Segment-specific Neuronal Sub-type Specification by the Integration of Anteroposterior and Temporal Cues
2010 (English)In: PLoS biology, ISSN 1544-9173, E-ISSN 1545-7885, Vol. 8, no 5Article in journal (Refereed) Published
The generation of distinct neuronal sub-types at different axial levels relies upon both anteroposterior and temporal cues. However, the integration between these cues is poorly understood. In the Drosophila CNS, the segmentally repeated neuroblast 5-6 generates a unique group of neurons, the Apterous cluster, only in thoracic segments. Recent studies have identified elaborate genetic pathways acting to control the generation of these neurons. These insights, combined with novel markers, provide a unique opportunity for addressing how anteroposterior and temporal cues are integrated to generate segment-specific neuronal sub-types. We find that Pbx/Meis, Hox and temporal genes act in three different ways. Posteriorly, Pbx/Meis and posterior Hox genes block lineage progression within an early temporal window, by triggering cell cycle exit. Because Ap neurons are generated late in the thoracic 5-6 lineage, this prevents generation of Ap cluster cells in the abdomen. Thoracically, Pbx/Meis and anterior Hox genes integrate with late temporal genes to specify Ap clusters, via activation of a specific feed-forward loop. In brain segments, ‘Ap cluster cells’ are present but lack both proper Hox and temporal coding. Only by simultaneously altering Hox and temporal gene activity in all segments can Ap clusters be generated throughout the neuroaxis. This study provides the first detailed analysis of an identified neuroblast lineage along the entire neuroaxis, and provides novel insight into how Hox/Pbx/Meis anteroposterior cues are integrated with temporal cues. It reveals a surprisingly restricted yet multifaceted function of the anteroposterior cues with respect to lineage control and cell fate specification.
Place, publisher, year, edition, pages
2010. Vol. 8, no 5
anteroposterior patterning, temporal transitions, Hox, Pbx/Meis, cell specification
IdentifiersURN: urn:nbn:se:liu:diva-51641DOI: 10.1371/journal.pbio.1000368ISI: 000278759600005OAI: oai:DiVA.org:liu-51641DiVA: diva2:276206
Daniel Karlsson, Magnus Baumgardt and Stefan Thor, Segment-specific Neuronal Sub-type Specification by the Integration of Anteroposterior and Temporal Cues, 2010, PLoS biology, (8), 5.
Licensee: Public Library of Science