Journal of Neuroscience, Vol 1, 103-106, Copyright © 1981 by Society for Neuroscience
Embryonic development of identified neurons: segment-specific differences in the H cell homologues
M Bate, CS Goodman and NC Spitzer
Although all of the segmental ganglia of the grasshopper come from
identical sets of embryonic precursor cells, there are striking differences
in the number and properties of the neurons in the mature ganglia. In every
segment, midline precursor 3 (MP3) divides once and gives rise to two
progeny. We describe the fate of the two MP3 progeny in different segments.
The morphology, physiology, and survival of the MP3 progeny depend upon
their segmental position in the embryo. In the meso- and metathoracic
segments (T2 and T3), one of the two progeny of MP3 transforms into the H
cell. In many of the abdominal segments, beginning with the fourth (A4),
both MP3 progeny die. A gradient of transformation and cell death is seen
in the intervening first three abdominal segments (A1 to A3). From A1 to
A3, the MP3 progeny acquire fewer of the morphological phenotypes of the H
cell. This is paralleled by the partial acquisition of the physiological
phenotypes of the H cell. Thus, cells that are the progeny of the same
precursor cell in different segments can either live or die and, if they
survive, can develop different morphological and physiological properties.