The last and hardest human chromosome was finally sequenced end to end. In 2023 researchers completed the Y chromosome, long resistant to assembly because of repetitive DNA. It closed a gap in the human reference.
The final chromosome
The Y was hardest. Its highly repetitive structure defied assembly for decades. New methods prevailed.
Long-read sequencing
Technology enabled it. Reading long stretches resolved the repeats. Assembly became possible.
Hidden genes
Surprises emerged. Previously unmapped genes came to light. Biology was revealed.
Fertility and disease
Relevance is clear. The Y bears genes tied to fertility. Medicine benefits.
Reference complete
A milestone reached. The human reference is now truly complete. A long effort ended.
Diversity next
Work continues. Many individuals’ Y chromosomes will follow. Variation will be mapped.
The bottom line
Researchers completed the human Y chromosome end to end in 2023, resolving its repetitive DNA with long reads. It revealed hidden genes and finished the reference. Broader diversity mapping follows.
