Editors: Naiyiri Kaissarian, Patricia Garay, and Shweta Ramdas
If you saw a hippo on campus, you would remember it. But, would you expect that seeing such a pachyderm roaming on a university would alter the expression of your DNA? A recent study found that rats placed in an environment that tested their memory had alterations to their DNA, or epigenetic changes.
For a long while, we have generally known that neurons within the hippocampus of our brains are responsible for memory. The current model for memory storage is due to the plasticity of neuronal connections, but researchers have recently found that it also involves active changes at the genetic level. These changes come from external factors and are linked to retaining long-term memories, which has implications in stress-related learning and memory disorders.
We have known tobacco to be a cause of many cancers for decades now. It is associated with it least 14 types of cancers (see Figure 1). Less understood is how tobacco causes cancer. The short answer—it causes mutations. Tobacco smoke is a mixture of many chemicals, including at least 60 carcinogens (cancer-causing chemicals).
A trans-national team of researchers has begun unearthing the distinct types of mutations caused by tobacco smoke to better understand the biological pathways leading to tobacco-induced cancer. They found that tobacco causes specific types of DNA damage in organs directly exposed to smoke (like the lungs) and that smoking tobacco generally leads to higher rates of mutation in all tissues. Understanding how the chemicals in tobacco smoke cause mutations can help scientists identify new and emerging mutagens and design better treatment strategies.
Imagine the year is 1856 and you are toiling in a quarry in the Neander Valley, a few kilometers from Düsseldorf, Germany. Strangely, something is abruptly sticking out of the landscape. You dig around and find ribs, a skull, and other bones—your best guess is that you have stumbled upon the final resting place of a bear. However, what you have actually found are the first identifiable remains of ancient hominins, later named Homo neanderthalensis.