Insights into neural stem cell biology from flies

Abstract

Drosophila neuroblasts are similar to mammalian neural stem cells in their ability to self-renew and to produce many different types of neurons and glial cells. In the past two decades, great advances have been made in understanding the molecular mechanisms underlying embryonic neuroblast formation, the establishment of cell polarity and the temporal regulation of cell fate. It is now a challenge to connect, at the molecular level, the different cell biological events underlying the transition from neural stem cell maintenance to differentiation. Progress has also been made in understanding the later stages of development, when neuroblasts become mitotically inactive, or quiescent, and are then reactivated postembryonically to generate the neurons that make up the adult nervous system. The ability to manipulate the steps leading from quiescence to proliferation and from proliferation to differentiation will have a major impact on the treatment of neurological injury and neurodegenerative disease.

Analysis of neural stem cell self-renewal and differentiation by transgenic RNAi in Drosophila

“…In Drosophila, neuroblasts give rise to differentiated neurons and glia cells in the central brain, optic lobes, and ventral nerve cord [14]. In this review, we will focus primarily on the mechanisms that underlie the specification and homeostasis of the neuroblasts in the central brain; similar mechanisms have been shown to operate in the neuroblasts of the optic lobes and ventral nerve cord, which have been recently reviewed elsewhere [3,5,6].…”

“…Neuroblasts, the neural stem cells in Drosophila, have the characteristic feature of the neural stem cells in vertebrates, namely to divide asymmetrically to self-renew while generating a wide range of more differentiated progeny [3][4][5][6][7]. In Drosophila, neuroblasts give rise to differentiated neurons and glia cells in the central brain, optic lobes, and ventral nerve cord [14].…”

“…The specified neuroblasts enlarge in size, delaminate basally from the neuroectoderm and then go on to divide asymmetrically along their apical-basal axis in a stem cell-like manner (Fig. 1A) [6,7].…”

“…In Drosophila, three cell fate determinants, Brat, Pros, and Numb, have been characterized and studied in some detail [5][6][7][8]. All three proteins asymmetrically localize to the basal cortex during neuroblast division and subsequently are inherited only by the smaller GMC.…”

“…In the past two decades, the fruit fly, Drosophila melanogaster, has proved to be a powerful model organism for studying the biology of neural stem cells [4][5][6][7]. Drosophila neural stem cells are called neuroblasts for historical reasons.…”