Dual role for Drosophila lethal of scute in CNS midline precursor formation and dopaminergic neuron and motoneuron cell fate

Abstract

SUMMARYDopaminergic neurons play important behavioral roles in locomotion, reward and aggression. The Drosophila H-cell is a dopaminergic neuron that resides at the midline of the ventral nerve cord. Both the H-cell and the glutamatergic H-cell sib are the asymmetric progeny of the MP3 midline precursor cell. H-cell sib cell fate is dependent on Notch signaling, whereas H-cell fate is Notch independent. Genetic analysis of genes that could potentially regulate H-cell fate revealed that the lethal of scute [l(1)sc], tailup and SoxNeuro transcription factor genes act together to control H-cell gene expression. The l(1)sc bHLH gene is required for all H-cell-specific gene transcription, whereas tailup acts in parallel to l(1)sc and controls genes involved in dopamine metabolism. SoxNeuro functions downstream of l(1)sc and controls expression of a peptide neurotransmitter receptor gene. The role of l(1)sc may be more widespread, as a l(1)sc mutant shows reductions in gene expression in non-midline dopaminergic neurons. In addition, l(1)sc mutant embryos possess defects in the formation of MP4-6 midline precursor and the median neuroblast stem cell, revealing a proneural role for l(1)sc in midline cells. The Notch-dependent progeny of MP4-6 are the mVUM motoneurons, and these cells also require l(1)sc for mVUM-specific gene expression. Thus, l(1)sc plays an important regulatory role in both neurogenesis and specifying dopaminergic neuron and motoneuron identities.

The Drosophila BTB Domain Protein Jim Lovell Has Roles in Multiple Larval and Adult Behaviors

“…The analyses of lov mRNA expression in the midline lineages performed previously [3]–[6] indicate that regulation of lov within the CNS is also dynamic and complex and that here too lov has roles in the final differentiation of particular neuronal sub-types. The single cell per segment that first expresses Lov protein in the CNS (Figure 5) has been identified by the Crews lab as one of the eight primordial midline precursor cells whose determination is controlled by singleminded .…”

“…Through stages 11–17 of embryogenesis lov mRNA is transiently expressed in the posterior midline glia, the median neuroblast (MNB) cell and a subset of ventral unpaired median motorneurons (VUMs) to give a final expression pattern at stage 17 in just three neurons: a single cell of the MNB progeny and the sister interneuron and motor neuron derived from division of midline precursor neuron 6 (MP6). Notch and lethal-of-scute act at various points to regulate these expression patterns [5], [6].…”

“…The critical role of transcription factor cascades has emerged from studies of the peripheral nervous system (PNS), where major components of the transcriptional hierarchies that give rise to various classes of sensory neurons have been identified (reviewed in [1], [2]). Similarly, gene profiling of the CNS midline cells has identified cell-type specific signatures of transcription factor expression [3], [4], whose roles in neural specification is being confirmed by genetic studies [5], [6]. However, many further steps in the processes leading to final differentiation of individual neurons remain to be identified.…”

Transcriptomic Analysis of Octanoic Acid Response inDrosophila sechelliaUsing RNA-Sequencing

“…In addition to Osi6 , we found five other genes that fall within other QTL for OA resistance. These genes include three genes without annotated function: CG15740 , CG1368 , and CG9672 ; a proneural gene, l ( 1 ) sc ( lethal of scute ), which plays an important regulatory role in both neurogenesis and dopaminergic neuron identity ( Stagg et al 2011 ); and TweedleY ( TwdlY ), a member of a Drosophila cuticle protein family that has been shown to alter body shape ( Guan et al 2006 ). These genes represent excellent candidates for further research into the molecular roles these genes play in D. sechellia and whether this is important for OA resistance.…”

The Osa-containing SWI/SNF chromatin-remodeling complex regulates stem cell commitment in the adult Drosophila intestine

“…Expression of Sc and Ase in the posterior midgut was below the detection level using specific antibodies Stagg et al, 2011) (supplementary material Fig. S9A,AЈ,C,CЈ).…”