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Tao C, Li J, Du W, Qin X, Cao J, Liu C, Cheng T. Broad Complex-Z2 directly activates BmMBF2 to inhibit the silk protein synthesis in the silkworm, Bombyx mori. Int J Biol Macromol 2024; 277:134211. [PMID: 39069049 DOI: 10.1016/j.ijbiomac.2024.134211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/27/2024] [Accepted: 07/25/2024] [Indexed: 07/30/2024]
Abstract
Silk proteins, as natural macromolecules, have extensive applications in biomaterials and biomedicine. In the silkworm, the expression of silk protein genes is negatively associated with ecdysone during the molt stage, while it is positively correlated with juvenile hormone during the intermolt stage. In our previous study, overexpression of an isoform Z2 of Broad Complex (BmBrC-Z2), an ecdysone early response factor, significantly reduced the expression of silk protein genes. However, the underlying regulatory mechanism remains unclear. In this study, we conducted transcriptomic analysis and found that overexpressing BmBrC-Z2 significantly upregulated the expression level of multiprotein bridging factor 2 (BmMBF2), an inhibitor of fibroin heavy chain (FibH). Further investigations revealed that BmBrC-Z2 directly regulated BmMBF2 by binding to cis-regulatory elements, as demonstrated using Dual-Luciferase Reporter Gene Assay, EMSA, and ChIP-PCR assay. Additionally, when using the CRISPR/Cas9 system to knock out BmMBF2, silk protein genes were significantly upregulated during the molt stage of mutant larvae. These findings uncover the negative regulation of silk protein synthesis by the ecdysone signaling cascade, specifically through the manipulation of BmMBF2 expression during the molt stage. This study enhances to our understanding of the temporal regulatory mechanism governing silk protein synthesis and offers a potential strategy for improving silk yield.
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Affiliation(s)
- Cuicui Tao
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400715, China
| | - Jiaojiao Li
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400715, China
| | - Wenjie Du
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400715, China
| | - Xiaodan Qin
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400715, China
| | - Jun Cao
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400715, China
| | - Chun Liu
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400715, China.
| | - Tingcai Cheng
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400715, China.
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Tello JA, Jiang L, Zohar Y, Restifo LL. Drosophila CASK regulates brain size and neuronal morphogenesis, providing a genetic model of postnatal microcephaly suitable for drug discovery. Neural Dev 2023; 18:6. [PMID: 37805506 PMCID: PMC10559581 DOI: 10.1186/s13064-023-00174-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 09/08/2023] [Indexed: 10/09/2023] Open
Abstract
BACKGROUND CASK-related neurodevelopmental disorders are untreatable. Affected children show variable severity, with microcephaly, intellectual disability (ID), and short stature as common features. X-linked human CASK shows dosage sensitivity with haploinsufficiency in females. CASK protein has multiple domains, binding partners, and proposed functions at synapses and in the nucleus. Human and Drosophila CASK show high amino-acid-sequence similarity in all functional domains. Flies homozygous for a hypomorphic CASK mutation (∆18) have motor and cognitive deficits. A Drosophila genetic model of CASK-related disorders could have great scientific and translational value. METHODS We assessed the effects of CASK loss of function on morphological phenotypes in Drosophila using established genetic, histological, and primary neuronal culture approaches. NeuronMetrics software was used to quantify neurite-arbor morphology. Standard nonparametric statistics methods were supplemented by linear mixed effects modeling in some cases. Microfluidic devices of varied dimensions were fabricated and numerous fluid-flow parameters were used to induce oscillatory stress fields on CNS tissue. Dissociation into viable neurons and neurite outgrowth in vitro were assessed. RESULTS We demonstrated that ∆18 homozygous flies have small brains, small heads, and short bodies. When neurons from developing CASK-mutant CNS were cultured in vitro, they grew small neurite arbors with a distinctive, quantifiable "bushy" morphology that was significantly rescued by transgenic CASK+. As in humans, the bushy phenotype showed dosage-sensitive severity. To overcome the limitations of manual tissue trituration for neuronal culture, we optimized the design and operation of a microfluidic system for standardized, automated dissociation of CNS tissue into individual viable neurons. Neurons from CASK-mutant CNS dissociated in the microfluidic system recapitulate the bushy morphology. Moreover, for any given genotype, device-dissociated neurons grew larger arbors than did manually dissociated neurons. This automated dissociation method is also effective for rodent CNS. CONCLUSIONS These biological and engineering advances set the stage for drug discovery using the Drosophila model of CASK-related disorders. The bushy phenotype provides a cell-based assay for compound screening. Nearly a dozen genes encoding CASK-binding proteins or transcriptional targets also have brain-development mutant phenotypes, including ID. Hence, drugs that improve CASK phenotypes might also benefit children with disorders due to mutant CASK partners.
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Affiliation(s)
- Judith A Tello
- Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, 85721, USA
- Department of Neurology, University of Arizona Health Sciences, 1501 N. Campbell Ave, Tucson, AZ, 85724-5023, USA
- Present address: Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY, 10010, USA
| | - Linan Jiang
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ, 85721, USA
| | - Yitshak Zohar
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ, 85721, USA
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, 85721, USA
- BIO5 Interdisciplinary Research Institute, University of Arizona, Tucson, AZ, 85721, USA
| | - Linda L Restifo
- Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, 85721, USA.
- Department of Neurology, University of Arizona Health Sciences, 1501 N. Campbell Ave, Tucson, AZ, 85724-5023, USA.
- BIO5 Interdisciplinary Research Institute, University of Arizona, Tucson, AZ, 85721, USA.
- Department of Cellular & Molecular Medicine, University of Arizona Health Sciences, Tucson, AZ, 85724, USA.
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Genome-Wide Identification, Expression Profiling, and Characterization of Cyclin-like Genes Reveal Their Role in the Fertility of the Diamondback Moth. BIOLOGY 2022; 11:biology11101493. [PMID: 36290396 PMCID: PMC9598266 DOI: 10.3390/biology11101493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 11/07/2022]
Abstract
Simple Summary Cyclin genes are known as cell cycle regulators and play a significant role in the fertility of different organisms, including mice and insects. Until now, no study has been performed on the complete identification of the cyclin genes in insects. Here, we identified 21 cyclin genes in the diamondback moth (DBM) genome through a comprehensive genome-wide analysis and evaluated the gene structure, genomic location, and evolutionary relationship. Cis-regulatory elements and potential miRNA targeting the cyclin genes were also assessed. By analyzing the transcriptomic and RT-qPCR based expression profiling at different stages and tissues, we found that the majority of the cyclin genes were significantly expressed in the reproductive tissues. Moreover, RNAi-mediated characterization of PxCyc B1 showed its role in female fertility. The current study provides a basis for further evaluation of the cyclin genes, which may be used as a potential target for pest management programs. Abstract Cyclin-like genes are primarily considered as cell cycle regulators and have shown to be crucial for insect growth, development, reproduction, and fertility. However, no research has been performed on the cyclin-like genes in the diamondback moth (Plutella xylostella). Here, we identified the 21 cyclin genes in the genome of P. xylostella and clustered them into four groups. Most cyclin genes showed a well-maintained gene structure and motif distribution within the same group. The putative promoter regions of cyclin genes contained several transcription binding factors related to reproduction, along with growth and development. Furthermore, 16 miRNAs were identified targeting the 13 cyclin genes. Transcriptome and quantitative real-time PCR (qRT-PCR)-based expression profiling of cyclin-like genes at different stages and tissues were evaluated, revealing that 16 out of 21 cyclin genes were highly expressed in reproductive tissues of adult females and males. The Cyclin B1 gene (PxCyc B1) was only expressed in the ovary of the adult female and selected for the subsequent analysis. RNAi-mediated suppression of PxCyc B1 interrupted the external genitalia and length of the ovariole of female adults. Furthermore, the egg-laying capacity and hatching rate were also significantly decreased by suppressing the PxCyc B1, indicating the importance of cyclin genes in the reproduction and fertility of P. xylostella. The current study explained the detailed genome-wide analysis of cyclin-like genes in P. xylostella, which provided a basis for subsequent research to assess the roles of cyclin genes in reproduction, and the cyclin gene may be considered an effective target site to control this pest.
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Guo MP, Qian WL, He XC, Peng J, Wang P, Wang WN, Xia QY, Cheng DJ. Genome-wide identification of target genes for transcription factor BR-C in the silkworm, Bombyx mori. INSECT SCIENCE 2021; 28:1530-1540. [PMID: 33372405 DOI: 10.1111/1744-7917.12893] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 10/23/2020] [Accepted: 11/22/2020] [Indexed: 06/12/2023]
Abstract
Transcription factor Broad Complex (BR-C) is an ecdysone primary response gene in insects and participates in the regulation of insect growth and development. In this study, we performed a genome-wide identification of BR-C target genes in silkworm (Bombyx mori) using chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq). As a result, a total of 1006 BR-C ChIP peaks were identified, and 15% of peaks were located in the promoter regions of 133 protein-coding genes. Functional annotation revealed that these ChIP peak-associated genes, as potential BR-C targets, were enriched in pathways related to biosynthetic process, metabolic process, and development. Transcriptome analysis and quantitative real-time polymerase chain reaction (PCR) examination revealed that developmental changes in expression patterns of a portion of potential BR-C targets, including HR96 and GC-α1, were similar to those of BR-C. ChIP-PCR examination confirmed that BR-C could directly bind to the promoters of potential targets. Further, dual luciferase assays demonstrated that HR96 promoter activity was significantly upregulated following BR-C overexpression, and this upregulation was abolished when the binding motif in the promoter was truncated. This study will be helpful for deciphering the regulatory roles of BR-C during insect growth and development.
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Affiliation(s)
- Meng-Pei Guo
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing, 400715, China
| | - Wen-Liang Qian
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing, 400715, China
| | - Xue-Chuan He
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing, 400715, China
| | - Jian Peng
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing, 400715, China
| | - Peng Wang
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing, 400715, China
| | - Wei-Na Wang
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing, 400715, China
| | - Qing-You Xia
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing, 400715, China
- Chongqing Key Laboratory of Sericultural Science, Southwest University, Chongqing, 400715, China
| | - Dao-Jun Cheng
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing, 400715, China
- Chongqing Key Laboratory of Sericultural Science, Southwest University, Chongqing, 400715, China
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Goodman LD, Cope H, Nil Z, Ravenscroft TA, Charng WL, Lu S, Tien AC, Pfundt R, Koolen DA, Haaxma CA, Veenstra-Knol HE, Wassink-Ruiter JSK, Wevers MR, Jones M, Walsh LE, Klee VH, Theunis M, Legius E, Steel D, Barwick KES, Kurian MA, Mohammad SS, Dale RC, Terhal PA, van Binsbergen E, Kirmse B, Robinette B, Cogné B, Isidor B, Grebe TA, Kulch P, Hainline BE, Sapp K, Morava E, Klee EW, Macke EL, Trapane P, Spencer C, Si Y, Begtrup A, Moulton MJ, Dutta D, Kanca O, Wangler MF, Yamamoto S, Bellen HJ, Tan QKG. TNPO2 variants associate with human developmental delays, neurologic deficits, and dysmorphic features and alter TNPO2 activity in Drosophila. Am J Hum Genet 2021; 108:1669-1691. [PMID: 34314705 PMCID: PMC8456166 DOI: 10.1016/j.ajhg.2021.06.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 06/27/2021] [Indexed: 12/11/2022] Open
Abstract
Transportin-2 (TNPO2) mediates multiple pathways including non-classical nucleocytoplasmic shuttling of >60 cargoes, such as developmental and neuronal proteins. We identified 15 individuals carrying de novo coding variants in TNPO2 who presented with global developmental delay (GDD), dysmorphic features, ophthalmologic abnormalities, and neurological features. To assess the nature of these variants, functional studies were performed in Drosophila. We found that fly dTnpo (orthologous to TNPO2) is expressed in a subset of neurons. dTnpo is critical for neuronal maintenance and function as downregulating dTnpo in mature neurons using RNAi disrupts neuronal activity and survival. Altering the activity and expression of dTnpo using mutant alleles or RNAi causes developmental defects, including eye and wing deformities and lethality. These effects are dosage dependent as more severe phenotypes are associated with stronger dTnpo loss. Interestingly, similar phenotypes are observed with dTnpo upregulation and ectopic expression of TNPO2, showing that loss and gain of Transportin activity causes developmental defects. Further, proband-associated variants can cause more or less severe developmental abnormalities compared to wild-type TNPO2 when ectopically expressed. The impact of the variants tested seems to correlate with their position within the protein. Specifically, those that fall within the RAN binding domain cause more severe toxicity and those in the acidic loop are less toxic. Variants within the cargo binding domain show tissue-dependent effects. In summary, dTnpo is an essential gene in flies during development and in neurons. Further, proband-associated de novo variants within TNPO2 disrupt the function of the encoded protein. Hence, TNPO2 variants are causative for neurodevelopmental abnormalities.
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Affiliation(s)
- Lindsey D Goodman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Heidi Cope
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA
| | - Zelha Nil
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Thomas A Ravenscroft
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Wu-Lin Charng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Shenzhao Lu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - An-Chi Tien
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Rolph Pfundt
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA, PO Box 9101, Nijmegen, the Netherlands
| | - David A Koolen
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA, PO Box 9101, Nijmegen, the Netherlands
| | - Charlotte A Haaxma
- Department of Pediatric Neurology, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, Geert Grooteplein Zuid 10, 6525 GA, PO Box 9101, the Netherlands
| | - Hermine E Veenstra-Knol
- Department of Genetics, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, the Netherlands
| | - Jolien S Klein Wassink-Ruiter
- Department of Genetics, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, the Netherlands
| | - Marijke R Wevers
- Department of Genetics, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, the Netherlands
| | - Melissa Jones
- Houston Area Pediatric Neurology, 24514 Kingsland Blvd, Katy, TX 77494, USA
| | - Laurence E Walsh
- Department of Pediatric Neurology, Riley Hospital for Children, Indianapolis, IN 46202, USA
| | - Victoria H Klee
- Department of Pediatric Neurology, Riley Hospital for Children, Indianapolis, IN 46202, USA
| | - Miel Theunis
- Center for Human Genetics, University Hospital Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Eric Legius
- Department of Human Genetics, University of Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Dora Steel
- Molecular Neurosciences, Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, UK; Department of Neurology, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Katy E S Barwick
- Molecular Neurosciences, Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, UK
| | - Manju A Kurian
- Molecular Neurosciences, Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, UK; Department of Neurology, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Shekeeb S Mohammad
- T.Y. Nelson Department of Neurology and Neurosurgery, The Children's Hospital at Westmead, Westmead, NSW 2145, Australia; Kids Neuroscience Centre, The Children's Hospital at Westmead, Faculty of Medicine and Health, Sydney Medical School, University of Sydney, Sydney, Westmead, NSW 2145, Australia
| | - Russell C Dale
- T.Y. Nelson Department of Neurology and Neurosurgery, The Children's Hospital at Westmead, Westmead, NSW 2145, Australia; Kids Neuroscience Centre, The Children's Hospital at Westmead, Faculty of Medicine and Health, Sydney Medical School, University of Sydney, Sydney, Westmead, NSW 2145, Australia
| | - Paulien A Terhal
- Department of Genetics, University Medical Center Utrecht, Lundlaan 6, 3584 EA Utrecht, the Netherlands
| | - Ellen van Binsbergen
- Department of Genetics, University Medical Center Utrecht, Lundlaan 6, 3584 EA Utrecht, the Netherlands
| | - Brian Kirmse
- Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Bethany Robinette
- Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Benjamin Cogné
- Centre hospitalier universitaire (CHU) de Nantes, Service de Génétique Médicale, 9 quai Moncousu, 44093 Nantes, France; INSERM, CNRS, UNIV Nantes, Centre hospitalier universitaire (CHU) de Nantes, l'institut du thorax, 44007 Nantes, France
| | - Bertrand Isidor
- Centre hospitalier universitaire (CHU) de Nantes, Service de Génétique Médicale, 9 quai Moncousu, 44093 Nantes, France; INSERM, CNRS, UNIV Nantes, Centre hospitalier universitaire (CHU) de Nantes, l'institut du thorax, 44007 Nantes, France
| | - Theresa A Grebe
- Phoenix Children's Hospital, Phoenix, AZ 85016, USA; Department of Child Health, University of Arizona College of Medicine Phoenix, Phoenix, AZ 85004, USA
| | - Peggy Kulch
- Phoenix Children's Hospital, Phoenix, AZ 85016, USA
| | - Bryan E Hainline
- Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Katherine Sapp
- Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Eva Morava
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA; Department of Clinical Genomics, Mayo Clinic, Rochester, MN 55905, USA
| | - Eric W Klee
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA; Department of Clinical Genomics, Mayo Clinic, Rochester, MN 55905, USA
| | - Erica L Macke
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Pamela Trapane
- University of Florida, College of Medicine, Jacksonville, Jacksonville, FL 32209, USA
| | - Christopher Spencer
- University of Florida, College of Medicine, Jacksonville, Jacksonville, FL 32209, USA
| | - Yue Si
- GeneDx, Gaithersburg, MD 20877, USA
| | | | - Matthew J Moulton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Debdeep Dutta
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Development, Disease Models & Therapeutics Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Development, Disease Models & Therapeutics Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Queenie K-G Tan
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA.
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Sood C, Doyle SE, Siegrist SE. Steroid hormones, dietary nutrients, and temporal progression of neurogenesis. CURRENT OPINION IN INSECT SCIENCE 2021; 43:70-77. [PMID: 33127508 PMCID: PMC8058227 DOI: 10.1016/j.cois.2020.10.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 10/10/2020] [Accepted: 10/16/2020] [Indexed: 05/13/2023]
Abstract
Temporal patterning of neural progenitors, in which different factors are sequentially expressed, is an evolutionarily conserved strategy for generating neuronal diversity during development. In the Drosophila embryo, mechanisms that mediate temporal patterning of neural stem cells (neuroblasts) are largely cell-intrinsic. However, after embryogenesis, neuroblast temporal patterning relies on extrinsic cues as well, as freshly hatched larvae seek out nutrients and other key resources in varying natural environments. We recap current understanding of neuroblast-intrinsic temporal programs and discuss how neuroblast extrinsic cues integrate and coordinate with neuroblast intrinsic programs to control numbers and types of neurons produced. One key emerging extrinsic factor that impacts temporal patterning of neuroblasts and their daughters as well as termination of neurogenesis is the steroid hormone, ecdysone, a known regulator of large-scale developmental transitions in insects and arthropods. Lastly, we consider evolutionary conservation and discuss recent work on thyroid hormone signaling in early vertebrate brain development.
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Affiliation(s)
- Chhavi Sood
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Susan E Doyle
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Sarah E Siegrist
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA.
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let-7-Complex MicroRNAs Regulate Broad-Z3, Which Together with Chinmo Maintains Adult Lineage Neurons in an Immature State. G3-GENES GENOMES GENETICS 2020; 10:1393-1401. [PMID: 32071070 PMCID: PMC7144073 DOI: 10.1534/g3.120.401042] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
During Drosophila melanogaster metamorphosis, arrested immature neurons born during larval development differentiate into their functional adult form. This differentiation coincides with the downregulation of two zinc-finger transcription factors, Chronologically Inappropriate Morphogenesis (Chinmo) and the Z3 isoform of Broad (Br-Z3). Here, we show that br-Z3 is regulated by two microRNAs, let-7 and miR-125, that are activated at the larval-to-pupal transition and are known to also regulate chinmo. The br-Z3 3′UTR contains functional binding sites for both let-7 and miR-125 that confers sensitivity to both of these microRNAs, as determined by deletion analysis in reporter assays. Forced expression of let-7 and miR-125 miRNAs leads to early silencing of Br-Z3 and Chinmo and is associated with inappropriate neuronal sprouting and outgrowth. Similar phenotypes were observed by the combined but not separate depletion of br-Z3 and chinmo. Because persistent Br-Z3 was not detected in let-7-C mutants, this work suggests a model in which let-7 and miR-125 activation at the onset of metamorphosis may act as a failsafe mechanism that ensures the coordinated silencing of both br-Z3 and chinmo needed for the timely outgrowth of neurons arrested during larval development. The let-7 and miR-125 binding site sequences are conserved across Drosophila species and possibly other insects as well, suggesting that this functional relationship is evolutionarily conserved.
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Zhou Y, Yang Y, Huang Y, Wang H, Wang S, Luo H. Broad Promotes Neuroepithelial Stem Cell Differentiation in the Drosophila Optic Lobe. Genetics 2019; 213:941-951. [PMID: 31530575 PMCID: PMC6827381 DOI: 10.1534/genetics.119.302421] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 09/08/2019] [Indexed: 11/18/2022] Open
Abstract
Brain development requires the generation of the right number, and type, of neurons and glial cells at the right time. The Drosophila optic lobe, like mammalian brains, develops from simple neuroepithelia; they first divide symmetrically to expand the progenitor pool and then differentiate into neuroblasts, which divide asymmetrically to generate neurons and glial cells. Here, we investigate the mechanisms that control neuroepithelial growth and differentiation in the optic lobe. We find that the Broad/Tramtrack/Bric a brac-zinc finger protein Broad, which is dynamically expressed in the optic lobe neuroepithelia, promotes the transition of neuroepithelial cells to medulla neuroblasts. Loss of Broad function causes neuroepithelial cells to remain highly proliferative and delays neuroepithelial cell differentiation into neuroblasts, which leads to defective lamina and medulla. Conversely, Broad overexpression induces neuroepithelial cells to prematurely transform into medulla neuroblasts. We find that the ecdysone receptor is required for neuroepithelial maintenance and growth, and that Broad expression in neuroepithelial cells is repressed by the ecdysone receptor. Our studies identify Broad as an important cell-intrinsic transcription factor that promotes the neuroepithelial-cell-to-neuroblast transition.
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Affiliation(s)
- Yanna Zhou
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yuqin Yang
- College of Biology, Hunan University, Changsha, Hunan 410082, China
| | - Yanyi Huang
- College of Biology, Hunan University, Changsha, Hunan 410082, China
| | - Hui Wang
- College of Biology, Hunan University, Changsha, Hunan 410082, China
| | - Shengyu Wang
- College of Biology, Hunan University, Changsha, Hunan 410082, China
| | - Hong Luo
- School of Life Sciences, Tsinghua University, Beijing 100084, China
- College of Biology, Hunan University, Changsha, Hunan 410082, China
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Techa S, Alvarez JV, Sook Chung J. Changes in ecdysteroid levels and expression patterns of ecdysteroid-responsive factors and neuropeptide hormones during the embryogenesis of the blue crab, Callinectes sapidus. Gen Comp Endocrinol 2015; 214:157-66. [PMID: 25101839 DOI: 10.1016/j.ygcen.2014.07.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 07/06/2014] [Accepted: 07/21/2014] [Indexed: 11/20/2022]
Abstract
Embryogenesis requires the involvement and coordination of multiple networks of various genes, according to a timeline governing development. Crustacean embryogenesis usually includes the first molt, a process that is known to be positively controlled by ecdysteroids. We determined the amounts of ecdysteroids, as well as other related factors: the ecdysone receptor (CasEcR), the retinoid X receptor (CasRXR), the molt-inhibiting hormone (CasMIH), and crustacean hyperglycemic hormone (CasCHH) during the ovarian and embryonic developments of Callinectes sapidus. In summary, the ovaries at stages 1-4 have expression levels of maternal CasEcR and CasRXR 10-50 times higher than levels seen in embryos at the yolk stage. This large difference in the amount of the these factors in C. sapidus ovaries suggests that these maternal ecdysteroid-responsive factors may be utilized at the initiation of embryogenesis. During embryogenesis, the changes in total ecdysteroids and levels of CasEcR and CasRXR expression are similar to those observed in juvenile molts. The full-length cDNA sequence of the C. sapidus BTB domain protein (CasBTBDP) initially isolated from Y-organ cDNA, contains only Broad-Complex, Tramtrack, and Bric a brac (BTB) domains. The levels of CasBTBDP are kept constant throughout embryogenesis. The expression profiles of CasMIH and CasCHH are similar to the titers of ecdysteroids. However, the timing of their appearance is followed by increases in CasEcRs and CasRXRs, implying that the expressions of these neuropeptides may be influenced by ecdysteroids. Moreover, the ecdysteroid profile during embryogenesis may track directly with the timing of organogenesis of Y-organs and their activity. Our work reports, for first time, the observed expression and changes of ecdysteroid-responsive factors, along with CasCHH and CasMIH, during embryogenesis in the crustacean C. sapidus.
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Affiliation(s)
- Sirinart Techa
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E. Pratt Street, Columbus Center, Baltimore, MD 21202, USA
| | - Javier V Alvarez
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E. Pratt Street, Columbus Center, Baltimore, MD 21202, USA
| | - J Sook Chung
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E. Pratt Street, Columbus Center, Baltimore, MD 21202, USA.
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Cheng D, Qian W, Wang Y, Meng M, Wei L, Li Z, Kang L, Peng J, Xia Q. Nuclear import of transcription factor BR-C is mediated by its interaction with RACK1. PLoS One 2014; 9:e109111. [PMID: 25280016 PMCID: PMC4184850 DOI: 10.1371/journal.pone.0109111] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 08/29/2014] [Indexed: 11/18/2022] Open
Abstract
The transcription factor Broad Complex (BR-C) is an early ecdysone response gene in insects and contains two types of domains: two zinc finger domains for the activation of gene transcription and a Bric-a-brac/Tramtrack/Broad complex (BTB) domain for protein-protein interaction. Although the mechanism of zinc finger-mediated gene transcription is well studied, the partners interacting with the BTB domain of BR-C has not been elucidated until now. Here, we performed a yeast two-hybrid screen using the BTB domain of silkworm BR-C as bait and identified the receptor for activated C-kinase 1 (RACK1), a scaffolding/anchoring protein, as the novel partner capable of interacting with BR-C. The interaction between BR-C and RACK1 was further confirmed by far-western blotting and pull-down assays. Importantly, the disruption of this interaction, via RNAi against the endogenous RACK1 gene or deletion of the BTB domain, abolished the nuclear import of BR-C in BmN4 cells. In addition, RNAi against the endogenous PKC gene as well as phosphorylation-deficient mutation of the predicted PKC phosphorylation sites at either Ser373 or Thr406 in BR-C phenocopied RACK1 RNAi and altered the nuclear localization of BR-C. However, when BTB domain was deleted, phosphorylation mimics of either Ser373 or Thr406 had no effect on the nuclear import of BR-C. Moreover, mutating the PKC phosphorylation sites at Ser373 and Thr406 or deleting the BTB domain significantly decreased the transcriptional activation of a BR-C target gene. Given that RACK1 is necessary for recruiting PKC to close and phosphorylate target proteins, we suggest that the PKC-mediated phosphorylation and nuclear import of BR-C is determined by its interaction with RACK1. This novel finding will be helpful for further deciphering the mechanism underlying the role of BR-C proteins during insect development.
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Affiliation(s)
- Daojun Cheng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Wenliang Qian
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Yonghu Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Meng Meng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Ling Wei
- School of Life Science, Southwest University, Chongqing, China
| | - Zhiqing Li
- Laboratory of Silkworm Science, Kyushu University Graduate School of Bioresource and Bioenvironmental Sciences, Fukuoka, Japan
| | - Lixia Kang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Jian Peng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- * E-mail:
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11
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Nagamine K, Kayukawa T, Hoshizaki S, Matsuo T, Shinoda T, Ishikawa Y. Cloning, phylogeny, and expression analysis of the Broad-Complex gene in the longicorn beetle Psacothea hilaris. SPRINGERPLUS 2014; 3:539. [PMID: 25279330 PMCID: PMC4175664 DOI: 10.1186/2193-1801-3-539] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 09/11/2014] [Indexed: 12/26/2022]
Abstract
Seven isoforms of Broad-Complex (PhBR-C), in which the sequence of the zinc finger domain differed (referred to as Z1, Z2, Z3, Z2/Z3, Z4, Z5/Z6, and Z6, respectively), were cloned from the yellow-spotted longicorn beetle Psacothea hilaris. The Z1–Z4 sequences were highly conserved among insect species. The Z5/Z6 isoform was aberrant in that it contained a premature stop codon. Z6 had previously only been detected in a hemimetabola, the German cockroach Blattella germanica. The presence of Z6 in P. hilaris, and not in other holometabolous model insects such as Drosophila melanogaster or Tribolium castaneum, suggests that Z6 was lost multiple times in holometabolous insects during the course of evolution. PhBR-C expression levels in the brain, salivary gland, and epidermis of larvae grown under different feeding regimens were subsequently investigated. PhBR-C expression levels increased in every tissue examined after the gut purge, and high expression levels were observed in prepupae. A low level of PhBR-C expression was continuously observed in the brain. An increase was noted in PhBR-C expression levels in the epidermis when 4th instar larvae were starved after 4 days of feeding, which induced precocious pupation. No significant changes were observed in expression levels in any tissues of larvae starved immediately after ecdysis into 4th instar, which did not grow and eventually died.
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Affiliation(s)
- Keisuke Nagamine
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 Japan ; National Institute of Agrobiological Sciences, Tsukuba, 305-8634 Japan
| | - Takumi Kayukawa
- National Institute of Agrobiological Sciences, Tsukuba, 305-8634 Japan
| | - Sugihiko Hoshizaki
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 Japan
| | - Takashi Matsuo
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 Japan
| | - Tetsuro Shinoda
- National Institute of Agrobiological Sciences, Tsukuba, 305-8634 Japan
| | - Yukio Ishikawa
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 Japan
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Levy P, Larsen C. Odd-skipped labels a group of distinct neurons associated with the mushroom body and optic lobe in the adult Drosophila brain. J Comp Neurol 2014; 521:3716-40. [PMID: 23749685 PMCID: PMC3957007 DOI: 10.1002/cne.23375] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 01/22/2013] [Accepted: 05/23/2013] [Indexed: 01/22/2023]
Abstract
Olfactory processing has been intensively studied in Drosophila melanogaster. However, we still know little about the descending neural pathways from the higher order processing centers and how these connect with other neural circuits. Here we describe, in detail, the adult projections patterns that arise from a cluster of 78 neurons, defined by the expression of the Odd-skipped transcription factor. We term these neurons Odd neurons. By using expression of genetically encoded axonal and dendritic markers, we show that a subset of the Odd neurons projects dendrites into the calyx of the mushroom body (MB) and axons into the inferior protocerebrum. We exclude the possibility that the Odd neurons are part of the well-known Kenyon cells whose projections form the MB and conclude that the Odd neurons belong to a previously not described class of extrinsic MB neurons. In addition, three of the Odd neurons project into the lobula plate of the optic lobe, and two of these cells extend axons ipsi- and contralaterally in the brain. Anatomically, these cells do not resemble any previously described lobula plate tangential cells (LPTCs) in Drosophila. We show that the Odd neurons are predominantly cholinergic but also include a small number of γ-aminobutyric acid (GABA)ergic neurons. Finally, we provide evidence that the Odd neurons are a hemilineage, suggesting they are born from a defined set of neuroblasts. Our anatomical analysis hints at the possibility that subgroups of Odd neurons could be involved in olfactory and visual processing.
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Affiliation(s)
- Peter Levy
- Medical Research Council Centre for Developmental Neurobiology, King's College London, London, United Kingdom
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Huang JH, Lozano J, Belles X. Broad-complex functions in postembryonic development of the cockroach Blattella germanica shed new light on the evolution of insect metamorphosis. Biochim Biophys Acta Gen Subj 2013; 1830:2178-87. [DOI: 10.1016/j.bbagen.2012.09.025] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 09/27/2012] [Accepted: 09/28/2012] [Indexed: 01/02/2023]
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Besson M, Sinakevitch I, Melon C, Iché-Torres M, Birman S. Involvement of the drosophila taurine/aspartate transporter dEAAT2 in selective olfactory and gustatory perceptions. J Comp Neurol 2011; 519:2734-57. [DOI: 10.1002/cne.22649] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Rybina OY, Pasyukova EG. A naturally occurring polymorphism at Drosophila melanogaster Lim3 Locus, a homolog of human LHX3/4, affects Lim3 transcription and fly lifespan. PLoS One 2010; 5:e12621. [PMID: 20838645 PMCID: PMC2935391 DOI: 10.1371/journal.pone.0012621] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2010] [Accepted: 08/05/2010] [Indexed: 11/18/2022] Open
Abstract
Lim3 encodes an RNA polymerase II transcription factor with a key role in neuron specification. It was also identified as a candidate gene that affects lifespan. These pleiotropic effects indicate the fundamental significance of the potential interplay between neural development and lifespan control. The goal of this study was to analyze the causal relationships between Lim3 structural variations, and gene expression and lifespan changes, and to provide insights into regulatory pathways controlling lifespan. Fifty substitution lines containing second chromosomes from a Drosophila natural population were used to analyze the association between lifespan and sequence variation in the 5'-regulatory region, and first exon and intron of Lim3A, in which we discovered multiple transcription start sites (TSS). The core and proximal promoter organization for Lim3A and a previously unknown mRNA named Lim3C were described. A haplotype of two markers in the Lim3A regulatory region was significantly associated with variation in lifespan. We propose that polymorphisms in the regulatory region affect gene transcription, and consequently lifespan. Indeed, five polymorphic markers located within 380 to 680 bp of the Lim3A major TSS, including two markers associated with lifespan variation, were significantly associated with the level of Lim3A transcript, as evaluated by real time RT-PCR in embryos, adult heads, and testes. A naturally occurring polymorphism caused a six-fold change in gene transcription and a 25% change in lifespan. Markers associated with long lifespan and intermediate Lim3A transcription were present in the population at high frequencies. We hypothesize that polymorphic markers associated with Lim3A expression are located within the binding sites for proteins that regulate gene function, and provide general rather than tissue-specific regulation of transcription, and that intermediate levels of Lim3A expression confer a selective advantage and longer lifespan.
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