The role of a Drosophila POU homeo domain gene in the specification of neural precursor cell identity in the developing embryonic central nervous system.
The Drosophila embryonic central nervous system (CNS) is derived from a stereotypic array of progenitor stem cells called neuroblasts (NBs). Each of the approximately 25 NBs per hemisegment undergoes repeated asymmetric divisions to produce, on average, 5-10 smaller ganglion mother cells (GMCs); each GMC, in turn, divides to produce two neurons. We demonstrate that the protein product encoded by a POU homeo domain gene (dPOU28/pdm-2) is expressed in the cell nuclei of a subset of NBs and GMCs. In the wild-type animal, GMC-1 is the only identified cell in the NB4-2 lineage that expresses dPOU28 protein to a high level, and it divides to produce the RP2 neuron and a second cell of unknown fate. Our results suggest that the presence of ectopically induced dPOU28/pdm-2 protein in the progeny of GMC-1 is sufficient to cause both of these cells to adopt their parental GMC-1 cell fate, leading to duplication of the RP2 neuron (and its sister cell) on the basis of both immunological and morphological criteria. These observations clearly implicate a role for dPOU28/pdm-2 in the specification of GMC-1 cell identity in the NB4-2 lineage and possibly in the specification of cell fate in other NB lineages in the developing embryonic CNS.
Yang
X
X
Drosophila Neurobiology Laboratory, National University of Singapore.
Yeo
S
S
Dick
T
T
Chia
W
W
D000818:Animals; D030801:Animals, Genetically Modified; D004261:DNA Replication; D004330:Drosophila / Q000196:embryology* / Q000235:genetics*; D004625:Embryo, Nonmammalian / Q000502:physiology; D005260:Female; D005724:Ganglia / Q000196:embryology / Q000502:physiology*; D005801:Genes, Homeobox; D006360:Heat-Shock Proteins / Q000235:genetics; D007150:Immunohistochemistry; D008297:Male; D009420:Nervous System / Q000196:embryology*; D009474:Neurons / Q000502:physiology*; D013234:Stem Cells / Q000502:physiology; D014170:Transformation, Genetic
D006360:Heat-Shock Proteins