期刊
JOURNAL OF EXPERIMENTAL BIOLOGY
卷 213, 期 23, 页码 4092-4098出版社
COMPANY OF BIOLOGISTS LTD
DOI: 10.1242/jeb.045088
关键词
pulmonate snail; metamorphosis; ion-selective microelectrode; ion transport; calcification; embryonic development
类别
资金
- NOAA, Environmental Cooperative Science Center
- RSMAS Marine Science Graduate Student Organization
The freshwater common pond snail Lymnaea stagnalis produces embryos that complete direct development, hatching as shell-bearing individuals within 10. days despite relatively low ambient calcium and carbonate availability. This development is impaired by removal of ambient total calcium but not by removal of bicarbonate and/or carbonate. In this study we utilized pharmacological agents to target possible acquisition pathways for both Ca2+ and accumulation of carbonate in post-metamorphic, shell-laying embryos. Using whole egg mass flux measurements and ion-specific microelectrode analytical techniques, we have demonstrated that carbonic anhydrase-catalyzed hydration of CO2 is central in the acquisition of both shell-forming ions because it provides the hydrogen ions for an electrogenic vacuolar-type H+-ATPase that fuels the uptake of Ca2+ via voltage-dependent Ca2+ channels and possibly an electrogenic Ca2+/1H(+) exchanger. Additionally, CO2 hydration provides an endogenous source of HCO3-. Thus, hydration of endogenous CO2 forms HCO3- for calcification while hydrogen ions are excreted, contributing to continued Ca2+ uptake, as well as creating favorable alkaline internal conditions for calcification. The connections between Ca2+ and HCO3- acquisition mechanisms that we describe here provide new insight into this efficient, embryonic calcification in freshwater.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据