@article {70139, title = {In-situ glial cell-surface proteomics identifies pro-longevity factors in Drosophila}, journal = {bioRxiv}, year = {2025}, month = {2025 Sep 28}, abstract = {

Much focus has shifted towards understanding how glial dysfunction contributes to age-related neurodegeneration due to the critical roles glial cells play in maintaining healthy brain function. Cell-cell interactions, which are largely mediated by cell-surface proteins, control many critical aspects of development and physiology; as such, dysregulation of glial cell-surface proteins in particular is hypothesized to play an important role in age-related neurodegeneration. However, it remains technically difficult to profile glial cell-surface proteins in intact brains. Here, we applied a cell-surface proteomic profiling method to glial cells from intact brains in Drosophila, which enabled us to fully profile cell-surface proteomes in-situ, preserving native cell-cell interactions that would otherwise be omitted using traditional proteomics methods. Applying this platform to young and old flies, we investigated how glial cell-surface proteomes change during aging. We identified candidate genes predicted to be involved in brain aging, including several associated with neural development and synapse wiring molecules not previously thought to be particularly active in glia. Through a functional genetic screen, we identified one surface protein, DIP-β, which is down-regulated in old flies and can increase fly lifespan when overexpressed in adult glial cells. We further performed whole-head single-nucleus RNA-seq, and revealed that DIP-β overexpression mainly impacts glial and fat cells. We also found that glial DIP-β overexpression was associated with improved cell-cell communication, which may contribute to the observed lifespan extension. Our study is the first to apply in-situ cell-surface proteomics to glial cells in Drosophila, and to identify DIP-β as a potential glial regulator of brain aging.Competing Interest StatementThe authors have declared no competing interest.The original mass spectra and the protein sequence databases used for searches have been deposited in the public proteomics repository MassIVE (http://massive.ucsd.edu) (username: MSV000099083; password: glial). These datasets will be made public upon acceptance of the manuscript. Original proteomic data prior to analyses is provided in the Supplementary Table 1. snRNA-seq data has been deposited to NCBI Gene Expression Omnibus (GSE308135).

}, doi = {10.1101/2025.09.26.678810}, url = {https://www.biorxiv.org/content/early/2025/09/28/2025.09.26.678810}, author = {Marques, Madeline P. and Sun, Bo and Park, Ye-Jin and Jackson, Tyler and Lu, Tzu-Chiao and Qi, Yanyan and Harrison, Erin and Wang, Miranda C. and Venkatachalam, Kartik and Pasha, Omar Moussa and Varanasi, Amogh and Carey, Dominique Kiki and Mani, D.R. and Zirin, Jonathan and Qadiri, Mujeeb and Hu, Yanhui and Perrimon, Norbert and Carr, Steven A. and Udeshi, Namrata D. and Luo, Liqun and Li, Jiefu and Li, Hongjie} } @article {69482, title = {Aging atlas reveals cell-type-specific effects of pro-longevity strategies.}, journal = {Nat Aging}, year = {2024}, month = {2024 May 30}, abstract = {

Organismal aging involves functional declines in both somatic and reproductive tissues. Multiple strategies have been discovered to extend lifespan across species. However, how age-related molecular changes differ among various tissues and how those lifespan-extending strategies slow tissue aging in distinct manners remain unclear. Here we generated the transcriptomic Cell Atlas of Worm Aging (CAWA, http://mengwanglab.org/atlas ) of wild-type and long-lived strains. We discovered cell-specific, age-related molecular and functional signatures across all somatic and germ cell types. We developed transcriptomic aging clocks for different tissues and quantitatively determined how three different pro-longevity strategies slow tissue aging distinctively. Furthermore, through genome-wide profiling of alternative polyadenylation (APA) events in different tissues, we discovered cell-type-specific APA changes during aging and revealed how these changes are differentially affected by the pro-longevity strategies. Together, this study offers fundamental molecular insights into both somatic and reproductive aging and provides a valuable resource for in-depth understanding of the diversity of pro-longevity mechanisms.

}, issn = {2662-8465}, doi = {10.1038/s43587-024-00631-1}, author = {Gao, Shihong Max and Qi, Yanyan and Zhang, Qinghao and Guan, Youchen and Lee, Yi-Tang and Ding, Lang and Wang, Lihua and Mohammed, Aaron S and Li, Hongjie and Fu, Yusi and Wang, Meng C} } @article {69534, title = {Molecular and cellular mechanisms of teneurin signaling in synaptic partner matching.}, journal = {Cell}, year = {2024}, month = {2024 Jul 03}, abstract = {

In developing brains, axons exhibit remarkable precision in selecting synaptic partners among many non-partner cells. Evolutionarily conserved teneurins are transmembrane proteins that instruct synaptic partner matching. However, how intracellular signaling pathways execute teneurins{\textquoteright} functions is unclear. Here, we use in situ proximity labeling to obtain the intracellular interactome of a teneurin (Ten-m) in the Drosophila brain. Genetic interaction studies using quantitative partner matching assays in both olfactory receptor neurons (ORNs) and projection neurons (PNs) reveal a common pathway: Ten-m binds to and negatively regulates a RhoGAP, thus activating the Rac1 small GTPases to promote synaptic partner matching. Developmental analyses with single-axon resolution identify the cellular mechanism of synaptic partner matching: Ten-m signaling promotes local F-actin levels and stabilizes ORN axon branches that contact partner PN dendrites. Combining spatial proteomics and high-resolution phenotypic analyses, this study advanced our understanding of both cellular and molecular mechanisms of synaptic partner matching.

}, issn = {1097-4172}, doi = {10.1016/j.cell.2024.06.022}, author = {Xu, Chuanyun and Li, Zhuoran and Lyu, Cheng and Hu, Yixin and McLaughlin, Colleen N and Wong, Kenneth Kin Lam and Xie, Qijing and Luginbuhl, David J and Li, Hongjie and Udeshi, Namrata D and Svinkina, Tanya and Mani, D R and Han, Shuo and Li, Tongchao and Li, Yang and Guajardo, Ricardo and Ting, Alice Y and Carr, Steven A and Li, Jiefu and Luo, Liqun} } @article {68933, title = {Biomechanical origins of proprioceptor feature selectivity and topographic maps in the Drosophila leg.}, journal = {Neuron}, year = {2023}, month = {2023 Aug 04}, abstract = {

Our ability to sense and move our bodies relies on proprioceptors, sensory neurons that detect mechanical forces within the body. Different subtypes of proprioceptors detect different kinematic features, such as joint position, movement, and vibration, but the mechanisms that underlie proprioceptor feature selectivity remain poorly understood. Using single-nucleus RNA sequencing (RNA-seq), we found that proprioceptor subtypes in the Drosophila leg lack differential expression of mechanosensitive ion channels. However, anatomical reconstruction of the proprioceptors and connected tendons revealed major biomechanical differences between subtypes. We built a model of the proprioceptors and tendons that identified a biomechanical mechanism for joint angle selectivity and predicted the existence of a topographic map of joint angle, which we confirmed using calcium imaging. Our findings suggest that biomechanical specialization is a key determinant of proprioceptor feature selectivity in Drosophila. More broadly, the discovery of proprioceptive maps reveals common organizational principles between proprioception and other topographically organized sensory systems.

}, issn = {1097-4199}, doi = {10.1016/j.neuron.2023.07.009}, author = {Mamiya, Akira and Sustar, Anne and Siwanowicz, Igor and Qi, Yanyan and Lu, Tzu-Chiao and Gurung, Pralaksha and Chen, Chenghao and Phelps, Jasper S and Kuan, Aaron T and Pacureanu, Alexandra and Lee, Wei-Chung Allen and Li, Hongjie and Mhatre, Natasha and Tuthill, John C} } @article {68422, title = {Fly Cell Atlas: A single-nucleus transcriptomic atlas of the adult fruit fly.}, journal = {Science}, volume = {375}, year = {2022}, month = {03/2022}, pages = {eabk2432}, abstract = {

For more than 100 years, the fruit fly has been one of the most studied model organisms. Here, we present a single-cell atlas of the adult fly, Tabula , that includes 580,000 nuclei from 15 individually dissected sexed tissues as well as the entire head and body, annotated to \>250 distinct cell types. We provide an in-depth analysis of cell type-related gene signatures and transcription factor markers, as well as sexual dimorphism, across the whole animal. Analysis of common cell types between tissues, such as blood and muscle cells, reveals rare cell types and tissue-specific subtypes. This atlas provides a valuable resource for the community and serves as a reference to study genetic perturbations and disease models at single-cell resolution.

}, keywords = {Animals, Cell Nucleus, Databases, Genetic, Drosophila melanogaster, Drosophila Proteins, Female, Gene Expression Regulation, Gene Regulatory Networks, Genes, Insect, Male, RNA-Seq, Sex Characteristics, Single-Cell Analysis, Transcription Factors, Transcriptome}, issn = {1095-9203}, doi = {10.1126/science.abk2432}, author = {Li, Hongjie and Janssens, Jasper and De Waegeneer, Maxime and Kolluru, Sai Saroja and Davie, Kristofer and Gardeux, Vincent and Saelens, Wouter and David, Fabrice P A and Brbi{\'c}, Maria and Spanier, Katina and Leskovec, Jure and McLaughlin, Colleen N and Xie, Qijing and Jones, Robert C and Brueckner, Katja and Shim, Jiwon and Tattikota, Sudhir Gopal and Schnorrer, Frank and Rust, Katja and Nystul, Todd G and Carvalho-Santos, Zita and Ribeiro, Carlos and Pal, Soumitra and Mahadevaraju, Sharvani and Przytycka, Teresa M and Allen, Aaron M and Goodwin, Stephen F and Berry, Cameron W and Fuller, Margaret T and White-Cooper, Helen and Matunis, Erika L and DiNardo, Stephen and Galenza, Anthony and O{\textquoteright}Brien, Lucy Erin and Dow, Julian A T and Jasper, Heinrich and Oliver, Brian and Perrimon, Norbert and Deplancke, Bart and Quake, Stephen R and Luo, Liqun and Aerts, Stein and Agarwal, Devika and Ahmed-Braimah, Yasir and Arbeitman, Michelle and Ariss, Majd M and Augsburger, Jordan and Ayush, Kumar and Baker, Catherine C and Banisch, Torsten and Birker, Katja and Bodmer, Rolf and Bolival, Benjamin and Brantley, Susanna E and Brill, Julie A and Brown, Nora C and Buehner, Norene A and Cai, Xiaoyu Tracy and Cardoso-Figueiredo, Rita and Casares, Fernando and Chang, Amy and Clandinin, Thomas R and Crasta, Sheela and Desplan, Claude and Detweiler, Angela M and Dhakan, Darshan B and Don{\`a}, Erika and Engert, Stefanie and Floc{\textquoteright}hlay, Swann and George, Nancy and Gonz{\'a}lez-Segarra, Amanda J and Groves, Andrew K and Gumbin, Samantha and Guo, Yanmeng and Harris, Devon E and Heifetz, Yael and Holtz, Stephen L and Horns, Felix and Hudry, Bruno and Hung, Ruei-Jiun and Jan, Yuh Nung and Jaszczak, Jacob S and Jefferis, Gregory S X E and Karkanias, Jim and Karr, Timothy L and Katheder, Nadja Sandra and Kezos, James and Kim, Anna A and Kim, Seung K and Kockel, Lutz and Konstantinides, Nikolaos and Kornberg, Thomas B and Krause, Henry M and Labott, Andrew Thomas and Laturney, Meghan and Lehmann, Ruth and Leinwand, Sarah and Li, Jiefu and Li, Joshua Shing Shun and Li, Kai and Li, Ke and Li, Liying and Li, Tun and Litovchenko, Maria and Liu, Han-Hsuan and Liu, Yifang and Lu, Tzu-Chiao and Manning, Jonathan and Mase, Anjeli and Matera-Vatnick, Mikaela and Matias, Neuza Reis and McDonough-Goldstein, Caitlin E and McGeever, Aaron and McLachlan, Alex D and Moreno-Roman, Paola and Neff, Norma and Neville, Megan and Ngo, Sang and Nielsen, Tanja and O{\textquoteright}Brien, Caitlin E and Osumi-Sutherland, David and Ozel, Mehmet Neset and Papatheodorou, Irene and Petkovic, Maja and Pilgrim, Clare and Pisco, Angela Oliveira and Reisenman, Carolina and Sanders, Erin Nicole and Dos Santos, Gilberto and Scott, Kristin and Sherlekar, Aparna and Shiu, Philip and Sims, David and Sit, Rene V and Slaidina, Maija and Smith, Harold E and Sterne, Gabriella and Su, Yu-Han and Sutton, Daniel and Tamayo, Marco and Tan, Michelle and Tastekin, Ibrahim and Treiber, Christoph and Vacek, David and Vogler, Georg and Waddell, Scott and Wang, Wanpeng and Wilson, Rachel I and Wolfner, Mariana F and Wong, Yiu-Cheung E and Xie, Anthony and Xu, Jun and Yamamoto, Shinya and Yan, Jia and Yao, Zepeng and Yoda, Kazuki and Zhu, Ruijun and Zinzen, Robert P} } @article {68419, title = {Transcription factor Acj6 controls dendrite targeting via a combinatorial cell-surface code.}, journal = {Neuron}, volume = {110}, year = {2022}, month = {07/2022}, pages = {2299-2314.e8}, abstract = {

Transcription factors specify the fate and connectivity of developing neurons. We investigate how a lineage-specific transcription factor, Acj6, controls the precise dendrite targeting of Drosophila olfactory projection neurons (PNs) by regulating the expression of cell-surface proteins. Quantitative cell-surface proteomic profiling of wild-type and acj6 mutant PNs in intact developing brains, and a proteome-informed genetic screen identified PN surface proteins that execute Acj6-regulated wiring decisions. These include canonical cell adhesion molecules and proteins previously not associated with wiring, such as Piezo, whose mechanosensitive ion channel activity is dispensable for its function in PN dendrite targeting. Comprehensive genetic analyses revealed that Acj6 employs unique sets of cell-surface proteins in different PN types for dendrite targeting. Combined expression of Acj6 wiring executors rescued acj6 mutant phenotypes with higher efficacy and breadth than expression of individual executors. Thus, Acj6 controls wiring specificity of different neuron types by specifying distinct combinatorial expression of cell-surface executors.

}, keywords = {Animals, Dendrites, Drosophila, Drosophila Proteins, Ion Channels, Membrane Proteins, Nerve Tissue Proteins, Olfactory Pathways, Olfactory Receptor Neurons, POU Domain Factors, Proteomics, Transcription Factors}, issn = {1097-4199}, doi = {10.1016/j.neuron.2022.04.026}, author = {Xie, Qijing and Li, Jiefu and Li, Hongjie and Udeshi, Namrata D and Svinkina, Tanya and Orlin, Daniel and Kohani, Sayeh and Guajardo, Ricardo and Mani, D R and Xu, Chuanyun and Li, Tongchao and Han, Shuo and Wei, Wei and Shuster, S Andrew and Luginbuhl, David J and Quake, Stephen R and Murthy, Swetha E and Ting, Alice Y and Carr, Steven A and Luo, Liqun} } @article {67737, title = {Cellular bases of olfactory circuit assembly revealed by systematic time-lapse imaging.}, journal = {Cell}, volume = {184}, year = {2021}, month = {2021 Sep 30}, pages = {5107}, abstract = {

Neural circuit assembly features simultaneous targeting of numerous neuronal processes from constituent neuron types, yet the dynamics is poorly understood. Here, we use the Drosophila olfactory circuit to investigate dynamic cellular processes by which olfactory receptor neurons (ORNs) target axons precisely to specific glomeruli in the ipsi- and contralateral antennal lobes. Time-lapse imaging of individual axons from 30 ORN types revealed a rich diversity in extension speed, innervation timing, and ipsilateral branch locations and identified that ipsilateral targeting occurs via stabilization of transient interstitial branches. Fast imaging using adaptive optics-corrected lattice light-sheet microscopy showed that upon approaching target, many ORN types exhibiting "exploring branches" consisted of parallel microtubule-based terminal branches emanating from an F-actin-rich hub. Antennal nerve ablations uncovered essential roles for bilateral axons in contralateral target selection and for ORN axons to facilitate dendritic refinement of postsynaptic partner neurons. Altogether, these observations provide cellular bases for wiring specificity establishment.

}, issn = {1097-4172}, doi = {10.1016/j.cell.2021.08.030}, author = {Li, Tongchao and Fu, Tian-Ming and Wong, Kenneth Kin Lam and Li, Hongjie and Xie, Qijing and Luginbuhl, David J and Wagner, Mark J and Betzig, Eric and Luo, Liqun} } @article {68425, title = {Single-cell transcriptomes of developing and adult olfactory receptor neurons in Drosophila}, journal = {Elife}, volume = {10}, year = {2021}, month = {02/2021}, abstract = {

Recognition of environmental cues is essential for the survival of all organisms. Transcriptional changes occur to enable the generation and function of the neural circuits underlying sensory perception. To gain insight into these changes, we generated single-cell transcriptomes of olfactory- (ORNs), thermo-, and hygro-sensory neurons at an early developmental and adult stage using single-cell and single-nucleus RNA sequencing. We discovered that ORNs maintain expression of the same olfactory receptors across development. Using receptor expression and computational approaches, we matched transcriptomic clusters corresponding to anatomically and physiologically defined neuron types across multiple developmental stages. We found that cell-type-specific transcriptomes partly reflected axon trajectory choices in development and sensory modality in adults. We uncovered stage-specific genes that could regulate the wiring and sensory responses of distinct ORN types. Collectively, our data reveal transcriptomic features of sensory neuron biology and provide a resource for future studies of their development and physiology.

}, keywords = {Animals, Drosophila melanogaster, Drosophila Proteins, Female, Male, Olfactory Receptor Neurons, Sequence Analysis, RNA, Single-Cell Analysis, Smell, Transcriptome}, issn = {2050-084X}, doi = {10.7554/eLife.63856}, author = {McLaughlin, Colleen N and Brbi{\'c}, Maria and Xie, Qijing and Li, Tongchao and Horns, Felix and Kolluru, Sai Saroja and Kebschull, Justus M and Vacek, David and Xie, Anthony and Li, Jiefu and Jones, Robert C and Leskovec, Jure and Quake, Stephen R and Luo, Liqun and Li, Hongjie} } @article {68426, title = {Temporal evolution of single-cell transcriptomes of olfactory projection neurons.}, journal = {Elife}, volume = {10}, year = {2021}, month = {01/2021}, abstract = {

Neurons undergo substantial morphological and functional changes during development to form precise synaptic connections and acquire specific physiological properties. What are the underlying transcriptomic bases? Here, we obtained the single-cell transcriptomes of olfactory projection neurons (PNs) at four developmental stages. We decoded the identity of 21 transcriptomic clusters corresponding to 20 PN types and developed methods to match transcriptomic clusters representing the same PN type across development. We discovered that PN transcriptomes reflect unique biological processes unfolding at each stage-neurite growth and pruning during metamorphosis at an early pupal stage; peaked transcriptomic diversity during olfactory circuit assembly at mid-pupal stages; and neuronal signaling in adults. At early developmental stages, PN types with adjacent birth order share similar transcriptomes. Together, our work reveals principles of cellular diversity during brain development and provides a resource for future studies of neural development in PNs and other neuronal types.

}, keywords = {Animals, Drosophila melanogaster, Neurites, Olfactory Nerve, Single-Cell Analysis, Time Factors, Transcriptome}, issn = {2050-084X}, doi = {10.7554/eLife.63450}, author = {Xie, Qijing and Brbi{\'c}, Maria and Horns, Felix and Kolluru, Sai Saroja and Jones, Robert C and Li, Jiefu and Reddy, Anay R and Xie, Anthony and Kohani, Sayeh and Li, Zhuoran and McLaughlin, Colleen N and Li, Tongchao and Xu, Chuanyun and Vacek, David and Luginbuhl, David J and Leskovec, Jure and Quake, Stephen R and Luo, Liqun and Li, Hongjie} } @article {68429, title = {Cell-Surface Proteomic Profiling in the Fly Brain Uncovers Wiring Regulators.}, journal = {Cell}, volume = {180}, year = {2020}, month = {01/2020}, pages = {373-386.e15}, abstract = {

Molecular interactions at the cellular interface mediate organized assembly of single cells into tissues and, thus, govern the development and physiology of multicellular organisms. Here, we developed a cell-type-specific, spatiotemporally resolved approach to profile cell-surface proteomes in intact tissues. Quantitative profiling of cell-surface proteomes of Drosophila olfactory projection neurons (PNs) in pupae and adults revealed global downregulation of wiring molecules and upregulation of synaptic molecules in the transition from developing to mature PNs. A proteome-instructed in\ vivo screen identified 20 cell-surface molecules regulating neural circuit assembly, many of which belong to evolutionarily conserved protein families not previously linked to neural development. Genetic analysis further revealed that the lipoprotein receptor LRP1 cell-autonomously controls PN dendrite targeting, contributing to the formation of a precise olfactory map. These findings highlight the power of temporally resolved in situ cell-surface proteomic profiling in discovering regulators of brain wiring.

}, keywords = {Animals, Axons, Brain, Dendrites, Drosophila melanogaster, Drosophila Proteins, Gene Expression Profiling, Gene Expression Regulation, Developmental, Membrane Proteins, Neurogenesis, Olfactory Nerve, Olfactory Pathways, Olfactory Receptor Neurons, Proteomics, Receptors, Lipoprotein, Smell}, issn = {1097-4172}, doi = {10.1016/j.cell.2019.12.029}, author = {Li, Jiefu and Han, Shuo and Li, Hongjie and Udeshi, Namrata D and Svinkina, Tanya and Mani, D R and Xu, Chuanyun and Guajardo, Ricardo and Xie, Qijing and Li, Tongchao and Luginbuhl, David J and Wu, Bing and McLaughlin, Colleen N and Xie, Anthony and Kaewsapsak, Pornchai and Quake, Stephen R and Carr, Steven A and Ting, Alice Y and Luo, Liqun} } @article {68428, title = {Single-Cell Transcriptomes Reveal Diverse Regulatory Strategies for Olfactory Receptor Expression and Axon Targeting.}, journal = {Curr Biol}, volume = {30}, year = {2020}, month = {04/2020}, pages = {1189-1198.e5}, abstract = {

The regulatory mechanisms by which neurons coordinate their physiology and connectivity are not well understood. The Drosophila olfactory receptor neurons (ORNs) provide an excellent system to investigate this question. Each ORN type expresses a unique olfactory receptor, or a combination thereof, and sends their axons to a stereotyped glomerulus. Using single-cell RNA sequencing, we identified 33 transcriptomic clusters for ORNs and mapped 20 to their glomerular types, demonstrating that transcriptomic clusters correspond well with anatomically and physiologically defined ORN types. Each ORN type expresses hundreds of transcription factors. Transcriptome-instructed genetic analyses revealed that (1) one broadly expressed transcription factor (Acj6) only regulates olfactory receptor expression in one ORN type and only wiring specificity in another type, (2) one type-restricted transcription factor (Forkhead) only regulates receptor expression, and (3) another type-restricted transcription factor (Unplugged) regulates both events. Thus, ORNs utilize diverse strategies and complex regulatory networks to coordinate their physiology and connectivity.

}, keywords = {Animals, Axons, Drosophila melanogaster, Drosophila Proteins, Forkhead Transcription Factors, Homeodomain Proteins, Nerve Tissue Proteins, Olfactory Receptor Neurons, POU Domain Factors, Receptors, Odorant, Single-Cell Analysis, Smell, Transcriptome}, issn = {1879-0445}, doi = {10.1016/j.cub.2020.01.049}, author = {Li, Hongjie and Li, Tongchao and Horns, Felix and Li, Jiefu and Xie, Qijing and Xu, Chuanyun and Wu, Bing and Kebschull, Justus M and McLaughlin, Colleen N and Kolluru, Sai Saroja and Jones, Robert C and Vacek, David and Xie, Anthony and Luginbuhl, David J and Quake, Stephen R and Luo, Liqun} } @article {68430, title = {Transsynaptic Fish-lips signaling prevents misconnections between nonsynaptic partner olfactory neurons.}, journal = {Proc Natl Acad Sci U S A}, volume = {116}, year = {2019}, month = {08/2019}, pages = {16068-16073}, abstract = {

Our understanding of the mechanisms of neural circuit assembly is far from complete. Identification of wiring molecules with novel mechanisms of action will provide insights into how complex and heterogeneous neural circuits assemble during development. In the olfactory system, 50 classes of olfactory receptor neurons (ORNs) make precise synaptic connections with 50 classes of partner projection neurons (PNs). Here, we performed an RNA interference screen for cell surface molecules and identified the leucine-rich repeat-containing transmembrane protein known as Fish-lips (Fili) as a novel wiring molecule in the assembly of the olfactory circuit. Fili contributes to the precise axon and dendrite targeting of a small subset of ORN and PN classes, respectively. Cell-type-specific expression and genetic analyses suggest that Fili sends a transsynaptic repulsive signal to neurites of nonpartner classes that prevents their targeting to inappropriate glomeruli in the antennal lobe.

}, keywords = {Animals, Axons, Dendrites, Drosophila melanogaster, Drosophila Proteins, Leucine-Rich Repeat Proteins, Membrane Proteins, Mutation, Olfactory Receptor Neurons, Phenotype, Proteins, Signal Transduction, Synapses}, issn = {1091-6490}, doi = {10.1073/pnas.1905832116}, author = {Xie, Qijing and Wu, Bing and Li, Jiefu and Xu, Chuanyun and Li, Hongjie and Luginbuhl, David J and Wang, Xin and Ward, Alex and Luo, Liqun} } @article {68435, title = {Linking neuronal lineage and wiring specificity.}, journal = {Neural Dev}, volume = {13}, year = {2018}, month = {04/2018}, pages = {5}, abstract = {

Brain function requires precise neural circuit assembly during development. Establishing a functional circuit involves multiple coordinated steps ranging from neural cell fate specification to proper matching between pre- and post-synaptic partners. How neuronal lineage and birth timing influence wiring specificity remains an open question. Recent findings suggest that the relationships between lineage, birth timing, and wiring specificity vary in different neuronal circuits. In this review, we summarize our current understanding of the cellular, molecular, and developmental mechanisms linking neuronal lineage and birth timing to wiring specificity in a few specific systems in Drosophila and mice, and review different methods employed to explore these mechanisms.

}, keywords = {Animals, Brain, Cell Lineage, Neural Pathways, Neurons}, issn = {1749-8104}, doi = {10.1186/s13064-018-0102-0}, author = {Li, Hongjie and Shuster, S Andrew and Li, Jiefu and Luo, Liqun} } @article {68432, title = { Stepwise wiring of the Drosophila olfactory map requires specific Plexin B levels}, journal = {Elife}, volume = {7}, year = {2018}, month = {08/2018}, abstract = {

The precise assembly of a neural circuit involves many consecutive steps. The conflict between a limited number of wiring molecules and the complexity of the neural network impels each molecule to execute multiple functions at different steps. Here, we examined the cell-type specific distribution of endogenous levels of axon guidance receptor Plexin B (PlexB) in the developing antennal lobe, the first olfactory processing center in . We found that different classes of olfactory receptor neurons (ORNs) express PlexB at different levels in two wiring steps - axonal trajectory choice and subsequent target selection. In line with its temporally distinct patterns, the proper levels of PlexB control both steps in succession. Genetic interactions further revealed that the effect of high-level PlexB is antagonized by its canonical partner Sema2b. Thus, PlexB plays a multifaceted role in instructing the assembly of the olfactory circuit through temporally-regulated expression patterns and expression level-dependent effects.

}, keywords = {Animals, Arthropod Antennae, Axons, Drosophila melanogaster, Drosophila Proteins, Models, Biological, Nerve Tissue Proteins, Olfactory Receptor Neurons, Receptors, Cell Surface, Smell}, issn = {2050-084X}, doi = {10.7554/eLife.39088}, author = {Li, Jiefu and Guajardo, Ricardo and Xu, Chuanyun and Wu, Bing and Li, Hongjie and Li, Tongchao and Luginbuhl, David J and Xie, Xiaojun and Luo, Liqun} } @article {68437, title = {Classifying Drosophila Olfactory Projection Neuron Subtypes by Single-Cell RNA Sequencing.}, journal = {Cell}, volume = {171}, year = {2017}, month = {11/2017}, pages = {1206-1220.e22}, abstract = {

The definition of neuronal type and how it relates to the transcriptome are open questions. Drosophila olfactory projection neurons (PNs) are among the best-characterized neuronal types: different PN classes target dendrites to distinct olfactory glomeruli, while PNs of the same class exhibit indistinguishable anatomical and physiological properties. Using single-cell RNA sequencing, we comprehensively characterized the transcriptomes of most PN classes and unequivocally mapped transcriptomes to specific olfactory function for six classes. Transcriptomes of\ closely related PN classes exhibit the largest differences during circuit assembly but become indistinguishable in adults, suggesting that neuronal subtype diversity peaks during development. Transcription factors and cell-surface molecules are the most differentially expressed genes between classes and are highly informative in encoding cell identity, enabling us to identify a new lineage-specific transcription factor that instructs PN dendrite targeting. These findings establish that neuronal transcriptomic identity corresponds with anatomical and physiological identity defined by connectivity and function.

}, keywords = {Animals, Brain, Cluster Analysis, Dendrites, Drosophila melanogaster, Gene Expression Profiling, Neurons, Olfactory Bulb, Organ Specificity, Pupa, Sequence Analysis, RNA, Single-Cell Analysis, Transcription Factors}, issn = {1097-4172}, doi = {10.1016/j.cell.2017.10.019}, author = {Li, Hongjie and Horns, Felix and Wu, Bing and Xie, Qijing and Li, Jiefu and Li, Tongchao and Luginbuhl, David J and Quake, Stephen R and Luo, Liqun} }