Scientists Map Genetic Organization in Tonsil Cells, Revealing New Insights into Immune Function

Yale School of Medicine researchers David G. Schatz and Siyuan Wang have mapped the 3D genetic organization of the human tonsil, creating the first image-based 3D genome atlas of any human organ. Published in Science, the study utilizes a novel imaging technique called MINA to trace chromosomes in intact tissue. The team demonstrated that 3D chromatin loops are essential for B-cell somatic hypermutation; degrading the loop-holding proteins completely halts this antibody-optimizing process, offering new insights into how off-target mutations may trigger B-cell lymphomas.

Human tonsil 3D genome atlas

• ▪Yale School of Medicine researchers David G. Schatz and Siyuan Wang mapped the three-dimensional genetic organization of the human tonsil, publishing their findings in Science on July 23, 2026.
• ▪The 3D genome atlas of the human tonsil represents the first single-cell 3D genome atlas of the human tonsil and the first image-based 3D genome atlas of any human organ.

MINA imaging technique

• ▪Unlike other 3D genome-mapping techniques that sequence individual cells out of context, the MINA technique traces chromosomes and their products within their local cellular neighborhoods.
• ▪The Multiplexed Imaging of Nucleome Architectures (MINA) technique, developed by Siyuan Wang's lab, uses specialized microscopes to image DNA, RNA, and proteins together in intact ultrathin slices of tonsil tissue.

Chromatin loop extrusion mechanisms

• ▪Yale School of Medicine researchers demonstrated that 3D genome organization and the molecular processes maintaining 3D chromatin loops play fundamental roles in B-cell somatic hypermutation.
• ▪When researchers rapidly degraded a protein holding the 3D chromatin loops together, somatic hypermutation in B cells completely stopped, though some looping interactions persisted and degraded more slowly.

B-cell somatic hypermutation

• ▪Somatic hypermutation is a process in which mutations are randomly introduced into antibody-encoding genes of B cells to potentially create a better match for a pathogen's antigen.
• ▪David G. Schatz identified 'hot' and 'cold' genomic regions for somatic hypermutation, finding that hot regions had more internal loops and cold regions had fewer.

B-cell lymphoma implications

• ▪When somatic hypermutation processes go awry and hit off-target genomic regions, they can introduce unnecessary, potentially cancer-causing mutations that are implicated in certain B-cell lymphomas.
• ▪Yale School of Medicine researchers are investigating which specific molecular factors are disrupted when somatic hypermutation goes haywire in B-cell lymphomas.

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