Two papers confirm the sequencing of dozens of Y chromosomes from men, a once-considered “impossible” task, marking the final step of fully sequencing the human genome – a much-anticipated goal now complete!
“[This] represents an impressive finale, thus marking the beginning of a whole new era in human genetics,” says Toomas Kivisild, a geneticist at KU Leuven, Belgium.
The first study identified dozens of new genes: the complex arrangement of 62 million bases from the Y chromosome was analyzed and detailed, adding 30 million that were missing from previous sequencing attempts. The second study not only sequenced 43 Y chromosomes from men around the world through the 1000 Genomes Project, but established that the number of genes varies widely from man to man. “I was surprised to see the extent of copy number variation for certain genes on the Y chromosome,” explains Charles Lee, a geneticist and director of the Jackson Laboratory for Genomic Medicine, in the United States. According to this study, the massive repetitive region of this chromosome varies in size and makeup. With between 17.6 and 37.2 million bases, this heterochromatic block is the largest in the human genome.