美國科學家的一項最新研究,，為一種進化理論找到了依據(jù)，即靈長動物的繁殖競爭在精子運動性層面上發(fā)生。相關(guān)論文在線發(fā)表于英國皇家學會《交界》(Journal of the Royal Society Interface)雜志上,。
領(lǐng)導該項研究的是美國加州大學爾灣分校和圣地亞哥分校的Michael Berns。他和同事在研究中發(fā)現(xiàn),，繁殖比較混雜的黑猩猩和獼猴精子的游動速度明顯比人類和大猩猩的更快,，力量也更大。
人類和大猩猩在一個繁殖周期中,，雌性個體只會與一個雄性交配,，而黑猩猩和獼猴一般都要與群體中的多個雄性交配。因此,，后兩者的雄性個體精子游動得越快越猛,，理論上與卵子成功結(jié)合的幾率就越大。論文第一作者Jaclyn Nascimento表示,，“在一夫多妻或一妻多夫制的交配模式中,，快速游動的精子是受到進化青睞的。這與我們在黑猩猩和獼猴中的研究測量相一致,。”
研究發(fā)現(xiàn),，這四種靈長動物按精子力量和速度排序依次是獼猴、黑猩猩,、人類和大猩猩,。人類不是最慢的，這一點讓研究人員大感驚訝,。Berns說,，“或許人類并不像自己認為的那樣，總是一夫一妻制,。”
Berns是“光鑷”(laser tweezers,，利用激光來捕獲和操控單個原子、分子)技術(shù)的先驅(qū)之一,，新的研究方法也是建立在改良后的光鑷技術(shù)上,。當精細胞被激光束捕獲后，光線的強度會發(fā)生同步減弱,，通過這種方式,，研究人員能得以在不同動物精子擺脫光鑷束縛時，精確測量它們產(chǎn)生的力,。
Berns表示,，“生物學家對精子競爭問題的興趣由來已久，但要真正檢驗該理論,，需要生物學家,、物理學家和工程師的通力協(xié)作。”(科學網(wǎng) 任霄鵬）
原始出處:
Journal of the Royal Society Interface
10.1098/rsif.2007.1118
2007年7月24日
The use of optical tweezers to study sperm competition and motility in primates
Jaclyn M. Nascimento1, Linda Z. Shi2, Stuart Meyers3, Pascal Gagneux4, Naida M. Loskutoff5, Elliot L. Botvinick6, Michael W. Berns2, 6
1Department of Electrical and Computer Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
2Department of Bioengineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
3Anatomy, Physiology and Cell Biology Department, School of Veterinary Medicine, University of California, One Shields Avenue, Davis, CA 95616, USA
4Glycobiology Research and Training Center, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
5Omaha's Henry Doorly Zoo, 3701 South 10th Street, Omaha, NB 68107, USA
6Beckman Laser Institute, University of California, Irvine, 1002 Health Sciences Road, Irvine, CA 92612, USA
摘要
Optical trapping is a non-invasive biophysical tool which has been widely applied to study physiological and biomechanical properties of cells. Using laser ‘tweezers’ in combination with custom-designed computer tracking algorithms, the swimming speeds and the relative swimming forces of individual sperm can be measured in real time. This combination of physical and engineering tools has been used to examine the evolutionary effect of sperm competition in primates. The results demonstrate a correlation between mating type and sperm motility: sperm from polygamous (multi-partner) primate species swim faster and with greater force than sperm from polygynous (single partner) primate species. In addition, sperm swimming force linearly increases with swimming speed for each species, yet the regression relating the two parameters is species specific. These results demonstrate the feasibility of using these tools to study rapidly moving (μms−1) biological cells.
Keywords
primate sperm competition, laser tweezers, sperm swimming force
