综合大实验能够训练学生灵活应用理论知识并掌握实验技能,成为当前实验课教学改革的重要方式。本文以人类的ABO血型性状为实验对象,设计了“人类ABO血型分子基因分型与群体遗传平衡分析”大实验。实验中提取同学唾液中黏膜细胞的DNA,经过PCR扩增目的片段、酶切及电泳分离一系列分子遗传技术分析,鉴定出每位同学的基因型;然后以全班同学为一个类似孟德尔群体调查ABO血型的各种基因型频数,用Popgene软件分析各种群体遗传参数。通过开放教学不仅让学生掌握了分子遗传实验技术和群体遗传分析技术及软件应用,还让学生自主设计方案优化分子技术环节,提高学生驾驭知识的能力。通过5年的教学探索与实践,建立了稳定的分子遗传实验体系,能够清楚地检测出ABO血型的6种基因型:IAIA、IAi、IBIB、Iai、IAIB、ii;综合了分子遗传与群体遗传的实验教学,统计全班同学6种基因型的频数,直接计算3个复等位基因的频率,进而应用软件分析群体遗传各种参数;实现了学生自主设计并完成实验的开放式实验教学;大实验教学获得了学生的好评,取得了很好的教学效果。该大实验可直接应用于生物类专业的遗传学实验教学,其中的教学理念和方法还可推广应用于其他生物学实验教学。
Abstract: Comprehensive laboratory courses, which enable students to aptly apply theoretic knowledge and master experiment skills, play an important role in the present educational reform of laboratory courses. We utilized human ABO blood type as the experimental subject, and designed the experiment Molecular Genotyping of Human ABO Blood Type and Analysis of Population Genetic Equilibrium. In the experiment, DNA in mucosal cells is ex- tracted from students' saliva, and each student's genotype is identified using a series of molecular genetics technolo- gies, including PCR amplification of target fragments, enzymatic digestion, and electrophoretic separation, Then, taking the whole class as an analogous Mendel population, a survey of genotype frequency of ABO blood type is conducted, followed with analyses of various population genetic parameters using Popgene. Through the open la- boratory course, students can not only master molecular genetic experimental skills, but also improve their under- standing of theoretic knowledge through independent design and optimization of molecular techniques. After five years of research and practice, a stable experimental system of molecular genetics has been established to identify six genotypes of ABO blood types, namely IAIA, IAi, IBIB, IBi, IAIB and ii. Laboratory courses of molecular and population genetics have been integrated by calculating the frequencies of the six genotypes and three multiple alleles and testing population genetic equilibrium. The goal of the open laboratory course with independent design and implementa- tion by the students has been achieved. This laboratory course has proved effective and received good reviews from the students. It could be applied as a genetics laboratory course for the biology majors directly, and its ideas and methods could be promoted and applied to other biological laboratory courses. Keywords: comprehensive experiment; ABO blood type; independent design; open laboratory course