Immunoglobulin superfamily member IgSF8 (EWI-2) and CD9 in fertilisation: evidence of distinct functions for CD9 and a CD9-associated protein in mammalian sperm-egg interaction
Immunoglobulin superfamily member IgSF8 (EWI-2) and CD9 in fertilisation: evidence of distinct functions for CD9 and a CD9-associated protein in mammalian sperm-egg interaction
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DOI：
10.1071/rd08158
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发表时间：
2009-01-01
影响因子：
1.9
通讯作者：
Evans, Janice P.
中科院分区：
文献类型：
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作者：
Glazar, Amanda I.;Evans, Janice P.
在小鼠卵子上，四跨膜蛋白CD 9几乎是精卵融合所必需的，另一种四跨膜蛋白CD 81起着补充作用。基于对这些蛋白质的了解，卵四跨膜蛋白可能通过与其他卵膜蛋白的结合参与膜秩序的调节。在这里，我们确定了一个第一级的相互作用（稳定在1%Triton X-100）之间的CD 9和免疫球蛋白超家族成员IgSF 8（也称为EWI-2），在鸡蛋中的第一个证据，这样的相互作用的CD 9与另一种蛋白质。我们还比较了抗体介导的IgSF 8和CD 9扰动的影响，评估了这些扰动在IVF条件下的稳健性，这些条件非常有利于受精和受精发生频率较低的条件。这些研究表明，IgSF 8参与小鼠配子相互作用，并确定抗体介导的CD 9和IgSF 8扰动的离散效应。抗IgSF 8抗体对精卵结合具有中等抑制作用，而抗CD 9抗体显著抑制精卵融合，并且在某些测定中，对结合也具有抑制作用。本研究强调了IVF实验设计的至关重要性，以检测实验操作对配子相互作用的不同影响。
On the mouse egg, the tetraspanin CD9 is nearly essential for sperm-egg fusion, with another tetraspanin, CD81, playing a complementary role. Based on what is known about these proteins, egg tetraspanins are likely to be involved in regulation of membrane order through associations with other egg membrane proteins. Here, we identify a first-level interaction (stable in 1% Triton X-100) between CD9 and the immunoglobulin superfamily member IgSF8 (also known as EWI-2), the first evidence in eggs of such an interaction of CD9 with another protein. We also compared the effects of antibody-mediated perturbation of IgSF8 and CD9, evaluating the robustness of these perturbations in IVF conditions that heavily favour fertilisation and those in which fertilisation occurs less frequently. These studies demonstrate that IgSF8 participates in mouse gamete interactions and identify discrete effects of antibody-mediated perturbation of CD9 and IgSF8. An anti-IgSF8 antibody had moderate inhibitory effects on sperm-egg binding, whereas an anti-CD9 antibody significantly inhibited sperm-egg fusion and, in certain assays, had an inhibitory effect on binding as well. The present study highlights the critical importance of design of IVF experiments for the detection of different effects of experimental manipulations on gamete interactions.