Meng Li, Luo Jinping, Li Chunhua, Kinsey William H
Center for Reproductive Sciences and Department of Anatomy and Cell Biology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, Kansas 66160, USA.
Reproduction. 2006 Sep;132(3):413-21. doi: 10.1530/rep.1.01151.
Fyn and other Src-family kinases play an essential role at several steps during egg activation following fertilization of externally fertilizing species, such as marine invertebrates, fish, and frogs. Recent studies demonstrate that the requirement for Src-family kinases in activation of the mammalian egg is different from lower species, and the objective of this study was to test the role of the Fyn kinase in the mouse egg activated by intracytoplasmic sperm injection (ICSI). An Src homology 2 (SH2) domain containing fusion protein was used to suppress Fyn function in the mouse zygote following ICSI. Eggs injected with the Fyn SH2 domain at an intracellular concentration of 4-8 microM exhibited reduced developmental potential with 100% of the zygotes being arrested following the first or the second cleavage. At higher concentrations, the protein blocked pronuclear congression and the zygotes remained at the pronuclear stage. The SH2 domain had no effect on sperm-induced calcium oscillations in distinct contrast to its effect on the eggs of lower species. The results indicate that the SH2 domain of Fyn kinase plays an important role in pronuclear congression as well as early cleavage events and that this effect appears not to involve disruption of calcium oscillations.
在体外受精物种（如海洋无脊椎动物、鱼类和青蛙）受精后的卵子激活过程中，Fyn及其他Src家族激酶在多个步骤中发挥着重要作用。最近的研究表明，Src家族激酶在哺乳动物卵子激活中的需求与低等物种不同，本研究的目的是测试Fyn激酶在通过胞浆内单精子注射（ICSI）激活的小鼠卵子中的作用。一种含有Src同源2（SH2）结构域的融合蛋白被用于在ICSI后抑制小鼠受精卵中的Fyn功能。以4-8微摩尔/升的细胞内浓度注射Fyn SH2结构域的卵子表现出发育潜力降低，100%的受精卵在第一次或第二次卵裂后停滞。在更高浓度下，该蛋白会阻止原核迁移，受精卵停留在原核阶段。与它对低等物种卵子的作用形成鲜明对比的是，SH2结构域对精子诱导的钙振荡没有影响。结果表明，Fyn激酶的SH2结构域在原核迁移以及早期卵裂事件中起重要作用，并且这种作用似乎不涉及钙振荡的破坏。
