Flu season is upon us, but there are actually “seasons” for many other infectious diseases. Chickenpox outbreaks peak each spring and polio transmission historically occurred in the summer. In fact, at least 69 infectious diseases vary seasonally. Micaela Elvira Martinez, assistant professor in the Department of Environmental Health Sciences at Columbia University, found this out…
The double-edged sword called oxygen
By Ananya Sen If you were to enter a time machine and go back to about 3.8 billion years ago, what would you find? Volcanoes spewing carbon dioxide, hydrogen, and methane into the atmosphere, some water, and no oxygen, which means that you would be dead in about six minutes. So how did humans, who…
Are we more bacteria than human? That depends when you last pooped
For decades, the notion that bacteria living on our bodies outnumbered human cells 10 to 1 was popular among microbiologists and the public. Turns out, this estimation is wrong. In 2016, Ron Sender, Shai Fuchs, and Ron Milo from the Weizmann Institute examined the origins of this estimation and found that the ratio is actually…
Meet Carsonella ruddii, a Microbe so Small That Might Not Even Be a Microbe
In 2006, Carsonella ruddii was reported as the smallest of the small: this microbe contains the smallest genome identified at the time, clocking in at 159,662 base pairs encoding 182 genes. The Escherichia coli genome on the other hand contains over 4 million base pairs encoding about 4,000 genes. Unlike E. coli, Carsonella ruddii is…
Protein Translation Can Initiate From 17 Start Codons
In the realm of biology, we are always finding exceptions to the rule. And now, we have just added another exception to the central dogma of genetics. But first, let’s review what the central dogma is. The central dogma states that that the flow of genetic information goes from DNA to mRNA to protein. In…