Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki 852-8521, Japan.
Institute of Aquaculture, College of Fisheries and Ocean Sciences, University of the Philippines Visayas, Miagao, Iloilo city 5023, Philippines.
Int J Mol Sci. 2021 Mar 23;22(6):3273. doi: 10.3390/ijms22063273.
This study evaluated the larval settlement inducing effect of sugars and a conspecific cue from adult shell extract of . To understand how the presence of different chemical cues regulate settlement behavior, oyster larvae were exposed to 12 types of sugars, shell extract-coated and non-coated surfaces, and under varied sugar exposure times. Lectin-glycan interaction effects on settlement and its localization on oyster larval tissues were investigated. The results showed that the conspecific cue elicited a positive concentration dependent settlement inducing trend. Sugars in the absence of a conspecific cue, adult shell extract, did not promote settlement. Whereas, in the presence of the cue, showed varied effects, most of which were found inhibitory at different concentrations. Sugar treated larvae exposed for 2 h showed significant settlement inhibition in the presence of a conspecific cue. Neu5Ac, as well as GlcNAc sugars, showed a similar interaction trend with wheat germ agglutinin (WGA) lectin. WGA-FITC conjugate showed positive binding on the foot, velum, and mantle when exposed to GlcNAc sugars. This study suggests that a WGA lectin-like receptor and its endogenous ligand are both found in the larval chemoreceptors and the shell Ethylenediaminetetraacetic acid (EDTA) extract that may complementarily work together to allow the oyster larva greater selectivity during site selection.
本研究评估了糖和来自成体贝壳提取物的同种诱导因子对牡蛎幼虫附着的诱导作用。为了了解不同化学信号如何调节附着行为，将牡蛎幼虫暴露于 12 种糖、涂有和未涂有贝壳提取物的表面以及不同的糖暴露时间下。研究了凝集素-糖相互作用对牡蛎幼虫附着及其在组织上定位的影响。结果表明，同种诱导因子表现出浓度依赖的正相关附着诱导趋势。没有同种诱导因子存在时，糖和成体贝壳提取物都不能促进附着。然而，在存在同种诱导因子的情况下，表现出不同的效果，大多数在不同浓度下表现出抑制作用。在同种诱导因子存在的情况下，暴露 2 小时的糖处理幼虫表现出显著的附着抑制。Neu5Ac 和 GlcNAc 糖与麦胚凝集素（WGA）凝集素有相似的相互作用趋势。当暴露于 GlcNAc 糖时，WGA-FITC 缀合物在足部、翼和套膜上表现出阳性结合。本研究表明，WGA 凝集素样受体及其内源性配体都存在于幼虫的化学感受器和壳乙二胺四乙酸（EDTA）提取物中，它们可能共同起作用，使牡蛎幼虫在选择附着位点时具有更大的选择性。
