Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan.
Cell Rep. 2013 Jan 31;3(1):1-7. doi: 10.1016/j.celrep.2012.11.012. Epub 2012 Dec 7.
Periodic somite segmentation is controlled by the cyclic gene Hes7, whose oscillatory expression depends upon negative feedback with a delayed timing. The mechanism that regulates the pace of segmentation remains to be determined, but mathematical modeling has predicted that negative feedback with shorter delays would give rise to dampened but more rapid oscillations. Here, we show that reducing the number of introns within the Hes7 gene shortens the delay and results in a more rapid tempo of both Hes7 oscillation and somite segmentation, increasing the number of somites and vertebrae in the cervical and upper thoracic region. These results suggest that the number of introns is important for the appropriate tempo of oscillatory expression and that Hes7 is a key regulator of the pace of the segmentation clock.
周期性体节的分割由 Hes7 基因控制，其周期性表达依赖于具有延迟时间的负反馈。调节分割节奏的机制仍有待确定，但数学模型预测，具有更短延迟的负反馈将导致减弱但更快的振荡。在这里，我们表明，减少 Hes7 基因中的内含子数量会缩短延迟时间，并导致 Hes7 振荡和体节分割的节奏更快，从而增加颈椎和上胸部区域的体节和椎骨数量。这些结果表明，内含子的数量对于振荡表达的适当节奏很重要，并且 Hes7 是分割时钟节奏的关键调节剂。
