川野　絵美Kawano-Yamashita Emiカワノ　エミ

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プロフィール情報

• 姓

  川野, カワノ

• 名

  絵美, エミ

学位

• 理学博士, 奈良女子大学

研究分野

• ライフサイエンス, 動物生理化学、生理学、行動学

経歴

• 2017年04月, 2021年05月, 奈良女子大学, 理学部 化学生物環境学科, 助教
• 2014年10月, 2017年03月, 日本学術振興会特別研究員（RPD）
• 2010年04月, 2014年09月, 日本学術振興会特別研究員（PD）
• 2007年04月, 2010年03月, 大阪市立大学大学院 理学研究科 博士研究員
• 2006年04月, 2007年03月, 日本学術振興会特別研究員（PD）
• 2005年04月, 2006年03月, 日本学術振興会特別研究員（DC2）
• 2021年06月, 9999年, 奈良女子大学 理学部 化学生物環境学科 准教授

学歴

• 2003年04月, 2006年03月, 奈良女子大学, 大学院人間文化研究科, 博士後期課程 共生自然科学専攻, 日本国
• 2001年04月, 2003年03月, 奈良女子大学, 大学院人間文化研究科, 博士前期課程 生物科学専攻, 日本国
• 1997年04月, 2001年03月, 奈良女子大学, 理学部, 生物科学科, 日本国

担当経験のある科目（授業）

• 動物環境応答学演習Ⅳ, 奈良女子大学, 2017年10月, 9999年
• 動物環境応答学演習Ⅱ, 奈良女子大学, 2017年10月, 9999年
• 生物形態分類学実習Ⅱ, 奈良女子大学, 2017年10月, 9999年
• 環境生物学実習, 奈良女子大学, 2017年10月, 9999年
• 神経生理学, 奈良女子大学, 2017年10月, 9999年
• 動物環境応答学特論, 奈良女子大学, 2017年06月, 9999年
• 動物環境応答学セミナーⅡ, 奈良女子大学, 2017年04月, 9999年
• 動物環境応答学セミナーⅠ, 奈良女子大学, 2017年04月, 9999年
• 動物環境応答学演習Ⅲ, 奈良女子大学, 2017年04月, 9999年
• 動物環境応答学演習Ⅰ, 奈良女子大学, 2017年04月, 9999年
• 個体・集団生物学特論１, 奈良女子大学, 2017年04月, 9999年

所属学協会

• 日本動物学会
• 日本比較生理生化学会

Ⅱ．研究活動実績

論文

• 英語, BMC biology, Insights into the evolutionary origin of the pineal color discrimination mechanism from the river lamprey., Seiji Wada; Emi Kawano-Yamashita; Tomohiro Sugihara; Satoshi Tamotsu; Mitsumasa Koyanagi; Akihisa Terakita, BACKGROUND: Pineal-related organs in cyclostomes, teleosts, amphibians, and reptiles exhibit color opponency, generating antagonistic neural responses to different wavelengths of light and thereby sensory information about its "color". Our previous studies suggested that in zebrafish and iguana pineal-related organs, a single photoreceptor cell expressing both UV-sensitive parapinopsin and green-sensitive parietopsin generates color opponency in a "one-cell system." However, it remains unknown to what degree these opsins and the single cell-based mechanism in the pineal color opponency are conserved throughout non-mammalian vertebrates. RESULTS: We found that in the lamprey pineal organ, the two opsins are conserved but that, in contrast to the situation in other vertebrate pineal-related organs, they are expressed in separate photoreceptor cells. Intracellular electrophysiological recordings demonstrated that the parietopsin-expressing photoreceptor cells with Go-type G protein evoke a depolarizing response to visible light. Additionally, spectroscopic analyses revealed that parietopsin with 11-cis 3-dehydroretinal has an absorption maximum at ~570 nm, which is in approximate agreement with the wavelength (~560 nm) that produces the maximum rate of neural firing in pineal ganglion cells exposed to visible light. The vesicular glutamate transporter is localized at both the parietopsin- and parapinopsin-expressing photoreceptor terminals, suggesting that both types of photoreceptor cells use glutamate as a transmitter. Retrograde tracing of the pineal ganglion cells revealed that the terminal of the parietopsin-expressing cells is located close enough to form a neural connection with the ganglion cells, which is similar to our previous observation for the parapinopsin-expressing photoreceptor cells and the ganglion cells. In sum, our observations point to a "two-cell system" in which parietopsin and parapinopsin, expressed separately in two different types of photoreceptor cells,  contribute to the generation of color opponency in the pineal ganglion cells. CONCLUSION: Our results indicate that the jawless vertebrate, lamprey, employs a system for color opponency that differes from that described previously in jawed vertebrates. From a physiological viewpoint, we propose an evolutionary insight, the emergence of pineal "one-cell system" from the ancestral "multiple (two)-cell system," showing the opposite evolutionary direction to that of the ocular color opponency., 2021年09月16日, 19, 1, 188, 188, 研究論文（学術雑誌）, 国際誌, 10.1186/s12915-021-01121-1

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• その他, Zoological Science, Immunohistochemical Characterization of the Development of Long Photoreceptor Cells in the Lamprey Retina, Ferdousi Arjana Hoque; Emi Kawano-Yamashita; Yuka Miyamoto; Satoshi Tamotsu, 2021年05月13日, 38, 4, 研究論文（学術雑誌）, 10.2108/zs200151

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• 査読あり, 英語, Scientific reports, The non-visual opsins expressed in deep brain neurons projecting to the retina in lampreys., Emi Kawano-Yamashita; Mitsumasa Koyanagi; Seiji Wada; Tomoka Saito; Tomohiro Sugihara; Satoshi Tamotsu; Akihisa Terakita, In lower vertebrates, brain photoreceptor cells express vertebrate-specific non-visual opsins. We previously revealed that a pineal-related organ-specific opsin, parapinopsin, is UV-sensitive and allows pineal wavelength discrimination in lampreys and teleost. The Australian pouched lamprey was recently reported as having two parapinopsin-related genes. We demonstrate that a parapinopsin-like opsin from the Japanese river lamprey exhibits different molecular properties and distribution than parapinopsin. This opsin activates Gi-type G protein in a mammalian cell culture assay in a light-dependent manner. Heterologous action spectroscopy revealed that the opsin forms a violet to blue-sensitive pigment. Interestingly, the opsin is co-localised with green-sensitive P-opsin in the cells of the M5 nucleus of Schober (M5NS) in the mesencephalon of the river and brook lamprey. Some opsins-containing cells of the river lamprey have cilia and others an axon projecting to the retina. The opsins of the brook lamprey are co-localised in the cilia of centrifugal neurons projecting to the retina, suggesting that cells expressing the parapinopsin-like opsin and P-opsin are sensitive to violet to green light. Moreover, we found neural connections between M5NS cells expressing the opsins and the retina. These findings suggest that the retinal activity might be modulated by brain photoreception., 2020年06月15日, 10, 1, 9669, 9669, 研究論文（学術雑誌）, 国際誌, 10.1038/s41598-020-66679-2

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• 英語, Zoological letters, Functional identification of an opsin kinase underlying inactivation of the pineal bistable opsin parapinopsin in zebrafish., Baoguo Shen; Seiji Wada; Haruka Nishioka; Takashi Nagata; Emi Kawano-Yamashita; Mitsumasa Koyanagi; Akihisa Terakita, In the pineal organ of zebrafish larvae, the bistable opsin parapinopsin alone generates color opponency between UV and visible light. Our previous study suggested that dark inactivation of the parapinopsin photoproduct, which activates G-proteins, is important for the regulation of the amount of the photoproduct. In turn, the photoproduct is responsible for visible light sensitivity in color opponency. Here, we found that an opsin kinase or a G-protein-coupled receptor kinase (GRK) is involved in inactivation of the active photoproduct of parapinopsin in the pineal photoreceptor cells of zebrafish larvae. We investigated inactivation of the photoproduct in the parapinopsin cells of various knockdown larvae by measuring the light responses of the cells using calcium imaging. We found that GRK7a knockdown slowed recovery of the response of parapinopsin photoreceptor cells, whereas GRK1b knockdown or GRK7b knockdown did not have a remarkable effect, suggesting that GRK7a, a cone-type GRK, is mainly responsible for inactivation of the parapinopsin photoproduct in zebrafish larvae. We also observed a similar knockdown effect on the response of the parapinopsin photoreceptor cells of mutant larvae expressing the opsin SWS1, a UV-sensitive cone opsin, instead of parapinopsin, suggesting that the parapinopsin photoproduct was inactivated in a way similar to that described for cone opsins. We confirmed the immunohistochemical distribution of GRK7a in parapinopsin photoreceptor cells by comparing the immunoreactivity to GRK7 in GRK7a-knockdown and control larvae. These findings suggest that in pineal photoreceptor cells, the cone opsin kinase GRK7a contributes greatly to the inactivation of parapinopsin, which underlies pineal color opponency., 2021年02月12日, 7, 1, 1, 1, 研究論文（学術雑誌）, 国際誌, 10.1186/s40851-021-00171-1

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• 査読あり, 英語, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, Color opponency with a single kind of bistable opsin in the zebrafish pineal organ, Wada Seiji; Shen Baoguo; Kawano-Yamashita Emi; Nagata Takashi; Hibi Masahiko; Tamotsu Satoshi; Koyanagi Mitsumasa; Terakita Akihisa, Lower vertebrate pineal organs discriminate UV and visible light. Such color discrimination is typically considered to arise from antagonism between two or more spectrally distinct opsins, as, e.g., human cone-based color vision relies on antagonistic relationships between signals produced by red-, green-, and blue-cone opsins. Photosensitive pineal organs contain a bistable opsin (parapinopsin) that forms a signaling-active photoproduct upon UV exposure that may itself be returned to the signaling-inactive "dark" state by longer-wavelength light. Here we show the spectrally distinct parapinopsin states (with antagonistic impacts on signaling) allow this opsin alone to provide the color sensitivity of this organ. By using calcium imaging, we show that single zebrafish pineal photoreceptors held under a background light show responses of opposite signs to UV and visible light. Both such responses are deficient in zebrafish lacking parapinopsin. Expressing a UV-sensitive cone opsin in place of parapinopsin recovers UV responses but not color opponency. Changes in the spectral composition of white light toward enhanced UV or visible wavelengths respectively increased vs. decreased calcium signal in parapinopsin-sufficient but not parapinopsin-deficient photoreceptors. These data reveal color opponency from a single kind of bistable opsin establishing an equilibrium-like mixture of the two states with different signaling abilities whose fractional concentrations are defined by the spectral composition of incident light. As vertebrate visual color opsins evolved from a bistable opsin, these findings suggest that color opponency involving a single kind of bistable opsin might have been a prototype of vertebrate color opponency., 2018年10月30日, 115, 44, 11310, 11315, 研究論文（学術雑誌）, 国際誌, 10.1073/pnas.1802592115

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• 査読あり, 英語, Frontiers in Ecology and Evolution, Vertebrate bistable pigment parapinopsin: Implications for emergence of visual signaling and neofunctionalization of non-visual pigment, Mitsumasa Koyanagi; Emi Kawano-Yamashita; Seiji Wada; Akihisa Terakita, Opsins are light-sensor proteins, each absorbing a specific wavelength of light. This, in turn, drives a specific G protein-mediated phototransduction cascade, leading to a photoreceptor cell response. Recent genome projects have revealed an unexpectedly large number of opsin genes for vision and non-visual photoreception in various animals. However, the significance of this multiplicity of opsins remains largely unknown, except for that of cone visual opsins, which are diversified with respect to spectral sensitivity to achieve vertebrate color vision. Here, an implication of multiplicity is discussed, with focus on an ultraviolet-sensitive non-visual opsin-parapinopsin-that underlies pineal wavelength discrimination in lower vertebrates. Parapinopsins are phylogenetically close to vertebrate visual opsins, which have bleaching properties, but interestingly, parapinopsins are bleach-resistant bistable pigments, which photo-convert to stable photoproducts that revert to their original dark state by subsequent light absorption, similar to invertebrate rhodopsins. The unique characteristics of parapinopsin as an evolutionary intermediate between bistable and bleaching pigments provide insight into the evolutionary transition between signaling molecules that interact with two types of opsin-based pigments. Furthermore, the parapinopsin gene was duplicated in the teleost lineage and the spectral sensitivities of the duplicated parapinopsins were different from each other. On the basis of these results, together with the histochemical findings of parapinopsin, a plausible link between the diversification of a non-visual opsin parapinopsin and diverse pineal functions, wavelength discrimination, and melatonin secretion, implying why multiple opsins exist in animals, is proposed., 2017年04月11日, 5, 23, 10.3389/fevo.2017.00023

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• 査読あり, 英語, PLoS ONE, Activation of transducin by bistable pigment parapinopsin in the pineal organ of lower vertebrates, Emi Kawano-Yamashita; Mitsumasa Koyanagi; Seiji Wada; Hisao Tsukamoto; Takashi Nagata; Akihisa Terakita, Pineal organs of lower vertebrates contain several kinds of photosensitive molecules, opsins that are suggested to be involved in different light-regulated physiological functions. We previously reported that parapinopsin is an ultraviolet (UV)-sensitive opsin that underlies hyperpolarization of the pineal photoreceptor cells of lower vertebrates to achieve pineal wavelength discrimination. Although, parapinopsin is phylogenetically close to vertebrate visual opsins, it exhibits a property similar to invertebrate visual opsins and melanopsin: the photoproduct of parapinopsin is stable and reverts to the original dark states, demonstrating the nature of bistable pigments. Therefore, it is of evolutionary interest to identify a phototransduction cascade driven by parapinopsin and to compare it with that in vertebrate visual cells. Here, we showed that parapinopsin is coupled to vertebrate visual G protein transducin in the pufferfish, zebrafish, and lamprey pineal organs. Biochemical analyses demonstrated that parapinopsins activated transducin in vitro in a light-dependent manner, similar to vertebrate visual opsins. Interestingly, transducin activation by parapinopsin was provoked and terminated by UV- and subsequent orange-lights irradiations, respectively, due to the bistable nature of parapinopsin, which could contribute to a wavelength-dependent control of a second messenger level in the cell as a unique optogenetic tool. Immunohistochemical examination revealed that parapinopsin was colocalized with Gt2 in the teleost, which possesses rod and cone types of transducin, Gt1, and Gt2. On the other hand, in the lamprey, which does not possess the Gt2 gene, in situ hybridization suggested that parapinopsin- expressing photoreceptor cells contained Gt1 type transducin GtS, indicating that lamprey parapinopsin may use GtS in place of Gt2. Because it is widely accepted that vertebrate visual opsins having a bleaching nature have evolved from non-bleaching opsins similar to parapinopsin, these results implied that ancestral bistable opsins might acquire coupling to the transducin-mediated cascade and achieve light-dependent hyperpolarizing response of the photoreceptor cells., 2015年10月22日, 10, 10, e0141280, 研究論文（学術雑誌）, 10.1371/journal.pone.0141280

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• 査読あり, 英語, BMC Biology, Diversification of non-visual photopigment parapinopsin in spectral sensitivity for diverse pineal functions, Mitsumasa Koyanagi; Seiji Wada; Emi Kawano-Yamashita; Yuichiro Hara; Shigehiro Kuraku; Shigeaki Kosaka; Koichi Kawakami; Satoshi Tamotsu; Hisao Tsukamoto; Yoshinori Shichida; Akihisa Terakita, Background: Recent genome projects of various animals have uncovered an unexpectedly large number of opsin genes, which encode protein moieties of photoreceptor molecules, in most animals. In visual systems, the biological meanings of this diversification are clear multiple types of visual opsins with different spectral sensitivities are responsible for color vision. However, the significance of the diversification of non-visual opsins remains uncertain, in spite of the importance of understanding the molecular mechanism and evolution of varied non-visual photoreceptions. Results: Here, we investigated the diversification of the pineal photopigment parapinopsin, which serves as the UV-sensitive photopigment for the pineal wavelength discrimination in the lamprey, linking it with other pineal photoreception. Spectroscopic analyses of the recombinant pigments of the two teleost parapinopsins PP1 and PP2 revealed that PP1 is a UV-sensitive pigment, similar to lamprey parapinopsin, but PP2 is a blue-sensitive pigment, with an absorption maximum at 460-480 nm, showing the diversification of non-visual pigment with respect to spectral sensitivity. We also found that PP1 and PP2 exhibit mutually exclusive expressions in the pineal organs of three teleost species. By using transgenic zebrafish in which these parapinopsin-expressing cells are labeled, we found that PP1-expressing cells basically possess neuronal processes, which is consistent with their involvement in wavelength discrimination. Interestingly, however, PP2-expressing cells rarely possess neuronal processes, raising the possibility that PP2 could be involved in non-neural responses rather than neural responses. Furthermore, we found that PP2-expressing cells contain serotonin and aanat2, the key enzyme involved in melatonin synthesis from serotonin, whereas PP1-expressing cells do not contain either, suggesting that blue-sensitive PP2 is instead involved in light-regulation of melatonin secretion. Conclusions: In this paper, we have clearly shown the different molecular properties of duplicated non-visual opsins by demonstrating the diversification of parapinopsin with respect to spectral sensitivity. Moreover, we have shown a plausible link between the diversification and its physiological impact by discovering a strong candidate for the underlying pigment in light-regulated melatonin secretion in zebrafish the diversification could generate a new contribution of parapinopsin to pineal photoreception. Current findings could also provide an opportunity to understand the "color" preference of non-visual photoreception., 2015年09月15日, 13, 1, 研究論文（学術雑誌）, 10.1186/s12915-015-0174-9

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• 査読あり, 英語, PLoS ONE, Distribution of mammalian-like melanopsin in cyclostome retinas exhibiting a different extent of visual functions, Lanfang Sun; Emi Kawano-Yamashita; Takashi Nagata; Hisao Tsukamoto; Yuji Furutani; Mitsumasa Koyanagi; Akihisa Terakita, Mammals contain 1 melanopsin (Opn4) gene that is expressed in a subset of retinal ganglion cells to serve as a photopigment involved in non-image-forming vision such as photoentrainment of circadian rhythms. In contrast, most nonmammalian vertebrates possess multiple melanopsins that are distributed in various types of retinal cells however, their functions remain unclear. We previously found that the lamprey has only 1 type of mammalian-like melanopsin gene, which is similar to that observed in mammals. Here we investigated the molecular properties and localization of melanopsin in the lamprey and other cyclostome hagfish retinas, which contribute to visual functions including image-forming vision and mainly to non-image-forming vision, respectively. We isolated 1 type of mammalian-like melanopsin cDNA from the eyes of each species. We showed that the recombinant lamprey melanopsin was a blue light-sensitive pigment and that both the lamprey and hagfish melanopsins caused light-dependent increases in calcium ion concentration in cultured cells in a manner that was similar to that observed for mammalian melanopsins. We observed that melanopsin was distributed in several types of retinal cells, including horizontal cells and ganglion cells, in the lamprey retina, despite the existence of only 1 melanopsin gene in the lamprey. In contrast, melanopsin was almost specifically distributed to retinal ganglion cells in the hagfish retina. Furthermore, we found that the melanopsin-expressing horizontal cells connected to the rhodopsin-containing short photoreceptor cells in the lamprey. Taken together, our findings suggest that in cyclostomes, the global distribution of melanopsin in retinal cells might not be related to the melanopsin gene number but to the extent of retinal contribution to visual function., 2014年09月24日, 9, 9, e108209, 研究論文（学術雑誌）, 10.1371/journal.pone.0108209

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• 査読あり, 英語, PLoS ONE, Expression of UV-sensitive parapinopsin in the iguana parietal eyes and its implication in UV-sensitivity in vertebrate pineal-related organs, Seiji Wada; Emi Kawano-Yamashita; Mitsumasa Koyanagi; Akihisa Terakita, The pineal-related organs of lower vertebrates have the ability to discriminate different wavelengths of light. This wavelength discrimination is achieved through antagonistic light responses to UV or blue and visible light. Previously, we demonstrated that parapinopsin underlies the UV reception in the lamprey pineal organ and identified parapinopsin genes in teleosts and frogs of which the pineal-related organs were reported to discriminate light. In this study, we report the first identification of parapinopsin in the reptile lineage and show its expression in the parietal eye of the green iguana. Spectroscopic analysis revealed that iguana parapinopsin is a UV-sensitive pigment, similar to lamprey parapinopsin. Interestingly, immunohistochemical analyses using antibodies specific to parapinopsin and parietopsin, a parietal eye green-sensitive pigment, revealed that parapinopsin and parietopsin are colocalized in the outer segments of the parietal eye photoreceptor cells in iguanas. These results strongly suggest that parapinopsin underlies the wavelength discrimination involving UV reception in the iguana parietal eye. The current findings support the idea that parapinopsin is a common photopigment underlying the UV-sensitivity in wavelength discrimination of the pineal-related organs found from lampreys to reptiles. © 2012 Wada et al., 2012年06月14日, 7, 6, e39003, 研究論文（学術雑誌）, 10.1371/journal.pone.0039003

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• 査読あり, 英語, PLoS ONE, Beta-arrestin functionally regulates the non-bleaching pigment parapinopsin in lamprey pineal, Emi Kawano-Yamashita; Mitsumasa Koyanagi; Yoshinori Shichida; Tadashi Oishi; Satoshi Tamotsu; Akihisa Terakita, The light response of vertebrate visual cells is achieved by light-sensing proteins such as opsin-based pigments as well as signal transduction proteins, including visual arrestin. Previous studies have indicated that the pineal pigment parapinopsin has evolutionally and physiologically important characteristics. Parapinopsin is phylogenetically related to vertebrate visual pigments. However, unlike the photoproduct of the visual pigment rhodopsin, which is unstable, dissociating from its chromophore and bleaching, the parapinopsin photoproduct is stable and does not release its chromophore. Here, we investigated arrestin, which regulates parapinopsin signaling, in the lamprey pineal organ, where parapinopsin and rhodopsin are localized to distinct photoreceptor cells. We found that beta-arrestin, which binds to stimulated G proteincoupled receptors (GPCRs) other than opsin-based pigments, was localized to parapinopsin-containing cells. This result stands in contrast to the localization of visual arrestin in rhodopsin-containing cells. Beta-arrestin bound to cultured cell membranes containing parapinopsin light-dependently and translocated to the outer segments of pineal parapinopsincontaining cells, suggesting that beta-arrestin binds to parapinopsin to arrest parapinopsin signaling. Interestingly, betaarrestin colocalized with parapinopsin in the granules of the parapinopsin-expressing cell bodies under light illumination. Because beta-arrestin, which is a mediator of clathrin-mediated GPCR internalization, also served as a mediator of parapinopsin internalization in cultured cells, these results suggest that the granules were generated light-dependently by beta-arrestin-mediated internalization of parapinopsins from the outer segments. Therefore, our findings imply that betaarrestin- mediated internalization is responsible for eliminating the stable photoproduct and restoring cell conditions to the original dark state. Taken together with a previous finding that the bleaching pigment evolved from a non-bleaching pigment, vertebrate visual arrestin may have evolved from a "beta-like" arrestin by losing its clathrin-binding domain and its function as an internalization mediator. Such changes would have followed the evolution of vertebrate visual pigments, which generate unstable photoproducts that independently decay by chromophore dissociation. © 2011 Kawano-Yamashita et al., 2011年, 6, 1, e16402, 研究論文（学術雑誌）, 10.1371/journal.pone.0016402

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• 査読あり, 英語, JOURNAL OF EXPERIMENTAL BIOLOGY, Immunohistochemical characterization of a parapinopsin-containing photoreceptor cell involved in the ultraviolet/green discrimination in the pineal organ of the river lamprey Lethenteron japonicum, Emi Kawano-Yamashita; Akihisa Terakita; Mitsumasa Koyanagi; Yoshinori Shichida; Tadashi Oishi; Satoshi Tamotsu, In the pineal organ, two types of ganglion cell exhibit antagonistic chromatic responses to UV and green light, and achromatic responses to visible light. In this study, we histologically characterized UV-sensitive photoreceptor cells that contain a unique non-visual UV pigment, lamprey parapinopsin, in order to elucidate the neural network that is associated with antagonistic chromatic responses. These characteristics were compared with those of lamprey rhodopsin-containing cells, most of which are involved in achromatic responses. RT-PCR analysis revealed that lamprey parapinopsin was expressed in the pineal organ but not in the retina, unlike lamprey rhodopsin, which was expressed in both. Lamprey parapinopsin and lamprey rhodopsin were immunohistochemically localized in the dorsal and ventral regions of the pineal organ, respectively. The two pigments were localized in distinct photoreceptor cells throughout the pineal organ, namely the dorsal and ventral regions as well as the peripheral region, which corresponds to the dorso-ventral border region. The ratio of the number of lamprey parapinopsin-containing cells to lamprey rhodopsin-containing cells around the peripheral region was higher than in the central region. Electron-microscopic analysis revealed that lamprey parapinopsin-containing dorsal cells have outer segments and synaptic ribbons similar to those of ventral photoreceptor cells. However, unlike lamprey rhodopsin-containing cells, lamprey parapinopsin-containing cells connected with each other in a wide area of dorsal and peripheral portions and made direct contact with ganglion cells, mainly in the peripheral portion. These results suggest that UV light information captured by lamprey parapinopsin-containing photoreceptor cells is converged and directly transmitted to chromatic-type ganglion cells in the peripheral region to generate antagonistic chromatic responses., 2007年11月, 210, 21, 3821, 3829, 研究論文（学術雑誌）, 10.1242/jeb.007161

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• 査読あり, 英語, ZOOLOGICAL SCIENCE, Neural interaction of gonadotropin-regulating hormone immunoreactive neurons and the suprachiasmatic nucleus with the paraventricular organ in the Japanese grass lizard (Takydromus Tachydromoides), E Kawano; Y Takahata; T Oishi; K Ukena; K Tsutsui; S Tamotsu, Our previous study demonstrated that the paraventricular organ (PVO) in the hypothalamus of the Japanese grass lizard (Takydromus tachydromoides) showed immunoreactivity against the light signal-transducing G-protein, transducin. This finding suggested that the PVO was a candidate for the deep-brain photoreceptor in this species. To understand functions of the PVO, we investigated distributions of transducin, serotonin, gonadotropin-releasing hormone (GnRH), and gonadotropin-inhibitory hormone (GnIH) in the lizard's brain. We immunohistochemically confirmed co-localization of transducin and serotonin in PVO neurons that showed structural characteristics of cerebrospinal fluid (CSF)-contacting neurons. GnRH-immunoreactive (ir) cells were localized in the posterior commissure and lateral hypothalamic area. Some of the serotonin-ir fibers extending from the PVO to the lateral hypothalamic area contacted the GnRH-ir cell bodies. GnIH-ir cells were localized in the nucleus accumbens, paraventricular nucleus, and upper medulla, and GnIH-ir fibers from the paraventricular nucleus contacted the lateral processes of serotonin-ir neurons in the PVO. In addition, we found that serotonin-ir fibers from the PVO extended to the suprachiasmatic nucleus (SCN), and the retrograde transport method confirmed the PVO projections to the SCN. These findings suggest that the PVO, by means of innervation mediated by serotonin, plays an important role in the regulation of pituitary function and the biological clock in the Japanese grass lizard., 2006年03月, 23, 3, 277, 287, 研究論文（学術雑誌）, 10.2108/zsj.23.277

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• 査読あり, 英語, Proc. Natl. Acad. Sci. USA, Bistable UV pigment in the lamprey pineal, M Koyanagi; E Kawano; Y Kinugawa; T Oishi; Y Shichida; S Tamotsu; A Terakita, Lower vertebrates can detect UV light with the pineal complex independently of eyes. Electrophysiological studies, together with chromophore extraction analysis, have suggested that the underlying pigment in the lamprey pineal exhibits a bistable nature, that is, reversible photoreaction by UV and visible light, which is never achieved by known UV pigments. Here we addressed the molecular identification of the pineal UV receptor. Our results showed that the long-hypothesized pigment is a lamprey homologue of parapinopsin, which exhibits an absorption maximum at 370 nm, in the UV region. UV light causes cis-trans isomerization of its retinal(2) chromophore, forming a stable photoproduct having an absorption maximum at 515 nm, in the green region. The photoproduct reverts to the original pigment upon visible light absorption, showing photoregeneration of the pigment. In situ hybridization showed that parapinopsin is selectively expressed in the cells located in the dorsal region of the pineal organ. We successfully obtained the hyperpolarizing responses with a maximum sensitivity of approximate to380 nm from the photoreceptor cells at the dorsal region, in which the outer segment was clearly stained with anti-parapinopsin antibody. These results demonstrated that parapinopsin is the pineal UV pigment having photointerconvertible two stable states. The bistable nature of the parapinopsin can account for the photorecovery of the pineal UV sensitivity by background green light in the lamprey. Furthermore, we isolated the parapinopsin homologues from fish and frog pineal complexes that exhibit UV sensitivity, suggesting that parapinopsin is a common molecular basis for pineal UV reception in the vertebrate., 2004年04月, 101, 17, 6687, 6691, 研究論文（学術雑誌）, 10.1073/pnas.0400819101

  DOI URL

MISC

• 英語, Advances in experimental medicine and biology, Optogenetic Potentials of Diverse Animal Opsins: Parapinopsin, Peropsin, LWS Bistable Opsin., Mitsumasa Koyanagi; Tomoka Saito; Seiji Wada; Takashi Nagata; Emi Kawano-Yamashita; Akihisa Terakita, Animal opsin-based pigments are light-activated G-protein-coupled receptors (GPCRs), which drive signal transduction cascades via G-proteins. Thousands of animal opsins have been identified, and molecular phylogenetic and biochemical analyses have revealed the unexpected diversity in selectivity of G-protein activation and photochemical property. Here we discuss the optogenetic potentials of diverse animal opsins, particularly recently well-characterized three non-canonical opsins, parapinopsin, peropsin, and LWS bistable opsin. Unlike canonical opsins such as vertebrate visual opsins that have been conventionally used for optogenetic applications, these opsins are bistable; opsin-based pigments do not release the chromophore retinal after light absorption, and the stable photoproducts revert to their original dark states upon subsequent light absorption. Parapinopsins have a "complete photoregeneration ability," which allows a clear color-dependent regulation of signal transductions. On the other hand, peropsins serve as a "dark-active and light-inactivated" GPCR to regulate signal transductions in the opposite way compared with usual opsins. In addition, an LWS bistable opsin from a butterfly was revealed to be the longest wavelength-sensitive animal opsin with its absorption maximum at ~570 nm. The property-dependent optical regulations of signal transductions were demonstrated in mammalian cultured cells, showing potentials of new optogenetic tools., 2021年, 1293, 141, 151, 国際誌, 10.1007/978-981-15-8763-4_8

  DOI URL
• 査読無し, その他, 日本比較生理生化学, 松果体波長識別の分子基盤に関する分子生理学的解析と進化学的考察, 川野 絵美, 2015年, 32, 1, 2, 9, 10.3330/hikakuseiriseika.32.2

  DOI URL
• 査読あり, 英語, Wiley Interdisciplinary Reviews: Membrane Transport and Signaling, Evolution and diversity of opsins, Akihisa Terakita; Emi Kawano-Yamashita; Mitsumasa Koyanagi, Many animals capture light information via opsin-based pigments. Several thousands of opsins have been identified thus far and the opsin family is divided into eight groups. Members belonging to four out of the eight groups have been elucidated to couple to transducin, Go, Gs, and Gq, respectively, in photoreceptor cells. Accumulated evidence suggests a novel classification of the animal phototransductions, cyclic nucleotide signaling mediated by transducin, Go or Gs in ciliary photoreceptor cells and phosphoinositol signaling mediated by Gq in rhabdomeric photoreceptor cells. Varied opsin-based pigments are spectroscopically classified into two types, bleaching and bistable pigments that is, the photoproduct of vertebrate visual pigments dissociates its chromophore retinal over time and bleaches, whereas most other opsin-based pigments convert to a stable photoproduct, which can revert to original dark state by subsequent light absorption. Mutational analyses of the both types of pigments implied that during molecular evolution of the vertebrae visual pigments, displacement of the counterion, important amino acid residue for visible light absorption of opsin-based pigment, resulted in not only unique bleaching property but also acquisition of red-sensitive visual pigment and higher G-protein activation ability generated by larger light-induced conformational change of the pigment. Interestingly, a bleaching pigment rhodopsin and parapinopsin, which closely relates to the vertebrate visual pigment but has a bistable nature, couple to visual arrestin and β arrestin, respectively, in the lamprey pineal organ, suggesting the bleaching property also might facilitate the evolution of visual arrestin which is specialized for vertebrate visual function. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.., 2012年01月, 1, 1, 104, 111, 10.1002/wmts.6

  DOI URL
• 査読無し, その他, 比較生理生化学, 脳室の感覚器官：室傍器官 -室傍器官と下垂体との関係-, 保智己; 川野絵美; 拜田由華, 2006年, 23, 3, 143, 152, 10.3330/hikakuseiriseika.23.143

  DOI URL
• 査読無し, その他, 月刊 海洋／号外, ヤツメウナギにおける側眼と松果体の光受容細胞, 保智己; 稲垣公美; 川野絵美, 2005年, 41, 238, 246
• 査読無し, 英語, BIOLOGICAL RHYTHM RESEARCH, SWETS ZEITLINGER PUBLISHERS, Circadian rhythms in amphibians and reptiles: Ecological implications, T Oishi; K Nagai; Y Harada; M Naruse; M Ohtani; E Kawano; S Tamotsu, Circadian rhythms of amphibians and reptiles in the field and under semi-natural conditions and the underlying mechanisms, including the ways of entrainment to environmental cues and the oscillators driving the rhythms, have been reviewed. Studies on the behavioral rhythms in the field are meager in both amphibians and reptiles. In anuran amphibians, Xenopus adults showed more robust nocturnal locomotor activity than did tadpoles. This indicates the ecological significance of the differences in activity pattern shown by amphibians at different life stages, because differences between adults and young in the same environment may serve to isolate partially the young from the adults' cannibalism. In reptiles, free-running rhythms are more robust and continue for a longer time compared to amphibians. In both amphibians and reptiles, multi-photoreceptors are involved in photo-entrainment of circadian rhythms. The eyes, pineal complex and deep brain comprise a multi-oscillator system as well as a multi-photoreceptor system., 2004年02月, 35, 1-2, 105, 120, 10.1080/09291010412331313278

  DOI URL
• 査読無し, その他, 比較生理生化学, 松果体の光感覚と紫外光受容, 保智己; 川野絵美, 2004年, 21, 4, 185, 194, 10.3330/hikakuseiriseika.21.185

  DOI URL

書籍等出版物

• 光と生命の事典, 朝倉書店, 非視覚系の波長識別, 2016年, その他, 査読無し, その他
• Evolution of visual and non-visual pigments., Springer, The evolution and diversity of pineal and parapineal photopigments., 2014年, その他, 査読無し, その他

受賞

• 大阪市立大学女性研究者博士研究員奨励賞[岡村賞], 2014年11月, 日本国
• 日本比較生理性化学会 吉田奨励賞, 2013年07月, 日本国

共同研究・競争的資金等の研究課題

• 基盤研究(C), 2018年04月01日, 2021年03月31日, 18K06336, 新規光受容タンパク質が発現する脳内光受容器官の新規の生理機能に関する解析, 山下 絵美, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 奈良女子大学, 4290000, 3300000, 990000, 下等脊椎動物は眼外に多様な光受容能を持っており、眼外からの光情報を視覚以外の様々な生理機能（例えば生体リズムなど）の調節に利用している。最近、最も下等な脊椎動物のひとつである無顎類ヤツメウナギの脳から、新規の光受容タンパク質遺伝子の単離に成功した。さらに、その光受容タンパク質が、ヤツメウナギの脳深部に存在する特徴的な組織学的特性を有する神経細胞で発現することも見出した。このことは、脳深部光受容器官が担うこれまでに知られていない新しい生理機能が存在する可能性を示唆するものであった。そこで本研究では、新規光受容タンパク質が発現する脳深部光受容器官に着目し、この光受容タンパク質が発現する細胞が、どのような波長の光情報をどの神経細胞に伝達するのかを解析して、ヤツメウナギの脳深部に発現する新規光受容タンパク質が関わる新しい生理機能を理解することを目指している。平成30年度は以下の解析を行った。 ・培養細胞系で新規オプシンを強制発現させ、細胞生物学的手法を用いて新規オプシンの光反応を測定したところ、光に対して明瞭な反応を示すことが明らかになった。また、同方法を用いることで、新規オプシンの波長感受性や、新規オプシンと共役するGタンパク質のサブタイプを決定することができた。 ・本研究で着目しているヤツメウナギの新規脳深部光受容細胞と類似した組織的特徴をもつ細胞集団は、魚類などの他の脊椎動物にも広く存在することが報告されている。そこで、様々な硬骨魚類を用いて、それらの細胞群の組織学的な同定を試みたところ、複数の神経核が標識され、それらを脳深部光受容器官の候補領域とした。
• 特別研究員奨励費, 2014年04月, 2017年03月, 14J40094, 研究代表者, 光受容タンパク質パラピノプシンを起点とする松果体及び副松果体の光受容機能の解析, 山下 絵美, 日本学術振興会, 科学研究費助成事業 特別研究員奨励費, 大阪市立大学, 4810000, 3700000, 1110000, ゼブラフィッシュ松果体と副松果体に存在する紫外光受容型パラピノプシンPP1が関わる多様な光受容機能を理解するために、以下の解析を行った。
  １、ゼブラフィッシュ松果体において、PP1がどのような生理機能を担うのかを明らかにすることを目指し、本年度は、様々な光条件下でのゼブラフィッシュの遊泳行動解析を行うために、LED照射装置を用いて水槽全体にUV光照射する装置を設計し、その作製を完了した。 ２、ゼブラフィッシュ副松果体におけるPP1発現細胞の特徴や機能についての知見を得るために、形態学的手法を中心とした解析を試みた。 ・副松果体にどのような種類の光受容タンパク質が発現するのかを明らかにするために、松果体での発現が主に知られているPP2（可視光受容型パラピノプシン）、エクソロドプシン、赤錐体オプシンなどの光受容タンパク質について、免疫組織化学的に局在を調べた。その結果、副松果体での光受容タンパク質の発現パターンは松果体とは異なることが明らかになった。 ・副松果体のPP1発現細胞が関わる機能を推定するために、まず、松果体の主な生理機能のひとつであるメラトニン合成・分泌に関わるかどうかを調べた。具体的には、メラトニンの前駆物質であるセロトニンの免疫組織化学的局在を検討した結果、副松果体では、セロトニンの免疫反応は観察されず、メラトニン合成・分泌に関わらない可能性が推測された。また、副松果体の関与が示唆される機能として、発生初期段階における脳の左右非対称形成にも着目し、それらに対するPP1によるUV光受容の影響を調べることを目指した。その準備段階として、副松果体が影響を及ぼすと考えられる脳領域（手綱核）の非対称性を示す組織学的解析に着手した。具体的には、LD条件下で飼育した野生型稚魚を用いて、左手綱核に多く発現するlovの発現パターンをin situ hybridizationで確認した。
• 特別研究員奨励費, 2010年04月, 2014年03月, 10J07650, 研究代表者, 光受容タンパク質パラピノプシンを基盤とする松果体の色検出応答の生理学的解析, 山下(川野) 絵美; 山下 絵美, 日本学術振興会, 科学研究費助成事業 特別研究員奨励費, 大阪市立大学, 4286808, 4016808, 270000, 下等脊椎動物の松果体には、紫外光と可視光の比率を検出する「色検出応答」が存在し、これまでに、パラピノプシンが松果体の紫外光受容の分子基盤であることを同定してきた。昨年度までの研究から、硬骨魚類ゼブラフィッシュにおいて、松果体と副松果体の両方に、パラピノプシンを発現していることを確認した。さらに、松果体のパラピノプシン発現細胞は神経節細胞を介して、副松果体のパラピノプシン発現細胞は（神経節細胞を介さず）直接的に、共に間脳の手綱核と呼ばれる領域に神経投射する可能性を見いだした。本年度は、松果体の色情報が手綱核に伝達されるのかについて、神経トレーサー法による検証実験を続けて行った。具体的には、パラピノプシン発現細胞に蛍光物質であるGFP（細胞全体を標識）を発現する遺伝子導入ゼブラフィッシュを用いて、手綱核にニューロビオチンやデキストランなどの神経トレーサー物質を取り込ませ、手綱核を中心とした神経回路について調べた。その結果、松果体に存在するGFP標識されたパラピノプシン発現細胞の神経終末と、手綱核からの神経トレーサー物質の注入により逆行性標識された神経節細胞の一部が接する様子が、共焦点レーザー顕微鏡を用いた解析により観察された。すなわち、パラピノプシンを含む紫外光受容細胞を出発点とする松果体由来の色情報は、神経節細胞を介して、手綱核へ伝達されるという、昨年度までの研究結果を裏付けるさらなる組織学的知見が得られた。
• 特別研究員奨励費, 2005年, 2006年, 05J00204, カワヤツメ松果体における紫外光受容システムを中心とした波長識別機構の生理的役割, 山下 絵美, 日本学術振興会, 科学研究費助成事業 特別研究員奨励費, 奈良女子大学, 1800000, 1800000, 下等脊椎動物の松果体には、緑色光で興奮性、UV光で抑制性応答する感色性神経節細胞があり、それらは波長識別を行うと考えられる。本研究は、カワヤツメ松果体を用いて、眼外の波長識別機構の解明を目的とする。これまでに、波長識別の光入力を担うUV色素パラピノプシンを同定し、UV光受容細胞からの伝達経路を明らかにしてきた。そこで、UV光受容システムと、引き起こされる波長識別の特性の解明を目指した。 感色性神経節細胞は応答様式から波長識別を行うと考えられたが、照射光中の波長成分の違いが実際に神経応答に反映されるかは明らかではない。そこで、細胞外誘導によりUV光と緑色光の比率の変化がもたらす応答性の違いについて検証した。具体的には、背景光に緑色光、テスト光にUV光を用い、UV光強度を段階的に強くし、応答に変化が見られるかをスパイク増減の割合により評価した。まず、緑色光照射でスパイクの発火頻度が増加し、UV光を重ねて照射するとスパイクが抑制された。UV光強度を段階的に上げ、照射光中のUV光の比率を高くすると、スパイク抑制の持続時間が長くなり、感色性応答はスパイク頻度を変化させ照射光中のUV/緑色光の比率を検出して波長識別を行う事が証明された。 組織学的に、UV光受容細胞と神経節細胞が直接連絡する事を明らかした。そこで実際に、シナプスを介した情報伝達がなされるかをシナプス遮断薬CoCl_2の投与により電気生理学的に検証した。すると、感色性応答が記録された後に、CoCl_2投与で神経節細胞の光反応が消失、リンガー液での洗浄後に再度記録され、感色性応答の興奮性、抑制性応答は共に光受容細胞からのシナプスを介した情報伝達により起こる反応であると示唆された。 これらより、感色性応答は緑色光を基準に照射光中のUV光の比率を検出し、そのUV光情報はパラピノプシン細胞から直接シナプスを介して伝達されると考えられた。
• 2003年04月, 2004年02月, 研究代表者, 下等脊椎動物網膜外光受容器官における光情報変換機構に関する電気生理学的解析, 川野絵美, 財団法人 日本科学協会, 笹川科学研究助成, 奈良女子大学
• 基盤研究(C), 2021年04月01日, 2024年03月31日, 21K06265, 非視覚の光受容がもたらす新しい生理機能の探索, 山下 絵美, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 奈良女子大学, 4160000, 3200000, 960000

Ⅲ．社会連携活動実績

１．公的団体の委員等（審議会、国家試験委員、他大学評価委員，科研費審査委員等）

• （公社）日本動物学会近畿支部, 支部委員, 2020年09月, 9999年, 学協会
• （公社）日本動物学会近畿支部, 教育委員会委員, 2020年05月, 9999年, 学協会
• 日本比較生理生化学会, 日本光生物学協会委員, 2020年01月, 2021年12月, 学協会
• 日本比較生理生化学会, 評議委員, 2016年01月, 2019年12月, 学協会
• （公社）日本動物学会, 第90回大阪大会実行委員, 2019年09月, 2019年09月, 学協会
• 日本比較生理生化学会, 第40回神戸大会実行委員, 2018年11月, 2018年11月, 学協会
• （公社）日本動物学会近畿支部, 支部委員, 2020年09月, 9999年
• （公社）日本動物学会近畿支部, 教育委員会委員, 2020年05月, 9999年
• 日本比較生理生化学会, 日本光生物学協会委員, 2020年01月, 2021年12月