Erratum: Proliferation of murine midbrain neural stem cells depends upon an endogenous sonic hedgehog (shh) Source

After publication of this article [1], the authors notified the journal of errors in Figs 4 and S2, which depict the results of western blot and microscopy experiments, respectively. Specifically: • The same data were reported in Fig 4B and 4D α-tubulin panels, and lane 2 in α-tubulin panels of Fig 4B and 4D reports the same data as lane 1 in the α-tubulin panel of Fig 4E, although with different aspect ratio. The authors noted that they inadvertently included incorrect α-tubulin loading controls when preparing Fig 4B and 4E, and that these errors also impacted the quantification of band intensity in the accompanying graphs. • When preparing each panel of Fig 4C, the authors spliced out irrelevant lanes from the blot images. Consequently, the panels show non-adjacent lanes of the indicated blots and there are vertical discontinuities between lanes 1 and 2. For each figure panel, the reported data were obtained from the same blot imaged at the same exposure. The authors provide with this notice an updated figure legend that explains these aspects of the figure’s preparation. • In S2C Fig, the W/O GF image was mistakenly shown in the E+F10 + Cyc panel, and the W/ O GF and E+F1+Shh panels reported overlapping fields of the same (E+F1+Shh) data. The authors noted that these issues resulted from errors in figure preparation. To address these errors, the authors provide here: 1. A revised version of Fig 4 with the correct loading controls and with re-quantified band intensities in panels B, D, and E. Raw blot images underlying the revised figure are provided in S1 and S2 Files, and quantification data are in S3 and S4 Files. Note that the same tubulin data apply to Fig 4D and 4E as the same samples and blot were used for these experiments. To generate the updated quantitative data, the original blot results were re-scanned; the images used for quantitative analyses are in S5 File. 2. A revised version of S2 Fig in which the E+F1+Shh and E+F10 + Cyc panels have been replaced with the correct representative microscopy images from the original experiments. The full set of unprocessed microscopy images obtained in this experiment and the quantification data used to generate the graph in Fig S2C are in S6 and S7 Files, respectively. The authors also provide the following clarifications regarding replication and the study design for experiments reported in Fig 4: Primary tectal neurosphere cultures were prepared from 8–12 embryos (littermates) and after the first passage we seeded embryonic dorsal murine mesencephalon NSC into collagen type-I gels to establish 3D cultures (typically 20+). For Fig 4 data presented in the paper, (Figure Presented).