摘要
用动物精子作为外源 DNA载体已成为转基因的主要方法之一 ,并在多种动物上获得成功。最近 ,人们对外源 DNA与精子结合的分子机理进行深入研究发现 :外源 DNA可与精子膜上 3 0～ 3 5k Da蛋白质特异结合 ,结合强度受精子膜上 MHCII因子的调节。精清中的 IF-1因子能抑制精子结合外源 DNA,从而维持物种的遗传稳定性。精子结合外源 DNA的量是恒定的 ,部分 DNA能进入精子核内 ,CD4蛋白具有转运外源 DNA进入精子核内的功能。进入核内的外源 DNA牢固结合在精子核骨架上 ,然后整合到染色体的特异位点。但是 ,精子与外源 DNA结合后能激活精子内的核酸酶 ,进而使外源 DNA分子降解 。
The sperm mediated gene transfer succeded in several species of animals,it has been one of the important methods for producing transgenic animals.Recently the molecular mechanism of sperm uptaking exogenous DNA was intensely studied.The 30～35 KD protein on the sperm head membrane specifically binds exogenous DNA,and another protein MHCII regulates the binding ability.The factor IF 1 from semen plasma inhibits the binding between DNA and sperm,it is very important to keep animal genetic stability.The amount of DNA uptaked by sperm is usually constant,and some DNA can be internalized into sperm nuclear.The protein CD4 may be responsible for this transport.The internalized DNA fist bond the sperm nuclear skeleton,then integrates into the host genome.However,exogenous DNA binding exerts nucleiacid enzyme which degenerates the foreign DNA.It may cause less stable results in sperm mediated gene transfer research.
出处
《国外畜牧科技》
2000年第2期28-30,共3页
Animal Science Abroad
