In vitro reprogramming of the photoperiodic clock in an insect brain-retrocerebral complex.
In vitro reprogramming of the photoperiodic clock in an insect brain-retrocerebral complex.
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昆虫脑-脑后复合体中光周期时钟的体外重新编程。
DOI：
10.1073/pnas.81.18.5881
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发表时间：
1984
影响因子：
11.1
通讯作者：
Gilbert,LI
中科院分区：
文献类型：
--
作者：
Bowen,MF;Saunders,DS;Bollenbacher,WE;Gilbert,LI
烟草赤眼蜂(Manduca Sexta Sexta)的蛹滞育是一种光周期诱导的事件，表现为缺乏脑肽促胸腺激素的释放。在幼虫发育期间的短日光周期(明暗交替，12：12)使大脑在幼虫发育阶段放弃释放促胸腺激素。如果发育中的幼虫在末龄早期经历长日光周期(明暗，16：8)3天，则可在蛹中释放促胸腺激素，可避免滞育。从接受这种长时间刺激的幼虫身上植入的大脑可以逆转短日饲养的滞育幼虫的滞育承诺，从而超过接受者的滞育计划。建立了一个系统，证明昆虫大脑的这种光周期重新编程是在体外发生的。取1龄幼虫的脑-脑后复合体，在长日照条件下体外培养3d。通过分析来自这些培养物的大脑对滞育幼虫非滞育发育的发生率的影响，评估了这种非滞育光周期对这些脑-脑后复合体滞育计划的影响。接受长日光周期的大脑逆转了受体幼虫的幼虫滞育计划，而接受短日光周期的大脑则无效。因此，这种昆虫的幼虫大脑-脑后复合体在体外能够接受光周期的光，因为它可以感觉到它暴露在光-暗周期中的次数，存储这种环境输入，并在9天后的另一个发育阶段表达信息。这些发现表明，在体外，动物的光周期时钟可以通过明暗循环进行重新编程。
Pupal diapause in the tobacco hornworm Manduca sexta is a photoperiodically induced event expressed by the absence of release of the cerebral peptide prothoracicotropic hormone. A short-day photoperiod (light-dark, 12:12) during larval development programs the brain to forego the release of prothoracicotropic hormone in the pupal stage. Prothoracicotropic hormone release can occur in the pupae and diapause can be averted if developing larvae experience an intervening long-day photoperiod (light-dark, 16:8) for 3 days early in the last larval instar. Implanted brains from larvae that received such long-day stimulation can reverse the diapause commitment of short-day-reared diapause-destined larvae, thus overriding the diapause program of the recipient. A system was established that demonstrated that this photoperiodic reprogramming of the insect's brain occurs in vitro. Brain-retrocerebral complexes from day 1 instar larvae were cultured in vitro for 3 days under long-day conditions. The effect of this non-diapause photoperiod on the diapause program of these brain-retrocerebral complexes was assessed by assaying the effect of the brains from these cultures on the incidence of non-diapause development in diapause-destined larval hosts. Brains that received a long-day photoperiod reversed the pupal diapause program of the recipient larvae, whereas brains that received a short-day photoperiod were ineffective. Therefore, the larval brain-retrocerebral complex of this insect is capable of photoperiodic light reception in vitro, in that it can sense the number of light-dark cycles to which it is exposed, store this environmental input, and express the information 9 days later at another stage of development. These findings demonstrate that the photoperiodic clock of an animal can be reprogrammed by a light-dark cycle in vitro.