@article {48366, title = {Facilitating neuron-specific genetic manipulations in Drosophila using a split GAL4 repressor.}, journal = {Genetics}, volume = {206}, year = {2017}, month = {2017 Mar 31}, pages = {775-84}, abstract = {

Efforts to map neural circuits have been galvanized by the development of genetic technologies that permit the manipulation of targeted sets of neurons in the brains of freely behaving animals. The success of these efforts relies on the experimenter{\textquoteright}s ability to target arbitrarily small subsets of neurons for manipulation, but such specificity of targeting cannot routinely be achieved using existing methods. In Drosophila melanogaster, a widely used technique for refined cell-type specific manipulation is the Split GAL4 system, which augments the targeting specificity of the binary GAL4-UAS system by making GAL4 transcriptional activity contingent upon two enhancers, rather than one. To permit more refined targeting, we introduce here the "Killer Zipper" (KZip(+)), a suppressor that makes Split GAL4 targeting contingent upon a third enhancer. KZip(+) acts by disrupting both the formation and activity of Split GAL4 heterodimers, and we show how this added layer of control can be used to selectively remove unwanted cells from a Split GAL4 expression pattern or to subtract neurons of interest from a pattern to determine their requirement in generating a given phenotype. To facilitate application of the KZip(+) technology, we have developed a versatile set of LexAop-KZip(+) fly lines that can be used directly with the large number of LexA driver lines with known expression patterns. The Killer Zipper significantly sharpens the precision of neuronal genetic control available in Drosophila and may be extended to other organisms where Split GAL4-like systems are used.

}, issn = {1943-2631}, doi = {10.1534/genetics.116.199687}, author = {Dolan, Michael-John and Luan, Haojiang and Shropshire, William C and Sutcliffe, Ben and Cocanougher, Benjamin and Scott, Robert L and Frechter, Shahar and Zlatic, Marta and Jefferis, Gregory S X E and White, Benjamin H} } @article {6876, title = {Drosophila intermediate neural progenitors produce lineage-dependent related series of diverse neurons.}, journal = {Development}, volume = {141}, year = {2014}, month = {2014 Jan}, pages = {253-8}, abstract = {

Drosophila type II neuroblasts (NBs), like mammalian neural stem cells, deposit neurons through intermediate neural progenitors (INPs) that can each produce a series of neurons. Both type II NBs and INPs exhibit age-dependent expression of various transcription factors, potentially specifying an array of diverse neurons by combinatorial temporal patterning. Not knowing which mature neurons are made by specific INPs, however, conceals the actual variety of neuron types and limits further molecular studies. Here we mapped neurons derived from specific type II NB lineages and found that sibling INPs produced a morphologically similar but temporally regulated series of distinct neuron types. This suggests a common fate diversification program operating within each INP that is modulated by NB age to generate slightly different sets of diverse neurons based on the INP birth order. Analogous mechanisms might underlie the expansion of neuron diversity via INPs in mammalian brain.

}, keywords = {Animals, Brain, Cell Lineage, Drosophila, Genetically Modified, Models, Neural Stem Cells, Neurogenesis, Neurological}, issn = {1477-9129}, doi = {10.1242/dev.103069}, author = {Wang, Yu-Chun and Yang, Jacob S and Johnston, Rebecca and Ren, Qingzhong and Lee, Ying-Jou and Luan, Haojiang and Brody, Thomas and Odenwald, Ward F and Lee, Tzumin} } @article {6898, title = {Making Drosophila lineage-restricted drivers via patterned recombination in neuroblasts.}, journal = {Nature Neuroscience}, volume = {17}, year = {2014}, month = {2014 Apr}, pages = {631-7}, abstract = {

The Drosophila cerebrum originates from about 100 neuroblasts per hemisphere, with each neuroblast producing a characteristic set of neurons. Neurons from a neuroblast are often so diverse that many neuron types remain unexplored. We developed new genetic tools that target neuroblasts and their diverse descendants, increasing our ability to study fly brain structure and development. Common enhancer-based drivers label neurons on the basis of terminal identities rather than origins, which provides limited labeling in the heterogeneous neuronal lineages. We successfully converted conventional drivers that are temporarily expressed in neuroblasts, into drivers expressed in all subsequent neuroblast progeny. One technique involves immortalizing GAL4 expression in neuroblasts and their descendants. Another depends on loss of the GAL4 repressor, GAL80, from neuroblasts during early neurogenesis. Furthermore, we expanded the diversity of MARCM-based reagents and established another site-specific mitotic recombination system. Our transgenic tools can be combined to map individual neurons in specific lineages of various genotypes.

}, issn = {1546-1726}, doi = {10.1038/nn.3654}, author = {Awasaki, Takeshi and Kao, Chih-Fei and Lee, Ying-Jou and Yang, Ching-Po and Huang, Yaling and Pfeiffer, Barret D and Luan, Haojiang and Jing, Xiaotang and Huang, Yu-Fen and He, Yisheng and Schroeder, Mark David and Kuzin, Alexander and Brody, Thomas and Zugates, Christopher T and Odenwald, Ward F and Lee, Tzumin} } @article {4140, title = {Combinatorial methods for refined neuronal gene targeting.}, journal = {Current Opinion in Neurobiology}, volume = {17}, year = {2007}, month = {2007 Oct}, pages = {572-80}, abstract = {

Methods for the selective and reproducible expression of genetically encoded tools in targeted subsets of cells are required to facilitate studies of neuronal development, connectivity, and function in living animals. In the absence of techniques for synthesizing promoters that target defined cell groups, current methods exploit the regulatory elements of endogenous genes to achieve specificity of transgene expression. However, single promoters often have expression patterns too broad to pinpoint the functional roles of specific neurons. In this review, we describe emerging combinatorial techniques that make transgene expression contingent not upon a single promoter, but upon two or more promoters. Although only a few such techniques are currently available, recent developments promise rapid growth in this area in the coming years.

}, keywords = {Gene Expression Regulation, Gene Targeting, Gene Transfer Techniques, Humans, Neurons, Transgenes}, issn = {0959-4388}, doi = {10.1016/j.conb.2007.10.001}, author = {Luan, Haojiang and White, Benjamin H} } @article {4142, title = {Functional dissection of a neuronal network required for cuticle tanning and wing expansion in Drosophila.}, journal = {The Journal of Neuroscience The Official Journal of the Society for Neuroscience}, volume = {26}, year = {2006}, month = {2006 Jan 11}, pages = {573-84}, abstract = {

A subset of Drosophila neurons that expresses crustacean cardioactive peptide (CCAP) has been shown previously to make the hormone bursicon, which is required for cuticle tanning and wing expansion after eclosion. Here we present evidence that CCAP-expressing neurons (NCCAP) consist of two functionally distinct groups, one of which releases bursicon into the hemolymph and the other of which regulates its release. The first group, which we call NCCAP-c929, includes 14 bursicon-expressing neurons of the abdominal ganglion that lie within the expression pattern of the enhancer-trap line c929-Gal4. We show that suppression of activity within this group blocks bursicon release into the hemolymph together with tanning and wing expansion. The second group, which we call NCCAP-R, consists of NCCAP neurons outside the c929-Gal4 pattern. Because suppression of synaptic transmission and protein kinase A (PKA) activity throughout NCCAP, but not in NCCAP-c929, also blocks tanning and wing expansion, we conclude that neurotransmission and PKA are required in NCCAP-R to regulate bursicon secretion from NCCAP-c929. Enhancement of electrical activity in NCCAP-R by expression of the bacterial sodium channel NaChBac also blocks tanning and wing expansion and leads to depletion of bursicon from central processes. NaChBac expression in NCCAP-c929 is without effect, suggesting that the abdominal bursicon-secreting neurons are likely to be silent until stimulated to release the hormone. Our results suggest that NCCAP form an interacting neuronal network responsible for the regulation and release of bursicon and suggest a model in which PKA-mediated stimulation of inputs to normally quiescent bursicon-expressing neurons activates release of the hormone.

}, keywords = {Animals, Bacterial Proteins, Cyclic AMP-Dependent Protein Kinases, Drosophila melanogaster, Drosophila Proteins, Electroretinography, Ganglia, Gene Targeting, Genetically Modified, Invertebrate, Invertebrate Hormones, Nerve Net, Neurons, Neuropeptides, Phenotype, Pigmentation, Recombinant Fusion Proteins, Shaker Superfamily of Potassium Channels, Sodium Channels, Synaptic Transmission, Wing}, issn = {1529-2401}, doi = {10.1523/JNEUROSCI.3916-05.2006}, author = {Luan, Haojiang and Lemon, William C and Peabody, Nathan C and Pohl, Jascha B and Zelensky, Paul K and Wang, Ding and Nitabach, Michael N and Holmes, Todd C and White, Benjamin H} }