Many animals gravitate towards heat, most often to regulate their own body temperatures. In rare cases, certain species—ticks, bedbugs, and some species of mosquitoes—seek out heat for food. For female mosquitoes, finding heat is essential for survival, as they need to feast on warm-blooded prey...

There are about 20,000 genes in the human genome, but not all are used in all cells at all times. At any given moment, a cell is converting only roughly half its genes into proteins. And of those active genes, about 75 percent are regulated by a process known as “RNA polymerase pausing.” This...

Some infectious diseases are particularly difficult to treat because of their ability to evade the immune system. One such illness, African sleeping sickness, is caused by the parasite Trypanosoma brucei, transmitted by the tsetse fly, and is fatal if left untreated. The trypanosome parasite is t...

For many living things, a roughly 24-hour internal clock governs the rhythms of life—everything from sleep in animals, to leaf opening in plants and reproduction in bread mold. Scientists have come to understand much about this internal time-keeping system, but one important aspect, its complex r...

Part of the reason people find smoking difficult to quit is that each time they have a cigarette, feelings of craving, irritability and anxiety melt away. This component of addiction is known as negative reward and is controlled in part by a region of the brain called the habenula. The neurotrans...

During embryonic development, billions of neurons nimbly reposition themselves within the brain and spinal cord, and connect branches to form the neural circuits that ultimately control our movements, perception, and memory. Scientists have long sought to understand the driving forces in this met...

For years, scientists have struggled to find a way to block a protein known to play an important role in many cancers. The protein, STAT3, acts as a transcription factor—it performs the crucial task of helping convert DNA into the RNA instructions used to make new proteins. But when overly acti...

Sometimes, the molecules that make up life exhibit strange behavior. For instance, in simple organisms such as yeast, when genetic material becomes damaged, the affected DNA strands increase their motion, waving about inside the cell like a sail unfurled. Over the years, scientists have seen more...

DNA replication is essential to all life, yet many basic mechanisms in that process remain unknown to scientists. The structure of the replisome—a block of proteins responsible for unwinding the DNA helix and then creating duplicate helices for cell division—is one such mystery. Now, for the ...

The sight of a face offers the brain something special. More than a set of features, it conveys the emotions, intent, and identity of the whole individual. The same is not true for the body; cues such as posture convey some social information, but the image of a body does not substitute for a fac...