The human Y chromosome has finally been fully sequenced, 20 years after the 1st draft

The Y chromosome, associated with the development of male sex characteristics, has been notoriously hard to sequence, as it contains lots of repeated DNA segments. (Image credit: Shutterstock)

Scientists have finally filled the gaps in the sequence of the human Y chromosome, 20 years after the first draft of its DNA code was published. 

The work reveals a complete catalog of the genes in the male sex chromosome — the last human chromosome to be fully sequenced — and how they're organized.