Tracing the start of COVID-19 in GA

At a time when COVID-19 appears to be receding in much of Georgia, it’s worth revisiting the start of the pandemic in early 2020. Emory virologist Anne Piantadosi and colleagues have a paper in Viral Evolution on the earliest SARS-CoV-2 genetic sequences detected in Georgia. Analyzing relationships between those virus sequences and samples from other states and countries can give us an idea about where the first COVID-19 infections in Georgia came from. We can draw Read more

Reddit as window into opioid withdrawal strategies

Drug abuse researchers are using the social media site Reddit as a window into the experiences of people living with opioid addiction. Abeed Sarker in Emory's Department of Biomedical Informatics has a paper in Clinical Toxicology focusing on the phenomenon of “precipitated withdrawal,” in collaboration with emergency medicine specialists from Penn, Rutgers and Mt Sinai. Precipitated withdrawal is a more intense form of withdrawal that can occur when someone who was using opioids starts medication-assisted treatment Read more

CROI: HIV cure report and ongoing research

The big news out of CROI (Conference on Retroviruses and Opportunistic Infections) was a report of a third person being cured of HIV infection, this time using umbilical cord blood for a hematopoetic stem cell transplant. Emory’s Carlos del Rio gave a nice overview of the achievement for NPR this morning. As del Rio explains, the field of HIV cure research took off over the last decade after Timothy Brown, known as “the Berlin patient,” Read more

N6-methyladenine

Mysterious DNA modification important in fly brain

Emory scientists have identified a function for a mysterious DNA modification in fruit flies’ brain development, which may provide hints to its role in humans.

The results were published Thursday, August 2 in Molecular Cell.

Epigenetics may mean “above the genes,” but a lot of the focus in the field is on DNA methylation, a chemical modification of DNA itself. Methylation doesn’t change the actual DNA letters (A, C, G and T), but it does change how DNA is handled by the cell. Generally, it shuts genes off and is essential for cell differentiation.

The most commonly studied form of DNA methylation appears on the DNA letter C (cytosine). Drosophila, despite being a useful genetic model of development, have very little of this form of DNA methylation. What they do have is methylation on A — technically, N6-methyladenine, although little was known about what this modification did for flies.

Editor’s note: See this 2017 Nature feature from Cassandra Willyard on an “epigenetics gold rush”, which mentions the discovery of N6-methyladenine’s presence in the genomes of several organisms.

Emory geneticists Bing Yao, PhD, Peng Jin, PhD and colleagues now have shown that an enzyme that removes methylation from A is critical for neuronal development in Drosophila.

This finding is significant because the enzyme is in the same family (TET for ten-eleven translocation) of demethylases that trigger removal of DNA methylation from C in mammals. The function of TET enzymes, revealing that cells actively removed DNA methylation rather than just letting it slough off, was discovered only in 2009. Read more

Posted on by Quinn Eastman in Neuro Leave a comment