bioRxiv Science⌕ Search

Biology subjects

Walmsley, E. L.

Publications and source records attributed to Walmsley, E. L..

2 recordsLinked to original sources

Condensin I subunit Cap-G is essential for proper gene expression during the maturation of post-mitotic neurons

The condensin complex is essential for mitotic chromosome assembly and segregation during cell divisions, however, little is known about its function in post-mitotic, differentiated cells. Here we report a novel role for the condensin I subunit Cap-G in Drosophila neurons. We show that, despite not requiring condensin for mitotic chromosome compaction, post-mitotic neurons express Cap-G and that knockdown of Cap-G specifically in neurons (from their birth onwards) results in developmental arrest, behavioural defects, and dramatic gene expression changes. These include reduced expression of a subset of neuronal genes and aberrant expression of genes that are not normally expressed in the developing brain. Knockdown of Cap-G in more mature neurons also results in similar phenotypes but to a lesser degree. Furthermore, we see dynamic binding of Cap-G to chromatin at distinct loci in neural stem cells and differentiated neurons. Therefore, Cap-G is essential for proper gene expression in neurons and plays an important role during the early stages of neuronal development. O_FIG O_LINKSMALLFIG WIDTH=197 HEIGHT=200 SRC="FIGDIR/small/904409v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@11a48aborg.highwire.dtl.DTLVardef@9912b7org.highwire.dtl.DTLVardef@19bd19dorg.highwire.dtl.DTLVardef@deb7f7_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

Dynamic neurotransmitter specific transcription factor expression profiles during Drosophila development

The remarkable diversity of neurons in the nervous system is generated during development, when properties such as cell morphology, receptor profiles and neurotransmitter identities are specified. In order to gain a greater understanding of neurotransmitter specification we profiled the transcription state of cholinergic, GABAergic and glutamatergic neurons in vivo at three developmental time points. We identified 86 differentially expressed transcription factors that are uniquely enriched, or uniquely depleted, in a specific neurotransmitter type. Some transcription factors show a similar profile across development, others only show enrichment or depletion at specific developmental stages. Profiling of Acj6 (cholinergic enriched) and Ets65A (cholinergic depleted) binding sites in vivo reveals that they both directly bind the ChAT locus, in addition to a wide spectrum of other key neuronal differentiation genes. We also show that cholinergic enriched transcription factors are expressed in mostly non-overlapping populations in the adult brain, implying the absence of combinatorial regulation of neurotransmitter fate in this context. Furthermore, our data underlines that, similar to C. elegans, there are no simple transcription factor codes for neurotransmitter type specification.

developmental biology↗