First published online March 9, 2007
Development 134, 702e (2007)
© The Company of Biologists Limited
A gap in the circuit
Drosophila embryonic neuroblasts give rise to larval-brain primary neurons,
from which secondary adult neurons are subsequently derived. The gap gene
empty spiracles (ems) has a well-known role in Drosophila embryonic brain
development, whereas little is known about its function in adult secondary
neurons. According to Lichtneckert et al., ems is expressed in a single
neuroblast in each hemisphere of the adult brain and autonomously determines
the number of progeny (as shown by MARCM clonal analysis) in the adult lineage
(see p. 1291).
Interestingly, ems expression persists throughout metamorphosis into
adulthood. In ems mutant lineages, neurite projections are short and
misdirected. This elegant study highlights how neuronal circuitry is
established and maintained into adulthood during brain development, and
reveals an unexpected role for a gap gene in translating lineage information
into cell-number control and into the correct projection of a clonal unit of
the adult brain. It also highlights conserved functions of orthologous ems/Emx
homeobox genes in the early embryo and during later brain development.
Related articles in Development:
- Cell lineage-specific expression and function of the empty spiracles gene in adult brain development of Drosophila melanogaster
- Robert Lichtneckert, Bruno Bello, and Heinrich Reichert
Development 2007 134: 1291-1300.
[Abstract]
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