Seeing Telomerase’s ‘Whiskers’ and ‘Toes’

Telomerase and its components.

The image here is the “front view” of telomerase, with the enzyme’s components shown in greater detail than ever before. Credit: UCLA Department of Chemistry and Biochemistry.

Like the features of a cat in a dark alley, those of an important enzyme called telomerase have been elusive. Using a combination of imaging techniques, a research team led by Juli Feigon Exit icon of the University of California, Los Angeles, has now captured the clearest view ever of the enzyme.

Telomerase maintains the DNA at the ends of our chromosomes, known as telomeres, which act like the plastic tips on the ends of shoelaces. In the absence of telomerase activity, telomeres get shorter each time our cells divide. Eventually, the telomeres become so short that the cells stop dividing or die. On the other hand, cells with abnormally high levels of telomerase activity can constantly rebuild their protective chromosomal caps. Telomerase is particularly active within cancer cells. Continue reading

Cool Image: Tracing Proteins in Action

Bright amorphous loops

These bright, amorphous loops represent a never-before-seen glimpse at how proteins that play a key role in cell duplication are themselves duplicated. Credit: Sue Jaspersen, Zulin Yu and Jay Unruh, Stowers Institute for Medical Research.

Looking like necklaces stacked on a dresser, these bright, amorphous loops show the outlines of yeast proteins that make up the spindle pole, a cellular component found in organisms as diverse as yeast and humans. Each cell starts with a single spindle pole, which must somehow duplicate to form the pair that works together to pull matching chromosomes apart during cell division. Scientists don’t completely understand how this duplication occurs, but they do know that errors in spindle pole copying can lead to a number of health conditions, including cancer. Continue reading

Sharing ‘Behind the Scene’ Stories About Scientific Discoveries

If a picture is worth a thousand words, what’s a video worth? For cell biologist Ron Vale, it’s priceless.

Screen shot from the video
In this iBiology Exit icon “discovery talk,” Ron Vale describes the twists and turns that led him to unexpected findings, including a motor protein involved in important cellular processes.

In 2006, Vale started a video-based science outreach project called iBiology Exit icon to give people around the world broader access to research seminars. The free online videos, which cover a range of biomedical fields and career-related topics, take viewers behind the scenes of scientific findings and convey the excitement of the discovery process.

While geared mostly for undergraduate students, graduate students and postdoctoral researchers, the videos are also a rich resource for anyone who wants a better understanding of many biomedical areas, including those we cover on this blog. Continue reading

Interview With a Worm: We’re Not So Different

Planarian
Credit: Alejandro Sánchez Alvarado, Stowers Institute for Medical Research.
Schmidtea mediterranea
Home: Freshwater habitats along the Mediterranean
Party trick: Regenerating its head
Most charismatic feature: Eyespots
Work site: Science labs worldwide

The planarian has a power few creatures can match. Remove its head, its tail or nearly any of its body parts, and this aquatic flatworm will simply grow it back. Humans can’t do that, of course. And yet many of the genes that help the planarian regenerate are also found in us. To learn more about this tiny marvel, we “interviewed” a representative. Continue reading

El Niño Season Temperatures Linked to Dengue Epidemics

Screen shot from the video showing dengue incidence in Southeast Asia.
Incidence of dengue fever across Southeast Asia, 1993-2010. Note increasing incidence (red) starting about June 1997, which corresponds to a period of higher temperatures driven by a strong El Niño season. At the end of the El Niño event, in January 1999, dengue incidence is much lower (green). Credit: Wilbert van Panhuis, University of Pittsburgh.

Weather forecasters are already warning about an intense El Niño season that’s expected to alter precipitation levels and temperatures worldwide. El Niño seasons, characterized by warmer Pacific Ocean water along the equator, may impact the spread of some infectious diseases transmitted by mosquitoes.

In a study published last month in the Proceedings of the National Academy of Sciences, researchers reported a link between intense dengue fever epidemics in Southeast Asia and the high temperatures that a previous El Niño weather event brought to that region.

Dengue fever, a viral infection transmitted by the Aedes mosquito, can cause life-threatening high fever, severe joint pain and bleeding. Infection rates soar every two to five years. Interested in understanding why, an international team of researchers collected and analyzed incidence reports including 3.5 million dengue fever cases across eight Southeast Asian countries spanning an 18-year period. The study is part of Project Tycho, an effort to study disease transmission dynamics by mining historical data and making that data freely available to others. Continue reading