A doubling of the human genome?

A new analysis of the well-studied chromosome 22 suggests that there may be far more than the estimated 30,000 genes in the human genome. “Our study reveals twice as many transcribed bases than have been reported previously,” said first author John L. Rinn, a fourth-year graduate student, “potentially indicating there are twice as many genes in the human genome.”

Rinn and colleagues in molecular, cellular and developmental biology used advanced microarray technology to map the 34 million bases of gene-dense chromosome 22. Earlier this year in the journal Genes & Development, the team reported finding previously undiscovered sequences which were also found in the mouse genome. “This study was a proof of the principle that we can find, en masse, all the regions of a chromosome that are biologically relevant,” Rinn said. “In the future we will scale this process to tackle the entire human genome.”