Martino Chiara, Chiarelli Roberto
Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, 90128 Palermo, Italy.
NBFC, National Biodiversity Future Center, Piazza Marina 61, 90133 Palermo, Italy.
Life (Basel). 2024 Oct 12;14(10):1296. doi: 10.3390/life14101296.
Exogenous DNA damage represents one of the most harmful outcomes produced by environmental, physical, or chemical agents. Here, a comparative analysis of DNA fragmentation was carried out on sea urchin embryos exposed to four common pollutants of the marine environment: vanadium, cadmium, gadolinium and selenium. Using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, fragmented DNA was quantified and localized in apoptotic cells mapping whole-mount embryos. This is the first study reporting how different chemicals are able to activate distinctive apoptotic features in sea urchin embryos, categorized as follows: (i) cell-selective apoptosis, showing DNA fragmentation restricted to a subset of extremely damaged cells, acting as an embryo survival mechanism; or (ii) total apoptosis, with fragmented DNA widespread throughout the cells of the entire embryo, leading to its death. Also, this is the first report of the effects of Se exposure on sea urchin embryos. These data confirm the TUNEL assay as the most suitable test to study DNA fragmentation in the sea urchin embryo model system. Taken together, this research highlights embryos' ability to find alternative pathways and set physiological limits for development under stress conditions.
外源性DNA损伤是环境、物理或化学因素产生的最有害的后果之一。在此，我们对暴露于海洋环境中四种常见污染物（钒、镉、钆和硒）的海胆胚胎进行了DNA片段化的比较分析。使用末端脱氧核苷酸转移酶dUTP缺口末端标记（TUNEL）测定法，对凋亡细胞中片段化的DNA进行定量并定位，从而绘制出完整胚胎图。这是第一项报告不同化学物质如何在海胆胚胎中激活独特凋亡特征的研究，这些特征分类如下：（i）细胞选择性凋亡，表现为DNA片段化仅限于一部分极度受损的细胞，这是一种胚胎存活机制；或（ii）完全凋亡，片段化DNA广泛分布于整个胚胎的细胞中，导致胚胎死亡。此外，这也是关于硒暴露对海胆胚胎影响的首次报告。这些数据证实TUNEL测定法是研究海胆胚胎模型系统中DNA片段化最合适的测试方法。综上所述，本研究突出了胚胎在应激条件下寻找替代途径并设定发育生理极限的能力。
