@article{b402293674204e42bad32b31e741efc7,
title = "Downregulation of Notch mediates the seamless transition of individual Drosophila neuroepithelial progenitors into optic medullar neuroblasts during prolonged G1",
abstract = "The first step in the development of the Drosophila optic medullar primordia is the expansion of symmetrically dividing neuroepithelial cells (NEs); this step is then followed by the appearance of asymmetrically dividing neuroblasts (NBs). However, the mechanisms responsible for the change from NEs to NBs remain unclear. Here, we performed detailed analyses demonstrating that individual NEs are converted into NBs. We also showed that this transition occurs during an elongated G1 phase. During this G1 phase, the morphological features and gene expressions of each columnar NE changed dynamically. Once the NE-to-NB transition was completed, the former NE changed its cell-cycling behavior, commencing asymmetric division. We also found that Notch signaling pathway was activated just before the transition and was rapidly downregulated. Furthermore, the clonal loss of the Notch wild copy in the NE region near the medial edge caused the ectopic accumulation of Delta, leading to the precocious onset of transition. Taken together, these findings indicate that the activation of Notch signaling during a finite window coordinates the proper timing of the NE-to-NB transition.",
keywords = "Drosophila, Neuroblast, Neuroepithelium, Notch, Optic lobe",
author = "Minako Orihara-Ono and Masako Toriya and Keiko Nakao and Hideyuki Okano",
note = "Funding Information: We thank Dr. F. Matsuzaki for the anti-Mir and anti-Pros antibodies, Dr. Y.N. Jan for the anti-Ase antiserum, Dr. Artavanis-Tsakonas for the transgenic fly strain with the p12×Su (H) bs-lacZ reporter, Dr. A. Spradling for the transgenic fly strain UAS-tubulin::GFP, Dr. M. Sato for the transgenic fly strain dpp (blk)-GAL4, DSHB (Developmental Studies Hybridoma Bank) for the anti-DEcad, anti-Delta, anti-Notch, and anti-Pros antibodies, and the DGRC (Drosophila Genetic Resource Center) and Bloomington Stock Center for the Drosophila MARCM-related strains. This work was supported by a Grant-in-Aid for Scientific Research from the Japan Science and Technology Corporation , Ministry of Education, Science, Sports, Culture and Technology, Japan , and by CREST (Core Research for Evolutional Science and Technology) and SORST (Solution Oriented Research for Science and Technology) of the Japan Science and Technology Corporation.",
year = "2011",
month = mar,
day = "1",
doi = "10.1016/j.ydbio.2010.12.044",
language = "English",
volume = "351",
pages = "163--175",
journal = "Developmental Biology",
issn = "0012-1606",
publisher = "Academic Press Inc.",
number = "1",
}