遗传 ›› 2015, Vol. 37 ›› Issue (1): 98-108.doi: 10.16288/j.yczz.2015.01.014

• 遗传学教学 • 上一篇    下一篇

遗传学教学中在细胞与分子水平上理解等位基因的显性与隐性

邢万金, 莫日根   

  1. 内蒙古大学生命科学学院,呼和浩特 010021
  • 收稿日期:2014-09-02 修回日期:2014-10-01 出版日期:2015-01-20 发布日期:2015-01-20
  • 作者简介:邢万金,博士,教授,研究方向:分子遗传学和基因工程。Tel: 0471-4992944; E-mail: xwanjin@imu.edu.cn
  • 基金资助:
    内蒙古自治区生物化学系列课程教学团队建设项目资助

Understanding the cellular and molecular mechanisms of dominant and recessive inheritance in genetics course

Wanjin Xing, Morigen   

  1. School of Life Sciences, Inner Mongolia University, Hohhot 010021, China
  • Received:2014-09-02 Revised:2014-10-01 Online:2015-01-20 Published:2015-01-20

摘要: 在孟德尔遗传学中显性与隐性描述一对等位基因在杂合体时的功能关系,把在表型上看出效果的等位基因称为显性等位基因,看不出效果的称为隐性等位基因,并由此提出分离定律和自由组合定律,开创了遗传学这一学科。这样的描述最初是逻辑推理的需要,但对于研究生命结构与功能关系的实验性科学而言,必须在细胞与大分子实体上找到显性与隐性的生物学基础。在遗传学教学中,如何用现代分子遗传学知识诠释经典的显性和隐性概念是教师经常面临的释疑问题。笔者认为要理解等位基因显性和隐性的实质,必须了解等位基因的差异及其产物RNA或蛋白质在细胞中的具体作用。不同等位基因的蛋白质或者RNA产物在细胞内的不同时间、不同地点所起的作用不同,赋予了在细胞、组织或器官水平上能够区分观测到的表型差异,即显性或者隐性。文章根据基因结构的变异、基因调控的差异、基因产物的类型与作用等在细胞与分子水平上分别举例探讨了等位基因显性与隐性的分子实质及其变化,以期在遗传学教学过程中使学生对基因的变异和功能有更全面、更具体的理解。

关键词: 遗传学, 教学, 等位基因, 显性, 隐性

Abstract: In Mendellian genetics, the dominance and recessiveness are used to describe the functional relationship between two alleles of one gene in a heterozygote. The allele which constitutes a phenotypical character over the other is named dominant and the one functionally masked is called recessive. The definitions thereby led to the creation of Mendel’s laws on segregation and independent assortment and subsequent classic genetics. The discrimination of dominance and recessiveness originally is a requirement for Mendel’s logical reasoning, but now it should be explained by cellular and molecular principles in the modern genetics. To answer the question raised by students of how the dominance and recessiveness are controlled, we reviewed the recent articles and tried to summarize the cellular and molecular basis of dominant and recessive inheritance. Clearly, understanding the essences of dominant and recessive inheritance requires us to know the dissimilarity of the alleles and their products (RNA and/or proteins), and the way of their function in cells. The alleles spatio-temporally play different roles on offering cells, tissues or organs with discernible phenotypes, namely dominant or recessive. Here, we discuss the changes of allele dominance and recessiveness at the cellular and molecular levels based on the variation of gene structure, gene regulation, function and types of gene products, in order to make students understand gene mutation and function more comprehensively and concretely.

Key words: genetics, teaching, alleles, dominance, recessiveness