John F. Marko

Mitotic chromosomes are mechanically connected by chromatin-based interchromosome linkers

The paper demonstrates that mitotic chromosomes are mechanically connected by DNA-based interchromosome linkers, identified through micropipette manipulation and enzymatic treatments.

Obstacle bypassing and intrinsically asymmetric loop extrusion in the segment-capture model of Structural Maintenance of Chromosomes complexes

This study shows the segment-capture model of SMC complexes can explain obstacle bypassing and loop extrusion, and proposes experiments to test the model.

Compaction and swelling of single stretched DNAs driven by molecular crowding

The paper develops a theory to predict how molecular crowding affects the extension of stretched DNA under tension, showing both compression and expansion effects depending on crowder density and size.

GapR is a nucleoid-associated protein that stiffens and overtwists DNA to promote transcription and replication

This study investigates GapR's role in DNA mechanics and transcription regulation using biophysical and computational methods, revealing its dual effects on DNA structure and transcription.

Molecular Crowding Suppresses Mechanical Stress-Driven DNA Strand Separation

This study investigates how molecular crowding and dehydrating co-solutes affect DNA supercoiling and base-pair stability using single molecule magnetic tweezers.

Independence of centromeric and pericentromeric chromatin stability on CCAN components

This study shows that centromeric chromatin is mechanically resilient and distinct from pericentromeric chromatin, which deforms under force, with CCAN components not affecting pericentromere stretching.

Isolation and manipulation of meiotic spindles from mouse oocytes reveals migration regulated by pulling force during asymmetric division

This study isolates meiotic spindles from mouse oocytes to investigate migration forces during asymmetric division, finding a net tensile force of ~680 pN.

Cell-cycle and Age-Related Modulations in Mouse Chromosome Stiffness

This study measures chromosome stiffness in mouse oocytes across cell cycle stages and age, finding increased stiffness in metaphase I oocytes and age-related stiffness changes.

High-resolution, genome-wide mapping of positive supercoiling in chromosomes

The paper introduces GapR-seq, a method to map positive supercoiling in genomes, and finds it widespread, associated with transcription and specific genomic features in E. coli and yeast.

Compartment-dependent chromatin interaction dynamics revealed by liquid chromatin Hi-C

This study introduces liquid chromatin Hi-C to analyze chromatin interaction dynamics and finds that compartmentalization stability varies with chromatin domain type and fragment size.

Condensin controls mitotic chromosome stiffness and stability without forming a structurally contiguous scaffold

This study shows condensin controls mitotic chromosome stiffness and stability by forming isolated compaction centers rather than a continuous scaffold.

Supercoiling DNA locates mismatches

This study demonstrates a method using magnetic tweezers to detect single base pair mismatches in DNA by observing plectoneme pinning under specific conditions.