Glass sponges arrest pumping in response to sediment: implications for the physiology of the hexactinellid conduction system
Glass sponges arrest pumping in response to sediment: implications for the physiology of the hexactinellid conduction system
复制标题
玻璃海绵响应沉积物而阻止泵送：对六线体传导系统生理学的影响
DOI：
10.1007/s00227-008-0987-y
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发表时间：
2008
期刊：
影响因子：
2.4
通讯作者：
S. Leys
中科院分区：
文献类型：
--
作者：
Gabrielle J Tompkins;S. Leys
的hexactinellid海绵Rhabdocalyptus dawsoni传播电信号，以阻止其喂养电流响应于机械刺激和沉积物。其他种类的玻璃海绵的深水栖息地，以及在体外处理组织的困难，迄今为止阻止了在本类其他成员中确认电信号。在这里，我们表明，在实验室实验（异位），机械和沉积物刺激触发立即逮捕在R。dawsoni和第二种hexactinellid，Aphrocalphus vastus，表明快速信号可能是玻璃海绵组织的一般特征。此外，这两个物种的反应不同，暗示了传导系统的潜在生理差异。R. dawsoni和A.股肌对沉积物敏感，但R. dawsoni，而A.每次停搏后立即恢复股静脉泵血。细颗粒泥沙（<25 μm）引起R. dawsoni和A.股，但具有较高的刺激阈值在A。vastus。大量的沉积物引发了这两个物种的重复逮捕，并延长暴露于沉积物（超过4小时）造成泵送逐渐减少，恢复需要长达25小时。在恢复过程中，两种海绵都进行了重复的停搏，这具有指示起搏器活动的精确周期性。对这些样本的组织进行扫描电子显微镜检查显示，许多腔室被堵塞。结果表明，玻璃海绵导电系统产生逮捕的饲养电流，防止少量的沉积物的吸收，每个物种有不同的阈值敏感性。然而，持续暴露于沉积物会堵塞过滤装置。
The hexactinellid sponge Rhabdocalyptus dawsoni propagates electrical signals to arrest its feeding current in response to mechanical stimuli and sediment. The deepwater habitat of other species of glass sponge, and the difficulty of working with the tissue in vitro have so far prevented confirmation of electrical signaling in other members of the Class. Here we show in laboratory experiments (ex situ) that mechanical and sediment stimuli trigger immediate arrest in R. dawsoni and in a second species of hexactinellid, Aphrocallistes vastus, suggesting that rapid signaling may be a general feature of glass sponge tissue. Further, responses of the two species differed, suggestive of underlying physiological differences in the conduction system. R. dawsoni and A. vastus were sensitive to sediment but arrests were often prolonged in R. dawsoni, whereas in A. vastus pumping resumed immediately following each arrest. Fine sediment (<25 μm) caused immediate arrests in R. dawsoni and A. vastus, but with a higher stimulus threshold in A. vastus. Large amounts of sediment triggered repeated arrests in both species, and prolonged exposure to sediment (over 4 h) caused a gradual reduction in pumping, with recovery taking up to 25 h. During recovery, both species of sponge carried out repeated arrests, which had a precise periodicity indicative of pacemaker activity. Scanning electron microscopy of the tissue of these specimens showed many chambers were clogged. The results suggest that the glass sponge conduction system generates arrest of the feeding current that prevent uptake of small amounts of sediment, and that each species has different threshold sensitivities. However, ongoing exposure to sediment can clog the filtration apparatus.