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A single cell analysis of engrailed expression in the early embryonic brain of the grasshopper Schistocerca gregaria : ontogeny and identity of the secondary headspot cells

Authors :
Leslie Williams
George Boyan
Source :
Arthropod Structure & Development. 30:207-218
Publication Year :
2002
Publisher :
Elsevier BV, 2002.

Abstract

The expression pattern of the segment polarity gene engrailed was studied at the single cell level in the protocerebrum of the early embryonic brain of the grasshopper Schistocerca gregaria, the neuromere containing the secondary headspot cells. The engrailed protein is first expressed in the protocerebrum at about 22% of embryogenesis by a group of identified neuroblasts bordering the antennal lobe. The number of immunoreactive neuroblasts increases up to 26% of embryogenesis and then rapidly declines so that by 30% only the three most posterior remain immunoreactive. These three neuroblasts become incorporated into the developing antennal lobe of the deutocerebrum. Subsequently, there is a progressive re-expression of the engrailed protein in the protocerebrum by the so-called six secondary headspot cells. These are the first born sibling progeny of three identified protocerebral neuroblasts which themselves expressed the engrailed protein prior to generating their lineages, and so represents a reacquisition of engrailed expression within identified clones. The secondary headspot cells are neurons which direct axonal processes into the developing optic tract and so contribute to the primary axon scaffold of the brain. From our analysis of their ontogeny, we conclude that the secondary headspot cells do not represent a segmental border in the brain.

Details

ISSN :
14678039
Volume :
30
Database :
OpenAIRE
Journal :
Arthropod Structure & Development
Accession number :
edsair.doi.dedup.....2afbb4b9076b6a17eee44ed6da5daad0
Full Text :
https://doi.org/10.1016/s1467-8039(01)00034-2