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Dive into the research topics where Tetsuya Nojima is active.

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Featured researches published by Tetsuya Nojima.


Current Biology | 2014

Sexually Dimorphic Octopaminergic Neurons Modulate Female Postmating Behaviors in Drosophila

Carolina Rezával; Tetsuya Nojima; Megan C. Neville; Andrew C. Lin; Stephen F. Goodwin

Mating elicits profound behavioral and physiological changes in many species that are crucial for reproductive success. After copulation, Drosophila melanogaster females reduce their sexual receptivity and increase egg laying [1, 2]. Transfer of male sex peptide (SP) during copulation mediates these postmating responses [1, 3-6] via SP sensory neurons in the uterus defined by coexpression of the proprioceptive neuronal marker pickpocket (ppk) and the sex-determination genes doublesex (dsx) and fruitless (fru) [7-9]. Although neurons expressing dsx downstream of SP signaling have been shown to regulate postmating behaviors [9], how the female nervous system coordinates the change from pre- to postcopulatory states is unknown. Here, we show a role of the neuromodulator octopamine (OA) in the female postmating response. Lack of OA disrupts postmating responses in mated females, while increase of OA induces postmating responses in virgin females. Using a novel dsx(FLP) allele, we uncovered dsx neuronal elements associated with OA signaling involved in modulation of postmating responses. We identified a small subset of sexually dimorphic OA/dsx(+) neurons (approximately nine cells in females) in the abdominal ganglion. Our results are consistent with a model whereby OA neuronal signaling increases after copulation, which in turn modulates changes in female behavior and physiology in response to reproductive state.


Proceedings of the National Academy of Sciences of the United States of America | 2012

Expression of a desaturase gene, desat1, in neural and nonneural tissues separately affects perception and emission of sex pheromones in Drosophila

François Bousquet; Tetsuya Nojima; Benjamin Houot; Isabelle Chauvel; Sylvie Chaudy; Stéphane Dupas; Daisuke Yamamoto; Jean-François Ferveur

Animals often use sex pheromones for mate choice and reproduction. As for other signals, the genetic control of the emission and perception of sex pheromones must be tightly coadapted, and yet we still have no worked-out example of how these two aspects interact. Most models suggest that emission and perception rely on separate genetic control. We have identified a Drosophila melanogaster gene, desat1, that is involved in both the emission and the perception of sex pheromones. To explore the mechanism whereby these two aspects of communication interact, we investigated the relationship between the molecular structure, tissue-specific expression, and pheromonal phenotypes of desat1. We characterized the five desat1 transcripts—all of which yielded the same desaturase protein—and constructed transgenes with the different desat1 putative regulatory regions. Each region was used to target reporter transgenes with either (i) the fluorescent GFP marker to reveal desat1 tissue expression, or (ii) the desat1 RNAi sequence to determine the effects of genetic down-regulation on pheromonal phenotypes. We found that desat1 is expressed in a variety of neural and nonneural tissues, most of which are involved in reproductive functions. Our results suggest that distinct desat1 putative regulatory regions independently drive the expression in nonneural and in neural cells, such that the emission and perception of sex pheromones are precisely coordinated in this species.


Current Biology | 2014

Male-Specific Fruitless Isoforms Target Neurodevelopmental Genes to Specify a Sexually Dimorphic Nervous System

Megan C. Neville; Tetsuya Nojima; Elizabeth A. Ashley; Darren J. Parker; John Walker; Tony D. Southall; Bram Van de Sande; Ana C. Marques; Bettina Fischer; Andrea H. Brand; Steven Russell; Michael G. Ritchie; Stein Aerts; Stephen F. Goodwin

Summary Background In Drosophila, male courtship behavior is regulated in large part by the gene fruitless (fru). fru encodes a set of putative transcription factors that promote male sexual behavior by controlling the development of sexually dimorphic neuronal circuitry. Little is known about how Fru proteins function at the level of transcriptional regulation or the role that isoform diversity plays in the formation of a male-specific nervous system. Results To characterize the roles of sex-specific Fru isoforms in specifying male behavior, we generated novel isoform-specific mutants and used a genomic approach to identify direct Fru isoform targets during development. We demonstrate that all Fru isoforms directly target genes involved in the development of the nervous system, with individual isoforms exhibiting unique binding specificities. We observe that fru behavioral phenotypes are specified by either a single isoform or a combination of isoforms. Finally, we illustrate the utility of these data for the identification of novel sexually dimorphic genomic enhancers and novel downstream regulators of male sexual behavior. Conclusions These findings suggest that Fru isoform diversity facilitates both redundancy and specificity in gene expression, and that the regulation of neuronal developmental genes may be the most ancient and conserved role of fru in the specification of a male-specific nervous system.


Current Biology | 2010

Neuronal Synaptic Outputs Determine the Sexual Fate of Postsynaptic Targets

Tetsuya Nojima; Ken-ichi Kimura; Masayuki Koganezawa; Daisuke Yamamoto

Synapses mediate inductive interactions for the proper development of pre- and postsynaptic cells: presynaptic electrical activities and synaptic transmission ensure the organization of postsynaptic structures, whereas neurotrophins produced in postsynaptic cells support the survival and enlargement of presynaptic partners. In Drosophila, a motor nerve has been implicated in the induction of the muscle of Lawrence (MOL), the formation of which is male specific and depends on the neural expression of fruitless (fru), a neural sex-determinant gene. Here we report the identification of a single motoneuron essential for inducing the MOL, which we call the MOL-inducing (Mind) motoneuron. The MOL is restored in fru mutant males, which otherwise lack the MOL, if the fru(+) transgene is selectively expressed in the Mind motoneuron by mosaic analysis with a repressible cell marker. We further demonstrate that synaptic outputs from the Mind motoneuron are indispensable to MOL induction, because the blockage of synaptic transmission by shibire(ts) (shi(ts)) during the critical period in development abolished the MOL formation in males. Our finding that sex-specific neurons instruct sexually dimorphic development of their innervating targets through synaptic interactions points to the novel mechanism whereby the pre- and postsynaptic partners coordinately establish their sexual identity.


eLife | 2016

Neural circuitry coordinating male copulation

Hania J. Pavlou; Andrew C. Lin; Megan C. Neville; Tetsuya Nojima; Fengqiu Diao; Brian E Chen; Benjamin H. White; Stephen F. Goodwin

Copulation is the goal of the courtship process, crucial to reproductive success and evolutionary fitness. Identifying the circuitry underlying copulation is a necessary step towards understanding universal principles of circuit operation, and how circuit elements are recruited into the production of ordered action sequences. Here, we identify key sex-specific neurons that mediate copulation in Drosophila, and define a sexually dimorphic motor circuit in the male abdominal ganglion that mediates the action sequence of initiating and terminating copulation. This sexually dimorphic circuit composed of three neuronal classes – motor neurons, interneurons and mechanosensory neurons – controls the mechanics of copulation. By correlating the connectivity, function and activity of these neurons we have determined the logic for how this circuitry is coordinated to generate this male-specific behavior, and sets the stage for a circuit-level dissection of active sensing and modulation of copulatory behavior. DOI: http://dx.doi.org/10.7554/eLife.20713.001


Current Biology | 2016

Activation of Latent Courtship Circuitry in the Brain of Drosophila Females Induces Male-like Behaviors.

Carolina Rezával; Siddharth Pattnaik; Hania J. Pavlou; Tetsuya Nojima; Birgit Brüggemeier; Luis A.D. D’Souza; Hany K.M. Dweck; Stephen F. Goodwin

Summary Courtship in Drosophila melanogaster offers a powerful experimental paradigm for the study of innate sexually dimorphic behaviors [1, 2]. Fruit fly males exhibit an elaborate courtship display toward a potential mate [1, 2]. Females never actively court males, but their response to the male’s display determines whether mating will actually occur. Sex-specific behaviors are hardwired into the nervous system via the actions of the sex determination genes doublesex (dsx) and fruitless (fru) [1]. Activation of male-specific dsx/fru+ P1 neurons in the brain initiates the male’s courtship display [3, 4], suggesting that neurons unique to males trigger this sex-specific behavior. In females, dsx+ neurons play a pivotal role in sexual receptivity and post-mating behaviors [1, 2, 5, 6, 7, 8, 9]. Yet it is still unclear how dsx+ neurons and dimorphisms in these circuits give rise to the different behaviors displayed by males and females. Here, we manipulated the function of dsx+ neurons in the female brain to investigate higher-order neurons that drive female behaviors. Surprisingly, we found that activation of female dsx+ neurons in the brain induces females to behave like males by promoting male-typical courtship behaviors. Activated females display courtship toward conspecific males or females, as well other Drosophila species. We uncovered specific dsx+ neurons critical for driving male courtship and identified pheromones that trigger such behaviors in activated females. While male courtship behavior was thought to arise from male-specific central neurons, our study shows that the female brain is equipped with latent courtship circuitry capable of inducing this male-specific behavioral program.


Current Biology | 2018

Drosophila Courtship: Love Is Not Blind.

Tetsuya Nojima; Annika Rings; Stephen F. Goodwin

Animals rely on sensory cues to help them find suitable mates. Visual cues are particularly useful for locating mates during the day. A new study has revealed key visual neurons in male Drosophila used to identify and pursue potential mates.


Fly | 2014

Fruitless isoforms and target genes specify the sexually dimorphic nervous system underlying Drosophila reproductive behavior

Tetsuya Nojima; Megan C. Neville; Stephen F. Goodwin


Archives of Insect Biochemistry and Physiology | 2007

Identification of trf2 mutants of Drosophila with defects in anterior spiracle eversion.

Seigo Shima; Toshiro Aigaki; Tetsuya Nojima; Daisuke Yamamoto


21. Congress of the european chemoreception research organisation (ECRO) | 2011

Desat expression in neural and non-neural tissues separately affects perception and emission of sex pheromones in Drosophila

François Bousquet; Tetsuya Nojima; Benjamin Houot; Isabelle Chauvel; Sylvie Chaudy; Stéphane Dupas; Daisuke Yamamoto; Jean-François Ferveur

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François Bousquet

Centre national de la recherche scientifique

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Isabelle Chauvel

Centre national de la recherche scientifique

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Stéphane Dupas

Centre national de la recherche scientifique

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