Why it matters

The new study explains a longstanding puzzle in medicine: why do some people who’ve inherited a disease-causing mutation experience fewer symptoms than others with the same mutation? “In many diseases, we’ll see that 90% of people who carry a mutation are sick, but 10% who carry the mutation don’t get sick at all,” says Bogunovic, a scientist who studies children with rare immunological disorders at Columbia University Irving Medical Center.

Enlisting an international team of collaborators, the researchers looked at several families with different genetic disorders affecting their immune systems. In each case, the disease-causing copy was more likely to be active in sick patients and suppressed in healthy relatives who had inherited the same genes.

In a groundbreaking study, scientists have discovered a way to manipulate the very fabric of life by using light to reshape DNA strands. This innovative approach provides new insights into the material properties of chromosomes, unlocking potential advancements in understanding gene expression and developing treatments for genetic diseases.

Chromatin, the material that makes up chromosomes, is a complex structure where long strands of DNA are wrapped tightly around proteins. Despite its compact nature, chromatin must unfurl in certain regions to allow cells to access and replicate genetic information.

Some areas remain rigid and coiled, silencing genes, while others are flexible and accessible, facilitating gene expression. This duality has led scientists to question whether chromatin behaves like a solid, a liquid, or a hybrid of both.

Summary: New research reveals that certain cells inactivate one parent’s copy of a gene, leading to a bias in gene activity that may explain why some individuals with disease-causing mutations remain symptom-free. This selective gene inactivation, known as monoallelic expression, affects about 1 in 20 genes and varies between cell types.

The study shows that in families with genetic disorders, the active copy of a gene often determines disease severity. These findings challenge traditional genetic paradigms and suggest new approaches to diagnosing and treating inherited diseases.

In a shocking turn of events, a surgeon operating on a cancer patient managed to contract the deadly disease in what is believed to be an unprecedented case. The doctor was performing surgery on a 32-year-old German man suffering from a rare type of cancer when he accidentally “transplanted” the disease into himself.

This occurred when cells from the patient’s tumor seeped into a cut on the surgeon’s hand. Despite immediate disinfection and bandaging, the 53-year-old medic noticed a hard lump developing at the base of his middle finger five months later.

A hand specialist identified the lump as a malignant tumor genetically identical to cancer suffered by his former patient. Doctors treating him concluded that he had contracted cancer when his patient’s tumor cells seeped into the cut.

Image credit: GrumpyBeere – Pixabay

Researchers used a refined method of ancestry analysis utilizing ancient DNA. This study represents a significant advancement in our understanding of historical population movements.

Researchers can trace human migration through DNA changes, but it’s challenging when historical groups are genetically similar.

We termed enhancers that gained (and maintained) H3K4me1 in obesity and WL ‘new enhancers’. Most of these ‘new enhancers’ were also active (that is, marked by H3K27ac) during obesity and/or WL (Fig. 4D). We then annotated the enhancers to their closest gene and performed a GSEA. In agreement with the promoter GSEA above, we found that the ‘new active enhancers’ were related to inflammatory signalling, lysosome activity and extracellular matrix remodelling (Fig. 4e and Extended Data Fig. 9i), indicating a persistent shift of adipocytes towards a more inflammatory and less adipogenic identity. Corroborating these results, Roh et al. had analysed H3K27ac in adipocytes of obese mice and reported impaired identity maintenance during obesity²⁵.

To combine our findings regarding retained translational changes and epigenetic memory, we investigated whether epigenetic mechanisms, such as differentially marked promoters or enhancers, could explain the persistent translational obesity-associated changes after WL. Notably, 57–62% of downregulated and 68–75% of upregulated persistent translational DEGs after WL could be accounted for by one or more of the analysed epigenetic modalities (Fig. 4f). Overall, these results strongly suggest the presence of stable cellular, epigenetic and transcriptional memory in mouse adipocytes that persists after WL.