Question

What are neuroblast cells? ​

Answer 1

Stem cells are cells that have the ability to divide and produce both new stem cells (a process called self-renewal) and specific types of cell (a process called differentiation). There are many different types of stem cell. The brain of the fruit fly Drosophila, for example, contains two different types of neural stem cell. Type I neuroblasts divide to produce a new type I neuroblast and a cell called a ganglion mother cell. The new neuroblast can undergo several more rounds of division, but the ganglion mother cell can only divide once, to produce specific cell types (either neurons or glia cells). Type II neuroblasts, on the other hand, divide to produce a new type II neuroblast and a cell called an intermediate neural progenitor. Each intermediate neural progenitor cell can undergo several rounds of proliferation, each of which produces a ganglion mother cell (Homem and Knoblich, 2012). This ‘amplifies’ the number of neurons and glia cells that are produced.

Controlling the proliferation and differentiation of intermediate neural progenitors as the brain develops is crucial because these cells can also undergo a developmental reversal that results in them becoming neuroblast-like cells. These can then overproliferate and form malignant tumours in the brain. Recent studies in Drosophila have identified several regulatory proteins that prevent this developmental reversal and restrict the proliferation of intermediate neural progenitors. These include the post-transcriptional regulator Brain tumor (Bello et al., 2006; Betschinger et al., 2006; Lee et al., 2006), the Notch signaling pathway component Numb (Wang et al., 2007), the Drosophila SWI/SNF chromatin remodeling complex (Eroglu et al., 2014), and the zinc-finger transcription factor Earmuff (Weng et al., 2010). These proteins also work together to restrict proliferation in type II neuroblasts and the cells that they generate (

Answer 2

A neuroblast or primitive nerve cell is a postmitotic cell that does not divide further, and which will develop into a neuron after a migration phase. Neuroblasts differentiate from radial glial cells and are committed to becoming neurons.