3′– UTR ‐dependent regulation of m RNA turnover is critical for differential distribution patterns of cyclic gene m RNA s

Somite segmentation, a prominent periodic event in the development of vertebrates, is instructed by cyclic expression of several genes, including Hes7 and Lunatic fringe ( Lfng ). Transcriptional regulation accounts for the cyclic expression. In addition, because the expression patterns vary in a cycle, rapid turnover of m RNA s should be involved in the cyclic expression, although its contribution remains unclear. Here, we demonstrate that 3′– UTR ‐dependent rapid turnover of Lfng and Hes7 plays a critical role in their dynamic expression patterns. The regions active in the transcription of Lfng and Hes7 are wholly overlapped in the posterior presomitic mesoderm ( PSM ) of the mouse embryo. However, their distribution patterns are slightly different; Hes7 m RNA shows a broader distribution pattern than Lfng m RNA in the posterior PSM. Lfng m RNA is less stable than Hes7 m RNA, where their 3′– UTR s are responsible for the different stability. Using transgenic mice expressing Venus under the control of the Hes7 promoter, which leads to cyclic transcription in the PSM , we reveal that the Lfng 3′– UTR provides the narrow distribution pattern of Lfng m RNA , whereas the Hes7 3′– UTR contributes the relatively broad distribution pattern of Hes7 m RNA . Thus, we conclude that 3′– UTR ‐dependent m RNA stability accounts for the differential distribution patterns of Lfng and Hes7 m RNA . Our findings suggest that 3′– UTR ‐dependent regulation of m RNA turnover plays a crucial role in the diverse patterns of m RNA distribution during development.