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Proto-point centromeres in Saccharomycodales yeasts reveal diversity in genetic centromere organization. Credit: Nature (2026). DOI: 10.1038/s41586-025-10092-0
Centromeres play virtually the same central role across the entire tree of life: They ensure the faithful segregation of chromosomes during cell division. Yet the striking diversity in centromere architecture—from large, repeat-rich DNA arrays to the minimalistic "point" centromeres in yeast—combined with their rapid evolution has puzzled scientists for decades.
Tracing the origin of yeast centromeres
A research team led by Andrea Musacchio, Director at the Max Planck Institute of Molecular Physiology in Dortmund, and Jef Boeke from the NYU Grossmann School of Medicine have now solved the enduring mystery about the yeast centromere's origin and evolution.
They have identified a "proto-point" centromere that bridges the gap between the actual tiny "point" centromere and its more elaborate ancestor that incorporated fragments of parasitic DNA. This discovery reveals one of the most dramatic evolutionary transitions at DNA level. The findings are published in the journal Nature.
Centromeres are regions of DNA where the cell's machinery grabs each chromosome and pulls it into the two daughter cells. Centromeres are essential for accurate chromosome segregation in every dividing cell, from yeast to humans. Although the machinery that governs chromosome segregation is deeply conserved, centromeric DNA evolves rapidly—a phenomenon known as the "centromere paradox."
A quirky evolutionary path in yeast
A particular striking example of this rapid evolution is the "point" centromere in yeast. In their new study, the teams from the MPI and NYU provide the first mechanistic route explaining the transition of the yeast centromere and identified its genetic origin.
"Our paper explains how a very important chromosome feature—the centromere—in brewer's yeast came to be. In ye
ast they are extremely small and precise—a striking oddity in the tree of life that has puzzled chromosome biologists for decades," explains Max Haase, the study's first author.
"In this work, we show a likely intermediate stage in their evolution and trace where the DNA for these special centromeres originally came from."
From jumping genes to core DNA
The researchers previously found unknown centromeres in related yeast species that look like halfway stages between large, repeat-rich centromeres and the tiny ones in brewer's yeast. The DNA at these centromeres is related to a class of "jumping genes" (mobile pieces of DNA) called retrotransposons, suggesting that these elements provided the raw material that evolution reshaped into modern yeast centromeres. This gives a concrete genetic explanation for how yeast ended up with this unusual centromere type.
Yeast centromeres were the first centromeres whose functional DNA sequence was isolated and worked out in detail, beginning with work by Clarke and Carbon in the early 1980s, yet it has remained a mystery how such tiny, precisely defined centromeres could have evolved.
"By showing how one kind of centromere can be rebuilt from another, our work addresses this long-standing question and shows how bits of 'selfish' or parasitic DNA can be tamed and turned into DNA that cells now rely on to organize their chromosomes," says Haase. "This provides a concrete example of how a core part of the chromosome can be completely restructured over evolution by repurposing DNA that once looked like genomic 'junk.'"
Next questions for chromosome biology
Next, the researchers want to understand how the kinetochore—the protein machinery that recognizes centromeres—can accommodate such dramatic changes in centromere DNA over evolutionary time. As part of this, they are tackling the open question of how centromeres assemble the kinetochore. They are also looking for additional cases where transposons have been re-used to build chromosome structures like centromeres, to see how common this kind of genome innovation is.
Publication details Max A. B. Haase et al, Ancient co-option of LTR retrotransposons as yeast centromeres, Nature (2026). DOI: 10.1038/s41586-025-10092-0 Journal information: Nature
— Source: Phys.org (https://phys.org/news/2026-02-uncovering-evolution-center-cell-division.html)
