Hypothalamic ventricular ependymal thyroid hormone deiodinases are an important element of circannual timing in the Siberian hamster (Phodopus sungorus).
Hypothalamic ventricular ependymal thyroid hormone deiodinases are an important element of circannual timing in the Siberian hamster (Phodopus sungorus).
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DOI：
10.1371/journal.pone.0062003
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Barrett P
中科院分区：
文献类型：
--
作者：
Herwig A;de Vries EM;Bolborea M;Wilson D;Mercer JG;Ebling FJ;Morgan PJ;Barrett P
暴露于短日照（SD）诱导西伯利亚仓鼠的生理和行为发生深刻变化，包括性腺退化和体重减轻高达30%。在持续SD环境中，约20周后，西伯利亚仓鼠自发恢复为长日照（LD）表型，这种现象称为光不应性反应。以前，我们已经确定了一些基因，短光周期调节的神经和心室室管膜（VE）细胞的下丘脑，虽然他们的重要性和贡献光周期诱导的生理尚不清楚。在这个难治性模型中，我们假设恢复到LD生理学涉及关键下丘脑基因的SD表达水平逆转到其LD值，从而涉及LD生理学所需的基因。雄性西伯利亚仓鼠在LD或SD中保持长达39周，在此期间SD仓鼠体重在增加之前下降，超过20周后恢复到LD值。在14和39周之间收集脑组织进行原位杂交，以确定下丘脑基因表达。SD光周期18周时，VE细胞nestin、vimentin、Crbp 1和Gpr 50的表达下调，但光不应性仓鼠的表达没有恢复到LD水平。Dio 2，Mct 8和Tsh-r的表达被SD光周期改变，并完全恢复，甚至超过LD仓鼠在不应状态下的值。在下丘脑核中，Srif和Mc 3r mRNA的表达在SD中在18周时改变，但与光不应性仓鼠中的LD表达值相似。我们的结论是，在难治性仓鼠，并不是所有的VE细胞功能所需的建立LD生理。然而，甲状腺激素信号从室管膜细胞和逆转神经元基因表达似乎是必不可少的SD难治性反应。
Exposure to short days (SD) induces profound changes in the physiology and behaviour of Siberian hamsters, including gonadal regression and up to 30% loss in body weight. In a continuous SD environment after approximately 20 weeks, Siberian hamsters spontaneously revert to a long day (LD) phenotype, a phenomenon referred to as the photorefractory response. Previously we have identified a number of genes that are regulated by short photoperiod in the neuropil and ventricular ependymal (VE) cells of the hypothalamus, although their importance and contribution to photoperiod induced physiology is unclear. In this refractory model we hypothesised that the return to LD physiology involves reversal of SD expression levels of key hypothalamic genes to their LD values and thereby implicate genes required for LD physiology. Male Siberian hamsters were kept in either LD or SD for up to 39 weeks during which time SD hamster body weight decreased before increasing, after more than 20 weeks, back to LD values. Brain tissue was collected between 14 and 39 weeks for in situ hybridization to determine hypothalamic gene expression. In VE cells lining the third ventricle, expression of nestin, vimentin, Crbp1 and Gpr50 were down-regulated at 18 weeks in SD photoperiod, but expression was not restored to the LD level in photorefractory hamsters. Dio2, Mct8 and Tsh-r expression were altered by SD photoperiod and were fully restored, or even exceeded values found in LD hamsters in the refractory state. In hypothalamic nuclei, expression of Srif and Mc3r mRNAs was altered at 18 weeks in SD, but were similar to LD expression values in photorefractory hamsters. We conclude that in refractory hamsters not all VE cell functions are required to establish LD physiology. However, thyroid hormone signalling from ependymal cells and reversal of neuronal gene expression appear to be essential for the SD refractory response.
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影响因子：
4.8
作者：
Murphy, Michelle;Jethwa, Preeti H.;Ebling, Francis J. P.
通讯作者：
Ebling, Francis J. P.
影响因子：
4.8
作者：
Adams, Van L.;Goodman, Robert L.;Lehman, Michael N.
通讯作者：
Lehman, Michael N.
DOI：
10.1073/pnas.232490799
发表时间：
2002-12-10
影响因子：
11.1
作者：
Prendergast, BJ;Mosinger, B;Nelson, RJ
通讯作者：
Nelson, RJ
影响因子：
4.8
作者：
Bolborea, Matei;Laran-Chich, Marie-Pierre;Klosen, Paul
通讯作者：
Klosen, Paul
影响因子：
4.8
作者：
Bockers, TM;Bockmann, J;Kreutz, MR
通讯作者：
Kreutz, MR