Recount slashes number of human genes
Humans have just 20,000 to 25,000 genes - well down on previous estimates of 27,000 to 40,000, says the latest analysis of the gene-containing portion of the human genome. And a separate study has found detailed flaws in "shotgun" sequencing, the more rapid of the two methods used to sequence genomes. The latest gene count reveals that researchers overestimated the number of genes lurking in heavily-duplicated regions of the human genome, which are extremely tricky to sequence because they are repeated DNA sequences… By analysing these "difficult" duplicated regions, Waterston and his colleagues in the International Human Genome Sequencing Consortium discovered that 1183 of the genes had recently been acquired through duplication and the evolution of pre-existing genes. "These segments are rapidly evolving and appear to be particularly prominent in primate and great ape genomes," says Waterston. "We can at last begin to learn about these and find out how they’ve contributed to evolution and disease."