Tan Chieh-Hsiang, Ding Keke, Zhang Mark G, Sternberg Paul W
Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
G3 (Bethesda). 2025 Sep 4. doi: 10.1093/g3journal/jkaf209.
The lysosome-related organelles ("gut granules") in the intestinal cells of many nematodes, including Caenorhabditis elegans, play an important role in metabolic and signaling processes, but they have not been fully characterized. We report here a previously undescribed phenomenon in which the autofluorescence of these granules displays a "flash" phenomenon in which fluorescence decreases are preceded by sharp increases in fluorescence intensity that expand into the surrounding area when the granules are stimulated with blue light. Autofluorescent granules are present in the intestinal cells of all six nematode species examined, with differences in morphology and distribution pattern. Five species exhibit the flash phenomenon: Panagrellus redivivus (Clade IV), Steinernema hermaphroditum (Clade IV), C. elegans (Clade V), Oscheius tipulae (Clade V), and Pristionchus pacificus (Clade V). The reaction of the granules to blue light stimulation greatly differs among different developmental stages and may also be dependent on physiological conditions. In addition, even within the same animal, the sensitivity of individual granules differs, with some of the variation associated with other characteristics of the granules, such as their overall location within the intestine. We hypothesize that the differences in response to blue light indicate the existence of different sub-populations of gut granules in nematode intestines, and the visually spectacular dynamic fluorescence phenomenon we describe might provide a handle on their eventual characterization.
包括秀丽隐杆线虫在内的许多线虫肠道细胞中的溶酶体相关细胞器（“肠道颗粒”）在代谢和信号传导过程中发挥着重要作用，但尚未得到充分表征。我们在此报告一种先前未描述的现象，即这些颗粒的自发荧光显示出一种“闪光”现象，当颗粒受到蓝光刺激时，荧光强度会先急剧增加，然后扩展到周围区域，随后荧光强度降低。在所检查的所有六种线虫的肠道细胞中均存在自发荧光颗粒，其形态和分布模式存在差异。五个物种表现出闪光现象：复苏短体线虫（进化枝IV）、雌雄同体斯氏线虫（进化枝IV）、秀丽隐杆线虫（进化枝V）、蒂普奥斯凯线虫（进化枝V）和太平洋前管线虫（进化枝V）。颗粒对蓝光刺激的反应在不同发育阶段有很大差异，并且可能还取决于生理条件。此外，即使在同一只动物体内，单个颗粒的敏感性也不同，其中一些差异与颗粒的其他特征有关，例如它们在肠道内的整体位置。我们推测，对蓝光反应的差异表明线虫肠道中存在不同亚群的肠道颗粒，并且我们所描述的这种视觉上引人注目的动态荧光现象可能有助于最终对它们进行表征。
