Seven up acts as a temporal factor during two different stages of neuroblast 5-6 development
2011 (English)In: Development, ISSN 0950-1991, E-ISSN 1477-9129, Vol. 138, no 24, 5311-5320 p.Article in journal (Refereed) Published
Drosophila embryonic neuroblasts generate different cell types at different time points. This is controlled by a temporal cascade of Hb -greater than Kr -greater than Pdm -greater than Cas -greater than Grh, which acts to dictate distinct competence windows sequentially. In addition, Seven up (Svp), a member of the nuclear hormone receptor family, acts early in the temporal cascade, to ensure the transition from Hb to Kr, and has been referred to as a switching factor. However, Svp is also expressed in a second wave within the developing CNS, but here, the possible role of Svp has not been previously addressed. In a genetic screen for mutants affecting the last-born cell in the embryonic NB5-6T lineage, the Ap4/FMRFamide neuron, we have isolated a novel allele of svp. Expression analysis shows that Svp is expressed in two distinct pulses in NB5-6T, and mutant analysis reveals that svp plays two distinct roles. In the first pulse, svp acts to ensure proper downregulation of Hb. In the second pulse, which occurs in a Cas/Grh double-positive window, svp acts to ensure proper sub-division of this window. These studies show that a temporal factor may play dual roles, acting at two different stages during the development of one neural lineage.
Place, publisher, year, edition, pages
Company of Biologists , 2011. Vol. 138, no 24, 5311-5320 p.
Temporal genes; COUP-TFI/II; Cell specification; Lineage progression; Drosophila
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-73311DOI: 10.1242/dev.070946ISI: 297329900004OAI: oai:DiVA.org:liu-73311DiVA: diva2:472083