Coming into the Genome Age Part I: The Challenge to Science Education
DNA Learning Center (DNALC), Cold Spring Harbor Laboratory
Updated March 2017
- Coming into the Genome Age Part II: Exploring Human Variation and Evolution
- Coming into the Genome Age Part III: The Molecular Genetic Basis of PTC Tasting
- Coming into the Genome Age Part IV: Detecting Transgenes in Genetically Modified Food
In his book Coming into the Country, John McPhee describes his experiences in that last great American frontier, the Alaskan wilderness of 1976. That time, just before the opening of Alaska's oil fields and pipelines, is an appropriate metaphor for genetic biology. Like Alaska was then, the genome landscapes of living organisms present vistas of almost limitless promise and offer challenges for people eager for knowledge, fortune, adventure, or contemplation.
The genome frontier also challenges educators. DNA sequences from thousands of organisms are available to anyone with an Internet connection-as are bioinformatics tools that allow one to explore sequence data, predict the presence of genes, and compare features shared between different organisms. At the same time, polymerase chain reaction (PCR) makes it possible for students to examine defined bits of the genomes of higher plants and animals—including their own. Thus, for the first time in the history of biology,
A new world for students to explore
Biology researchers and educators need to seize this opportunity to involve students in the trove of new DNA data that will change forever how we think about life. First, we need to enable students to look at their own DNA and use it as an entrée to the genomic world. Second, we must integrate bioinformatics with biochemistry labs, so that students become adept at moving between the in vitro and in silico worlds. Third, we need to develop more intuitive, visually pleasing computer tools that engage students and allow them to quickly learn the basics of gene analysis. Fourth, we need to welcome students as partners in the effort to annotate the vast majority of genes known only as computer-predicted models.
With support from the National Science Foundation and Howard Hughes Medical Institute, my group at the DNA Learning Center has worked with genome researchers to develop experiments and Internet-based tools that respond to the challenges of the genome age. In this and future articles, I will introduce a number of these resources, many of which come with easy-to-use kits that we have developed with our partners at Carolina Biological Supply Company. I hope that this will encourage biology educators to help their students come into the new country of genomes, a country that is free for all to explore.
First, let's consider a PCR experiment that puts students squarely in the middle of contemporary research to understand human variation and evolution. The experiment examines an insertion of an Alu "jumping gene"; on chromosome 16 that creates a simple genetic system with 2 alleles and 3 genotypes. This experiment illustrates that molecular genotypes are composed of DNA alleles that are physically different-in this case, length polymorphisms that are readily distinguished on a simple agarose gel. (Try Carolina's Using an Alu Insertion Polymorphism to Study Human Populations Kits.)
Students grasp the key concept of identity by descent by realizing that if this insertion occurred only once in human history, then all classmates who have an insertion allele must have inherited it from a common ancestor. Tallying class allele and genotype frequencies provides a ministudy in population genetics. Students then use an online facility, Allele Server (www.bioservers.org), to test Hardy-Weinberg equilibrium and compare their class data to world populations. Students' explanations of the pronounced east-west cline in frequency of the Alu insertion allele support one of 2 opposing models of human evolution-showing that data interpretation has theoretical consequences.
On another level, this experiment can provoke students to think about the structure and meaning of the human genome. The Alu transposon exists in a sort of molecular symbiosis with another transposon called L1; Alu depends entirely on L1 to provide the apparatus for jumping. Together, these transposons compose more than ¼ of the human genome! Why is this so? The jury is still out on whether these transposons are merely examples of selfish DNA, exquisitely adapted to reproduce by jumping, or whether they serve some larger purpose in the evolution of the human genome.