Operons are a phenomenal way to regulate the expression of several genes at once. They are widely used in the prokaryotic world but scantly among the eukaryotes (and then with variations on their usage). Why haven't eukaryotes made greater use of this ingenious device?
by Heidi Arjes — Have you ever wondered how individual fingers form? If you have taken a developmental biology class, you know that the hand first develops as a mitten-like structure with the future fingers connected (Figure 1). Later, during normal development, the cells in the areas between the fingers undergo programmed cell death, and thus…
by Merry Youle — No matter where a bacterium lives, its DNA is sometimes damaged by UV radiation, reactive oxygen species (ROSs), toxins, or other nasty things. Faced with such assaults, as well as problems inherent in DNA replication, bacteria evolved sophisticated mechanisms to detect and repair DNA damage. One widely conserved system, the SOS response, was first...
by James Gregory — Malaria is a big killer and a major worldwide health concern. The number of malaria-related deaths has fallen to approximately 650,000 in 2010, from well over 1 million just ten years ago, thanks to the World Health Organization (WHO) and to philanthropic organizations, including the Bill and Melinda Gates Foundation. This effort, composed…
by Elio — Interesting, how we get carried away by exciting concepts. I am thinking about how the study of pathogens has focused so much on the microbes' virulence factors, by which we mean nasty substances such as toxins, adhesins, and invasins that participate directly in the disease process. Their study has dominated microbial…
by Roberto — More than fifty years ago, towards the end of Spring term in May 1971, university campuses across the U.S. were rife with protests over the Vietnam war. Students skipped classes and left labs to participate in marches and sit-ins. In addition, the memory of Woodstock (August 1969) was still fresh in everyone's mind.
by Gemma Reguera — Our appreciation of the colors of nature is limited by the narrow wavelengths of the electromagnetic spectrum that our eyes can detect. This portion of the electromagnetic spectrum between 390 and 750 nm is what we refer to as the visible (vis) light or, simply, light. We cannot see below…
