Transcriptomes of lineage-specific Drosophila neuroblasts profiled via genetic targeting and robotic sorting

Abstract

A brain consists of numerous distinct neurons arising from a limited number of progenitors, called neuroblasts in Drosophila. Each neuroblast produces a specific neuronal lineage. To unravel the transcriptional networks that underlie the development of distinct neuroblast lineages, we marked and isolated lineage-specific neuroblasts for RNA sequencing. We labeled particular neuroblasts throughout neurogenesis by activating a conditional neuroblast driver in specific lineages using various intersection strategies. The targeted neuroblasts were efficiently recovered using a custom-built device for robotic single-cell picking. Transcriptome analysis of mushroom body, antennal lobe and type II neuroblasts compared with non-selective neuroblasts, neurons and glia revealed a rich repertoire of transcription factors expressed among neuroblasts in diverse patterns. Besides transcription factors that are likely to be pan-neuroblast, many transcription factors exist that are selectively enriched or repressed in certain neuroblasts. The unique combinations of transcription factors present in different neuroblasts may govern the diverse lineage-specific neuron fates.

Pa2G4 is a novel Six1 co-factor that is required for neural crest and otic development

“…While there is substantial information about the multiple functions of Pa2G4/Ebp1 in cancer cells (Ko et al, 2016), there is a paucity of detail regarding its developmental functions. The Drosophila homologue CG105756 is highly expressed in all cerebral neuroblast populations of the developing brain (Yang et al, 2016). CG10576 over-expression by P-element insertion resulted in embryos with neurogenic-like patches within developing muscle populations (Bidet et al, 2003).…”

Extraction of Hemocytes from <em>Drosophila melanogaster</em> Larvae for Microbial Infection and Analysis

“…For example, Kurucz et al, have developed antibodies that could be used to isolate the Drosophila hemocyte subsets that could be used for transcriptional or proteomic profiling following various stimuli. Additionally, the recent development of single cell RNAseq technology could define transcriptomes of each cell type without the use of antibodies to initially separate each cell type36,37,38,39. Furthermore, one could ask questions regarding gene regulation in the hemocyte subsets that may help us understand how human blood cell lineages originated and evolved from ancient organisms through comparative genomics efforts.…”

Unc-4 acts to promote neuronal identity and development of the take-off circuit in the Drosophila CNS

“…We used two GAL4 driver lines in conjunction with our unc4 FRT line to remove Unc-4 function in both the CNS and PNS or just the CNS. We used sca-GAL4 to remove Unc-4 function in both the CNS and PNS (MLODZIK et al 1990) and dpn EE -GAL4 to remove Unc-4 function only in the CNS (YANG et al 2016) ( Figure 3A-H). sca-GAL4 removed most Unc-4 expression from the CNS, all of Unc-4 expression from the progenitors of chordotonal sense organs, and also Unc-4 expression in epithelial cells of the leg disc ( Figure 3B, F).…”

“…sca-GAL4 removed most Unc-4 expression from the CNS, all of Unc-4 expression from the progenitors of chordotonal sense organs, and also Unc-4 expression in epithelial cells of the leg disc ( Figure 3B, F). dpn EE -GAL4 which is expressed specifically in CNS NBs (EMERY AND BIER 1995;YANG et al 2016) removed most Unc-4 expression from the CNS but left Unc-4 expression in leg discs largely intact ( Figure 3C, G). sca-GAL4 mediated knock-out of Unc-4 function led to the same behavioral defects observed in unc-4 mutant animals: all had erect wings, failed to fly, and showed grooming and climbing defects (Table 1; Video 8).…”