Credit: N. Hanacek/NIST
A team of researchers led by the National Human Genome Research Institute (NHGRI) at the National Institute of Standards and Technology (NIST) have fully sequenced the Y chromosome for the first time. The findings will make it possible to detect the source of certain genetic disorders as well as provide a method to easily identify others.
Much like using a photo to piece together a puzzle, researchers often rely on specialized software to piece together fragments of sequenced DNA. “Chromosomes all contain sections of very repetitive DNA, but well over half of the Y chromosome is like that,” said Justin Zook, a co-author of the study and leader of NIST’s Genome in a Bottle (GIAB). “If you use the puzzle analogy, a lot of the Y chromosome looks like the backgrounds often do, where all the pieces look really similar.”
Previously, Genome in a Bottle had not produced a Y chromosome benchmark however their extensive collection of Y chromosome data did serve as a starting point for the researchers in their endeavor to sequence the chromosome.
In the study, published in Nature, the researchers utilized high fidelity and nanopore sequencing to enlarge the DNA fragments to make them easier to assemble. That, combined with machine learning analysis tools provided the team with a system to assemble the chromosome. After piecing together more than 62 million letters of genetic code, the team finally fully sequenced the GIAB Y chromosome from start to finish.
The findings will play a critical role in the future of health diagnostics, allowing researchers to uncover new genes and the function they play in the body. “There are certainly aspects of fertility and some genetic disorders that are connected to genes in the Y chromosome,” Zook said. “But because it’s been so hard to analyze up to this point, we may not even know yet just how important the Y chromosome is.”