Preferential expulsion of dividing algal cells as a mechanism for regulating algal-cnidarian symbiosis
Preferential expulsion of dividing algal cells as a mechanism for regulating algal-cnidarian symbiosis
复制标题
DOI：
10.2307/1543184
复制
发表时间：
2000-12-01
影响因子：
1.6
通讯作者：
Muscatine, L
中科院分区：
文献类型：
--
作者：
Baghdasarian, G;Muscatine, L
与海洋刺胞动物共生的藻类种群动态受到多种内在因素和环境因素的影响。目前的研究表明，由刺胞宿主排出的藻类损失是共生体种群密度的主要调节因素之一。由于藻类排出率与藻类分裂率之间存在显著的线性相关性，因此增加分裂率的因素（如温度升高）也会增加排出率。此外，h -3-胸腺嘧啶被排出体外的藻类所吸收的程度要大于被保留在宿主刺胞体中的藻类所吸收的程度。综上所述，关于排出率、不同温度下的分裂率和3h -胸腺嘧啶的吸收的数据表明，正在分裂的藻类细胞优先从宿主中排出。分裂细胞的优先驱逐可能是调节藻类种群密度的一种机制，其中藻类的驱逐率可能是宿主细胞容纳新藻类子细胞能力的反函数。这种调节存在于一些刺胞动物物种中（例如，Aiptasia pulchella, Pocillopora damicornis），但并非存在于所有物种（例如，Montipora verrucosa， Porites compressa和Fungia scutaria）。
A wide range of both intrinsic and environmental factors can influence the population dynamics of algae in symbiosis with marine cnidarians. The present study shows that loss of algae by expulsion from cnidarian hosts is one of the primary regulators of symbiont population density. Because there is a significant linear correlation between the rate of algal expulsion and the rate of algal division, factors that increase division rates (e.g., elevated temperature) also increase expulsion rates. Additionally, H-3-thymidine is taken up to a greater extent by algae destined to be expelled than by algae retained in the host cnidarians. Taken together, data for rates of expulsion, rates of division at different temperatures, and uptake of 3H-thymidine suggest that dividing algal cells are preferentially expelled from their hosts. The preferential expulsion of dividing cells may be a mechanism for regulation of algal population density, where the rate of expulsion of algae may be an inverse function of the ability of host cells to accommodate new algal daughter cells. This kind of regulation is present in some cnidarian species (e.g., Aiptasia pulchella, Pocillopora damicornis), but not in all (e.g., Montipora verrucosa, Porites compressa, and Fungia scutaria).