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Wang B, Mao Z, Chen Y, Ying J, Wang H, Sun Z, Li J, Zhang C, Zhuo J. Identification and Functional Analysis of the fruitless Gene in a Hemimetabolous Insect, Nilaparvata lugens. INSECTS 2024; 15:262. [PMID: 38667392 PMCID: PMC11050625 DOI: 10.3390/insects15040262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 04/01/2024] [Accepted: 04/10/2024] [Indexed: 04/28/2024]
Abstract
The fruitless (fru) gene functions as a crucial "tuner" in male insect courtship behavior through distinct expression patterns. In Nilaparvata lugens, our previous research showed doublesex (dsx) influencing male courtship songs, causing mating failures with virgin females. However, the impact of fru on N. lugens mating remains unexplored. In this study, the fru homolog (Nlfru) in N. lugens yielded four spliceosomes: Nlfru-374-a/b, Nlfru-377, and Nlfru-433, encoding proteins of 374aa, 377aa, and 433aa, respectively. Notably, only Nlfru-374b exhibited male bias, while the others were non-sex-specific. All NlFRU proteins featured the BTB conserved domain, with NlFRU-374 and NlFRU-377 possessing the ZnF domain with different sequences. RNAi-mediated Nlfru or its isoforms' knockdown in nymph stages blocked wing-flapping behavior in mating males, while embryonic knockdown via maternal RNAi resulted in over 80% of males losing wing-flapping ability, and female receptivity was reduced. Nlfru expression was Nldsx-regulated, and yet courtship signals and mating success were unaffected. Remarkably, RNAi-mediated Nlfru knockdown up-regulated the expression of flightin in macropterous males, which regulated muscle stiffness and delayed force response, suggesting Nlfru's involvement in muscle development regulation. Collectively, our results indicate that Nlfru functions in N. lugens exhibit a combination of conservation and species specificity, contributing insights into fru evolution, particularly in Hemiptera species.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Jichong Zhuo
- State Key Laboratory for ManagingBiotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Biotechnology in Plant Protection of MARA and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo 315211, China; (B.W.); (Z.M.); (Y.C.); (J.Y.); (H.W.); (Z.S.); (J.L.); (C.Z.)
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2
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Palmateer CM, Artikis C, Brovero SG, Friedman B, Gresham A, Arbeitman MN. Single-cell transcriptome profiles of Drosophila fruitless-expressing neurons from both sexes. eLife 2023; 12:e78511. [PMID: 36724009 PMCID: PMC9891730 DOI: 10.7554/elife.78511] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 01/08/2023] [Indexed: 02/02/2023] Open
Abstract
Drosophila melanogaster reproductive behaviors are orchestrated by fruitless neurons. We performed single-cell RNA-sequencing on pupal neurons that produce sex-specifically spliced fru transcripts, the fru P1-expressing neurons. Uniform Manifold Approximation and Projection (UMAP) with clustering generates an atlas containing 113 clusters. While the male and female neurons overlap in UMAP space, more than half the clusters have sex differences in neuron number, and nearly all clusters display sex-differential expression. Based on an examination of enriched marker genes, we annotate clusters as circadian clock neurons, mushroom body Kenyon cell neurons, neurotransmitter- and/or neuropeptide-producing, and those that express doublesex. Marker gene analyses also show that genes that encode members of the immunoglobulin superfamily of cell adhesion molecules, transcription factors, neuropeptides, neuropeptide receptors, and Wnts have unique patterns of enriched expression across the clusters. In vivo spatial gene expression links to the clusters are examined. A functional analysis of fru P1 circadian neurons shows they have dimorphic roles in activity and period length. Given that most clusters are comprised of male and female neurons indicates that the sexes have fru P1 neurons with common gene expression programs. Sex-specific expression is overlaid on this program, to build the potential for vastly different sex-specific behaviors.
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Affiliation(s)
- Colleen M Palmateer
- Department of Biomedical Sciences, Florida State University, College of MedicineTallahasseeUnited States
| | - Catherina Artikis
- Department of Biomedical Sciences, Florida State University, College of MedicineTallahasseeUnited States
| | - Savannah G Brovero
- Department of Biomedical Sciences, Florida State University, College of MedicineTallahasseeUnited States
| | - Benjamin Friedman
- Department of Biomedical Sciences, Florida State University, College of MedicineTallahasseeUnited States
| | - Alexis Gresham
- Department of Biomedical Sciences, Florida State University, College of MedicineTallahasseeUnited States
| | - Michelle N Arbeitman
- Department of Biomedical Sciences, Florida State University, College of MedicineTallahasseeUnited States
- Program of Neuroscience, Florida State UniversityTallahasseeUnited States
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3
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Connahs H, Tan EJ, Ter YT, Dion E, Matsuoka Y, Bear A, Monteiro A. The yellow gene regulates behavioural plasticity by repressing male courtship in Bicyclus anynana butterflies. Proc Biol Sci 2022; 289:20212665. [PMID: 35382598 PMCID: PMC8984812 DOI: 10.1098/rspb.2021.2665] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Seasonal plasticity in male courtship in Bicyclus anynana butterflies is due to variation in levels of the steroid hormone 20E (20-hydroxyecdysone) during pupation. Wet season (WS) males have high levels of 20E and become active courters. Dry season (DS) males have lower levels of 20E and reduced courtship rates. However, WS courtship rates can be achieved if DS male pupae are injected with 20E at 30% of pupation. Here, we investigated the genes involved in male courtship plasticity and examined whether 20E plays an organizational role in the pupal brain that later influences the sexual behaviour of adults. We show that DS pupal brains have a sevenfold upregulation of the yellow gene relative to the WS brains, and that knocking out yellow leads to increased male courtship. We find that injecting 20E into DS pupa reduced yellow expression although not significantly. Our results show that yellow is a repressor of the neural circuity for male courtship behaviour in B. anynana. 20E levels experienced during pupation could play an organizational role during pupal brain development by regulating yellow expression, however, other factors might also be involved. Our findings are in striking contrast to Drosophila where yellow is required for male courtship.
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Affiliation(s)
- Heidi Connahs
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543
| | - Eunice Jingmei Tan
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543.,Yale-NUS College, 16 College Avenue West, Singapore 138527
| | - Yi Ting Ter
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543
| | - Emilie Dion
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543
| | - Yuji Matsuoka
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543
| | - Ashley Bear
- Department of Ecology and Evolutionary Biology, Yale University, CT 06511, USA
| | - Antónia Monteiro
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543.,Yale-NUS College, 16 College Avenue West, Singapore 138527
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4
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The nuclear receptor Hr46/Hr3 is required in the blood brain barrier of mature males for courtship. PLoS Genet 2022; 18:e1009519. [PMID: 35077443 PMCID: PMC8815886 DOI: 10.1371/journal.pgen.1009519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 02/04/2022] [Accepted: 12/24/2021] [Indexed: 11/19/2022] Open
Abstract
The blood brain barrier (BBB) forms a stringent barrier that protects the brain from components in the circulation that could interfere with neuronal function. At the same time, the BBB enables selective transport of critical nutrients and other chemicals to the brain. Beyond these functions, another recently recognized function is even less characterized, specifically the role of the BBB in modulating behavior by affecting neuronal function in a sex-dependent manner. Notably, signaling in the adult Drosophila BBB is required for normal male courtship behavior. Courtship regulation also relies on male-specific molecules in the BBB. Our previous studies have demonstrated that adult feminization of these cells in males significantly lowered courtship. Here, we conducted microarray analysis of BBB cells isolated from males and females. Findings revealed that these cells contain male- and female-enriched transcripts, respectively. Among these transcripts, nuclear receptor Hr46/Hr3 was identified as a male-enriched BBB transcript. Hr46/Hr3 is best known for its essential roles in the ecdysone response during development and metamorphosis. In this study, we demonstrate that Hr46/Hr3 is specifically required in the BBB cells for courtship behavior in mature males. The protein is localized in the nuclei of sub-perineurial glial cells (SPG), indicating that it might act as a transcriptional regulator. These data provide a catalogue of sexually dimorphic BBB transcripts and demonstrate a physiological adult role for the nuclear receptor Hr46/Hr3 in the regulation of male courtship, a novel function that is independent of its developmental role.
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5
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Wat LW, Chowdhury ZS, Millington JW, Biswas P, Rideout EJ. Sex determination gene transformer regulates the male-female difference in Drosophila fat storage via the adipokinetic hormone pathway. eLife 2021; 10:e72350. [PMID: 34672260 PMCID: PMC8594944 DOI: 10.7554/elife.72350] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 10/07/2021] [Indexed: 12/17/2022] Open
Abstract
Sex differences in whole-body fat storage exist in many species. For example, Drosophila females store more fat than males. Yet, the mechanisms underlying this sex difference in fat storage remain incompletely understood. Here, we identify a key role for sex determination gene transformer (tra) in regulating the male-female difference in fat storage. Normally, a functional Tra protein is present only in females, where it promotes female sexual development. We show that loss of Tra in females reduced whole-body fat storage, whereas gain of Tra in males augmented fat storage. Tra's role in promoting fat storage was largely due to its function in neurons, specifically the Adipokinetic hormone (Akh)-producing cells (APCs). Our analysis of Akh pathway regulation revealed a male bias in APC activity and Akh pathway function, where this sex-biased regulation influenced the sex difference in fat storage by limiting triglyceride accumulation in males. Importantly, Tra loss in females increased Akh pathway activity, and genetically manipulating the Akh pathway rescued Tra-dependent effects on fat storage. This identifies sex-specific regulation of Akh as one mechanism underlying the male-female difference in whole-body triglyceride levels, and provides important insight into the conserved mechanisms underlying sexual dimorphism in whole-body fat storage.
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Affiliation(s)
- Lianna W Wat
- Department of Cellular and Physiological Sciences, The University of British ColumbiaVancouverCanada
| | - Zahid S Chowdhury
- Department of Cellular and Physiological Sciences, The University of British ColumbiaVancouverCanada
| | - Jason W Millington
- Department of Cellular and Physiological Sciences, The University of British ColumbiaVancouverCanada
| | - Puja Biswas
- Department of Cellular and Physiological Sciences, The University of British ColumbiaVancouverCanada
| | - Elizabeth J Rideout
- Department of Cellular and Physiological Sciences, The University of British ColumbiaVancouverCanada
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6
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Palmateer CM, Moseley SC, Ray S, Brovero SG, Arbeitman MN. Analysis of cell-type-specific chromatin modifications and gene expression in Drosophila neurons that direct reproductive behavior. PLoS Genet 2021; 17:e1009240. [PMID: 33901168 PMCID: PMC8102012 DOI: 10.1371/journal.pgen.1009240] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 05/06/2021] [Accepted: 04/05/2021] [Indexed: 02/06/2023] Open
Abstract
Examining the role of chromatin modifications and gene expression in neurons is critical for understanding how the potential for behaviors are established and maintained. We investigate this question by examining Drosophila melanogaster fru P1 neurons that underlie reproductive behaviors in both sexes. We developed a method to purify cell-type-specific chromatin (Chromatag), using a tagged histone H2B variant that is expressed using the versatile Gal4/UAS gene expression system. Here, we use Chromatag to evaluate five chromatin modifications, at three life stages in both sexes. We find substantial changes in chromatin modification profiles across development and fewer differences between males and females. Additionally, we find chromatin modifications that persist in different sets of genes from pupal to adult stages, which may point to genes important for cell fate determination in fru P1 neurons. We generated cell-type-specific RNA-seq data sets, using translating ribosome affinity purification (TRAP). We identify actively translated genes in fru P1 neurons, revealing novel stage- and sex-differences in gene expression. We also find chromatin modification enrichment patterns that are associated with gene expression. Next, we use the chromatin modification data to identify cell-type-specific super-enhancer-containing genes. We show that genes with super-enhancers in fru P1 neurons differ across development and between the sexes. We validated that a set of genes are expressed in fru P1 neurons, which were chosen based on having a super-enhancer and TRAP-enriched expression in fru P1 neurons.
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Affiliation(s)
- Colleen M. Palmateer
- Department of Biomedical Sciences, Florida State University, College of Medicine, Tallahassee, Florida, United States of America
| | - Shawn C. Moseley
- Department of Biomedical Sciences, Florida State University, College of Medicine, Tallahassee, Florida, United States of America
| | - Surjyendu Ray
- Department of Biomedical Sciences, Florida State University, College of Medicine, Tallahassee, Florida, United States of America
| | - Savannah G. Brovero
- Department of Biomedical Sciences, Florida State University, College of Medicine, Tallahassee, Florida, United States of America
| | - Michelle N. Arbeitman
- Department of Biomedical Sciences, Florida State University, College of Medicine, Tallahassee, Florida, United States of America
- Program of Neuroscience, Florida State University, Tallahassee, Florida, United States of America
- * E-mail:
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7
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Brovero SG, Fortier JC, Hu H, Lovejoy PC, Newell NR, Palmateer CM, Tzeng RY, Lee PT, Zinn K, Arbeitman MN. Investigation of Drosophila fruitless neurons that express Dpr/DIP cell adhesion molecules. eLife 2021; 10:e63101. [PMID: 33616528 PMCID: PMC7972454 DOI: 10.7554/elife.63101] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 02/22/2021] [Indexed: 12/16/2022] Open
Abstract
Drosophila reproductive behaviors are directed by fruitless neurons. A reanalysis of genomic studies shows that genes encoding dpr and DIP immunoglobulin superfamily (IgSF) members are expressed in fru P1 neurons. We find that each fru P1 and dpr/DIP (fru P1 ∩ dpr/DIP) overlapping expression pattern is similar in both sexes, but there are dimorphisms in neuronal morphology and cell number. Behavioral studies of fru P1 ∩ dpr/DIP perturbation genotypes indicate that the mushroom body functions together with the lateral protocerebral complex to direct courtship behavior. A single-cell RNA-seq analysis of fru P1 neurons shows that many DIPs have high expression in a small set of neurons, whereas the dprs are often expressed in a larger set of neurons at intermediate levels, with a myriad of dpr/DIP expression combinations. Functionally, we find that perturbations of sex hierarchy genes and of DIP-ε change the sex-specific morphologies of fru P1 ∩ DIP-α neurons.
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Affiliation(s)
- Savannah G Brovero
- Department of Biomedical Sciences and Program of Neuroscience, Florida State University, College of MedicineTallahasseeUnited States
| | - Julia C Fortier
- Department of Biomedical Sciences and Program of Neuroscience, Florida State University, College of MedicineTallahasseeUnited States
| | - Hongru Hu
- Department of Biomedical Sciences and Program of Neuroscience, Florida State University, College of MedicineTallahasseeUnited States
| | - Pamela C Lovejoy
- Department of Biomedical Sciences and Program of Neuroscience, Florida State University, College of MedicineTallahasseeUnited States
| | - Nicole R Newell
- Department of Biomedical Sciences and Program of Neuroscience, Florida State University, College of MedicineTallahasseeUnited States
| | - Colleen M Palmateer
- Department of Biomedical Sciences and Program of Neuroscience, Florida State University, College of MedicineTallahasseeUnited States
| | - Ruei-Ying Tzeng
- Department of Biomedical Sciences and Program of Neuroscience, Florida State University, College of MedicineTallahasseeUnited States
| | - Pei-Tseng Lee
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Kai Zinn
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
| | - Michelle N Arbeitman
- Department of Biomedical Sciences and Program of Neuroscience, Florida State University, College of MedicineTallahasseeUnited States
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8
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Millington JW, Brownrigg GP, Chao C, Sun Z, Basner-Collins PJ, Wat LW, Hudry B, Miguel-Aliaga I, Rideout EJ. Female-biased upregulation of insulin pathway activity mediates the sex difference in Drosophila body size plasticity. eLife 2021; 10:e58341. [PMID: 33448263 PMCID: PMC7864645 DOI: 10.7554/elife.58341] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 01/11/2021] [Indexed: 12/14/2022] Open
Abstract
Nutrient-dependent body size plasticity differs between the sexes in most species, including mammals. Previous work in Drosophila showed that body size plasticity was higher in females, yet the mechanisms underlying increased female body size plasticity remain unclear. Here, we discover that a protein-rich diet augments body size in females and not males because of a female-biased increase in activity of the conserved insulin/insulin-like growth factor signaling pathway (IIS). This sex-biased upregulation of IIS activity was triggered by a diet-induced increase in stunted mRNA in females, and required Drosophila insulin-like peptide 2, illuminating new sex-specific roles for these genes. Importantly, we show that sex determination gene transformer promotes the diet-induced increase in stunted mRNA via transcriptional coactivator Spargel to regulate the male-female difference in body size plasticity. Together, these findings provide vital insight into conserved mechanisms underlying the sex difference in nutrient-dependent body size plasticity.
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Affiliation(s)
- Jason W Millington
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - George P Brownrigg
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - Charlotte Chao
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - Ziwei Sun
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - Paige J Basner-Collins
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - Lianna W Wat
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - Bruno Hudry
- MRC London Institute of Medical Sciences, and Institute of Clinical Sciences, Faculty of Medicine, Imperial College LondonLondonUnited Kingdom
| | - Irene Miguel-Aliaga
- MRC London Institute of Medical Sciences, and Institute of Clinical Sciences, Faculty of Medicine, Imperial College LondonLondonUnited Kingdom
| | - Elizabeth J Rideout
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
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9
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Zhang JL, Yuan XB, Chen SJ, Chen HH, Xu N, Xue WH, Fu SJ, Zhang CX, Xu HJ. The histone deacetylase NlHDAC1 regulates both female and male fertility in the brown planthopper, Nilaparvata lugens. Open Biol 2019; 8:180158. [PMID: 30977704 PMCID: PMC6303786 DOI: 10.1098/rsob.180158] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Histone acetylation is a specific type of chromatin modification that serves as a key regulatory mechanism for many cellular processes in mammals. However, little is known about its biological function in invertebrates. Here, we identified 12 members of histone deacetylases (NlHDACs) in the brown planthopper (BPH), Nilaparvata lugens. RNAi-mediated silencing assay showed that NlHdac1, NlHdac3 and NlHdac4 played critical roles in female fertility via regulating ovary maturation or ovipositor development. Silencing of NlHdac1 substantially increased acetylation level of histones H3 and H4 in ovaries, indicating NlHDAC1 is the main histone deacetylase in ovaries of BPH. RNA sequencing (RNA-seq) analysis showed that knockdown of NlHdac1 impaired ovary development via multiple signalling pathways including the TOR pathway. Acoustic recording showed that males with NlHdac1 knockdown failed to make courtship songs, and thus were unacceptable to wild-type females, resulting in unfertilized eggs. Competition mating assay showed that wild-type females overwhelmingly preferred to mate with control males over NlHdac1-knockdown males. These findings improve our understanding of reproductive strategies controlled by HDACs in insects and provide a potential target for pest control.
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Affiliation(s)
- Jin-Li Zhang
- State Key Laboratory of Rice and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institutes of Insect Sciences, Zhejiang University , Hangzhou 310058 , People's Republic of China
| | - Xiao-Bo Yuan
- State Key Laboratory of Rice and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institutes of Insect Sciences, Zhejiang University , Hangzhou 310058 , People's Republic of China
| | - Sun-Jie Chen
- State Key Laboratory of Rice and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institutes of Insect Sciences, Zhejiang University , Hangzhou 310058 , People's Republic of China
| | - Hao-Hao Chen
- State Key Laboratory of Rice and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institutes of Insect Sciences, Zhejiang University , Hangzhou 310058 , People's Republic of China
| | - Nan Xu
- State Key Laboratory of Rice and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institutes of Insect Sciences, Zhejiang University , Hangzhou 310058 , People's Republic of China
| | - Wen-Hua Xue
- State Key Laboratory of Rice and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institutes of Insect Sciences, Zhejiang University , Hangzhou 310058 , People's Republic of China
| | - Sheng-Jie Fu
- State Key Laboratory of Rice and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institutes of Insect Sciences, Zhejiang University , Hangzhou 310058 , People's Republic of China
| | - Chuan-Xi Zhang
- State Key Laboratory of Rice and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institutes of Insect Sciences, Zhejiang University , Hangzhou 310058 , People's Republic of China
| | - Hai-Jun Xu
- State Key Laboratory of Rice and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institutes of Insect Sciences, Zhejiang University , Hangzhou 310058 , People's Republic of China
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10
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Camara N, Whitworth C, Dove A, Van Doren M. Doublesex controls specification and maintenance of the gonad stem cell niches in Drosophila. Development 2019; 146:dev.170001. [PMID: 31043421 DOI: 10.1242/dev.170001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 04/23/2019] [Indexed: 11/20/2022]
Abstract
Sex-specific development of the gonads is a key aspect of sexual dimorphism that is regulated by Doublesex/Mab3-related transcription factors (DMRTs) in diverse animal species. We find that in mutants for Drosophila dsx, important components of the male and female gonad stem cell niches (hubs and terminal filaments/cap cells, respectively) still form. Initially, gonads in all dsx mutants (both XX and XY) initiate the male program of development, but later half of these gonads switch to form female stem cell niche structures. One individual can have both male-type and female-type gonad niches; however, male and female niches are usually not observed in the same gonad, indicating that cells make a 'group decision' about which program to follow. We conclude that dsx does not act in an instructive manner to regulate male versus female niche formation, as these structures form in the absence of dsx function. Instead, dsx acts to 'tip the balance' between the male or female programs, which are then executed independently of dsx We show that bric a brac acts downstream of dsx to control the male versus female niche decision. These results indicate that, in both flies and mammals, the sexual fate of the somatic gonad is remarkably plastic and is controlled by a combination of autonomous and non-autonomous cues.
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Affiliation(s)
- Nicole Camara
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Cale Whitworth
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Abigail Dove
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Mark Van Doren
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
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11
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Nässel DR, Zandawala M. Recent advances in neuropeptide signaling in Drosophila, from genes to physiology and behavior. Prog Neurobiol 2019; 179:101607. [PMID: 30905728 DOI: 10.1016/j.pneurobio.2019.02.003] [Citation(s) in RCA: 171] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/18/2019] [Accepted: 02/28/2019] [Indexed: 12/11/2022]
Abstract
This review focuses on neuropeptides and peptide hormones, the largest and most diverse class of neuroactive substances, known in Drosophila and other animals to play roles in almost all aspects of daily life, as w;1;ell as in developmental processes. We provide an update on novel neuropeptides and receptors identified in the last decade, and highlight progress in analysis of neuropeptide signaling in Drosophila. Especially exciting is the huge amount of work published on novel functions of neuropeptides and peptide hormones in Drosophila, largely due to the rapid developments of powerful genetic methods, imaging techniques and innovative assays. We critically discuss the roles of peptides in olfaction, taste, foraging, feeding, clock function/sleep, aggression, mating/reproduction, learning and other behaviors, as well as in regulation of development, growth, metabolic and water homeostasis, stress responses, fecundity, and lifespan. We furthermore provide novel information on neuropeptide distribution and organization of peptidergic systems, as well as the phylogenetic relations between Drosophila neuropeptides and those of other phyla, including mammals. As will be shown, neuropeptide signaling is phylogenetically ancient, and not only are the structures of the peptides, precursors and receptors conserved over evolution, but also many functions of neuropeptide signaling in physiology and behavior.
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Affiliation(s)
- Dick R Nässel
- Department of Zoology, Stockholm University, Stockholm, Sweden.
| | - Meet Zandawala
- Department of Zoology, Stockholm University, Stockholm, Sweden; Department of Neuroscience, Brown University, Providence, RI, USA.
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12
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Millington JW, Rideout EJ. Sex differences in Drosophila development and physiology. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2018.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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13
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Abstract
Sex differences in the brain are prominent features across the animal kingdom. Understanding the anatomical and regulatory mechanisms behind these differences is critical for both explaining sexually dimorphic behaviors and developing sex-targeted treatments for neurological disorders. Clinical studies considering sex biases and basic research on animal models have provided much evidence for the existence of sex differences in the brain and, in a larger sense, sexual dimorphisms in the nervous system. However, due to the complexity of structure and dimorphic behaviors, it is yet unclear precisely how neuronal sexual dimorphisms are regulated on a molecular or cellular level. This commentary reviews available tools for investigating sexual dimorphisms using a simple model organism, the roundworm Caenorhabditis elegans ( C. elegans), which enables one to study gene regulation at single-cell resolution with a number of cutting-edge molecular and genetic technologies. I highlight the doublesex/mab-3 family of transcription factors, first discovered in invertebrates, and their roles in a potentially universal regulatory mechanism underlying neuronal sexual dimorphisms. Studies of these transcription factors using C. elegans, fruit flies, and vertebrates will promote our understanding of fundamental mechanisms behind sex differences in the brain.
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Affiliation(s)
- Chen Wang
- Department of Biological Sciences, Columbia University, New York, NY, USA
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14
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The Genetics of a Behavioral Speciation Phenotype in an Island System. Genes (Basel) 2018; 9:genes9070346. [PMID: 29996514 PMCID: PMC6070818 DOI: 10.3390/genes9070346] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/03/2018] [Accepted: 07/03/2018] [Indexed: 12/30/2022] Open
Abstract
Mating behavior divergence can make significant contributions to reproductive isolation and speciation in various biogeographic contexts. However, whether the genetic architecture underlying mating behavior divergence is related to the biogeographic history and the tempo and mode of speciation remains poorly understood. Here, we use quantitative trait locus (QTL) mapping to infer the number, distribution, and effect size of mating song rhythm variations in the crickets Laupala eukolea and Laupala cerasina, which occur on different islands (Maui and Hawaii). We then compare these results with a similar study of an independently evolving species pair that diverged within the same island. Finally, we annotate the L. cerasina transcriptome and test whether the QTL fall in functionally enriched genomic regions. We document a polygenic architecture behind the song rhythm divergence in the inter-island species pair that is remarkably similar to that previously found for an intra-island species pair in the same genus. Importantly, the QTL regions were significantly enriched for potential homologs of the genes involved in pathways that may be modulating the cricket song rhythm. These clusters of loci could constrain the spatial genomic distribution of the genetic variation underlying the cricket song variation and harbor several candidate genes that merit further study.
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15
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Analysis of natural female post-mating responses of Anopheles gambiae and Anopheles coluzzii unravels similarities and differences in their reproductive ecology. Sci Rep 2018; 8:6594. [PMID: 29700344 PMCID: PMC5920108 DOI: 10.1038/s41598-018-24923-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 03/20/2018] [Indexed: 11/18/2022] Open
Abstract
Anopheles gambiae and An. coluzzii, the two most important malaria vectors in sub-Saharan Africa, are recently radiated sibling species that are reproductively isolated even in areas of sympatry. In females from these species, sexual transfer of male accessory gland products, including the steroid hormone 20-hydroxyecdysone (20E), induces vast behavioral, physiological, and transcriptional changes that profoundly shape their post-mating ecology, and that may have contributed to the insurgence of post-mating, prezygotic reproductive barriers. As these barriers can be detected by studying transcriptional changes induced by mating, we set out to analyze the post-mating response of An. gambiae and An. coluzzii females captured in natural mating swarms in Burkina Faso. While the molecular pathways shaping short- and long-term mating-induced changes are largely conserved in females from the two species, we unravel significant inter-specific differences that suggest divergent regulation of key reproductive processes such as egg development, processing of seminal secretion, and mating behavior, that may have played a role in reproductive isolation. Interestingly, a number of these changes occur in genes previously shown to be regulated by the sexual transfer of 20E and may be due to divergent utilization of this steroid hormone in the two species.
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16
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Abstract
During courtship, Drosophila melanogaster males sing to females a song composed of rhythmic pulses and sine song. In this issue of Developmental Cell, Shirangi et al. (2016) show that a cluster of doublesex-expressing neurons directs the production of the sine song component through functional linkages to wing motoneurons.
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Affiliation(s)
- Michelle N Arbeitman
- Biomedical Sciences Department, College of Medicine, Florida State University, Tallahassee, FL 32306, USA.
| | - Nicole R Newell
- Biomedical Sciences Department, College of Medicine, Florida State University, Tallahassee, FL 32306, USA
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17
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Li P, Liu Y, Luo D, Song C, Cui Z. Two spliced isoforms of the sex-determination gene fruitless in the Chinese mitten crab Eriocheir sinensis. Comp Biochem Physiol B Biochem Mol Biol 2017; 208-209:75-83. [PMID: 28438684 DOI: 10.1016/j.cbpb.2017.04.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 04/11/2017] [Accepted: 04/17/2017] [Indexed: 01/06/2023]
Abstract
The fruitless (fru) gene plays an important role in the sex determination pathway and courtship behavior of Drosophila melanogaster. In the present study, two fru isoforms (Esfru1 and Esfru2) were identified from the Chinese mitten crab Eriocheir sinensis. Sequence analysis showed that Esfru1 and Esfru2 were encoded by the same genomic locus and generated by alternative splicing of pre-mRNA. Esfru1 had all introns completely spliced out, while Esfru2 had a longer exon1 with an additional 78bp sequence. They both contained a conserved BTB domain which was also found in D. melanogaster Fru isoforms. Analysis on temporal expression profiles of Esfru1-2 (a common region of Esfru1 and Esfru2) and Esfru2 (a specific region of Esfru2) showed that they expressed in similar patterns during embryonic development but in different patterns during larval development. The expression of Esfru1-2 decreased gradually from zoea III stage, however, Esfru2 increased from zoea IV stage and reached the peak at megalopa stage. Expression distribution in tissues and in situ hybridization analysis revealed that they showed sexually dimorphic expression in gonads, hepatopancreas and brains. Esfru1-2 showed significantly higher expression in female gonads and hepatopancreas than in males, but highly expressed in male brains than that in females. Interestingly, Esfru2 was displayed in a male-specific manner in each tissue, especially in gonads and hepatopancreas. Our results indicate that Esfru1 might be involved in both sexual brain neuronal structure development and related to female-specific character development. Esfru2 may participate in male-specific character development. This is the first report that characterizes two spliced variants of fru in crustaceans and provides basic information for further functional studies of the crab sex-determination mechanism.
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Affiliation(s)
- Peiyao Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuan Liu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Danli Luo
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Chengwen Song
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Zhaoxia Cui
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
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18
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Neurons That Underlie Drosophila melanogaster Reproductive Behaviors: Detection of a Large Male-Bias in Gene Expression in fruitless-Expressing Neurons. G3-GENES GENOMES GENETICS 2016; 6:2455-65. [PMID: 27247289 PMCID: PMC4978899 DOI: 10.1534/g3.115.019265] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Male and female reproductive behaviors in Drosophila melanogaster are vastly different, but neurons that express sex-specifically spliced fruitless transcripts (fru P1) underlie these behaviors in both sexes. How this set of neurons can generate such different behaviors between the two sexes is an unresolved question. A particular challenge is that fru P1-expressing neurons comprise only 2-5% of the adult nervous system, and so studies of adult head tissue or whole brain may not reveal crucial differences. Translating Ribosome Affinity Purification (TRAP) identifies the actively translated pool of mRNAs from fru P1-expressing neurons, allowing a sensitive, cell-type-specific assay. We find four times more male-biased than female-biased genes in TRAP mRNAs from fru P1-expressing neurons. This suggests a potential mechanism to generate dimorphism in behavior. The male-biased genes may direct male behaviors by establishing cell fate in a similar context of gene expression observed in females. These results suggest a possible global mechanism for how distinct behaviors can arise from a shared set of neurons.
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19
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Sex Differences in Drosophila Somatic Gene Expression: Variation and Regulation by doublesex. G3-GENES GENOMES GENETICS 2016; 6:1799-808. [PMID: 27172187 PMCID: PMC4938635 DOI: 10.1534/g3.116.027961] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Sex differences in gene expression have been widely studied in Drosophila melanogaster. Sex differences vary across strains, but many molecular studies focus on only a single strain, or on genes that show sexually dimorphic expression in many strains. How extensive variability is and whether this variability occurs among genes regulated by sex determination hierarchy terminal transcription factors is unknown. To address these questions, we examine differences in sexually dimorphic gene expression between two strains in Drosophila adult head tissues. We also examine gene expression in doublesex (dsx) mutant strains to determine which sex-differentially expressed genes are regulated by DSX, and the mode by which DSX regulates expression. We find substantial variation in sex-differential expression. The sets of genes with sexually dimorphic expression in each strain show little overlap. The prevalence of different DSX regulatory modes also varies between the two strains. Neither the patterns of DSX DNA occupancy, nor mode of DSX regulation explain why some genes show consistent sex-differential expression across strains. We find that the genes identified as regulated by DSX in this study are enriched with known sites of DSX DNA occupancy. Finally, we find that sex-differentially expressed genes and genes regulated by DSX are highly enriched on the fourth chromosome. These results provide insights into a more complete pool of potential DSX targets, as well as revealing the molecular flexibility of DSX regulation.
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20
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Verhulst EC, van de Zande L. Double nexus--Doublesex is the connecting element in sex determination. Brief Funct Genomics 2015; 14:396-406. [PMID: 25797692 PMCID: PMC4652034 DOI: 10.1093/bfgp/elv005] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
In recent years, our knowledge of the conserved master-switch gene doublesex (dsx) and its function in regulating the development of dimorphic traits in insects has deepened considerably. Here, a comprehensive overview is given on the properties of the male- and female-specific dsx transcripts yielding DSXF and DSXM proteins in Drosophila melanogaster, and the many downstream targets that they regulate. As insects have cell-autonomous sex determination, it was assumed that dsx would be expressed in every somatic cell, but recent research showed that dsx is expressed only when a cell is required to show its sexual identity through function or morphology. This spatiotemporal regulation of dsx expression has not only been established in D. melanogaster but in all insect species studied. Gradually, it has been appreciated that dsx could no longer be viewed as the master-switch gene orchestrating sexual development and behaviour in each cell, but instead should be viewed as the interpreter for the sexual identity of the cell, expressing this identity only on request, making dsx the central nexus of insect sex determination.
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21
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Constraints on the evolution of a doublesex target gene arising from doublesex's pleiotropic deployment. Proc Natl Acad Sci U S A 2015; 112:E852-61. [PMID: 25675536 DOI: 10.1073/pnas.1501192112] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
"Regulatory evolution," that is, changes in a gene's expression pattern through changes at its regulatory sequence, rather than changes at the coding sequence of the gene or changes of the upstream transcription factors, has been increasingly recognized as a pervasive evolution mechanism. Many somatic sexually dimorphic features of Drosophila melanogaster are the results of gene expression regulated by the doublesex (dsx) gene, which encodes sex-specific transcription factors (DSX(F) in females and DSX(M) in males). Rapid changes in such sexually dimorphic features are likely a result of changes at the regulatory sequence of the target genes. We focused on the Flavin-containing monooxygenase-2 (Fmo-2) gene, a likely direct dsx target, to elucidate how sexually dimorphic expression and its evolution are brought about. We found that dsx is deployed to regulate the Fmo-2 transcription both in the midgut and in fat body cells of the spermatheca (a female-specific tissue), through a canonical DSX-binding site in the Fmo-2 regulatory sequence. In the melanogaster group, Fmo-2 transcription in the midgut has evolved rapidly, in contrast to the conserved spermathecal transcription. We identified two cis-regulatory modules (CRM-p and CRM-d) that direct sexually monomorphic or dimorphic Fmo-2 transcription, respectively, in the midguts of these species. Changes of Fmo-2 transcription in the midgut from sexually dimorphic to sexually monomorphic in some species are caused by the loss of CRM-d function, but not the loss of the canonical DSX-binding site. Thus, conferring transcriptional regulation on a CRM level allows the regulation to evolve rapidly in one tissue while evading evolutionary constraints posed by other tissues.
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22
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Lebreton S, Grabe V, Omondi AB, Ignell R, Becher PG, Hansson BS, Sachse S, Witzgall P. Love makes smell blind: mating suppresses pheromone attraction in Drosophila females via Or65a olfactory neurons. Sci Rep 2014; 4:7119. [PMID: 25406576 PMCID: PMC4236738 DOI: 10.1038/srep07119] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 11/04/2014] [Indexed: 01/29/2023] Open
Abstract
In Drosophila, the male sex pheromone cis-vaccenyl acetate (cVA) elicits aggregation and courtship, through the odorant receptor Or67d. Long-lasting exposure to cVA suppresses male courtship, via a second channel, Or65a. In females, the role of Or65a has not been studied. We show that, shortly after mating, Drosophila females are no longer attracted to cVA and that activation of olfactory sensory neurons (OSNs) expressing Or65a generates this behavioral switch: when silencing Or65a, mated females remain responsive to cVA. Neurons expressing Or67d converge into the DA1 glomerulus in the antennal lobe, where they synapse onto projection neurons (PNs), that connect to higher neural circuits generating the attraction response to cVA. Functional imaging of these PNs shows that the DA1 glomerulus is inhibited by simultaneous activation of Or65a OSNs, which leads to a suppression of the attraction response to cVA. The behavioral role of postmating cVA exposure is substantiated by the observation that matings with starved males, which produce less cVA, do not alter the female response. Moreover, exposure to synthetic cVA abolishes attraction and decreases sexual receptivity in unmated females. Taken together, Or65a mediates an aversive effect of cVA and may accordingly regulate remating, through concurrent behavioral modulation in males and females.
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Affiliation(s)
- Sébastien Lebreton
- 1] Swedish University of Agricultural Sciences, Department of Plant Protection Biology, Chemical Ecology Unit, 230 53 Alnarp, Sweden [2] Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Veit Grabe
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Aman B Omondi
- Swedish University of Agricultural Sciences, Department of Plant Protection Biology, Chemical Ecology Unit, 230 53 Alnarp, Sweden
| | - Rickard Ignell
- Swedish University of Agricultural Sciences, Department of Plant Protection Biology, Chemical Ecology Unit, 230 53 Alnarp, Sweden
| | - Paul G Becher
- Swedish University of Agricultural Sciences, Department of Plant Protection Biology, Chemical Ecology Unit, 230 53 Alnarp, Sweden
| | - Bill S Hansson
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Silke Sachse
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Peter Witzgall
- Swedish University of Agricultural Sciences, Department of Plant Protection Biology, Chemical Ecology Unit, 230 53 Alnarp, Sweden
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23
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Schinaman JM, Giesey RL, Mizutani CM, Lukacsovich T, Sousa-Neves R. The KRÜPPEL-like transcription factor DATILÓGRAFO is required in specific cholinergic neurons for sexual receptivity in Drosophila females. PLoS Biol 2014; 12:e1001964. [PMID: 25291190 PMCID: PMC4188565 DOI: 10.1371/journal.pbio.1001964] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 08/28/2014] [Indexed: 01/22/2023] Open
Abstract
Courtship is a widespread behavior in which one gender conveys to the other a series of cues about their species identity, gender, and suitability as mates. In many species, females decode these male displays and either accept or reject them. Despite the fact that courtship has been investigated for a long time, the genes and circuits that allow females to generate these mutually exclusive responses remain largely unknown. Here, we provide evidence that the Krüppel-like transcription factor datilógrafo (dati) is required for proper locomotion and courtship acceptance in adult Drosophila females. dati mutant females are completely unable to decode male courtship and almost invariably reject males. Molecular analyses reveal that dati is broadly expressed in the brain and its specific removal in excitatory cholinergic neurons recapitulates the female courtship behavioral phenotype but not the locomotor deficits, indicating that these are two separable functions. Clonal analyses in female brains identified three discrete foci where dati is required to generate acceptance. These include neurons around the antennal lobe, the lateral horn, and the posterior superior lateral protocerebrum. Together, these results show that dati is required to organize and maintain a relatively simple excitatory circuit in the brain that allows females to either accept or reject courting males.
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Affiliation(s)
- Joseph Moeller Schinaman
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Rachel Lynn Giesey
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Claudia Mieko Mizutani
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Tamas Lukacsovich
- Department of Developmental & Cell Biology, School of Biological Sciences, University of California, Irvine, California, United States of America
| | - Rui Sousa-Neves
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
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24
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Lawton KJ, Wassmer TL, Deitcher DL. Conserved role of Drosophila melanogaster FoxP in motor coordination and courtship song. Behav Brain Res 2014; 268:213-21. [PMID: 24747661 DOI: 10.1016/j.bbr.2014.04.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 03/12/2014] [Accepted: 04/07/2014] [Indexed: 01/03/2023]
Abstract
FoxP2 is a highly conserved vertebrate transcription factor known for its importance in human speech and language production. Disruption of FoxP2 in several vertebrate models indicates a conserved functional role for this gene in both sound production and motor coordination. Although FoxP2 is known to be strongly expressed in brain regions important for motor coordination, little is known about FoxP2's role in the nervous system. The recent discovery of the well-conserved Drosophila melanogaster homolog, FoxP, provides an opportunity to study the role of this crucial gene in an invertebrate model. We hypothesized that, like FoxP2, Drosophila FoxP is important for behaviors requiring fine motor coordination. We used targeted RNA interference to reduce expression of FoxP and assayed the effects on a variety of adult behaviors. Male flies with reduced FoxP expression exhibit decreased levels of courtship behavior, altered pulse-song structure, and sex-specific motor impairments in walking and flight. Acute disruption of synaptic activity in FoxP expressing neurons using a temperature-sensitive shibire allele dramatically impaired motor coordination. Utilizing a GFP reporter to visualize FoxP in the fly brain reveals expression in relatively few neurons in distributed clusters within the larval and adult CNS, including distinct labeling of the adult protocerebral bridge - a section of the insect central complex known to be important for motor coordination and thought to be homologous to areas of the vertebrate basal ganglia. Our results establish the necessity of this gene in motor coordination in an invertebrate model and suggest a functional homology with vertebrate FoxP2.
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Affiliation(s)
- Kristy J Lawton
- Department of Neurobiology and Behavior, Cornell University, 215 Tower Rd., Mudd Hall, Ithaca, NY 14853, USA.
| | - Taryn L Wassmer
- Department of Neurobiology and Behavior, Cornell University, 215 Tower Rd., Mudd Hall, Ithaca, NY 14853, USA
| | - David L Deitcher
- Department of Neurobiology and Behavior, Cornell University, 215 Tower Rd., Mudd Hall, Ithaca, NY 14853, USA
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25
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A small subset of fruitless subesophageal neurons modulate early courtship in Drosophila. PLoS One 2014; 9:e95472. [PMID: 24740138 PMCID: PMC3989346 DOI: 10.1371/journal.pone.0095472] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 03/27/2014] [Indexed: 11/19/2022] Open
Abstract
We show that a small subset of two to six subesophageal neurons, expressing the male products of the male courtship master regulator gene products fruitlessMale (fruM), are required in the early stages of the Drosophila melanogaster male courtship behavioral program. Loss of fruM expression or inhibition of synaptic transmission in these fruM(+) neurons results in delayed courtship initiation and a failure to progress to copulation primarily under visually-deficient conditions. We identify a fruM-dependent sexually dimorphic arborization in the tritocerebrum made by two of these neurons. Furthermore, these SOG neurons extend descending projections to the thorax and abdominal ganglia. These anatomical and functional characteristics place these neurons in the position to integrate gustatory and higher-order signals in order to properly initiate and progress through early courtship.
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26
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Genome wide identification of fruitless targets suggests a role in upregulating genes important for neural circuit formation. Sci Rep 2014; 4:4412. [PMID: 24642956 PMCID: PMC3958720 DOI: 10.1038/srep04412] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 02/28/2014] [Indexed: 11/09/2022] Open
Abstract
The fruitless gene (fru) encodes a set of transcription factors (Fru) that display sexually dimorphic gene expression in the brain of the fruit-fly; Drosophila melanogaster. Behavioural studies have demonstrated that fru is essential for courtship behaviour in the male fly and is thought to act by directing the development of sex-specific neural circuitry that encodes this innate behavioural response. This study reports the identification of direct regulatory targets of the sexually dimorphic isoforms of the Fru protein using an in vitro model system. Genome wide binding sites were identified for each of the isoforms using Chromatin Immunoprecipitation coupled to deep sequencing (ChIP-Seq). Putative target genes were found to be involved in processes such as neurotransmission, ion-channel signalling and neuron development. All isoforms showed a significant bias towards genes located on the X-chromosome, which may reflect a specific role for Fru in regulating x-linked genes. Taken together with expression analysis carried out in Fru positive neurons specifically isolated from the male fly brain, it appears that the Fru protein acts as a transcriptional activator. Understanding the regulatory cascades induced by Fru will help to shed light on the molecular mechanisms that are important for specification of neural circuitry underlying complex behaviour.
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27
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Castellanos MC, Tang JCY, Allan DW. Female-biased dimorphism underlies a female-specific role for post-embryonic Ilp7 neurons in Drosophila fertility. Development 2013; 140:3915-26. [PMID: 23981656 DOI: 10.1242/dev.094714] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In Drosophila melanogaster, much of our understanding of sexually dimorphic neuronal development and function comes from the study of male behavior, leaving female behavior less well understood. Here, we identify a post-embryonic population of Insulin-like peptide 7 (Ilp7)-expressing neurons in the posterior ventral nerve cord that innervate the reproductive tracts and exhibit a female bias in their function. They form two distinct dorsal and ventral subsets in females, but only a single dorsal subset in males, signifying a rare example of a female-specific neuronal subset. Female post-embryonic Ilp7 neurons are glutamatergic motoneurons innervating the oviduct and are required for female fertility. In males, they are serotonergic/glutamatergic neuromodulatory neurons innervating the seminal vesicle but are not required for male fertility. In both sexes, these neurons express the sex-differentially spliced fruitless-P1 transcript but not doublesex. The male fruitless-P1 isoform (fruM) was necessary and sufficient for serotonin expression in the shared dorsal Ilp7 subset, but although it was necessary for eliminating female-specific Ilp7 neurons in males, it was not sufficient for their elimination in females. By contrast, sex-specific RNA-splicing by female-specific transformer is necessary for female-type Ilp7 neurons in females and is sufficient for their induction in males. Thus, the emergence of female-biased post-embryonic Ilp7 neurons is mediated in a subset-specific manner by a tra- and fru-dependent mechanism in the shared dorsal subset, and a tra-dependent, fru-independent mechanism in the female-specific subset. These studies provide an important counterpoint to studies of the development and function of male-biased neuronal dimorphism in Drosophila.
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Affiliation(s)
- Monica C Castellanos
- Department of Cellular and Physiological Sciences, 2401 Life Sciences Centre, 2350 Health Sciences Mall, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
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28
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Dalton JE, Fear JM, Knott S, Baker BS, McIntyre LM, Arbeitman MN. Male-specific Fruitless isoforms have different regulatory roles conferred by distinct zinc finger DNA binding domains. BMC Genomics 2013; 14:659. [PMID: 24074028 PMCID: PMC3852243 DOI: 10.1186/1471-2164-14-659] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 09/20/2013] [Indexed: 11/25/2022] Open
Abstract
Background Drosophila melanogaster adult males perform an elaborate courtship ritual to entice females to mate. fruitless (fru), a gene that is one of the key regulators of male courtship behavior, encodes multiple male-specific isoforms (FruM). These isoforms vary in their carboxy-terminal zinc finger domains, which are predicted to facilitate DNA binding. Results By over-expressing individual FruM isoforms in fru-expressing neurons in either males or females and assaying the global transcriptional response by RNA-sequencing, we show that three FruM isoforms have different regulatory activities that depend on the sex of the fly. We identified several sets of genes regulated downstream of FruM isoforms, including many annotated with neuronal functions. By determining the binding sites of individual FruM isoforms using SELEX we demonstrate that the distinct zinc finger domain of each FruM isoforms confers different DNA binding specificities. A genome-wide search for these binding site sequences finds that the gene sets identified as induced by over-expression of FruM isoforms in males are enriched for genes that contain the binding sites. An analysis of the chromosomal distribution of genes downstream of FruM shows that those that are induced and repressed in males are highly enriched and depleted on the X chromosome, respectively. Conclusions This study elucidates the different regulatory and DNA binding activities of three FruM isoforms on a genome-wide scale and identifies genes regulated by these isoforms. These results add to our understanding of sex chromosome biology and further support the hypothesis that in some cell-types genes with male-biased expression are enriched on the X chromosome.
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Affiliation(s)
- Justin E Dalton
- Biomedical Sciences Department and Program in Neuroscience, Florida State University, College of Medicine, Tallahassee, FL 32303, USA.
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29
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Latham KL, Liu YS, Taylor BJ. A small cohort of FRU(M) and Engrailed-expressing neurons mediate successful copulation in Drosophila melanogaster. BMC Neurosci 2013; 14:57. [PMID: 23688386 PMCID: PMC3664081 DOI: 10.1186/1471-2202-14-57] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 05/14/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In Drosophila, male flies require the expression of the male-specific Fruitless protein (FRU(M)) within the developing pupal and adult nervous system in order to produce male courtship and copulation behaviors. Recent evidence has shown that specific subsets of FRU(M) neurons are necessary for particular steps of courtship and copulation. In these neurons, FRU(M) function has been shown to be important for determining sex-specific neuronal characteristics, such as neurotransmitter profile and morphology. RESULTS We identified a small cohort of FRU(M) interneurons in the brain and ventral nerve cord by their co-expression with the transcription factor Engrailed (En). We used an En-GAL4 driver to express a fru(M) RNAi construct in order to selectively deplete FRU(M) in these En/FRU(M) co-expressing neurons. In courtship and copulation tests, these males performed male courtship at wild-type levels but were frequently sterile. Sterility was a behavioral phenotype as these En-fru(M)RNAi males were less able to convert a copulation attempt into a stable copulation, or did not maintain copulation for long enough to transfer sperm and/or seminal fluid. CONCLUSIONS We have identified a population of interneurons necessary for successful copulation in Drosophila. These data confirm a model in which subsets of FRU(M) neurons participate in independent neuronal circuits necessary for individual steps of male behavior. In addition, we have determined that these neurons in wild-type males have homologues in females and fru mutants, with similar placement, projection patterns, and neurochemical profiles.
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Affiliation(s)
- Kristin L Latham
- Department of Zoology, Molecular and Cellular Biology Program, Oregon State University, Corvallis, OR 97331-2914, USA.
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Meier N, Käppeli SC, Hediger Niessen M, Billeter JC, Goodwin SF, Bopp D. Genetic control of courtship behavior in the housefly: evidence for a conserved bifurcation of the sex-determining pathway. PLoS One 2013; 8:e62476. [PMID: 23630634 PMCID: PMC3632534 DOI: 10.1371/journal.pone.0062476] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 03/21/2013] [Indexed: 12/30/2022] Open
Abstract
In Drosophila melanogaster, genes of the sex-determination hierarchy orchestrate the development and differentiation of sex-specific tissues, establishing sex-specific physiology and neural circuitry. One of these sex-determination genes, fruitless (fru), plays a key role in the formation of neural circuits underlying Drosophila male courtship behavior. Conservation of fru gene structure and sex-specific expression has been found in several insect orders, though it is still to be determined whether a male courtship role for the gene is employed in these species due to the lack of mutants and homologous experimental evidence. We have isolated the fru ortholog (Md-fru) from the common housefly, Musca domestica, and show the gene's conserved genomic structure. We demonstrate that male-specific Md-fru transcripts arise by conserved mechanisms of sex-specific splicing. Here we show that Md-fru, is similarly involved in controlling male courtship behavior. A male courtship behavioral function for Md-fru was revealed by the behavioral and neuroanatomical analyses of a hypomorphic allele, Md-tra(man) , which specifically disrupted the expression of Md-fru in males, leading to severely impaired male courtship behavior. In line with a role in nervous system development, we found that expression of Md-fru was confined to neural tissues in the brain, most prominently in optic neuropil and in peripheral sensory organs. We propose that, like in Drosophila, overt sexual differentiation of the housefly depends on a sex-determining pathway that bifurcates downstream of the Md-tra gene to coordinate dimorphic development of non-neuronal tissues mediated by Md-dsx with that of neuronal tissues largely mediated by Md-fru.
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Affiliation(s)
- Nicole Meier
- Institute of Molecular Life Sciences, University of Zürich, Zürich, Switzerland
| | | | | | | | - Stephen F. Goodwin
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Daniel Bopp
- Institute of Molecular Life Sciences, University of Zürich, Zürich, Switzerland
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Salvemini M, D'Amato R, Petrella V, Aceto S, Nimmo D, Neira M, Alphey L, Polito LC, Saccone G. The orthologue of the fruitfly sex behaviour gene fruitless in the mosquito Aedes aegypti: evolution of genomic organisation and alternative splicing. PLoS One 2013; 8:e48554. [PMID: 23418412 PMCID: PMC3572092 DOI: 10.1371/journal.pone.0048554] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Accepted: 09/26/2012] [Indexed: 12/23/2022] Open
Abstract
In Drosophila melanogaster the doublesex (dsx) and fruitless (fru) regulatory genes act at the bottom of the somatic sex determination pathway. Both are regulated via alternative splicing by an upstream female-specific TRA/TRA-2 complex, recognizing a common cis element. dsx controls somatic sexual differentiation of non-neural as well as of neural tissues. fru, on the other hand, expresses male-specific functions only in neural system where it is required to built the neural circuits underlying proper courtship behaviour. In the mosquito Aedes aegypti sex determination is different from Drosophila. The key male determiner M, which is located on one of a pair of homomorphic sex chromosomes, controls sex-specific splicing of the mosquito dsx orthologue. In this study we report the genomic organization and expression of the fru homologue in Ae. aegypti (Aeafru). We found that it is sex-specifically spliced suggesting that it is also under the control of the sex determination pathway. Comparative analyses between the Aeafru and Anopheles gambiae fru (Angfru) genomic loci revealed partial conservation of exon organization and extensive divergence of intron lengths. We find that Aeadsx and Aeafru share novel cis splicing regulatory elements conserved in the alternatively spliced regions. We propose that in Aedes aegypti sex-specific splicing of dsx and fru is most likely under the control of splicing regulatory factors which are different from TRA and TRA-2 found in other dipteran insects and discuss the potential use of fru and dsx for developing new genetic strategies in vector control.
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Affiliation(s)
- Marco Salvemini
- Department of Biological Sciences - Section of Genetics and Molecular Biology, University of Naples Federico II, Naples, Italy.
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Hoxha V, Lama C, Chang PL, Saurabh S, Patel N, Olate N, Dauwalder B. Sex-specific signaling in the blood-brain barrier is required for male courtship in Drosophila. PLoS Genet 2013; 9:e1003217. [PMID: 23359644 PMCID: PMC3554526 DOI: 10.1371/journal.pgen.1003217] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 11/20/2012] [Indexed: 01/12/2023] Open
Abstract
Soluble circulating proteins play an important role in the regulation of mating behavior in Drosophila melanogaster. However, how these factors signal through the blood–brain barrier (bbb) to interact with the sex-specific brain circuits that control courtship is unknown. Here we show that male identity of the blood–brain barrier is necessary and that male-specific factors in the bbb are physiologically required for normal male courtship behavior. Feminization of the bbb of adult males significantly reduces male courtship. We show that the bbb–specific G-protein coupled receptor moody and bbb–specific Go signaling in adult males are necessary for normal courtship. These data identify sex-specific factors and signaling processes in the bbb as important regulators of male mating behavior. Complex behaviors such as mating behavior are controlled by the brain. Ensembles of brain cells work in networks to ensure proper behavior at the right time. While the state of these cells plays an important role in whether and how the behavior is displayed, information from outside the brain is also required. Often, this information is provided by hormones that are present in the circulating fluid (such as the blood). However, the brain is protected by a layer of very tight cells, the so-called blood–brain barrier, that keeps unwanted molecules out. So how then do hormones and other regulatory factors “talk” to the brain? We are studying this question by examining the mating behavior of males of a model organism, the fruit fly Drosophila melanogaster. We have found that the blood–brain barrier cells themselves contain male-specific molecules that play an important role. When they are absent, courtship behavior is compromised. We have also identified how outside factors talk to the brain: by using a cellular signaling protein and a particular signaling pathway. Together they are well suited to pass on outside information to the brain network that regulates mating behavior.
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Affiliation(s)
- Valbona Hoxha
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
| | - Chamala Lama
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
| | - Peter L. Chang
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Sumit Saurabh
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
| | - Naiya Patel
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
| | - Nicole Olate
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
| | - Brigitte Dauwalder
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
- * E-mail:
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Two Drosophila DEG/ENaC channel subunits have distinct functions in gustatory neurons that activate male courtship. J Neurosci 2012; 32:11879-89. [PMID: 22915128 DOI: 10.1523/jneurosci.1376-12.2012] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Trimeric sodium channels of the DEG/ENaC family have important roles in neurons, but the specific functions of different subunits present in heteromeric channels are poorly understood. We previously reported that the Drosophila DEG/ENaC subunit Ppk25 is essential in a small subset of gustatory neurons for activation of male courtship behavior, likely through detection of female pheromones. Here we show that, like mutations in ppk25, mutations in another Drosophila DEG/ENaC subunit gene, nope, specifically impair male courtship of females. nope regulatory sequences drive reporter gene expression in gustatory neurons of the labellum wings, and legs, including all gustatory neurons in which ppk25 function is required for male courtship of females. In addition, gustatory-specific knockdown of nope impairs male courtship. Further, the impaired courtship response of nope mutant males to females is rescued by targeted expression of nope in the subset of gustatory neurons in which ppk25 functions. However, nope and ppk25 have nonredundant functions, as targeted expression of ppk25 does not compensate for the lack of nope and vice versa. Moreover, Nope and Ppk25 form specific complexes when coexpressed in cultured cells. Together, these data indicate that the Nope and Ppk25 polypeptides have specific, nonredundant functions in a subset of gustatory neurons required for activation of male courtship in response to females, and suggest the hypothesis that Nope and Ppk25 function as subunits of a heteromeric DEG/ENaC channel required for gustatory detection of female pheromones.
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Identification of gene expression changes associated with long-term memory of courtship rejection in Drosophila males. G3-GENES GENOMES GENETICS 2012; 2:1437-45. [PMID: 23173095 PMCID: PMC3484674 DOI: 10.1534/g3.112.004119] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 09/16/2012] [Indexed: 11/18/2022]
Abstract
Long-term memory formation in Drosophila melanogaster is an important neuronal function shaping the insect’s behavioral repertoire by allowing an individual to modify behaviors on the basis of previous experiences. In conditioned courtship or courtship suppression, male flies that have been repeatedly rejected by mated females during courtship advances are less likely than naïve males to subsequently court another mated female. This long-term courtship suppression can last for several days after the initial rejection period. Although genes with known functions in many associative learning paradigms, including those that function in cyclic AMP signaling and RNA translocation, have been identified as playing critical roles in long-term conditioned courtship, it is clear that additional mechanisms also contribute. We have used RNA sequencing to identify differentially expressed genes and transcript isoforms between naïve males and males subjected to courtship-conditioning regimens that are sufficient for inducing long-term courtship suppression. Transcriptome analyses 24 hours after the training regimens revealed differentially expressed genes and transcript isoforms with predicted and known functions in nervous system development, chromatin biology, translation, cytoskeletal dynamics, and transcriptional regulation. A much larger number of differentially expressed transcript isoforms were identified, including genes previously implicated in associative memory and neuronal development, including fruitless, that may play functional roles in learning during courtship conditioning. Our results shed light on the complexity of the genetics that underlies this behavioral plasticity and reveal several new potential areas of inquiry for future studies.
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Pikielny CW. Sexy DEG/ENaC Channels Involved in Gustatory Detection of Fruit Fly Pheromones. Sci Signal 2012; 5:pe48. [DOI: 10.1126/scisignal.2003555] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Fabre CCG, Hedwig B, Conduit G, Lawrence PA, Goodwin SF, Casal J. Substrate-borne vibratory communication during courtship in Drosophila melanogaster. Curr Biol 2012; 22:2180-5. [PMID: 23103187 PMCID: PMC3502867 DOI: 10.1016/j.cub.2012.09.042] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 09/07/2012] [Accepted: 09/25/2012] [Indexed: 12/02/2022]
Abstract
Courtship in Drosophila melanogaster has become an iconic example of an innate and interactive series of behaviors [1–11]. The female signals her acceptance of copulation by becoming immobile in response to a male's display of stereotyped actions. The male and female communicate via vision, air-borne sounds, and pheromones [1, 2], but what triggers the female's immobility is undetermined. Here, we describe an overlooked and important component of Drosophila courtship. Video recordings and laser vibrometry show that the male abdomen shakes (“quivers”), generating substrate-borne vibrations at about six pulses per second. We present evidence that the female becomes receptive and stops walking because she senses these vibrations, rather than as a response to air-borne songs produced by the male fluttering the wings [1, 2, 12]. We also present evidence that the neural circuits expressing the sex-determination genes fruitless and doublesex [8] drive quivering behavior. These abdominal quivers and associated vibrations, as well as their effect on female receptivity, are conserved in other Drosophila species. Substrate-borne vibrations are an ancient form of communication that is widespread in animals. Our findings in Drosophila open a door to study the neuromuscular circuitry responsible for these signals and the sensory systems needed for their reception.
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Affiliation(s)
- Caroline C G Fabre
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 2EJ, UK.
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Pavlou HJ, Goodwin SF. Courtship behavior in Drosophila melanogaster: towards a 'courtship connectome'. Curr Opin Neurobiol 2012; 23:76-83. [PMID: 23021897 PMCID: PMC3563961 DOI: 10.1016/j.conb.2012.09.002] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 08/29/2012] [Accepted: 09/08/2012] [Indexed: 01/24/2023]
Abstract
The construction of a comprehensive structural, and importantly functional map of the network of elements and connections forming the brain represents the Holy Grail for research groups working in disparate disciplines. Although technical limitations have restricted the mapping of human and mouse ‘connectomes’ to the level of brain regions, a finer degree of functional resolution is attainable in the fruit fly, Drosophila melanogaster, due to the armamentarium of genetic tools available for this model organism. Currently, one of the most amenable approaches employed by Drosophila neurobiologists involves mapping neuronal circuitry underlying complex innate behaviors – courtship being a classic paradigm. We discuss recent studies aimed at identifying the cellular components of courtship neural circuits, mapping function in these circuits and defining causal relationships between neural activity and behavior.
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Affiliation(s)
- Hania J Pavlou
- Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, OX1 3PT, UK
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