Practice question

Ectodermal patterning along dorsoventral axis separates dorsal amnioserosa, dorsal ectoderm and ventrolateral neurogenic ectoderm. Intermediate levels of nuclear Dorsal activate proneural genes achaete-scute complex in neurogenic region. Under Notch-mediated lateral inhibition, single neuroblasts delaminate from neurogenic ectoderm through de-epithelialization, proliferate asymmetrically to generate neurons and glia of ventral nerve cord. This lineage establishes central nervous system. Non-neurogenic dorsal ectoderm forms epidermis, mesoderm forms muscles. Therefore neurogenic ectoderm specifically gives rise to nervous system representing neural progenitor domain specified by Dorsal gradient.