Faculty Profiles - YOSHIMURA, Takashi

Papers - YOSHIMURA, Takashi

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Molecular mechanism of the photoperiodic response of gonads in birds and mammals Invited Reviewed

Yoshimura T

Comparative Biochemistry and Physiology Vol. 144 page： 345-350 2006

Molecular mechanism of photoperiodic time measurement in the brain of Japanese quail

Yasuo S, Watanabe M, Iigo M, Yamamura T, Nakao N, Takagi T, Ebihara S, Yoshimura T

CHRONOBIOLOGY INTERNATIONAL Vol. 23 ( 1-2 ) page： 307 - 315 2006

Publisher：Chronobiology International

In most organisms living in temperate zones, reproduction is under photoperiodic control. Although photoperiodic time measurement has been studied in organisms ranging from plants to vertebrates, the underlying molecular mechanism is not well understood. The Japanese quail (Coturnix japonica) represents an excellent model to study this problem because of the rapid and dramatic photoperiodic response of its hypothalamic-pituitary-gonadal axis. Recent investigations of Japanese quail show that long-day-induced type 2 deiodinase (Dio2) expression in the mediobasal hypothalamus (MBH) plays an important role in the photoperiodic gonadal regulation by catalyzing the conversion of the prohormone thyroxine (T4) to bioactive 3,5,3′-triiodothyronine (T3). The T3 content in the MBH is approximately 10-fold higher under long than short days and conditions, and the intracerebroventricular infusion of T3 under short days and conditions mimics the photoperiodic gonadal response. While Dio2 generates active T3 from T4 by outer ring deiodination, type 3 deiodinase (Dio3) catalyzes the conversion of both T3 and T 4 into inactive forms by inner ring deiodination. In contrast to Dio2 expression, Dio3 expression in the MBH is suppressed under the long-day condition. Photoperiodic changes in the expression of both genes during the photoinduction process occur before the changes in the level of luteinizing hormone (LH) secretion, suggesting that the reciprocal changes in Dio2 and Dio3 expression act as gene switches of the photoperiodic molecular cascade to trigger induction of LH secretion. Copyright © Taylor & Francis Group, LLC.

DOI： 10.1080/07420520500521913

Web of Science

Scopus

Conservation of novel <i>Mahya</i> genes shows the existence of neural functions common between Hymenoptera and Deuterostome

Tsuchimoto M, Yasuo S, Funada M, Aoki M, Sasagawa H, Yoshimura T, Tadauchi O, Cameron SA, Kitagawa Y, Kadowaki T

DEVELOPMENT GENES AND EVOLUTION Vol. 215 ( 11 ) page： 564 - 574 2005.11

Publisher：Development Genes and Evolution

Honeybees have been shown to exhibit cognitive performances that were thought to be specific to some vertebrates. However, the molecular and cellular mechanisms of such cognitive abilities of the bees have not been understood. We have identified a novel gene, Mahya, expressed in the brain of the honeybee, Apis mellifera, and other Hymenoptera. Mahya orthologues are present in Deuterostomes but are absent or highly diverged in nematodes and, intriguingly, in two dipteran insects (fruit fly and mosquito) and Lepidoptera (silk moth). Mahya genes encode novel secretory proteins with a follistatin-like domain (Kazal-type serine/ threonine protease inhibitor domain and EF-hand calcium-binding domain), two immunoglobulin domains, and a C-terminal novel domain. Honeybee Mahya is expressed in the mushroom bodies and antennal lobes of the brain. Zebra fish Mahya orthologues are expressed in the olfactory bulb, telencephalon, habenula, optic tectum, and cerebellum of the brain. Mouse Mahya orthologues are expressed in the olfactory bulb, hippocampus, and cerebellum of the brain. These results suggest that Mahya may be involved in learning and memory and in processing of sensory information in Hymenoptera and vertebrates. Furthermore, the limited existence of Mahya in the genomes of Hymenoptera and Deuterostomes supports the hypothesis that the genes typically represented by Mahya were lost or highly diverged during the evolution of the central nervous system of specific Bilaterian branches under the specific selection and subsequent adaptation associated with different ecologies and life histories. © Springer-Verlag 2005.

DOI： 10.1007/s00427-005-0021-z

Web of Science

Scopus

The reciprocal switching of two thyroid hormone-activating and -inactivating enzyme genes is involved in the photoperiodic gonadal response of Japanese quail

Yasuo S, Watanabe M, Nakao N, Takagi T, Follett BK, Ebihara S, Yoshimura T

ENDOCRINOLOGY Vol. 146 ( 6 ) page： 2551 - 2554 2005.6

生物はいかにして季節を読み取っているか？－春を知らせる甲状腺ホルモン－ Invited

山村崇,安尾しのぶ，中尾暢宏，海老原史樹文，吉村崇

化学と生物 Vol. 43 page： 172-176 2005

脊椎動物における光周性の制御機構 Invited Reviewed

海老原史樹文, 安尾しのぶ, 吉村崇

生物物理 Vol. 45 page： 185-191 2005

脊椎動物の光周性の分子機構の解明にむけて Invited

吉村崇

時間生物学 Vol. 11 page： 3-7 2005

脊椎動物の光周性 Invited

中尾暢宏, 安尾しのぶ, 山村崇, 海老原史樹文, 吉村崇

比較生理生化学 Vol. 22 page： 20-26 2005

生物はいかにして季節を読み取っているか？－春を知らせる甲状腺ホルモン－ Invited

山村崇, 安尾しのぶ, 中尾暢宏, 海老原史樹文, 吉村崇

化学と生物 Vol. 43 page： 172-176 2005

Seasonal morphological changes in the neuro-glial interaction between gonadotropin-releasing hormone nerve terminals and glial endfeet in Japanese quail

Yamamura T, Hirunagi K, Ebihara S, Yoshimura T

ENDOCRINOLOGY Vol. 145 ( 9 ) page： 4264 - 4267 2004.9

Publisher：Endocrinology

In a previous study we showed that photoperiodically generated T 3 in the hypothalamus is critical for the photoperiodic response of gonads in Japanese quail. The expression of thyroid hormone receptors in the median eminence (ME) suggested that photoperiodically generated T3 acts on the ME. Because thyroid hormone is known to play a critical role in the development and plasticity of the central nervous system, in the present study we have examined ultrastructure of the ME in Japanese quail kept in short-day and long-day environments. Immunoelectron microscopy revealed that GnRH nerve terminals are in close proximity to the basal lamina under long-day conditions, and conventional transmission electron microscopy demonstrated the encasement of the terminals by the endfeet of glia under short-day conditions. These morphological changes may regulate photoperiodic GnRH secretion.

DOI： 10.1210/en.2004-0366

Web of Science

Scopus

Circadian expression of clock gene in the optic tectum of Japanese quail

Yasuo S, Ebihara S, Yoshimura T

BRAIN RESEARCH Vol. 1005 ( 1-2 ) page： 193 - 196 2004.4

Publisher：Brain Research

The physiological activity of avian optic tectum (TeO) is known to be regulated by the circadian system. In a previous study, we found clock gene expression in the TeO of Japanese quail. Here we report rhythmic expression of the Per2 gene in the stratum griseum et fibrosum (SGF) of the TeO under a light-dark (LD) cycle, constant darkness (DD), and constant light (LL) conditions. However, light pulse did not affect Per2 expression in the TeO. These results suggest that light stimulus and melatonin rhythm are not essential for rhythmic expression of Per2 in the avian TeO in spite of the localization of melatonin receptors and retinal input. © 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.brainres.2004.01.031

Web of Science

Scopus

Characterization of the two distinct subtypes of metabotropic glutamate receptors from honeybee, Apis mellifera

M Funada, S Yasuo, T Yoshimura, S Ebihara, H Sasagawa, Y Kitagawa, T Kadowaki

NEUROSCIENCE LETTERS Vol. 359 ( 3 ) page： 190 - 194 2004.4

Language：English Publisher：ELSEVIER SCI IRELAND LTD

L-Glutamate is a major neurotransmitter at the excitatory synapses in the vertebrate brain. It is also the excitatory neurotransmitter at neuromuscular junctions in insects, however its functions in their brains remain to be established. We identified and characterized two different subtypes (AmGluRA and AmGluRB) of metabotropic glutamate receptors (mGluRs) from an eusocial insect, honeybee. Both AmGluRA and AmGluRB form homodimers independently on disulfide bonds, and bind [H-3]glutamate with K-D values of 156.7 and 80.7 nM, respectively. AmGluRB is specifically expressed in the brain, while AmGluRA is expressed in the brain and other body parts, suggesting that AmGluRA is also present at the neuromuscular junctions. Both mGluRs are expressed in the mushroom bodies and the brain regions of honeybees, where motor neurons are clustered. Their expression in the brain apparently overlaps, suggesting that they may interact with each other to modulate the glutamatergic neurotransmission. (C) 2004 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.neulet.2004.02.004

Web of Science

Scopus

Photoperiodic regulation of type 2 deiodinase gene in Djungarian hamster: Possible homologies between avian and mammalian photoperiodic regulation of reproduction

Watanabe M, Yasuo S, Watanabe T, Yamamura T, Nakao N, Ebihara S, Yoshimura T

ENDOCRINOLOGY Vol. 145 ( 4 ) page： 1546 - 1549 2004.4

Photoinducible phase-specific light induction of Cry1 gene in the pars tuberalis of Japanese quail

Yasuo S, Watanabe M, Tsukada A, Takagi T, Iigo M, Shimada K, Ebihara S, Yoshimura T

ENDOCRINOLOGY Vol. 145 ( 4 ) page： 1612 - 1616 2004.4

ウズラ Coturnix japonica Invited

吉村崇

細胞工学 Vol. 23 page： 492-493 2004.4

Circadian expression of clock gene in the optic tectum of Japanese quail

Yasuo S, Ebihara S, Yoshimura T

Brain Research Vol. 1005 page： 193-196 2004.1

Seasonal morphological changes in the neuro-glial interaction between gonadotropin-releasing hormone nerve terminals and glial endfeet in Japanese quail. Reviewed

Yamamura T, Hirunagi K, Ebihara S, Yoshimura T

Endocrinology Vol. 145 page： 4264-4267 2004

鳥類の時計遺伝子と光周性 Invited Reviewed

安尾しのぶ, 渡邊美和, 海老原史樹文, 吉村崇

時間生物学 Vol. 10 page： 35-40 2004

Molecular bases for seasonal reproduction in birds Invited Reviewed

Yoshimura T

Journal of Poultry Science Vol. 41 page： 251-258 2004

Oral thyroxine administration mimics photoperiodically induced gonadal growth in Japanese quail Reviewed

Animal Science Journal Vol. 75 page： 497-410 2004

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Papers - YOSHIMURA, Takashi