The process of cell death has been detected in the midgut epithelium of four tardigrade species which belong to Parachela: Macrobiotus diversus, Macrobiotus polonicus, Hypsibius dujardini and Xerobiotus pseudohufelandi. They originated from different environments so they have been affected by different stressors: M. polonicus was extracted from a moss sample collected from a railway embankment; M. diversus was extracted from a moss sample collected from a petrol station; X. pseudohufelandi originated from sandy and dry soil samples collected from a pine forest; H. dujardini was obtained commercially but it lives in a freshwater or even in wet terrestrial environment. Autophagy is caused in the digestive cells of the midgut epithelium by different factors. However, a distinct crosstalk between autophagy and necrosis in tardigrades’ digestive system has been described at the ultrastructural level. Apoptosis has not been detected in the midgut epithelium of analyzed species. We also determined that necrosis is the major process that is responsible for the degeneration of the midgut epithelium of tardigrades, and “apoptosis–necrosis continuum” which is the relationship between these two processes, is disrupted.

中文翻译：

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自噬在 Parachela (Tardigrada) 中肠上皮中的作用

在属于 Parachela 的四种缓步动物的中肠上皮中检测到细胞死亡过程：Macrobiotus diversus、Macrobiotus polonicus、Hypsibius dujardini 和 Xerobiotus pseudohufelandi。它们来自不同的环境，因此受到不同压力源的影响：M. polonicus 是从铁路路堤收集的苔藓样本中提取的；M. diversus 是从从加油站收集的苔藓样本中提取的；X. pseudohufelandi 来源于从松林中采集的沙质和干燥土壤样品；H. dujardini 是商业获得的，但它生活在淡水甚至潮湿的陆地环境中。自噬是由不同因素在中肠上皮消化细胞中引起的。然而，在超微结构水平上描述了缓步动物消化系统中自噬和坏死之间的明显串扰。在分析物种的中肠上皮中未检测到细胞凋亡。我们还确定坏死是导致缓步动物中肠上皮退化的主要过程，并且这两个过程之间的关系“细胞凋亡 - 坏死连续体”被破坏。