摘    要  小鼠作为哺乳动物遗传研究中首选的模式生物。几十年的努力后，培养转基因小鼠已经变得大众化，以目前的技术可以获得在蛋白质以及核酸水平上的突变种。现在，诸如此种基因组修饰变得越来越进化。

神经系统主要由神经元所组成。神经系统由中枢神经系统和周围神经系统两部分所组成的。存在所有控制着各种生命活动的中枢神经。而周围神经系统则包括各种神经和神经节。其中与大脑相连的称为脑神经，与脊髓相连的称为脊神经，起着支配内脏器官的为植物性神经。各类神经则通过其末梢并与其他器官系统相互联系。神经系统具有重要的功能和作用，是在人体内起主导作用的系统。首先它控制其与协调着各器官系统的生命活动作用，使人体成为一个完整统一的系统。其次它通过神经系统之间的分析与综合作用，使机体对环境变化作出相应的反应并作出应激作用的反应，达到机体与周围环境相互统一的作用。于此同时神经系统对生理机能基本的活动形式是反射弧。由于大脑的高度发达，大脑皮质成为控制整个机体功能的指挥部位，具有思维意识等。神经系统是由外胚层发育而来。神经系统在人体中作为主导的地位。它对人体而言是非常复杂的，体内各器官系统与功能之间和各种生理过程都不是独立存在地，而是在神经系统的调节控制和配合下，使人体成为一个完整的统一的有机体的结构，从而实现着和维持着正常的生命活动。然而，人体是生活在变化多端的环境中，环境的变化必然会影响着体内的各种功能反应，那这也需要神经系统的参与对体内各种功能之间，不断进行迅速而完善的调整与协调，从而使人体适应体内外环境的变化。由此可见，神经系统在人体生命活动中起着主导的调节作用，人类的神经系统高度发展，特别是大脑皮层不仅进化成为调节控制人体活动的最高中枢，而且进化成为能进行思维活动的器官。所以我想通过进一步研究和探讨Isl2基因，然后来分析其对神经系统发育的影响和重要的作用。90496

Abstract Mouse as the preferred model organism in the study of mammalian genetics。 After decades of efforts, cultivate gene targeting and transgenic mice have become very common, to the current technology can be obtained at the nucleic acid level of the mutant lines。 Now, such as the modification of the genome is becoming more and more precise。

Nervous system is composed mainly of neurons。 It is composed of the nervous system and the central nervous system throughout the body of the two parts of the peripheral nervous system thereof。 All controls exist various life activities of the central nervous system。 The peripheral nervous system includes a variety of nerve and ganglion。 Which is connected with the brain we call known as the brain, spinal cord and spinal nerve is connected to what we call, and plays a dominant internal organs we are called autonomic nerves。 Various types of nerve endings and through its interlinked with other organ systems。 Nervous system has an important function and role, is playing a leading role in the human body system。 First, it controls their life activities and coordination role of the various organ systems of the body to become a complete and unified system。 Secondly, through the analysis and synthesis between the role of the nervous system, so that the body of the response to environmental change and respond to the effects of stress, the body with the surrounding environment to achieve mutually consistent role。 At the same time the basic physiology of the nervous system activity in the form of reflex arc。 Since the height of the development of the human brain, the cortex of the brain controls the entire body functions become the most senior command position, and has thought, consciousness and other physiological functions。 Nervous system occurred in early embryonic development, is developed from the ectoderm。 The nervous system play a leading role in the human body。 It terms of structure and function of the human body is very complex, and a variety of physiological processes between various organ systems and functions in vivo not exist independently, but under the regulatory control and with the nervous system, the body becomes a complete unified organism structure, in order to achieve and maintain a normal life activities。 However, the human body is living in the changing environment, changes in the environment is bound to affect the various functions of the body's reaction, and that this also requires the participation of the nervous system of the body between the various functions, quickly and continuously adjust and improve coordination, so that the body adapt to changes in vivo environment。 Thus, in the human nervous system plays a role in regulating life activities leading, highly developed human nervous system, especially the cerebral cortex evolved into not only regulate the activities of the highest central control body, and can evolve into a thinking activity of organs。 Thus, humans not only can adapt to the environment, but also to understand and transform the world。 So I want to further study and discussion Isl2  gene and to analyze their effects on the developing nervous system and important role。