Sulfated fucans from the egg jellies of the closely related sea urchins Strongylocentrotus droebachiensis and Strongylocentrotus pallidus ensure species-specific fertilization
Sulfated fucans from the egg jellies of the closely related sea urchins Strongylocentrotus droebachiensis and Strongylocentrotus pallidus ensure species-specific fertilization
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DOI：
10.1074/jbc.m108496200
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发表时间：
2002-01-04
影响因子：
4.8
通讯作者：
Mourao, PAS
中科院分区：
文献类型：
--
作者：
Vilela-Silva, ACES;Castro, MO;Mourao, PAS
来自卵冻的硫酸多糖是负责诱导海胆精子顶体反应的分子。这是精子与卵子结合和融合的必经过程。来自海胆的硫酸化多糖具有简单的、明确定义的重复结构，并且每个物种代表硫酸盐取代的特定模式。在这里，我们研究了海胆兄弟物种Strongylocentrotus droebachiensis和Strongylocentrotus pallidus的卵冻。令人惊讶的是，S. droebachiensis的卵含有两种可能的硫酸化岩藻聚糖之一，这两种硫酸化岩藻聚糖的2-O-硫酸化程度不同。硫酸化岩藻聚糖I主要由四个残基的规则序列组成（[4-alpha-L-Fucp-2（OSO 3）-1->4-alpha-L-Fucp-2（OSO 3）-1->4-alpha-L-Fucp-1->4-alpha-L-Fucp-1]（n）），而硫酸化岩藻聚糖II是4-alpha-L-Fucp-2（OSO 3）-1单元的均聚物。S.的雌性。苍白球含有具有以下重复结构的单一硫酸化岩藻聚糖：[3-α-L-Fucp-2（OSO 3）-1->3-α-L-Fucp-2（OSO 3）-1->3-α-L-Fucp-4（OSO 3）-1->3-α-L-Fucp-4（OSO 3）-1]（n）。这两种海胆的卵凝胶诱导同源（而非异源）精子的顶体反应。因此，S. pallidus和S. droebachiensis，其硫酸化模式和糖苷键的位置不同，确保了精子顶体反应的物种特异性，并防止了种间杂交。此外，我们的观察允许一个清晰的欣赏的共同结构特征之间的硫酸多糖从海胆卵冻，并帮助确定结构，赋予更精细的物种特异性的识别顶体反应。
Sulfated polysaccharides from egg jelly are the molecules responsible for inducing the sperm acrosome reaction in sea urchins. This is an obligatory event for sperm binding to, and fusion with, the egg. The sulfated polysaccharides from sea urchins have simple, well defined repeating structures, and each species represents a particular pattern of sulfate substitution. Here, we examined the egg jellies of the sea urchin sibling species Strongylocentrotus droebachiensis and Strongylocentrotus pallidus. Surprisingly, females of S. droebachiensis possess eggs containing one of two possible sulfated fucans, which differ in the extent of their 2-O-sulfation. Sulfated fucan I is mostly composed of a regular sequence of four residues ([4-alpha-L-Fucp-2(OSO3)-1-->4-alpha-L-Fucp-2(OSO3)-1-->4-alpha-L-Fucp-1-->4-alpha-L-Fucp-1](n)), whereas sulfated fucan II is a homopolymer of 4-alpha-L-Fucp-2(OSO3)-1 units. Females of S. pallidus contain a single sulfated fucan with the following repeating structure: [3-alpha-L-Fucp-2(OSO3)-1-->3-alpha-L-Fucp-2(OSO3)-1-->3-alpha-L-Fucp4(OSO3)-1-->3-alpha-L-Fucp-4(OSO3)-1](n). The egg jellies of these two species of sea urchins induce the acrosome reaction in homologous (but not heterologous) sperm. Therefore, the fine structure of the sulfated a-fucans from the egg jellies of S. pallidus and S. droebachiensis, which differ in their sulfation patterns and in the position of their glycosidic linkages, ensures species specificity of the sperm acrosome reaction and prevents interspecies crosses. In addition, our observations allow a clear appreciation of the common structural features among the sulfated polysaccharides from sea urchin egg jelly and help to identify structures that confer finer species specificity of recognition in the acrosome reaction.