@article {49232, title = {Lineage-guided Notch-dependent gliogenesis by multi-potent progenitors.}, journal = {Development (Cambridge, England)}, year = {2018}, month = {2018 May 15}, abstract = {

Macroglial cells in the central nervous system exhibit regional specialization and carry out region-specific functions. Diverse glial cells arise from specific progenitors in specific spatiotemporal patterns. This raises an interesting possibility that there exist glial precursors with distinct developmental fates, which govern region-specific gliogenesis. Here we mapped the glial progeny produced by the type II neuroblasts, which, like vertebrate radial glia cells, yield both neurons and glia via intermediate neural progenitors (INPs). Distinct type II neuroblasts produce different characteristic sets of glia. A single INP can make both astrocyte-like and ensheathing glia, which co-occupy a relatively restrictive subdomain. Blocking apoptosis uncovers further lineage distinctions in the specification, proliferation, and survival of glial precursors. Both the switch from neurogenesis to gliogenesis and the subsequent glial expansion depend on Notch signaling. Taken together, lineage origins preconfigure the development of individual glial precursors with involvement of serial Notch actions in promoting gliogenesis.

}, issn = {1477-9129}, doi = {10.1242/dev.160127}, author = {Ren, Qingzhong and Awasaki, Takeshi and Wang, Yu-Chun and Huang, Yu-Fen and Lee, Tzumin} } @article {47849, title = {Cell class-lineage analysis reveals sexually dimorphic lineage compositions in the Drosophila brain.}, journal = {Current Biology : CB}, volume = {26}, year = {2016}, month = {2016 Sep 08}, pages = {2583-93}, abstract = {

The morphology and physiology of neurons are directed by developmental decisions made within their lines of descent from single stem cells. Distinct stem cells may produce neurons having shared properties that define their cell class, such as the type of secreted neurotransmitter. The relationship between cell class and lineage is complex. Here we developed the transgenic cell class-lineage intersection (CLIn) system to assign cells of a particular class to specific lineages within the Drosophila brain. CLIn also enables birth-order analysis and genetic manipulation of particular cell classes arising from particular lineages. We demonstrated the power of CLIn in the context of the eight central brain type II lineages, which produce highly diverse progeny through intermediate neural progenitors. We mapped 18 dopaminergic neurons from three distinct clusters to six type\ II lineages that show lineage-characteristic neurite trajectories. In addition, morphologically distinct dopaminergic neurons are produced within a given lineage, and they arise in an invariant sequence. We also identified type II lineages that produce doublesex- and fruitless-expressing neurons and examined whether female-specific apoptosis in these lineages accounts for the lower number of these neurons in the female brain. Blocking apoptosis in these lineages resulted in more cells in both sexes with males still carrying more cells than females. This argues that sex-specific stem cell fate together with differential progeny apoptosis contribute to the final sexual dimorphism.

}, issn = {1879-0445}, doi = {10.1016/j.cub.2016.07.086}, author = {Ren, Qingzhong and Awasaki, Takeshi and Huang, Yu-Fen and Liu, Zhiyong 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 {6284, title = {Clonal development and organization of the adult Drosophila central brain.}, journal = {Current biology : CB}, volume = {23}, year = {2013}, month = {2013 Apr 22}, pages = {633-43}, abstract = {BACKGROUND: The insect brain can be divided into neuropils that are formed by neurites of both local and remote origin. The complexity of the interconnections obscures how these neuropils are established and interconnected through development. The Drosophila central brain develops from a fixed number of neuroblasts (NBs) that deposit neurons in regional clusters. RESULTS: By determining individual NB clones and pursuing their projections into specific neuropils, we unravel the regional development of the brain neural network. Exhaustive clonal analysis revealed 95 stereotyped neuronal lineages with characteristic cell-body locations and neurite trajectories. Most clones show complex projection patterns, but despite the complexity, neighboring clones often coinnervate the same local neuropil or neuropils and further target a restricted set of distant neuropils. CONCLUSIONS: These observations argue for regional clonal development of both neuropils and neuropil connectivity throughout the Drosophila central brain.}, issn = {1879-0445}, doi = {10.1016/j.cub.2013.02.057}, author = {Yu, Hung-Hsiang and Awasaki, Takeshi and Schroeder, Mark David and Long, Fuhui and Yang, Jacob S and He, Yisheng and Ding, Peng and Kao, Jui-Chun and Wu, Gloria Yueh-Yi and Peng, Hanchuan and Myers, Gene and Lee, Tzumin} } @article {6277, title = {Diverse neuronal lineages make stereotyped contributions to the Drosophila locomotor control center, the central complex.}, journal = {The Journal of Comparative Neurology}, volume = {521}, year = {2013}, month = {2013 Aug 15}, pages = {2645-62, Spc1}, abstract = {

The Drosophila central brain develops from a fixed number of neuroblasts. Each neuroblast makes a clone of neurons that exhibit common trajectories. Here we identified 15 distinct clones that carry larval-born neurons innervating the Drosophila central complex (CX), which consists of four midline structures including the protocerebral bridge (PB), fan-shaped body (FB), ellipsoid body (EB), and noduli (NO). Clonal analysis revealed that the small-field CX neurons, which establish intricate projections across different CX substructures, exist in four isomorphic groups that respectively derive from four complex posterior asense-negative lineages. In terms of the region-characteristic large-field CX neurons, we found that two lineages make PB neurons, 10 lineages produce FB neurons, three lineages generate EB neurons, and two lineages yield NO neurons. The diverse FB developmental origins reflect the discrete input pathways for different FB subcompartments. Clonal analysis enlightens both development and anatomy of the insect locomotor control center.

}, issn = {1096-9861}, doi = {10.1002/cne.23339}, author = {Yang, Jacob S and Awasaki, Takeshi and Yu, Hung-Hsiang and He, Yisheng and Ding, Peng and Kao, Jui-Chun and Lee, Tzumin} } @article {4486, title = {Use of a Drosophila genome-wide conserved sequence database to identify functionally related cis-regulatory enhancers.}, journal = {Developmental Dynamics: An Official Publication of the American Association of Anatomists}, volume = {241}, year = {2012}, month = {2012 Jan}, pages = {169-89}, abstract = {

Phylogenetic footprinting has revealed that cis-regulatory enhancers consist of conserved DNA sequence clusters (CSCs). Currently, there is no systematic approach for enhancer discovery and analysis that takes full-advantage of the sequence information within enhancer CSCs.

}, issn = {1097-0177}, doi = {10.1002/dvdy.22728}, author = {Brody, Thomas and Yavatkar, Amarendra S and Kuzin, Alexander and Kundu, Mukta and Tyson, Leonard J and Ross, Jermaine and Lin, Tzu-Yang and Lee, Chi-Hon and Awasaki, Takeshi and Lee, Tzumin and Odenwald, Ward F} } @article {4300, title = {Glia instruct developmental neuronal remodeling through TGF-β signaling.}, journal = {Nature Neuroscience}, volume = {14}, year = {2011}, month = {2011 Jun 19}, pages = {821-3}, abstract = {

We found that glia secrete myoglianin, a TGF-β ligand, to instruct developmental neural remodeling in Drosophila. Glial myoglianin upregulated neuronal expression of an ecdysone nuclear receptor that triggered neurite remodeling following the late-larval ecdysone peak. Thus glia orchestrate developmental neural remodeling not only by engulfment of unwanted neurites but also by enabling neuron remodeling.

}, keywords = {Animals, Developmental, Double-Stranded, Drosophila, Drosophila Proteins, Gene Expression Regulation, Genetically Modified, Green Fluorescent Proteins, MicroRNAs, Models, Mushroom Bodies, Mutation, Neurogenesis, Neuroglia, Neurological, RNA, Signal Transduction, Transforming Growth Factor beta}, issn = {1546-1726}, doi = {10.1038/nn.2833}, author = {Awasaki, Takeshi and Huang, Yaling and O{\textquoteright}Connor, Michael B and Lee, Tzumin} } @article {4301, title = {New tools for the analysis of glial cell biology in Drosophila.}, journal = {Glia}, volume = {59}, year = {2011}, month = {2011 Sep}, pages = {1377-86}, abstract = {

Because of its genetic, molecular, and behavioral tractability, Drosophila has emerged as a powerful model system for studying molecular and cellular mechanisms underlying the development and function of nervous systems. The Drosophila nervous system has fewer neurons and exhibits a lower glia:neuron ratio than is seen in vertebrate nervous systems. Despite the simplicity of the Drosophila nervous system, glial organization in flies is as sophisticated as it is in vertebrates. Furthermore, fly glial cells play vital roles in neural development and behavior. In addition, powerful genetic tools are continuously being created to explore cell function in vivo. In taking advantage of these features, the fly nervous system serves as an excellent model system to study general aspects of glial cell development and function in vivo. In this article, we review and discuss advanced genetic tools that are potentially useful for understanding glial cell biology in Drosophila.

}, keywords = {Animals, Cell Biology, Drosophila, Drosophila Proteins, Gene Expression, Genes, Molecular Biology, Mutation, Neuroglia, Reporter, Transcription Factors, Transgenes, Upstream Stimulatory Factors}, issn = {1098-1136}, doi = {10.1002/glia.21133}, author = {Awasaki, Takeshi and Lee, Tzumin} } @article {794, title = {Clonal analysis of Drosophila antennal lobe neurons: diverse neuronal architectures in the lateral neuroblast lineage.}, journal = {Development}, volume = {135}, year = {2008}, month = {2008 Sep}, pages = {2883-93}, abstract = {

The antennal lobe (AL) is the primary structure in the Drosophila brain that relays odor information from the antennae to higher brain centers. The characterization of uniglomerular projection neurons (PNs) and some local interneurons has facilitated our understanding of olfaction; however, many other AL neurons remain unidentified. Because neuron types are mostly specified by lineage and temporal origins, we use the MARCM techniques with a set of enhancer-trap GAL4 lines to perform systematical lineage analysis to characterize neuron morphologies, lineage origin and birth timing in the three AL neuron lineages that contain GAL4-GH146-positive PNs: anterodorsal, lateral and ventral lineages. The results show that the anterodorsal lineage is composed of pure uniglomerular PNs that project through the inner antennocerebral tract. The ventral lineage produces uniglomerular and multiglomerular PNs that project through the middle antennocerebral tract. The lateral lineage generates multiple types of neurons, including uniglomeurlar PNs, diverse atypical PNs, various types of AL local interneurons and the neurons that make no connection within the ALs. Specific neuron types in all three lineages are produced in specific time windows, although multiple neuron types in the lateral lineage are made simultaneously. These systematic cell lineage analyses have not only filled gaps in the olfactory map, but have also exemplified additional strategies used in the brain to increase neuronal diversity.

}, keywords = {Animal Structures, Animals, Axons, Cell Lineage, Clone Cells, Drosophila melanogaster, Enhancer Elements, Genetic, Mosaicism, Neurons}, issn = {0950-1991}, doi = {10.1242/dev.024380}, author = {Lai, Sen-Lin and Awasaki, Takeshi and Ito, Kei and Lee, Tzumin} } @article {795, title = {Organization and postembryonic development of glial cells in the adult central brain of Drosophila.}, journal = {The Journal of Neuroscience: The Official Journal of the Society for Neuroscience}, volume = {28}, year = {2008}, month = {2008 Dec 17}, pages = {13742-53}, abstract = {

Glial cells exist throughout the nervous system, and play essential roles in various aspects of neural development and function. Distinct types of glia may govern diverse glial functions. To determine the roles of glia requires systematic characterization of glia diversity and development. In the adult Drosophila central brain, we identify five different types of glia based on its location, morphology, marker expression, and development. Perineurial and subperineurial glia reside in two separate single-cell layers on the brain surface, cortex glia form a glial mesh in the brain cortex where neuronal cell bodies reside, while ensheathing and astrocyte-like glia enwrap and infiltrate into neuropils, respectively. Clonal analysis reveals that distinct glial types derive from different precursors, and that most adult perineurial, ensheathing, and astrocyte-like glia are produced after embryogenesis. Notably, perineurial glial cells are made locally on the brain surface without the involvement of gcm (glial cell missing). In contrast, the widespread ensheathing and astrocyte-like glia derive from specific brain regions in a gcm-dependent manner. This study documents glia diversity in the adult fly brain and demonstrates involvement of different developmental programs in the derivation of distinct types of glia. It lays an essential foundation for studying glia development and function in the Drosophila brain.

}, keywords = {Animals, Antigens, Brain, Cell Count, Cell Differentiation, Cell Lineage, Clone Cells, Differentiation, DNA-Binding Proteins, Drosophila, Drosophila Proteins, Embryo, Genetically Modified, Homeodomain Proteins, Larva, Neuroglia, Neurons, Neuropil, Nonmammalian, Transcription Factors}, issn = {1529-2401}, doi = {10.1523/JNEUROSCI.4844-08.2008}, author = {Awasaki, Takeshi and Lai, Sen-Lin and Ito, Kei and Lee, Tzumin} } @article {792, title = {Gradients of the Drosophila Chinmo BTB-zinc finger protein govern neuronal temporal identity.}, journal = {Cell}, volume = {127}, year = {2006}, month = {2006 Oct 20}, pages = {409-22}, abstract = {

Many neural progenitors, including Drosophila mushroom body (MB) and projection neuron (PN) neuroblasts, sequentially give rise to different subtypes of neurons throughout development. We identified a novel BTB-zinc finger protein, named Chinmo (Chronologically inappropriate morphogenesis), that governs neuronal temporal identity during postembryonic development of the Drosophila brain. In both MB and PN lineages, loss of Chinmo autonomously causes early-born neurons to adopt the fates of late-born neurons from the same lineages. Interestingly, primarily due to a posttranscriptional control, MB neurons born at early developmental stages contain more abundant Chinmo than their later-born siblings. Further, the temporal identity of MB progeny can be transformed toward earlier or later fates by reducing or increasing Chinmo levels, respectively. Taken together, we suggest that a temporal gradient of Chinmo (Chinmo(high) {\textendash}\> Chinmo(low)) helps specify distinct birth order-dependent cell fates in an extended neuronal lineage.

}, keywords = {5{\textquoteright} Untranslated Regions, Amino Acid Sequence, Animals, Brain, Cell Differentiation, Cell Lineage, Developmental, Drosophila, Drosophila Proteins, Gene Expression Regulation, Larva, Molecular Sequence Data, Morphogenesis, Mushroom Bodies, Mutation, Nerve Tissue Proteins, Neurons, Post-Translational, Protein Processing, Time Factors, Transgenes, Zinc Fingers}, issn = {0092-8674}, doi = {10.1016/j.cell.2006.08.045}, author = {Zhu, Sijun and Lin, Suewei and Kao, Chih-Fei and Awasaki, Takeshi and Chiang, Ann-Shyn and Lee, Tzumin} }