POST-MOULT CALCIFICATION IN THE BLUE CRAB, CALLINECTES SAPIDUS: TIMING AND MECHANISM
POST-MOULT CALCIFICATION IN THE BLUE CRAB, CALLINECTES SAPIDUS: TIMING AND MECHANISM
复制标题
DOI：
--
复制
发表时间：
1989-05
期刊：
影响因子：
--
通讯作者：
J. N. Cameron
中科院分区：
文献类型：
--
作者：
J. N. Cameron
本文通过一系列的实验研究了青蟹蜕皮前后的变化。螃蟹体重增加（主要是水）的水平超过两倍的蜕皮前值不包括棚甲壳。在蜕皮前4小时左右开始增加，在蜕皮时迅速加速到最大速率，并在蜕皮后2小时基本完成。钙化和净H +排泄保持在对照（换羽间）水平，直到换羽后1-2小时，此后两者开始非常迅速地增加，两个过程的时间过程相同。内部与外部的钙浓度的比例下降，从1.4：1在换羽间期到0.85：1换羽后2天，逆转的电化学梯度在换羽后期间。蛋白质合成抑制剂放线菌素D和放线菌酮强烈抑制钙化。孤立的全鳃和鳃片没有显示出显着的变化率相关的换羽期的钙吸收，表明整个鳃的钙的吸收可能在很大程度上是被动的。低亲和力的Ca 2+激活的ATP酶存在于鳃和上皮细胞中，但只有上皮细胞的活性在蜕皮后的几个小时内显示出实质性的（5倍）增加。刺激运输过程的控制机制仍然难以捉摸。无眼蟹的进展正常通过蜕皮和蜕皮后钙化。来自血液和来自疑似神经激素产生组织的肽谱在蜕皮阶段显著不同，但是使用来自蟹组织和脊椎动物来源的肽开发生物测定的几种不同方法一直不成功。在蜕皮的几个小时内发生的生理事件表明了一系列复杂而精确的控制信号。
A series of experiments was conducted to elucidate the events immediately preceding and following moulting (ecdysis) in the blue crab, Callinectes sapldus Rathbun. The crabs gain weight (mostly water) to a level more than twice the premoult value excluding the shed carapace. The gain begins about 4 h before ecdysis, accelerates rapidly to a maximum rate at about the time of ecdysis, and is essentially complete by 2h after ecdysis. Both calcification and net H + excretion remain at control (intermoult) levels until 1–2 h post-moult, whereupon a very rapid increase in both begins, with the same time course for both processes. The ratio of internal to external calcium concentration drops from 1.4:1 during intermoult to 0.85:1 by 2 days after the moult, reversing the electrochemical gradient during the post-moult period. Calcification is strongly inhibited by the protein synthesis inhibitors actinomycin D and cycloheximide. Isolated whole gills and gill slices do not show significant changes in rates of calcium uptake related to moult stage, indicating that the uptake of calcium across the gills may be largely passive. A low-affinity Ca 2+ -activated ATPase is present in both gills and epithelium, but only the epithelial activity shows a substantial (fivefold) increase in the hours after ecdysis. The control mechanisms for stimulation of the transport processes remain elusive. Eyestalkless crabs progress normally through moult and post-moult calcification. Peptide profiles from blood and from suspected neurohormone- producing tissues differ markedly with moult stage, but several different approaches to developing a bioassay using peptides from crab tissues and vertebrate sources have been unsuccessful. The physiological events in the hours surrounding ecdysis suggest a complex and precisely timed series of control signals.