New insights into ion regulation of cephalopod molluscs: A role of epidermal ionocytes in acid-base regulation during embryogenesis

Marian Y. Hu, Yung-Che Tseng, Li Yih Lin, Po Yen Chen, Mireille Charmantier-Daures, Pung Pung Hwang*, Frank Melzner

*此作品的通信作者

研究成果: 雜誌貢獻期刊論文同行評審

25 引文 斯高帕斯(Scopus)

摘要

The constraints of an active life in a pelagic habitat led to numerous convergent morphological and physiological adaptations that enable cephalopod molluscs and teleost fishes to compete for similar resources. Here, we show for the first time that such convergent developments are also found in the ontogenetic progression of ion regulatory tissues; as in teleost fish, epidermal ionocytes scattered on skin and yolk sac of cephalopod embryos appear to be responsible for ionic and acid-base regulation before gill epithelia become functional. Ion and acid-base regulation is crucial in cephalopod embryos, as they are surrounded by a hypercapnic egg fluid with a PCO 2 between 0.2 and 0.4 kPa. Epidermal ionocytes were characterized via immunohistochemistry, in situ hybridization, and vital dye-staining techniques. We found one group of cells that is recognized by concavalin A and MitoTracker, which also expresses Na +/H + exchangers (NHE3) and Na +-K +-ATPase. Similar to findings obtained in teleosts, these NHE3-rich cells take up sodium in exchange for protons, illustrating the energetic superiority of NHE-based proton excretion in marine systems. In vivo electrophysiological techniques demonstrated that acid equivalents are secreted by the yolk and skin integument. Intriguingly, epidermal ionocytes of cephalopod embryos are ciliated as demonstrated by scanning electron microscopy, suggesting a dual function of epithelial cells in water convection and ion regulation. These findings add significant knowledge to our mechanistic understanding of hypercapnia tolerance in marine organisms, as it demonstrates that marine taxa, which were identified as powerful acid-base regulators during hypercapnic challenges, already exhibit strong acid-base regulatory abilities during embryogenesis.

原文英語
頁(從 - 到)1700-1709
頁數10
期刊American Journal of Physiology - Regulatory Integrative and Comparative Physiology
301
發行號6
DOIs
出版狀態已發佈 - 2011 12月

ASJC Scopus subject areas

  • 生理學
  • 生理學(醫學)

指紋

深入研究「New insights into ion regulation of cephalopod molluscs: A role of epidermal ionocytes in acid-base regulation during embryogenesis」主題。共同形成了獨特的指紋。

引用此