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.
Present address: Innoland biosciences, Hangzhou, 310000, China.
bioRxiv. 2023 Oct 18:2023.10.16.562538. doi: 10.1101/2023.10.16.562538.
The biological roles of the autofluorescent lysosome-related organelles ("gut granules") in the intestinal cells of many nematodes, including s, have been shown to 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 increased and then decreased in a rapid and dynamic manner that may be associated with nutrient availability. We observed that two distinct types of fluorophores are likely present in the gut granules. One displays a "flashing" phenomenon, in which fluorescence decrease is preceded by a sharp increase in fluorescence intensity that expands into the surrounding area, while the other simply decreases in intensity. Gut granule flashing was observed in the different life stages of and was also observed in , an evolutionarily distant nematode. We hypothesize that the "flashing" fluorophore is pH-sensitive, and the fluorescence intensity change results from the fluorophore being released from the lysosome-related organelles into the relatively higher pH environment of the cytosol. The visually spectacular dynamic fluorescence phenomenon we describe might provide a handle on the biochemistry and genetics of these lysosome-related organelles.
包括秀丽隐杆线虫在内的许多线虫肠道细胞中，自发荧光的溶酶体相关细胞器（“肠道颗粒”）的生物学作用已被证明在代谢和信号传导过程中发挥重要作用，但尚未得到充分表征。我们在此报告一种以前未描述的现象，即这些颗粒的自发荧光以快速且动态的方式先增加然后减少，这可能与营养物质的可用性有关。我们观察到肠道颗粒中可能存在两种不同类型的荧光团。一种呈现“闪烁”现象，即荧光强度在急剧增加并扩展到周围区域之后出现荧光下降，而另一种则只是强度降低。在秀丽隐杆线虫的不同生命阶段观察到了肠道颗粒闪烁现象，在进化关系较远的线虫——巴氏新小杆线虫中也观察到了该现象。我们推测“闪烁”荧光团对pH敏感，荧光强度变化是由于荧光团从溶酶体相关细胞器释放到细胞质中pH相对较高的环境所致。我们所描述的这种视觉上引人注目的动态荧光现象可能为研究这些溶酶体相关细胞器的生物化学和遗传学提供一个切入点。
