We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Chromosome structure in Drosophila is determined by boundary pairing not loop extrusion.
- Authors
Bing, Xinyang; Ke, Wenfan; Fujioka, Miki; Kurbidaeva, Amina; Levitt, Sarah; Levine, Mike; Schedl, Paul; Jaynes, James B
- Abstract
Two different models have been proposed to explain how the endpoints of chromatin looped domains ('TADs') in eukaryotic chromosomes are determined. In the first, a cohesin complex extrudes a loop until it encounters a boundary element roadblock, generating a stem-loop. In this model, boundaries are functionally autonomous: they have an intrinsic ability to halt the movement of incoming cohesin complexes that is independent of the properties of neighboring boundaries. In the second, loops are generated by boundary:boundary pairing. In this model, boundaries are functionally non-autonomous, and their ability to form a loop depends upon how well they match with their neighbors. Moreover, unlike the loop-extrusion model, pairing interactions can generate both stem-loops and circle-loops. We have used a combination of MicroC to analyze how TADs are organized, and experimental manipulations of the even skipped TAD boundary, homie, to test the predictions of the 'loop-extrusion' and the 'boundary-pairing' models. Our findings are incompatible with the loop-extrusion model, and instead suggest that the endpoints of TADs in flies are determined by a mechanism in which boundary elements physically pair with their partners, either head-to-head or head-to-tail, with varying degrees of specificity. Although our experiments do not address how partners find each other, the mechanism is unlikely to require loop extrusion.
- Subjects
CHROMOSOME structure; DROSOPHILA; COHESINS; CHROMOSOMES
- Publication
eLife, 2024, p1
- ISSN
2050-084X
- Publication type
Academic Journal
- DOI
10.7554/eLife.94070