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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2009.03.005 Byline: Mirjam Froehlicher (a), Anja Liedtke (a), Ksenia Groh (a), Hernan Lopez-Schier (b), Stephan C.F. Neuhauss (c), Helmut Segner (d), Rik I.L. Eggen (a) Keywords: Estrogen receptor; Neuromast; Zebrafish; Notch signaling Abstract: Estrogens are known to play a role in both reproductive and non-reproductive functions in mammals. Estrogens and their receptors are involved in the development of the central nervous system (brain development, neuronal survival and differentiation) as well as in the development of the peripheral nervous system (sensory-motor behaviors). In order to decipher possible functions of estrogens in early development of the zebrafish sensory system, we investigated the role of estrogen receptor [beta].sub.2 (ER[beta].sub.2) by using a morpholino (MO) approach blocking er[beta].sub.2 RNA translation. We further investigated the development of lateral line organs by cell-specific labeling, which revealed a disrupted development of neuromasts in morphants. The supporting cells developed and migrated normally. Sensory hair cells, however, were absent in morphants' neuromasts. Microarray analysis and subsequent in situ hybridizations indicated an aberrant activation of the Notch signaling pathway in ER[beta].sub.2 morphants. We conclude that signaling via ER[beta].sub.2 is essential for hair cell development and may involve an interaction with the Notch signaling pathway during cell fate decision in the neuromast maturation process. Author Affiliation: (a) Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dubendorf, Switzerland (b) Center for genomic regulation (CRG), C/Dr. Aiguadar 88, 08003 Barcelona, Spain (c) Institute of Zoology, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland (d) Center of Fish and Wildlife Health, University of Bern, Postbox 8466, CH-3001 Bern, Switzerland Article History: Received 15 October 2008; Revised 5 March 2009; Accepted 5 March 2009

The polarization of the anteroposterior (AP) axis during Drosophila oogenesis by focusing on the function of the notch signaling pathway and its relationship to the activation of the epidermal growth factor receptor is discussed. Some aspects of Notch activity regulation during oogenesis that appear to depart from the canonical pathway are examined.

Research demonstrates that the timing of follicle cell differentiation in Drosophila is controlled by the Notch ligand Delta sending signals from germ cells. Data indicate that in the early oogenesis, Delta signals from the germ line to Notch and controls polar and stalk follicle cells differentiation.

Accidental wounding of the peripheral nervous system leads to acute neural dysfunction. Normally, chronic deficits are overcome because peripheral nerves naturally regenerate. However, various genetic and metabolic defects can impair their natural regenerative capacity, which may be due to neuron-extrinsic mechanisms. Therefore, characterizing the behavior of multiple cells during nerve injury and repair in vivo is a pressing need in regenerative medicine. Here, we detail a method for precise wounding of sensory axons in zebrafish, followed by high-resolution in toto long-term quantitative videomicroscopy of neurons, Schwann cells, and macrophages. This protocol can be easily adapted to study the effects of targeted genetic or metabolic disruptions in zebrafish and other suitable organisms, as well as for screening pharmacological agents with therapeutic potential. Graphical overview., Competing Interests: Competing interestsHL-S is scientific advisor and paid consultant for Sensorion (France). The company had no role in this study. No competing interests exist with any vendor cited in this work., (Copyright © 2023 The Authors; exclusive licensee Bio-protocol LLC.)