科學(xué)界已經(jīng)知曉,，在人類(lèi)卵子的受精過(guò)程中,，卵子表面的一系列特殊糖分子起著重要作用。只有精子頭部的蛋白質(zhì)與這些糖分子完全匹配后,，精子和卵子的表層才開(kāi)始綁定,，隨后二者開(kāi)始合并，精子開(kāi)始向卵子內(nèi)部釋放DNA,，卵子也就開(kāi)始受精,。但在綁定“前戲”發(fā)生時(shí)，哪類(lèi)糖分子或者糖分子組合最關(guān)鍵呢,？一個(gè)國(guó)際研究團(tuán)隊(duì)給出了答案,。
在一項(xiàng)新研究中，英國(guó)倫敦帝國(guó)學(xué)院,、美國(guó)密蘇里大學(xué),、中國(guó)香港大學(xué)和臺(tái)灣“中央研究院”研究人員，使用了超靈敏光譜成像技術(shù)找出了促使精卵“牽手”的最重要“紅娘”——名為SLeX的糖鏈（糖分子按特定序列形成的鏈狀物）,。他們發(fā)現(xiàn),，SLeX在卵子表面異常豐富，進(jìn)一步的實(shí)驗(yàn)室研究確認(rèn),，正是這種糖鏈將精子綁定于卵子,。
這項(xiàng)研究成果8月19日發(fā)表在美國(guó)新一期《科學(xué)》雜志上。
參與研究的倫敦帝國(guó)學(xué)院教授安妮·德?tīng)柋硎荆?ldquo;我們發(fā)現(xiàn)的這些細(xì)節(jié)填補(bǔ)了對(duì)受精知識(shí)理解的空白,，我們希望能最終幫助那些目前還沒(méi)法生育的人群”,。(生物谷 Bioon.com)
doi:10.1126/science.1207438
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Human Sperm Binding Is Mediated by the Sialyl-Lewisx Oligosaccharide on the Zona Pellucida
Pang, Poh-Choo; Chiu, Philip C. N.; Lee, Cheuk-Lun; Chang, Lan-Yi; Panico, Maria; Morris, Howard R.; Haslam, Stuart M.; Khoo, Kay-Hooi; Clark, Gary F.; Yeung, William S. B.; Dell, Anne
Human fertilization begins when spermatozoa bind to the extracellular matrix coating of the oocyte, known as the zona pellucida (ZP). One spermatozoan then penetrates this matrix and fuses with the egg cell, generating a zygote. Although carbohydrate sequences on the ZP have been implicated in sperm binding, the nature of the ligand was unknown. Here, ultrasensitive mass spectrometric analyses revealed that the sialyl-Lewisx sequence (NeuAcα2-3Galβ1-4(Fucα1-3)GlcNAc), a well-known selectin ligand, is the most abundant terminal sequence on the N- and O-glycans of human ZP. Sperm-ZP binding was largely inhibited by glycoconjugates terminated with sialyl-Lewisx sequences or by antibodies directed against this sequence. Thus, the sialyl-Lewisx sequence represents the major carbohydrate ligand for human sperm-egg binding.
