Dark zones in your genome
There are dark zones in your genome, but nothing shadowy is going on. They’re “dark” because regions — long stretches of ATCG code — haven’t been entirely or correctly mapped.
Scientists assumed the regions didn’t have important functions, such as genes coding for a protein. Some thought the DNA in the dark zones was junk, and that was just plain wrong and silly — for most suspected the zones were hiding critical information.
It’s a technology problem. Current sequencing machines called NexGen use short-read technology. It’s a fast and cheap method that sequences (reads) short stretches of DNA molecules.
NexGen is adequate for most applications, but reassembling short pieces of a sequence is tricky. The order of the ATs and CGs can get mixed up. More importantly, the machines can’t identify long, repetitive sequences and large duplications in the non-coding zones.
Newer, long-read technology can light up complex areas of the genome. Biotech companies such as PacBio and Oxford Nanopore specialize in long-read tech. They sequence whole, individual molecules rather than breaking them into bits for reassembly.
Now scientists can see into the dark zones. No longer considered junk, the non-coding regions are the frontiers of genomic discovery. Researchers are using long-read technology to: