There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
The number and pattern of neuroblasts that initially segregate from the neuroectoderm
in the early Drosophila embryo is identical in thoracic and abdominal segments. However,
during late embryogenesis differences in the numbers of neuroblasts and in the extent
of neuroblast proliferation arise between these regions. We show that the homeotic
genes Ultrabithorax and abdominal-A regulate these late differences, and that misexpression
of either gene in thoracic neuroblasts after segregation is sufficient to induce abdominal
behaviour. However, in wild type embryos we only detect abdominal-A and Ultrabithorax
proteins in early neuroblasts. Furthermore, transplantation experiments reveal that
segment-specific behaviour is determined prior to neuroblast segregation. Thus, the
segment-specific differences in neuroblast behaviour seem to be determined in the
early embryo, mediated through the expression of homeotic genes in early neuroblasts,
and executed in later programmes controlling neuroblast numbers and proliferation.
Copyright 1998 Elsevier Science Ireland Ltd. All rights reserved