ABSTRACT

Intertidal dwellers exhibit a circatidal rhythm corresponding to the tidal cycles, but its molecular mechanism remains largely unknown. The mangrove cricket Apteronemobius asahinai simultaneously exhibits circatidal and circadian rhythms in its locomotor activity. In A. asahinai, it is considered that the circatidal rhythm is generated by the circatidal clock, and its molecular mechanism appears to differ from that of the circadian clock. For the molecular dissection, it is necessary to investigate the effects of a candidate gene disruption in several circatidal rhythms. However, the circatidal rhythms other than locomotor activity have not been examined in this species. Here, to identify biological processes related to the circatidal rhythm, we performed whole-transcriptome analysis using RNA sequencing with RNA samples extracted from whole crickets. Under a light-dark cycle without tidal stimuli, more contigs showed a diel expression pattern than a tidal expression pattern. Gene ontology (GO) enrichment analysis revealed that most GO terms overrepresented in contigs related to the tidal cycle were also overrepresented in contigs related to the diel cycle. GO terms specific to tide-related contigs were related to cuticle development, melanization, and sclerotization. These results suggest that physiological events in the cuticle may be controlled by the circatidal clock.

摘要

潮间带居民表现出与潮汐周期相对应的昼夜节律，但其分子机制仍然很大程度上未知。红树林蟋蟀Apteronemobius asahinai 在其运动活动中同时表现出昼夜节律和昼夜节律。在A. asahinai，认为昼夜节律是由生物钟产生的，其分子机制似乎与生物钟不同。对于分子解剖，有必要研究候选基因破坏在几个昼夜节律中的影响。然而，除运动活动外，还没有在该物种中检查过昼夜节律。在这里，为了识别与昼夜节律相关的生物过程，我们使用 RNA 测序对从整个蟋蟀中提取的 RNA 样本进行了全转录组分析。在没有潮汐刺激的明暗循环下，更多的重叠群显示出 diel 表达模式而不是潮汐表达模式。基因本体 (GO) 富集分析显示，大多数 GO 术语在与潮汐周期相关的重叠群中过多表示，在与昼夜周期相关的重叠群中也过多。特定于潮汐相关重叠群的 GO 术语与角质层发育、黑化和硬化有关。这些结果表明，角质层中的生理事件可能受生物钟控制。