chapter  4
16 Pages

Gene expression maps

The cartography of transcription
WithScott F. Gilbert

So what has mapping to do with genetics? In population genetics, gene mapping refers to allele frequency distribution over space. Thus, Cavelli-Sforza and colleagues call their book History and Geography of Human Genes. Lisa Gannett and Jim Griesemer discuss this tradition in volume 1 (Chapter 4) of this publication. To a developmental geneticist, mapping refers to representations of gene expression over the space of an embryo or part of an embryo. Thus, developmental genetics has a major program in mapping gene expression. Third, in medical and transmission genetics, maps are used to indicate the relative positions of genes on a chromosome. “Genomic geography” is the keyword for chromosome linkage “maps” at a US Department of Energy website called “Know Ourselves.” This site also talks about “Exploring the Genomic Landscape,” and it informs us that “one of the central goals of the Human Genome Project is to produce a detailed ‘map’ of the human genome. But, just as there are topographic maps and political maps and highway maps of the United States, so there are different kinds of genome maps, the variety of which is suggested in Genomic geography.” It is interesting that this site problematizes the map metaphor with its quotation marks.1