“The Y chromosome is the smallest of the 46 pairs of human chromosomes, and it is the most difficult to sequence because it is highly repetitive. I have been working on the Y chromosome for more than 20 years, and recently, we were able to read the complete chromosome thanks to long-read sequencing technology using biophysical instruments that can sequence longer DNA pieces that we can read in their order. The advances in computational biology that can assemble those pieces into one long strand are also important.

“These advances are really helping us study the structure of the human Y chromosome. We have found that the Y chromosome has fewer genes than other chromosomes, but those are very important for spermatogenesis and male fertility. Infertility can be caused by many factors, but the genetic factors associated with male infertility are mostly located in the Y chromosome, so improved sequencing means that we could look for mutations and as such potentially better diagnose infertility. The Y chromosome is also important for some determinant predispositions to certain cancers.

“Now, we also have Y chromosome sequences for several great ape species. The species we studied are endangered; the sequences will help us trace genetic markers to study, for example, how male apes move in the wild. With new research, we can facilitate conservation genetics efforts, using high-quality sequencing to help breeding programs in zoos.”