Tag Archives: muscle

Protein interplay in muscle tied to life span

Brown University biologists have uncovered a complicated chain of molecular events that leads from insulin to protein degradation in muscles and significantly diminished life span in fruit flies. The new study in PLoS Genetics, which may have broad implications across species, identifies the fly version of the mammalian protein activin as the central culprit in the process.

PROVIDENCE, R.I. [Brown University] — Fruit flies are notoriously short-lived but scientists interested in the biology of aging in all animals have begun to understand why some fruit flies live longer than others. They have documented a direct association between insulin and life span, for example, and have observed a tradeoff between prolific reproduction and longevity. A new study, which may have broad implications across species, ties those findings more closely together by tracing an insulin signaling cascade through to protein quality control in muscle tissue and shortened life span. (more…)

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Celebrated jumping frogs: For top hops, scientists look to Calaveras pros

The Calaveras County Jumping Frog Jubilee has entered the scientific record via a new paper in the Journal of Experimental Biology. Experienced bullfrog ‘jockeys’ at the event routinely get their frogs to jump much farther than researchers had ever measured in the lab. How? Decades of refined technique, uncommonly motivated humans and herps, and good old-fashioned large sample size.

PROVIDENCE, R.I. [Brown University] — One day, amid his decades-long study of how animals move, including how frogs jump, Brown University biologist Thomas Roberts found himself and colleague Richard Marsh puzzling over the Guinness Book of World Records. A bullfrog named Rosie the Ribiter reportedly had jumped more than 2.1 meters in a single hop at the Calaveras County Jumping Frog Jubilee in 1986, but scientific studies had never reported a bullfrog jump beyond 1.3 meters. (more…)

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Tiny Piece of RNA Keeps ‘Clock’ Running in Earliest Stages of Life

COLUMBUS, Ohio – New research shows that a tiny piece of RNA has an essential role in ensuring that embryonic tissue segments form properly.

The study, conducted in chicken embryos, determined that this piece of RNA regulates cyclical gene activity that defines the timing of the formation of tissue segments that later become muscle and vertebrae.

Genes involved in this activity are turned on and off in an oscillating pattern that matches the formation of each tissue segment. If the timing of these genes’ activity doesn’t remain tightly regulated, the tissue either won’t form at all or will form with defects. (more…)

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Size of Lunch Dictates Force of Crunch

Even in the same animal, not all bites are the same. A new study finds that because the force in a muscle depends on how much it is stretched, an animal’s bite force depends on the size of what it is biting. The finding has direct implications for ecology and evolution.

PROVIDENCE, R.I. [Brown University] — Many animals prefer food — snails, nuts, etc. — that must be cracked and crushed. Scientists have measured the maximum force of their impressive bites before, but a new study introduces a significant subtlety: bite force depends not only on the size and strength of the eater, but also the size of the eatee. That insight has important implications in the lives of predators and prey. (more…)

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How Do Cells Tell Time? Scientists Develop Single-Cell Imaging to Watch the Cell Clock

COLUMBUS, Ohio – A new way to visualize single-cell activity in living zebrafish embryos has allowed scientists to clarify how cells line up in the right place at the right time to receive signals about the next phase of their life.

Scientists developed the imaging tool in single living cells by fusing a protein defining the cells’ cyclical behavior to a yellow fluorescent protein that allows for visualization. Zebrafish embryos are already transparent, but with this closer microscopic look at the earliest stages of life, the researchers have answered two long-standing questions about how cells cooperate to form embryonic segments that later become muscle and vertebrae. (more…)

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Adult Stem Cells Use Special Pathways to Repair Damaged Muscle, MU Researchers Find

*Discovery could help future treatments for muscle repairs, disorders*

COLUMBIA, Mo. – When a muscle is damaged, dormant adult stem cells called satellite cells are signaled to “wake up” and contribute to repairing the muscle. University of Missouri researchers recently found how even distant satellite cells could help with the repair, and are now learning how the stem cells travel within the tissue. This knowledge could ultimately help doctors more effectively treat muscle disorders such as muscular dystrophy, in which the muscle is easily damaged and the patient’s satellite cells have lost the ability to repair. (more…)

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West Nile Virus More Prevalent in Low-income Neighborhoods, Study Finds

Image credit: University of California

Low-income neighborhoods appear to be the most susceptible to West Nile virus, a mosquito-transmitted disease that is linked to more than 1,000 deaths since in the United States since 1999, according to new UCLA-lead research.

Using data on infected humans and mosquitoes from the West Nile virus hotspot of Orange County, Calif., from 2005-08, scientists found that per-capita income and other economic conditions were the single greatest predictor of occurrence, explaining 85-95 percent of the variation. While economic conditions have previously been linked to disease, the study is the first to use a rigorous statistical model.  (more…)

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