ABSTRACT
The standard therapies for polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes (POEMS) syndrome are radiation therapy, high-dose chemotherapy followed by autologous stem cell transplantation, and lenalidomide combined with dexamethasone. Daratumumab was reported to be effective for treatment-naive and relapsed POEMS syndrome, but treatment options for relapsed POEMS syndrome with poor prognostic factors or cytogenetic abnormalities have not been established due to a lack of studies in these patients. Here, we describe a case of relapsed POEMS syndrome with bone plasmacytoma harboring a newly detected 17p deletion after high-dose chemotherapy followed by autologous stem cell transplantation and radiation therapy in a male patient. He was successfully treated with daratumumab plus lenalidomide and dexamethasone (Dara-Rd). Dara-Rd could be effective in relapsed POEMS syndrome with 17p deletion, which is known as a poor cytogenetic abnormality in multiple myeloma. This report may broaden the application of Dara-Rd for POEMS syndrome.
Subject(s)
Hematopoietic Stem Cell Transplantation , POEMS Syndrome , Plasmacytoma , Humans , Male , Lenalidomide/therapeutic use , Thalidomide , POEMS Syndrome/drug therapy , Plasmacytoma/drug therapy , Plasmacytoma/genetics , Dexamethasone , Transplantation, AutologousABSTRACT
Aberrant expression of ecotropic viral integration site-1 (EVI1+) is associated with very poor outcomes in acute myeloid leukemia (AML), mechanisms of which are only partially understood. Using the green fluorescent protein reporter system to monitor EVI1 promoter activity, we demonstrated that Evi1high KMT2A-MLLT1-transformed AML cells possess distinct features from Evi1low cells: the potential for aggressive disease independent of stem cell activity and resistance to cytotoxic chemotherapy, along with the consistent gene expression profiles. RNA sequencing and chromatin immunoprecipitation sequencing in EVI1-transformed AML cells and normal hematopoietic cells combined with functional screening by cell proliferation-related short hairpin RNAs revealed that the erythroblast transformation-specific transcription factor ERG (E26 transformation-specific [ETS]-related gene) and cyclin D1 were downstream targets and therapeutic vulnerabilities of EVI1+ AML. Silencing Erg in murine EVI1+ AML models severely impaired cell proliferation, chemoresistance, and leukemogenic capacity. Cyclin D1 is also requisite for efficient EVI1-AML development, associated with gene expression profiles related to chemokine production and interferon signature, and T- and natural killer-cell exhaustion phenotype, depending on the interferon gamma (IFN-γ)/STAT1 pathway but not on CDK4/CDK6. Inhibiting the IFN-γ/STAT1 pathway alleviated immune exhaustion and impaired EVI1-AML development. Overexpression of EVI1 and cyclin D1 was associated with IFN-γ signature and increased expression of chemokines, with increased exhaustion molecules in T cells also in human AML data sets. These data collectively suggest that ERG and cyclin D1 play pivotal roles in the biology of EVI1+ AML, where ERG contributes to aggressive disease nature and chemoresistance, and cyclin D1 leads to IFN-γ signature and exhausted T-cell phenotypes, which could potentially be targeted.
Subject(s)
DNA-Binding Proteins , Leukemia, Myeloid, Acute , Humans , Animals , Mice , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , MDS1 and EVI1 Complex Locus Protein/genetics , Cyclin D1/genetics , Proto-Oncogenes , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/metabolism , Transcriptional Regulator ERG/genetics , Transcription Factors/geneticsABSTRACT
Bing-Neel syndrome (BNS) is a rare central nervous system manifestation of lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM). We herein report a 62-year-old man with LPL/WM after multiple chemotherapies. He had weakness of lower extremities and elevated serum IgM levels. A bone marrow examination showed lymphoplasmacytic cells infiltration. Contrast-enhanced magnetic resonance imaging suggested enhancing lesions in the cauda equina roots. He was diagnosed with BNS and started on treatment with tirabrutinib 480 mg daily. Within three months, he showed clinical and radiologic improvement. Tirabrutinib may have utility as an effective treatment for BNS.
Subject(s)
Brain Diseases , Neurodegenerative Diseases , Waldenstrom Macroglobulinemia , Humans , Male , Middle Aged , Brain Diseases/drug therapy , Neurodegenerative Diseases/drug therapy , Pyrimidines/therapeutic use , Syndrome , Waldenstrom Macroglobulinemia/complications , Waldenstrom Macroglobulinemia/drug therapy , Waldenstrom Macroglobulinemia/pathologyABSTRACT
BACKGROUND: Performing stem cell collection after mobilization chemotherapy was a well-balanced strategy between anti-tumor effect and efficient collection of CD34+ cells, but deep and prolonged nadir exposed patients to risk of febrile neutropenia. Febrile neutropenia was known to be associated with lower yields of CD34+ cells, but quantitative data referring to association between yields of CD34+ cells and severity of neutropenia was lacking. We hypothesized that D-index, which was developed for quantitative evaluation of severity of neutropenia especially in the field of hematologic malignancies, could predict yields of CD34+ cells. METHODS: We performed a single center, retrospective analysis of patients with relapsed or refractory aggressive lymphoma who were mobilized with ESHAP or modified ESHAP. We evaluated the association between yields of CD34+ cells at first apheresis and D-index. RESULTS: Thirty-six patients were included, and we demonstrated that yields of CD34+ cells from patients with higher D-index were significantly lower than those from patients with lower D-index. Multivariate linear regression analysis and logistic regression analysis also demonstrated the significant predictive power of D-index. Further, D-index was significantly correlated to platelet count before starting mobilization chemotherapy. Platelet count was known to predict yields of CD34+ cells, and combination of platelet count and D-index could identify patients with lowest CD34+ yields. CONCLUSION: D-index could predict yields of CD34+ cells and it seemed that its predictive power was not less than that of platelet count. Prospective studies including more heterogeneous patients were needed to validate our study.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Blood Component Removal , Lymphoma/therapy , Adolescent , Adult , Aged , Antigens, CD34 , Cisplatin/therapeutic use , Cytarabine/therapeutic use , Etoposide/therapeutic use , Female , Humans , Lymphoma/pathology , Male , Methylprednisolone/therapeutic use , Middle Aged , Retrospective Studies , Salvage Therapy , Severity of Illness Index , Young AdultABSTRACT
Bendamusutine plus rituximab (BR) regimen is one of the standard regimens for indolent B-cell lymphomas, yet the possibility of reduction of cycles of BR therapy without compromising therapeutic effects is not still uncovered. We retrospectively surveyed 57 cases including 40 follicular lymphoma cases who underwent BR regimen in our institute. The overall response (OR) rate and complete response (CR) rate were 86.0% (95% confidential interval (CI), 74.2-93.7) and 54.4% (40.7-67.6), respectively. Five-year overall survival (OS) and 5-years progression-free survival (PFS) were 76.8% and 45.7%, respectively. We then grouped the patients by the number of administered cycles of BR regimen. PFS was significantly longer in 41 cases of the later cessation group (cycle 4-6) than in 16 cases of the earlier cessation group (cycle 1-3) (p = 0.012, 5-years PFS; 46.8% vs. 35.2%, respectively), and both of OR and CR rate of the former was better than the latter (OR rate; 95.1% vs. 62.5%, p < 0.01, CR rate; 61.4% vs. 31.3%, p = 0.04). Interestingly PFS of twenty-one (36.8%) cases receiving just 4 cycles was longer than that of 20 cases who received five or 6 cycles (p < 0.01, 5-years PFS; 71.8% vs. 23.2%, respectively). Focusing on the group of four cycles, the 12 case with CR revealed longer PFS than seven cases with partial response (PR), and median PFS was not reached in CR cases and 16.9 months in the PR cases (p < 0.01). These results suggest that four cycles at least should be administered if possible, and the outcome of the patients who discontinued BR after four cycles was not inferior to that of the cases who received five or six cycles. In conclusion, discontinuation after four cycles may be permissible in some cases with complete response to BR regimen.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Bendamustine Hydrochloride/therapeutic use , Lymphoma, Follicular/drug therapy , Rituximab/therapeutic use , Aged , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Bendamustine Hydrochloride/pharmacology , Humans , Middle Aged , Rituximab/pharmacologyABSTRACT
In this study, metal spheres were implanted into glass by continuous-wave (CW) laser illumination, which manipulated the metal sphere inside the glass. The spheres moved at approximately 100 mm/s, which is 100 times faster compared to conventional movement. The movement mechanism was clarified by in situ, cross-sectional, and microscopic observations. With a high laser power density, the metal spheres moved fast with plasma emission, and their trajectory contained fine iron particles. The temperatures of the metal sphere with slow (<0.1 mm/s) and fast (>1 mm/s) speeds were 1,900 and 2,900 K, respectively.
ABSTRACT
With the introduction of tyrosine kinase inhibitors (TKIs), prognosis of chronic myelogenous leukemia (CML) has improved dramatically. However, treatment for blast phase (BP) CML remains a challenge. CML infiltration of the central nervous system (CNS) is particularly rare and no effective treatment strategy has been established. The present case reports a 30-year-old man presenting with sensory deafness. Marked leukocytosis with p210 BCR-ABL1 mRNA positivity and Philadelphia chromosome detected by bone marrow biopsy confirmed the diagnosis of CML. Dura thickening in brain MRI and immature cells with Philadelphia chromosome in spinal fluid confirmed CNS invasion of CML and he was diagnosed with BP-CML. Two cycles of hyper-CVAD/MA (cyclophosphamide, vincristine, doxorubicin and dexamethasone/ high-dose methotrexate and cytarabine) therapy with dasatinib and concomitant intrathecal chemotherapy induced complete cytogenetic response and remission of CNS involvement. Bone marrow transplantation from an unrelated HLA-mismatched donor was performed and complete molecular response in bone marrow and complete remission in CNS disease was achieved. To our knowledge, this the first report of BP-CML with CNS infiltration at initial diagnosis, and shows that CNS-directed chemotherapy with dasatinib followed by allogeneic hematopoietic stem cell transplantation is useful in the treatment for BP-CML with CNS invasion in the TKI era.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Central Nervous System Neoplasms/secondary , Central Nervous System Neoplasms/therapy , Hematopoietic Stem Cell Transplantation , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology , Adult , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Biomarkers , Biopsy , Bone Marrow/pathology , Central Nervous System Neoplasms/diagnosis , Combined Modality Therapy , Hematopoietic Stem Cell Transplantation/adverse effects , Hematopoietic Stem Cell Transplantation/methods , Humans , Magnetic Resonance Imaging , Male , Transplantation, Homologous , Treatment OutcomeABSTRACT
Extranodal NK/T cell lymphoma, nasal type (ENKL) developed in a patient with intestinal Epstein-Barr virus (EBV)-positive T/NK-cell lymphoproliferative disorder (LPD). The patient was a 46-year-old Chinese man who complained of diarrhea and abdominal pain without immune-deficiency. Endoscopy demonstrated ileum ulcers like Crohn's disease, without histological granulomas. His symptoms continued waxing and waning for 3 years until he developed overt lymphoma (ENKL) in the nasal cavity. The ileum lesions exacerbated into a large deep ulcer, and the biopsy specimens from the ileum, including the one 3 years ago, showed infiltration of small lymphocytes containing many EBV-positive T/NK cells without atypia. Thus, the patient illness of intestine was revealed as intestinal EBV-positive T/NK-cell LPD, which might be closely associated with development of ENKL in this patient. In cases of inflammatory bowel disease without typical clinical courses and histological findings, check-up of EBV in the biopsy might help correct diagnosis.
Subject(s)
Epstein-Barr Virus Infections/virology , Lymphoma, Extranodal NK-T-Cell/virology , Lymphoproliferative Disorders/pathology , Nasal Cavity/pathology , Natural Killer T-Cells/virology , Biopsy , Epstein-Barr Virus Infections/pathology , Humans , Intestines/pathology , Intestines/virology , Lymphoma, Extranodal NK-T-Cell/diagnosis , Lymphoma, Extranodal NK-T-Cell/pathology , Lymphoproliferative Disorders/diagnosis , Lymphoproliferative Disorders/virology , Male , Middle Aged , Nasal Cavity/diagnostic imaging , Natural Killer T-Cells/pathologySubject(s)
Antigens, Viral/immunology , Bendamustine Hydrochloride/adverse effects , Cytomegalovirus Infections/chemically induced , Cytomegalovirus/immunology , Gastrointestinal Diseases/etiology , Hematologic Neoplasms/drug therapy , Aged , Aged, 80 and over , Antineoplastic Agents, Alkylating/adverse effects , Cytomegalovirus Infections/epidemiology , Cytomegalovirus Infections/immunology , Cytomegalovirus Infections/virology , Female , Follow-Up Studies , Hematologic Neoplasms/pathology , Humans , Male , Middle Aged , Prognosis , Retrospective Studies , Virus Activation/drug effects , Virus Activation/immunologyABSTRACT
Light is able to remotely move matter. Among various driving forces, laser-induced metal sphere migration in glass has been reported. The temperature on the laser-illuminated side of the sphere was higher than that on the non-illuminated side. This temperature gradient caused non-uniformity in the interfacial tension between the glass and the melted metal as the tension decreased with increasing temperature. In the present study, we investigated laser-induced metal sphere migration in different glasses using thermal flow calculations, considering the temperature dependence of the material parameters. In addition, the velocity of the glass flow generated by the metal sphere migration was measured and compared with thermal flow calculations. The migration velocity of the stainless steel sphere increased with increasing laser power density; the maximum velocity was 104 µm/s in borosilicate glass and 47 µm/s in silica glass. The sphere was heated to more than 2000 K. The temperature gradient of the interfacial tension between the stainless steel sphere and the glass was calculated to be -2.29 × 10-5 N/m/K for borosilicate glass and -2.06 × 10-5 N/m/K for silica glass. Glass flowed in the region 15-30 µm from the surface of the sphere, and the 80-µm sphere migrated in a narrow softened channel.
ABSTRACT
The facile alkylative intramolecular cyclization of 3-alkoxycarbonyl-2-oxopropyldiphenylsulfonium salts is described. This simple method can be readily applied to the synthesis of a novel family of 4-alkylated 3(2H)-furanones in moderate to high yields under mild conditions via a one-pot process.
ABSTRACT
Precise positioning of dendritic branches is a critical step in the establishment of neuronal circuitry. However, there is limited knowledge on how environmental cues translate into dendrite initiation or branching at a specific position. Here, through a combination of mutation, RNAi, and imaging experiments, we found that a Dscam-Dock-Pak1 hierarchical interaction defines the stereotypical dendrite growth site in the Drosophila aCC motoneuron. This interaction localizes the Cdc42 effector Pak1 to the plasma membrane at the dendrite initiation site before the activation of Cdc42. Ectopic expression of membrane-anchored Pak1 overrides this spatial specification of dendritogenesis, confirming its function in guiding Cdc42 signaling. We further discovered that Dscam1 localization in aCC occurs through an inter-neuronal contact that involves Dscam1 in the partner MP1 neuron. These findings elucidate a mechanism by which Dscam1 controls neuronal morphogenesis through spatial regulation of Cdc42 signaling and, subsequently, cytoskeletal remodeling.
Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Dendrites/physiology , Drosophila Proteins/metabolism , GTP-Binding Proteins/metabolism , Motor Neurons/cytology , Nerve Tissue Proteins/metabolism , Neural Cell Adhesion Molecules/metabolism , p21-Activated Kinases/metabolism , Adaptor Proteins, Signal Transducing/genetics , Animals , Animals, Genetically Modified/genetics , Animals, Genetically Modified/growth & development , Animals, Genetically Modified/metabolism , Cell Adhesion Molecules , Cell Differentiation , Cell Membrane/metabolism , Cells, Cultured , Cytoskeleton/metabolism , Drosophila/genetics , Drosophila/growth & development , Drosophila/metabolism , Drosophila Proteins/antagonists & inhibitors , Drosophila Proteins/genetics , Embryo, Nonmammalian/cytology , Embryo, Nonmammalian/metabolism , GTP-Binding Proteins/genetics , Gene Expression Regulation, Developmental , Immunoenzyme Techniques , Interneurons/cytology , Interneurons/metabolism , Morphogenesis/physiology , Motor Neurons/metabolism , Nerve Tissue Proteins/genetics , Neural Cell Adhesion Molecules/antagonists & inhibitors , Neural Cell Adhesion Molecules/genetics , RNA, Small Interfering/genetics , p21-Activated Kinases/geneticsABSTRACT
Strain-promoted click chemistry of nucleosides and nucleotides with an azido group directly attached to the purine and pyrimidine rings with various cyclooctynes in aqueous solution at ambient temperature resulted in efficient formation (3 min to 3 h) of fluorescent, light-up, triazole products. The 2- and 8-azidoadenine nucleosides reacted with fused cyclopropyl cyclooctyne, dibenzylcyclooctyne, or monofluorocyclooctyne to produce click products functionalized with hydroxyl, amino, N-hydroxysuccinimide, or biotin moieties. The 5-azidouridine and 5-azido-2'-deoxyuridine were similarly converted to the analogous triazole products in quantitative yields in less than 5 min. The 8-azido-ATP quantitatively afforded the triazole product with fused cyclopropyl cyclooctyne in aqueous acetonitrile (3 h). The novel triazole adducts at the 2- or 8-position of adenine or 5-position of uracil rings induce fluorescence properties which were used for direct imaging in MCF-7 cancer cells without the need for traditional fluorogenic reporters. FLIM of the triazole click adducts demonstrated their potential utility for dynamic measuring and tracking of signaling events inside single living cancer cells.
Subject(s)
Adenosine Triphosphate/analogs & derivatives , Alkynes/chemistry , Azides/chemistry , Click Chemistry , Cyclooctanes/chemistry , Fluorescent Dyes/chemistry , Nucleosides/chemistry , Pyrimidines/chemistry , Triazoles/chemistry , Adenosine Triphosphate/chemistry , Cell Membrane Permeability , Cell Proliferation , Humans , MCF-7 Cells , Microscopy, FluorescenceABSTRACT
The Japanese bush warbler has a very distinctive song, shows marked sexual size dimorphism, and has a polygynous mating system. However, the physical traits of males and seasonal variation in such traits have remained unknown. Twenty-five anatomical measurements representing physical traits of males in the breeding (summer, n = 5) and non-breeding (winter, n = 5) seasons were examined morphologically and compared statistically. Differences were evident between summer and winter (P < 0.05, t test) in the following seven items: body mass (19.8 ± 0.7 g vs. 15.6 ± 1.2 g [mean ± SD]), mass of male reproductive organs (184.0 ± 25.7 mg vs. 6.0 ± 1.4 mg), hind limb (3789.2 ± 346.2 mg vs. 3003.4 ± 226.8 mg), leg muscles (883.0 ± 63.5 mg vs. 581.4 ± 33.2 mg in either side), skin around the neck/throat (1280 ± 34.9 mg vs. 287.2 ± 84.7 mg), and syrinx (35.8 ± 2.39 mg vs. 25.0 ± 3.24 mg), and circumference of the neck/throat (52.1 ± 2.3 mm vs. 38.3 ± 2.6 mm). In contrast to winter males, summer males had thickened flabby skin prominently in the neck/throat area and an inflatable esophagus, perhaps a morphological basis for the throat sac as a vocal resonator. Also, the remarkable development of the flexor muscles of the legs of summer males suggests that perching and movement using the legs increases during the breeding season. These distinct characteristics of summer males may be related to the polygynous mating system of this species.
Subject(s)
Hindlimb/physiology , Muscle, Skeletal/physiology , Seasons , Songbirds/physiology , Vocalization, Animal , Animals , Japan , Male , Songbirds/anatomy & histologyABSTRACT
Protein interactions underlie the complexity of neuronal function. Potential interactions between specific proteins in the brain are predicted from assays based on genetic interaction and/or biochemistry. Genetic interaction reveals endogenous, but not necessarily direct, interactions between the proteins. Biochemistry-based assays, on the other hand, demonstrate direct interactions between proteins, but often outside their native environment or without a subcellular context. We aimed to achieve the best of both approaches by visualizing protein interaction directly within the brain of a live animal. Here, we show a proof-of-principle experiment in which the Cdc42 GTPase associates with its alleged partner WASp within neurons during the time and space that coincide with the newly developing CNS.
Subject(s)
Central Nervous System/embryology , Central Nervous System/metabolism , Molecular Dynamics Simulation , Molecular Imaging/methods , cdc42 GTP-Binding Protein/metabolism , Animals , Animals, Genetically Modified , Drosophila Proteins/metabolism , Drosophila melanogaster/embryology , Drosophila melanogaster/genetics , Embryo, Nonmammalian , Fluorescence Resonance Energy Transfer/methods , Molecular Imaging/instrumentation , Neurons/metabolism , Protein Binding , Protein Interaction Maps , Signal Transduction/physiology , Wiskott-Aldrich Syndrome Protein/metabolism , cdc42 GTP-Binding Protein/geneticsABSTRACT
We exploit the morphological stereotypy and relative simplicity of the Drosophila nervous system to model the diverse neuronal morphologies of individual motor neurons and understand underlying principles of synaptic connectivity in a motor circuit. In our analysis, we use images depicting single neurons labeled with green fluorescent protein (GFP) and serially imaged with laser scanning confocal microscopy. We model morphology with a novel formulation of Conditional Random Fields, a hierarchical latent-state CRF, to capture the highly varying compartment-based structure of the neurons (soma-axon-dendrites). In the training phase, we follow two approaches: (i) hierarchical learning, where compartment labels are given, and (ii) latent-state learning, where compartment labels are not given in the samples. We demonstrate the accuracy of our approach using wild-type motor neurons in the larval ventral nerve cord. However, our method can also be used for the identification of motor neuron mutations, as well as the automated annotation of the motor circuitry in wild type and mutant animals. Our method is directly applicable to the recognition of compartment-defined structures.
Subject(s)
Central Nervous System/embryology , Drosophila melanogaster/embryology , Models, Neurological , Motor Neurons/cytology , Neurogenesis/physiology , Animals , Body Patterning/physiology , Central Nervous System/cytology , Microscopy, ConfocalABSTRACT
We optically manipulated a metal particle in borosilicate glass. The glass in the neighborhood of the laser-heated metal particle softened; hence, the metal particle was able to migrate in the glass. In this letter, the driving force of the metal particle toward the light source in the glass provided by laser illumination was investigated. The variation in the surface tension of the glass at the interface between the glass and the metal particle induced by the temperature gradient was calculated via a numerical temperature calculation. It was found that the temperature at the laser-illuminated surface of a stainless-steel particle with a radius of 40 µm was ~320 K higher than that on the nonilluminated side. The force applied to the metal particle from the surrounding glass was calculated to be ~100 µN, which was approximately equal to the viscous resistance force. In addition, the experimental and numerically calculated speeds of the moving particle, which was measured while varying the laser power, are discussed.
ABSTRACT
We describe LOLLIbow, a Brainbow-based live imaging system with applications in developmental biology and neurobiology. The development of an animal, including the environmentally sensitive adaptation of its brain, is thought to proceed through continual orchestration among diverse cell types as they divide, migrate, transform and interact with one another within the body. To facilitate direct visualization of such dynamic morphogenesis by individual cells in vivo, we have modified the original Brainbow for Drosophila in which live imaging is practical during much of its development. Our system offers permanent fluorescent labels that reveal fine morphological details of individual cells without requiring dissection or fixation of the samples. It also features a non-invasive means to control the timing of stochastic tricolor cell labeling with a light pulse. We demonstrate applicability of the new system in a variety of settings that could benefit from direct imaging of the developing multicellular organism with single-cell resolution.
Subject(s)
Cell Tracking/methods , Drosophila/cytology , Staining and Labeling , Animals , Animals, Genetically Modified , Color , Cryptochromes/genetics , Cryptochromes/metabolism , Diagnostic Imaging , Drosophila/embryology , Drosophila Proteins/genetics , Drosophila Proteins/metabolism , Embryo, Nonmammalian , Integrases/genetics , Integrases/metabolism , Microscopy, Video , Models, Biological , Morphogenesis/physiology , Staining and Labeling/methods , Transcription Factors/genetics , Transcription Factors/metabolismABSTRACT
Type-specific dendritic arborization patterns dictate synaptic connectivity and are fundamental determinants of neuronal function. We exploit the morphological stereotypy and relative simplicity of the Drosophila nervous system to model the diverse neuronal morphologies of individual motor neurons (MNs) and understand underlying principles of synaptic connectivity in a motor circuit. Our computational approach aims at the reconstruction of the neuron morphology, namely the robust segmentation of the neuron volumes from their surroundings with the simultaneous partitioning into their compartments, namely the soma, axon, and dendrites. We use the idea of cosegmentation, where every image along the z -axis (depth) is segmented using information from "neighboring" depths. We use 3-D Haar-like features to model appearance. Because soma and axon are determined by their distinctive shapes, we define an implicit shape representation of the 2-D segmentation sets to drive cosegmentation and achieve the desired partitioning. We validate our method using image stacks depicting single neurons labeled with green fluorescent protein (GFP) and serially imaged with laser scanning confocal microscopy.