In the Drosophila CNS, early neuroblast formation and fate are controlled by the pair-rule class of segmentation genes. The distantly related Schistocerca (grasshopper) embryo has a similar arrangement of neuroblasts, despite lack of known pair-rule gene function. Does divergent pair-rule gene function lead to different neuroblast identities, or can different patterning mechanisms produce homologous neuroblasts? We use four molecular markers to compare Drosophila and Schistocerca neuroblast identity: seven-up, prospero, engrailed, and fushi-tarazu/Dax. In both insects some early-forming neuroblasts share key features of neuroblast identity (position, time of formation, and temporally accurate gene expression); thus, different patterning mechanisms can generate similar neuroblast fates. In contrast, several later-forming neuroblasts show species-specific differences in position and/or gene expression; these neuroblast identities seem to have diverged, suggesting that evolution of the insect central nervous system can occur through changes in embryonic neuroblast identity.
Evolution of neuroblast identity: seven-up and prospero expression reveal homologous and divergent neuroblast fates in Drosophila and Schistocerca
- Views Icon Views
- PDF LinkPDF
- Share Icon Share
- Search Site
J. Broadus, C.Q. Doe; Evolution of neuroblast identity: seven-up and prospero expression reveal homologous and divergent neuroblast fates in Drosophila and Schistocerca. Development 1 December 1995; 121 (12): 3989–3996. doi: https://doi.org/10.1242/dev.121.12.3989
Download citation file: