Wildlife, Fish and Conservation Biology, University of California Davis, Davis, California, United States.
Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, United States.
Am J Physiol Regul Integr Comp Physiol. 2024 Apr 1;326(4):R277-R296. doi: 10.1152/ajpregu.00223.2023. Epub 2024 Jan 8.
The inner ear of teleost fish regulates the ionic and acid-base chemistry and secretes protein matrix into the endolymph to facilitate otolith biomineralization, which is used to maintain vestibular and auditory functions. The otolith is biomineralized in a concentric ring pattern corresponding to seasonal growth, and this calcium carbonate (CaCO) polycrystal has become a vital aging and life-history tool for fishery managers, ecologists, and conservation biologists. Moreover, biomineralization patterns are sensitive to environmental variability including climate change, thereby threatening the accuracy and relevance of otolith-reliant toolkits. However, the cellular biology of the inner ear is poorly characterized, which is a hurdle for a mechanistic understanding of the underlying processes. This study provides a systematic characterization of the cell types in the inner ear of splitnose rockfish (). Scanning electron microscopy revealed the apical morphologies of six inner ear cell types. In addition, immunostaining and confocal microscopy characterized the expression and subcellular localization of the proteins Na-K-ATPase, carbonic anhydrase, V-type H-ATPase, Na-K-2Cl-cotransporter, otolith matrix protein 1, and otolin-1 in six inner ear cell types bordering the endolymph. This fundamental cytological characterization of the rockfish inner ear epithelium illustrates the intricate physiological processes involved in otolith biomineralization and highlights how greater mechanistic understanding is necessary to predict their multistressor responses to future climate change.
硬骨鱼类的内耳调节离子和酸碱化学平衡，并将蛋白质基质分泌到内淋巴中，以促进耳石生物矿化，从而维持前庭和听觉功能。耳石以与季节性生长相对应的同心环模式生物矿化，这种碳酸钙（CaCO）多晶体已成为渔业管理者、生态学家和保护生物学家重要的衰老和生活史工具。此外，生物矿化模式对环境变化（包括气候变化）很敏感，从而威胁到依赖耳石的工具包的准确性和相关性。然而，内耳的细胞生物学特征描述不足，这是对潜在过程进行机制理解的一个障碍。本研究对裂鼻岩鱼（）内耳的细胞类型进行了系统表征。扫描电子显微镜揭示了六种内耳细胞类型的顶极形态。此外，免疫染色和共聚焦显微镜对六种与内淋巴相邻的内耳细胞类型中 Na-K-ATP 酶、碳酸酐酶、V 型 H-ATP 酶、Na-K-2Cl 共转运蛋白、耳石基质蛋白 1 和 otolin-1 的蛋白表达和亚细胞定位进行了特征描述。岩鱼内耳上皮细胞的这种基本细胞学特征说明了耳石生物矿化所涉及的复杂生理过程，并强调了需要更深入的机制理解来预测它们对未来气候变化的多胁迫反应。
