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Suzuki A.,National Institute of Genetics NIG | Suzuki A.,Graduate University for Advanced Studies | Lee L.-J.,National Taiwan University | Hayashi Y.,RIKEN | And 5 more authors.
Neuroscience | Year: 2015

Cyclic AMP signaling is critical for activity-dependent refinement of neuronal circuits. Global disruption of adenylyl cyclase 1 (AC1), the major calcium/calmodulin-stimulated adenylyl cyclase in the brain, impairs formation of whisker-related discrete neural modules (the barrels) in cortical layer 4 in mice. Since AC1 is expressed both in the thalamus and the neocortex, the question of whether pre- or postsynaptic (or both) AC1 plays a role in barrel formation has emerged. Previously, we generated cortex-specific AC1 knockout (Cx-AC1KO) mice and found that these animals develop histologically normal barrels, suggesting a potentially more prominent role for thalamic AC1 in barrel formation. To determine this, we generated three new lines of mice: one in which AC1 is disrupted in nearly half of the thalamic ventrobasal nucleus cells in addition to the cortical excitatory neurons (Cx/pTh-AC1KO mouse), and another in which AC1 is disrupted in the thalamus but not in the cortex or brainstem nuclei of the somatosensory system (Th-AC1KO mouse). Cx/pTh-AC1KO mice show severe deficits in barrel formation. Th-AC1KO mice show even more severe disruption in barrel patterning. In these two lines, single thalamocortical (TC) axon labeling revealed a larger lateral extent of TC axons in layer 4 compared to controls. In the third line, all calcium-stimulated adenylyl cyclases (both AC1 and AC8) are deleted in cortical excitatory neurons. These mice have normal barrels. Taken together, these results indicate that thalamic AC1 plays a major role in patterning and refinement of the mouse TC circuitry. © 2015 IBRO.


Takahashi A.,National Institute of Genetics NIG | Takahashi A.,Graduate University for Advanced Studies | Nagayasu K.,Osaka University | Nagayasu K.,Kyoto University | And 4 more authors.
PLoS ONE | Year: 2014

Aggressive behavior is widely observed throughout the animal kingdom because of its adaptiveness for social animals. However, when aggressive behavior exceeds the species-typical level, it is no longer adaptive, so there should be a mechanism to control excessive aggression to keep it within the adaptive range. Using optogenetics, we demonstrate that activation of excitatory neurons in the medial prefrontal cortex (mPFC), but not the orbitofrontal cortex (OFC), inhibits intermale aggression in mice. At the same time, optogenetic silencing of mPFC neurons causes an escalation of aggressive behavior both quantitatively and qualitatively. Activation of the mPFC suppresses aggressive bursts and reduces the intensity of aggressive behavior, but does not change the duration of the aggressive bursts. Our findings suggest that mPFC activity has an inhibitory role in the initiation and execution, but not the termination, of aggressive behavior, and maintains such behavior within the adaptive range. © 2014 Takahashi et al.


Takahashi A.,University of Tsukuba | Takahashi A.,National Institute of Genetics NIG | Takahashi A.,Graduate University for Advanced Studies | Lee R.X.,National Institute of Genetics NIG | And 9 more authors.
Journal of Neuroscience | Year: 2015

Although the dorsal raphe nucleus (DRN) has long been linked to neural control of aggression, little is known about the regulatory influences of the DRN when an animal engages in either adaptive species-typical aggressive behavior or escalated aggression. Therefore it is important to explore which neurotransmitter inputs into theDRNdetermine the escalation of aggression in male mice. Previously,we observed that microinjection of the GABAB receptor agonist baclofen into the DRN escalates aggressive behavior in male mice. Here, we used a serotonin (5-HT) neuron-specific GABAB receptor knock-out mouse to demonstrate that baclofen acts on nonserotonergic neurons to escalate aggression. Intra-DRN baclofen administration increased glutamate release, but did not alter GABA release, within the DRN. Microinjection of L-glutamate into the DRN escalated dose-dependently attack bites toward an intruder. In vivo microdialysis showed that glutamate release increased in the DRN during an aggressive encounter, and the level of glutamate was further increased when the animal was engaged in escalated aggressive behavior after social instigation. Finally, 5-HT release was increased within theDRN and also in the medial prefrontal cortex when animals were provoked by social instigation, and during escalated aggression after social instigation, but this increase in 5-HT release was not observed when animals were engaged in species-typical aggression. In summary, glutamate input into theDRNis enhanced during escalated aggression, which causes a phasic increase of 5-HT release from theDRN5-HT neurons. © 2015 the authors.


Komiya R.,National Institute of Genetics NIG | Komiya R.,Okinawa Institute of Science and Technology | Ohyanagi H.,Plant Genetics Laboratory | Ohyanagi H.,Mitsubishi Group | And 7 more authors.
Plant Journal | Year: 2014

Small RNAs that interact with Argonaute (AGO) proteins play central roles in RNA-mediated silencing. MEIOSIS ARRESTED AT LEPTOTENE1 (MEL1), a rice AGO, has specific functions in the development of pre-meiotic germ cells and the progression of meiosis. Here, we show that MEL1, which is located mostly in the cytoplasm of germ cells, associates preferentially with 21-nucleotide phased small interfering RNAs (phasiRNAs) that bear a 5′-terminal cytosine. Most phasiRNAs are derived from 1171 intergenic clusters distributed on all rice chromosomes. From these clusters, over 700 large intergenic, non-coding RNAs (lincRNAs) that contain the consensus sequence complementary to miR2118 are transcribed specifically in inflorescences, and cleaved within the miR2118 site. Cleaved lincRNAs are processed via DICER-LIKE4 (DCL4) protein, resulting in production of phasiRNAs. This study provides the evidence that the miR2118-dependent and the DCL4-dependent pathways are both required for biogenesis of 21-nt phasiRNAs associated with germline-specific MEL1 AGO in rice, and over 700 lincRNAs are key factors for induction of this biogenesis during reproductive-specific stages. © 2014 John Wiley & Sons Ltd.


Sultana Z.,Kyoto University | Sultana Z.,National Institute of Genetics NIG | Asakura A.,Kyoto University
Zootaxa | Year: 2015

The complete larval development of the hermit crab Pagurus maculosus, is described and illustrated based on specimens reared in the laboratory at 15°C and 33-35 PSU. Newly hatched larvae invariably passed through a short prezoeal stage (10 minutes to 2 hours), four zoeal stages (each of 7 days,) and one megalopal stage (14 days). Distinct morphological features of each larval stage of the present study are compared with other closely related species in Japanese waters, and we found many differences in morphology and the duration of zoeal stages between them. We mentioned significant diagnostic characters separating this species from other congeners in Japanese waters that include the presence of red-yellowish chromatophores on the maxillipeds. This is the first report of complete larvae development of Pagurus maculosus. Copyright © 2015 Magnolia Press.


Komiya R.,National Institute of Genetics NIG | Nonomura K.-I.,National Institute of Genetics NIG
Methods in Molecular Biology | Year: 2014

The small noncoding RNAs in plants are categorized into two major classes, 21-nucleotides (nt) micro RNA (miRNA) and 21- or 24-nt small-interfering RNA (siRNA). ARGONAUTE (AGO) proteins associate with small RNAs and play central roles in transcriptional and posttranscriptional gene regulation. In plants, AGO1-miRNA complexes mainly regulate developmental processes, and AGO4-siRNA complexes suppress the activity of transposons and exogenous viral infections via RNA-directed DNA methylation. In many animal species, the PIWI-subfamily AGOs interact with PIWI-interacting RNAs (piRNAs), which are most commonly 24-34 nt, and function to tame transposons and to regulate mRNA translation and stability in the germline. The rice protein MEIOSIS ARRESTED AT LEPTOTENE1 (MEL1) is a plant AGO member that has roles specific to development and maintenance of germ cells before meiosis. MEL1-binding small RNAs are mainly 21 nt, have a 5′-terminal cytosine, and are distinct from animal piRNAs. In this chapter, we describe methods for RNA-immunoprecipitation (RNA-IP) using a specific antibody that recognizes MEL1 and subsequent purification of MEL1-associating small RNAs from the IP fraction. We also introduce the bioinformatic procedures including mapping, annotation, and identifying small RNA clusters on the rice genome. © 2014 Springer Science+Business Media, LLC.


PubMed | National Institute of Genetics NIG and Nagaoka University of Technology
Type: Journal Article | Journal: PloS one | Year: 2016

Caspr3 (Contactin-associated protein-like 3, Cntnap3) is a neural cell adhesion molecule belonging to the Caspr family. We have recently shown that Caspr3 is expressed abundantly between the first and second postnatal weeks in the mouse basal ganglia, including the striatum, external segment of the globus pallidus, subthalamic nucleus, and substantia nigra. However, its physiological role remains largely unknown. In this study, we conducted a series of behavioral analyses on Capsr3-knockout (KO) mice and equivalent wild-type (WT) mice to investigate the role of Caspr3 in brain function. No significant differences were observed in most behavioral traits between Caspr3-KO and WT mice, but we found that Caspr3-KO mice performed poorly during the early phase of the accelerated rotarod task in which latency to falling off a rod rotating with increasing velocity was examined. In the late phase, the performance of the Caspr3-KO mice caught up to the level of WT mice, suggesting that the deletion of Caspr3 caused a delay in motor learning. We then examined changes in neural activity after training on the accelerated rotarod by conducting immunohistochemistry using antibody to c-Fos, an indirect marker for neuronal activity. Experience of the accelerated rotarod task caused increases in the number of c-Fos-positive cells in the dorsal striatum, cerebellum, and motor cortex in both Caspr3-KO and WT mice, but the number of c-Fos-positive cells was significantly lower in the dorsal striatum of Caspr3-KO mice than in that of WT mice. The expression of c-Fos in the ventral striatum of Caspr3-KO and WT mice was not altered by the training. Our findings suggest that reduced activation of neural cells in the dorsal striatum in Caspr3-KO mice leads to a decline in motor learning in the accelerated rotarod task.


PubMed | National Institute of Genetics NIG
Type: | Journal: Methods in molecular biology (Clifton, N.J.) | Year: 2013

The small noncoding RNAs in plants are categorized into two major classes, 21-nucleotides (nt) micro RNA (miRNA) and 21- or 24-nt small-interfering RNA (siRNA). ARGONAUTE (AGO) proteins associate with small RNAs and play central roles in transcriptional and posttranscriptional gene regulation. In plants, AGO1-miRNA complexes mainly regulate developmental processes, and AGO4-siRNA complexes suppress the activity of transposons and exogenous viral infections via RNA-directed DNA methylation. In many animal species, the PIWI-subfamily AGOs interact with PIWI-interacting RNAs (piRNAs), which are most commonly 24-34 nt, and function to tame transposons and to regulate mRNA translation and stability in the germline. The rice protein MEIOSIS ARRESTED AT LEPTOTENE1 (MEL1) is a plant AGO member that has roles specific to development and maintenance of germ cells before meiosis. MEL1-binding small RNAs are mainly 21 nt, have a 5-terminal cytosine, and are distinct from animal piRNAs. In this chapter, we describe methods for RNA-immunoprecipitation (RNA-IP) using a specific antibody that recognizes MEL1 and subsequent purification of MEL1-associating small RNAs from the IP fraction. We also introduce the bioinformatic procedures including mapping, annotation, and identifying small RNA clusters on the rice genome.


PubMed | Aichi University of Technology, Tokyo Electron, Tokyo University of Information Sciences, National Institute of Genetics NIG and 4 more.
Type: | Journal: Journal of neuroscience methods | Year: 2014

Owing to their complex nature, social interaction tests normally require the observation of video data by a human researcher, and thus are difficult to use in large-scale studies. We previously established a statistical method, a hidden Markov model (HMM), which enables the differentiation of two social states (interaction and indifference), and three social states (sniffing, following, and indifference), automatically in silico.Here, we developed freeware called DuoMouse for the rapid evaluation of social interaction behavior. This software incorporates five steps: (1) settings, (2) video recording, (3) tracking from the video data, (4) HMM analysis, and (5) visualization of the results.Using DuoMouse, we mapped a genetic locus related to social interaction. We previously reported that a consomic strain, B6-Chr6C(MSM), with its chromosome 6 substituted for one from MSM/Ms, showed more social interaction than C57BL/6 (B6). We made four subconsomic strains, C3, C5, C6, and C7, each of which has a shorter segment of chromosome 6 derived from B6-Chr6C, and conducted social interaction tests on these strains. DuoMouse indicated that C6, but not C3, C5, and C7, showed higher interaction, sniffing, and following than B6, specifically in males.The data obtained by human observation showed high concordance to those from DuoMouse. The results indicated that the MSM-derived chromosomal region present in C6-but not in C3, C5, and C7-associated with increased social behavior.This method to analyze social interaction will aid primary screening for difference in social behavior in mice.


PubMed | Ibaraki University, Transdisciplinary Research Integration Center, The Institute of Statistical Mathematics of Tokyo, National Institute of Genetics NIG and Jichi Medical University
Type: Journal Article | Journal: PloS one | Year: 2015

Despite high estimates of the heritability of aggressiveness, the genetic basis for individual differences in aggression remains unclear. Previously, we showed that the wild-derived mouse strain MSM/Ms (MSM) exhibits highly aggressive behaviors, and identified chromosome 15 (Chr 15) as the location of one of the genetic factors behind this escalated aggression by using a panel of consomic strains of MSM in a C57BL/6J (B6) background. To understand the genetic effect of Chr 15 derived from MSM in detail, this study examined the aggressive behavior of a Chr 15 consomic strain towards different types of opponent. Our results showed that both resident and intruder animals had to have the same MSM Chr 15 genotype in order for attack bites to increase and attack latency to be reduced, whereas there was an intruder effect of MSM Chr 15 on tail rattle behavior. To narrow down the region that contains the genetic loci involved in the aggression-eliciting effects on Chr 15, we established a panel of subconsomic strains of MSM Chr 15. Analysis of these strains suggested the existence of multiple genes that enhance and suppress aggressive behavior on Chr 15, and these loci interact in a complex way. Regression analysis successfully identified four genetic loci on Chr 15 that influence attack latency, and one genetic locus that partially elicits aggressive behaviors was narrowed down to a 4.1-Mbp region (from 68.40 Mb to 72.50 Mb) on Chr 15.

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