NB 4-3 details
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NB 4-3 delaminates during S5.
There is no information about the lineage derived from NB 4-3 from other insects.
NB 4-3 expresses huckebein (hkb) and seven-up-lacZ (svp-lacZ) as it forms (Chu LaGraff et al, 1995; Broadus et al, 1995). Recent work has shown that it also expresses muscle-specific homeobox gene 1 (msh) and Klumpfuss (Klu) at S5 as well (Buescher et al, 1996; Isshiki, et al, 1997; Yang, et al, 1997).
Schmidt et al. (1997) described this lineage as containing 8-13 neurons, including many motoneurons projecting into the SN whose endings could not be identified. They also found an obligate epidermal clone and frequently observed a PNS clone. We generated 5 abdominal NB 4-3 clones, scoring 1 at stage 15, 2 at stage 16, and 2 at stage 17. We believe the cells previously identified as motoneurons (Schmidt et al., 1997) are actually neurosecretory cells of the TN.
A. Neurosecretory Cells
There are 2-3 neurosecretory cells that project together out of the CNS, appearing to join the TN in the periphery. These cells are slightly smaller than most motoneurons (5.3 mm; n=4) and correlate well with the positions and projections of the Bursicon-containing B1, B2 and B3 neurosecretory cells in Manduca (Taghert and Truman 1982a,b; Carr and Taghert, 1988a,b; Broadie et al., 1990; Tublitz and Sylwester, 1990).
B. Interneurons
There are an additional 10-12 small (3.1 mm; n=6) axonless interneurons at stage 17.
References
Broadie, K., Sylwester, A., Bate, M., and Tublitz, N. J. (1990). Immunological, biochemical and physiological analyses of cardioacceleratory peptide 2 (CAP2) activity in the embryo of the tobacco hawkmoth, Manduca sexta. Development 108: 59-71.
Broadus, J., Skeath, J.B., Spana, E. P., Bossing, T., Technau, G.M., and Doe, C.Q. (1995). New neuroblast markers and the origin of the aCC/pCC neurons in the Drosophila central nervous system. Mech Dev 53: 393-402.
Buescher, M., and Chia, W. (1997). Mutations in lottchen cause cell fate transformations in both neuroblast and glioblast lineages in the Drosophila embryonic central nervous system. Development 124(3): 673-81.
Carr, J.N., and Taghert, P. H. (1988a). Formation of the Transverse Nerve in moth embryos: I. A scaffold of non-neuronal cells prefigures the nerve. Dev Biol 130: 487-99.
Carr, J.N., and Taghert, P. H. (1988b). Formation of the Transverse Nerve in moth embryos. II. Stereotyped growth by the axons of identified neuroendocrine neurons. Dev Biol 130: 500-512.
Chu-LaGraff, Q., Schmid, A., Leidel, J., Broenner, G., Jaeckle, H., and Doe, C. Q. (1995). huckebein specifies aspects of CNS precursor identity required for motoneuron axon pathfinding. Neuron 15: 1041-1051.
Isshiki, T., Takeichi, M., and Nose, A. (1997). The role of the msh homeobox gene during Drosophila neurogenesis: implication for the dorsoventral specification of the neurectoderm. Development 124(16): 3099-3109.
Schmidt, H., Rickert, C., Bossing, T., Vef, O., Urban, J., and Technau, G. M. (1997). The embryonic Central Nervous System lineages of Drosophila melanogaster II. Neuroblast lineages derived from the dorsal part of the neurectoderm. Dev Biol 189: 186-204.
Taghert, P.M., and Truman, J. W. (1982a). The distribution and molecular characterization of the tanning hormone buriscon in the tobacco hornworm, Manduca sexta. J Exp Biol 98: 373-383.
Taghert, P.M., and Truman, J. W. (1982b). Identification of the bursicon-containing neurones in abdominal ganglia of the tobacco hornworm, Manduca sexta. J Exp Biol 98: 385-401.
Tublitz, N. J., and Sylwester, A. W. (1990). Postembryonic alteration of transmitter phenotype in individually identified peptidergic neurons. J. Neurosci 10(1): 161-8.
Yang, X., Bahri, S., Klein, T., and Chia, W. (1997). Klumpfuss, a putative Drosophila zinc finger transcription factor, acts to differentiate between the identities of two secondary precursor cells within one neuroblast lineage. Genes Dev 11(11):1396-1408.