Genetics & Molecular Biology

Some basic biology may need revising. It's broadly assumed that cells degrade and recycle their own old or damaged organelles, but researchers writing in PNAS say that some neurons transfer unwanted mitochondria, the tiny power plants inside cells, to supporting glial cells called astrocytes for disposal.  

The researchers looked specifically at the axons of retinal ganglion cells in mice, a type of neuron that transmits visual information from the eye to the brain. The investigation was prompted by observations while studying a mouse model of glaucoma that protein products from the retina were accumulating in the optic nerve head (ONH) just behind the eye. 

The kidney, unlike its neighbor the liver, was once understood to be a static organ once it had fully developed, but doctors have observed patients with kidney disease experiencing renal regeneration.  

A new study conducted by researchers at Sheba Medical Center, Tel Aviv University and Stanford University have pinpointed the precise cellular signaling responsible for renal regeneration and exposing the multi-layered nature of kidney growth. The research was conducted by principal investigators Dr. Benjamin Dekel of TAU's Sackler School of Medicine and Sheba Medical Center and Dr. Irving L. Weissman of Stanford University's School of Medicine, working with teams of researchers from both universities.

In the most comprehensive genetic study of the Mexican population to date, researchers from  Mexico's National Institute of Genomic Medicine (INMEGEN), UC San Francisco and Stanford University, have identified tremendous genetic diversity.

So much diversity there basically are no Mexicans.  But it explains some confounding aspects of Latino health, like why there is such a variety of health factors among Latinos of Mexican descent, including differing rates of breast cancer and asthma, as well as therapeutic response.  

Researchers have developed biomaterials for bone regeneration from beer brewing waste.

A molecular pathway called mTORC1 controls the conversion of unhealthy white fat into beige fat, an appealing target for increasing energy expenditure and reducing obesity, according to a new study. The team also found that a protein, Grb10, serves as the on-off switch for mTORC1 signaling and the "beigeing" of fat.

Researchers have found a way to prevent nonalcoholic fatty liver disease, the most common cause of chronic liver disease worldwide, in mice.

By blocking a path that delivers dietary fructose to the liver, mice were prevented from developing the condition, according to investigators at Washington University School of Medicine in St. Louis writing in the Journal of Biological Chemistry.

In people, nonalcoholic fatty liver disease often accompanies obesity, elevated blood sugar, high blood pressure and other markers of metabolic syndrome. Some estimate as many as 1 billion people worldwide have fatty liver disease, even if they don't realize it.

Like blonde hair? You can thank the Kit ligand gene.

A single-letter change in the genetic code is enough to generate blond hair in humans, according to a new analysis by Howard Hughes Medical Institute scientists which has pinpointed that change, common in the genomes of Northern Europeans.

A handful of genes likely determine hair color in humans and the precise molecular basis of the trait remains poorly understood, and discovery of the genetic hair-color switch didn't begin with a deep curiosity about golden locks. It began with fish.

Researchers have defined a previously unrecognized genetic cause for two types of birth defects found in newborn boys 

"Cryptorchidism and hypospadias are among the most common birth defects but the causes are usually unknown," said Dr. Dolores Lamb, director of the Center for Reproductive Medicine at Baylor and lead author of the report in Nature Medicine

Cryptorchidism is characterized by the failure of descent of one or both testes into the scrotum during fetal development. In the adult man, the testes produce sperm and the male hormone, testosterone. Hypospadias is the abnormal placement of the opening of the urethra on the penis. Both birth defects are usually surgically repaired during infancy.

The clinical promise of stem cells has been dampened by concerns that the immune system will reject the transplanted cells before they could render any long-term benefit.

Previous research in mice has suggested that even adult stem cells produced from a subject's own tissue, induced pluripotent stem (iPS) cells, can trigger an immune attack.

Now researchers at the Stanford University School of Medicine have found that differentiating iPS cells in the laboratory to become more-specialized progeny cells before transplantation into mice allows them to be tolerated by the body's immune system.

How dare biologists create something not found in nature!

Well, mankind has a lot of experience in trying to keep nature from killing us - the war between man and nature is a grudge match whose history and resentments run deep.  When scientists stop trying to keep nature from killing us is when we should worry.