Mammalian centromere organization and function are particularly difficult to study and assemble
due to the presence of large arrays of near-identical repeats known as satellite DNA. The advent of
long-read sequencing technologies has now made it possible for the first time to reliably assemble i)
entire genomes at high-quality resolution and ii) highly complex repetitive DNA regions. Several
medical genetic reports have described the acquisition of centromeric functions in chromosomal
fragments devoid of satellite DNA, thus recovered as supernumerary chromosomes with an
activated neocentromere. These de novo centromeres are associated with negative phenotypic
consequences. Recently, a few karyotypically normal individuals with a free-satellite centromere
“shifted” to a new location have been found. Lately, we discovered that the same phenomenon
occurred during evolution identifying the evolutionary new centromeres (ENCs). In spite of these
exciting advancements, the mechanisms underlying ENC formation and evolution are still unclear.
We propose to fill this scientific gap using a combination of long-read sequencing technologies,
sequence assembly algorithms and cell biological approaches. The Research Units involved in this
proposal are highly qualified to join their complementary expertise and resources to fully cover all
the aims of this project. Thanks to the availability of unique, precious biological materials and
cutting-edge technologies, we will obtain insights into the organization, evolution, and function of
novel and canonical centromeres and their impact on human disease and evolution.