Another satellite DNA sequence that Gomes de Lima helped discover is a brand-new repeat comprised of one large component and one small component. He named the element Ajax and Teucer after Greek mythological half-brothers, one large and one small, who fought together in the Trojan War. The two components have evolved in tandem as if one big repeat. The Ajax and Teucer element is found on several chromosomes, including acrocentric chromosomes. Its origins and function are unknown.

One type of satellite DNA for which the function is well known is present in centromeric regions. Centromeric satellite DNA in humans is called alpha satellite DNA. These sequences are critical for centromere function. Every centromere has an alpha satellite DNA sequence, and each centromere has a unique but similar DNA sequence for each array.

“Centromeric arrays were the most substantial gaps in the original human genome project. Given their importance in transmission of chromosomes, one of the most meaningful accomplishments of the T2T consortium was the linear assembly of these arrays for each chromosome, led by the Phillippy and Miga Labs,” said Gerton.

Gomes de Lima contributed to experimental confirmation of the centromeric and ribosomal DNA array sizes by a method called digital droplet PCR. Details of the methodology are described in an independent report in Cell Genomics. In the study, Gomes de Lima and colleagues demonstrated that each person contains a unique combination of centromeres, like a fingerprint. He went on to demonstrate that centromeric satellite DNA is unstable in cancer, an exciting insight for researchers who study cancer genomics.

• Completing the sequence - Introduction
• Part 1: Seeing is believing
• Part 2: Insights from evolutionary biology
• Part 3: A ‘big data, AI, and genomics’ approach to identifying variation