Amelio Daniela, Garofalo Filippo
Department of Biology, Ecology and Earth Science, University of Calabria, 87036 Arcavacata di Rende, CS, Italy.
Comp Biochem Physiol B Biochem Mol Biol. 2023 Jun-Jul;266:110846. doi: 10.1016/j.cbpb.2023.110846. Epub 2023 Mar 7.
African dipnoi (Protopterus sp.) are obligate air-breathing fish that, during dry season, may experience a period of dormancy named aestivation. Aestivation is characterized by complete reliance on pulmonary breathing, general decrease of metabolism and down-regulation of respiratory and cardiovascular functions. To date, little is known about morpho-functional rearrangements induced by aestivation in the skin of African lungfishes. Our study aims to identify, in the skin of P. dolloi, structural modifications and stress-induced molecules in response to short-term (6 days) and long-term (40 days) aestivation. Light microscopy showed that short-term aestivation induces major reorganization, with narrowing of epidermal layers and decrease of mucous cells; prolonged aestivation is characterized by regenerative processes and re-thickening of epidermal layers. Immunofluorescence reveals that aestivation correlates with an increased oxidative stress and changes of Heat Shock Proteins expression, suggesting a protective role for these chaperons. Our findings revealed that lungfish skin undergoes remarkable morphological and biochemical readjustments in response to stressful conditions associated with aestivation.
非洲肺鱼（原鳍鱼属）是专性呼吸空气的鱼类，在旱季可能会经历一段名为夏眠的休眠期。夏眠的特征是完全依赖肺呼吸、新陈代谢普遍下降以及呼吸和心血管功能下调。迄今为止，关于夏眠对非洲肺鱼皮肤诱导的形态功能重排知之甚少。我们的研究旨在确定多氏原鳍鱼皮肤中，对短期（6天）和长期（40天）夏眠产生的结构改变和应激诱导分子。光学显微镜显示，短期夏眠会引发重大重组，表皮层变窄且黏液细胞减少；长期夏眠的特征是再生过程和表皮层重新增厚。免疫荧光显示，夏眠与氧化应激增加和热休克蛋白表达变化相关，表明这些伴侣蛋白具有保护作用。我们的研究结果表明，肺鱼皮肤会因与夏眠相关的应激条件而发生显著的形态和生化调整。
