Dipartimento di Biologia, Università degli Studi di Padova, Padova, Italy.
Laboratory of Chronobiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
Sci Rep. 2019 Sep 25;9(1):13894. doi: 10.1038/s41598-019-50282-1.
Antarctic krill (Euphausia superba) is a high latitude pelagic organism which plays a central role in the Southern Ocean ecosystem. E. superba shows daily and seasonal rhythms in physiology and behaviour, which are synchronized with the environmental cycles of its habitat. Recently, the main components of the krill circadian machinery have been identified and characterized. However, the exact mechanisms through which the endogenous timing system operates the control and regulation of the overt rhythms remains only partially understood. Here we investigate the involvement of the circadian clock in the temporal orchestration of gene expression by using a newly developed version of a krill microarray platform. The analysis of transcriptome data from krill exposed to both light-dark cycles (LD 18:6) and constant darkness (DD), has led to the identification of 1,564 putative clock-controlled genes. A remarkably large proportion of such genes, including several clock components (clock, period, cry2, vrille, and slimb), show oscillatory expression patterns in DD, with a periodicity shorter than 24 hours. Energy-storage pathways appear to be regulated by the endogenous clock in accordance with their ecological relevance in daily energy managing and overwintering. Our results provide the first representation of the krill circadian transcriptome under laboratory, free-running conditions.
南极磷虾（Euphausia superba）是一种高纬度海洋浮游生物，在南大洋生态系统中起着核心作用。E. superba 在生理和行为上表现出昼夜和季节性节律，与栖息地的环境周期同步。最近，已经确定并描述了磷虾昼夜节律机制的主要组成部分。然而，内源性定时系统如何控制和调节明显的节律的具体机制仍部分未知。在这里，我们通过使用新开发的磷虾微阵列平台来研究生物钟在基因表达的时间协调中的参与。对暴露于光-暗循环（LD 18:6）和持续黑暗（DD）的磷虾的转录组数据进行分析，确定了 1564 个可能的时钟控制基因。这种基因的很大一部分，包括几个时钟组件（时钟、周期、cry2、vrille 和 slimb），在 DD 中表现出短于 24 小时的周期性表达模式。根据其在日常能量管理和越冬过程中的生态相关性，能量储存途径似乎受到内源性时钟的调节。我们的结果提供了实验室自由运行条件下磷虾昼夜转录组的首次代表。
