Notch signal organizes the Drosophila olfactory circuitry by diversifying the sensory neuronal lineages.
An essential feature of the organization and function of the vertebrate and insect olfactory systems is the generation of a variety of olfactory receptor neurons (ORNs) that have different specificities in regard to both odorant receptor expression and axonal targeting. Yet the underlying mechanisms that generate this neuronal diversity remain elusive. Here we demonstrate that the Notch signal is involved in the diversification of ORNs in Drosophila melanogaster. A systematic clonal analysis showed that a cluster of ORNs housed in each sensillum were differentiated into two classes, depending on the level of Notch activity in their sibling precursors. Notably, ORNs of different classes segregated their axonal projections into distinct domains in the antennal lobes. In addition, both the odorant receptor expression and the axonal targeting of ORNs were specified according to their Notch-mediated identities. Thus, Notch signaling contributes to the diversification of ORNs, thereby regulating multiple developmental events that establish the olfactory map in Drosophila.
Endo
Keita
K
Laboratory for Neural Network Development, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-minami, Chuo, Kobe, Hyogo 650-0047, Japan.
Aoki
Tomoko
T
Yoda
Yuka
Y
Kimura
Ken-ichi
K
Hama
Chihiro
C
D000818:Animals; D001921:Brain / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics*; D019070:Cell Lineage / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D020439:Growth Cones / Q000378:metabolism / Q000648:ultrastructure; D007605:Juvenile Hormones / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D009833:Olfactory Pathways / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D018034:Olfactory Receptor Neurons / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism*; D018035:Receptors, Odorant / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics
D029721:Drosophila Proteins; D007605:Juvenile Hormones; D009687:Nuclear Proteins; D051880:Receptors, Notch; D018035:Receptors, Odorant; C085316:mam protein, Drosophila; C060606:numb protein, Drosophila