord. In contrast to the Hes5(e1) reporter plasmid, significant coexpression of Olig2 and GFP in the pMN domain is detected (E). Note that E-box mutation reduced the basal activity of the reporter such that longer exposure times were needed to achieve the signal levels seen in the intermediate spinal cord with the nonmutated Hes5(e1) reporter . (F) Scatter dot plots display the dorsal-ventral positions (distance from the roof plate) of individual cells expressing the Hes5(e1) and Hes5(e1ΔE) reporters, relative to CMV/β-actin::-nLacZ and Olig2. Results are aggregated from five representative sections taken from five well-electroporated and stage-matched spinal cords. The Hes5(e1ΔE) reporter exhibits a significant ventral shift in its activity and considerable overlap with Olig2 expression (blue dotted box). Box plots include the median and whiskers represent 5th and 95th percentiles. Data points that lay outside the DV scale used to assess these experiments were excluded from this analysis. ** p = 0.0005, Mann-Whitney test; p = 0.6649. Underlying data are provided in . (G) EGFP expression in Hes5(e1)-nEGFP whole mount embryos at e10.5. (H–H″) Cryosections of Hes5(e1)-nEGFP embryos at e10.5 assayed for GFP, Olig2, and Hes5. EGFP expression colocalizes with Hes5 expression (H″) but not with Olig2 (H). (I–N) Hes5(e1)-nEGFP expression in Olig2 heterozygous (I, K, L) and homozygous mutants (J, M, N). In Olig2 heterozygotes, little nEGFP expression can be detected in the Olig2 expression domain, resulting in a pronounced gap between the expression domains of EGFP, Nkx2.2, and Hes1 (K, L). By contrast, the EGFP, Nkx2.2, and Hes1 expression domains directly abut each other in Olig2 homozygous mutants (M, N). β-Gal, beta-galactosidase; βGlob, beta-globin; CMV/β-actin::nLacZ, cytomegalovirus/chick beta-actin promoter driving nuclear LacZ gene expression; ΔE, E-box deletion; E-box, bHLH protein binding site; EGFP, enhanced green fluorescent protein; FP, floor plate; GFP, green fluorescent protein; H5(e1), Hes5(e1) genomic element; ns, not significant; pMN, motor neuron progenitor; WT, wild-type.
Article Snippet: Additional primary antibodies were used as follows: goat anti-β-galactosidase (Biogenesis 4600–1409 1:2,000), mouse anti-Cre (Covance MMS-106P, 1:2,000), rabbit anti-Dbx1 (kind gift of Susan Morten and Thomas Jessell, 1:8,000), rabbit anti-Fabp7 (Abcam ab32423, 1:2,000 or Chemical AB9558, 1:2,000), rat anti-FLAG (Stratagene 200474, 1:1,500), chicken anti-GFP (Abcam ab13970, 1:20,000), sheep anti-GFP (AbD Serotec 4745–1051, 1:800), rabbit anti-Hes1 ([ ], 1:1,000), mouse anti-Hoxc6 (Santa Cruz Biotechnology sc-376330, 1:250), mouse anti-Hb9/Mnx1 (DSHB, 1:40), mouse anti-Isl1/2 (DSHB, 1:100), goat anti-Isl1 (R&D AF1837, 1:1,000), rabbit anti-Lhx3 (Abcam ab14555, 1:500), mouse anti-NeuN (Rbfox3, Chemicon/Millipore MAB377, 1:1,000), rat anti-chick Neurod4 (NeuroM [ ]), goat anti-Ngn2 (Santa Cruz Biotechnology sc-19233, 1:500), mouse anti-Ngn2 (5C6, [ ], 1:50), guinea pig anti-chick Ngn2 ([ ], 1:32,000), mouse anti-Nkx2.2 (DSHB, 1:25), mouse anti-Nkx6.1 (DSHB, 1:100), rabbit anti-Olig2 (Millipore AB9610, 1:1,000), guinea pig anti-mouse Olig2 ([ ] 1:20,000), guinea pig anti-chick Olig2 ([ ], 1:8,000), rabbit anti-Pax6 (Millipore AB2237, 1:1,000), mouse anti-Pax6 (DSHB, 1:25), goat anti-Sox1 (R&D AF3369, 1:500), goat anti-Sox2 (Santa Cruz Biotechnology sc-17320, 1:2,000), rabbit anti-Sox2 ([ ], 1:2500), rabbit anti-TagRFP (Evrogen AB233, 1:1,000), rabbit anti-Tubb3 (Covance PRB-435P, 1:2,000), mouse anti-Tubb3 (Covance MMS-435P, 1:1,000), rabbit anti-Zbtb18 (Proteintech 12714-1-AP, 1:1,000).
Techniques: Electroporation, Staining, Expressing, Clone Assay, Gene Expression, Binding Assay, Plasmid Preparation, Mutagenesis, Activity Assay, MANN-WHITNEY, Protein Binding