Khaled Ben El Kadhi

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Khaled Ben El Kadhi is a developmental neurobiologist investigating the mechanisms responsible for neuronal diversity.

Before joining the Desplan Lab, Khaled completed his M.Sc and PhD in Molecular biology at the University of Montreal. During his PhD, he mainly studied an orphan disease: the Lowe Syndrome. His work allowed a better understanding of this disease and the discovery of a potential therapeutic strategy to treat it. In 2017 Khaled joined the Desplan lab, first in NYU-NY and then in NYU-AD.

Research

The Drosophila compound eye is composed of 800 unit eyes; each contains 8 photoreceptors (PRs). The visual information collected by the PRs is transferred to the 4 visual processing centers of the optic lobe, the lamina, medulla, lobula, and lobula plate. The medulla is the most complex structure of the optical lobe. It consists of 40,000 neurons belonging to more than 80 different cell types. These neurons are the progeny of 800 medulla NeuroBlasts (NBs) that derive from a larval neuroepithelium, the Outer Proliferation Center (OPC). The OPC's NBs divide asymmetrically to self-renew and to produce a Ganglion Mother Cell (GMC) that will produce two different medulla neurons. The work of Dr. Desplan's lab (with others) has shown that the sequential expression of 6 temporal transcription factors (tTF) (Hth-Klu-Ey-Slp-D-Tll) in NBs generates neuronal diversity. Indeed, a young NB of the OPC begins by expressing Hth, divides twice, and produces 2 types of neurons. Then, as it ages, the NB transits to expressing the following tTF and generates other types of neurons, and so on until the end of neurogenesis. Although the tTF cascade was identified, we do not have dynamic information about the timing mechanisms, the duration of each temporal identity, and how the transition occurs between tTFs. The general aim of my work is to develop a NBs primary culture to define the molecular clock of the tTF cascade using live-imaging.