Genetics & Molecular Biology

Though cultural advocates invoke cancer for their causes, genetics is the dominant risk factor in common breast, prostate and colorectal cancers. 


Writing in the Proceedings of the National Academy of Sciences, scientists have shown regulatory proteins in the nucleus to adopt a kind of “Tom Sawyer” behavior when it comes to the work of initiating gene activation. 

Transcription factors are proteins that orchestrate the flow of genetic information from DNA to messenger RNA (mRNA) and the results show how transcription factors (TFs) activate mRNA synthesis of a gene, and leave the scene – in a model termed “hit-and-run” transcription.

In rodent models, a drug that blocks the action of the enzyme Cdk5 could substantially reduce brain damage if administered shortly after a stroke, according to a new paper in the Journal of Neuroscience, because aberrant Cdk5 activity causes nerve cell death during stroke.


A promising molecule that blocks bone destruction could provide a potential therapeutic target for osteoporosis and bone metastases of cancer, according to a new study.

The molecule, miR-34a, belongs to a family of small molecules called microRNAs (miRNAs) that serve as brakes to help regulate how much of a protein is made, which in turn, determines how cells respond.

Mice with higher than normal levels of miR-34a had increased bone mass and reduced bone breakdown. This outcome is achieved because miR-34a blocks the development of bone-destroying cells called osteoclasts, which make the bone less dense and prone to fracture.


Significant progress has been made over the last 25 years to identify genetic abnormalities associated with congenital myasthenic syndromes (CMS) but many patients remain genetically undiagnosed. A new report identifies a gene defect in mitochondria, specifically the citrate carrier SLC25A1, that may underlie deficits in neuromuscular transmission seen in two siblings.

"While mitochondrial gene defects can cause a myriad of neurological disorders including myopathies and neuropathies, these have not been specifically implicated in defects of the neuromuscular junction," says Hanns Lochmüller, MD, Professor of Experimental Myology, Institute of Genetic Medicine, MRC Centre for Neuromuscular Diseases, Newcastle University, Newcastle upon Tyne, UK.


If you could live longer, would you be weaned on an extreme, emaciating diet?

The search for the foundation of youth has been happening forever and a popular idea in recent years has been caloric restriction - mice weaned on starvation diets live long and a new study of the tiny nematode worm C. elegans finds results even more alarming - it triggered a state of arrested development.


Researchers have developed a new technique to control populations of a major livestock pest in Australia and New Zealand.

They genetically modified lines of female Australian sheep blowflies (Lucilia cuprina), making female flies dependent upon a common antibiotic -
tetracycline
- to survive. 

Dr. Max Scott, professor of entomology at North Carolina State University, and colleagues say that female blowflies that did not receive the antibiotic died in the late larval or pupal stages, before reaching adulthood. Several genetically modified lines lacking tetracycline showed 100 percent female deaths.


Chronic tissue inflammation is typically associated with obesity and metabolic disease, but new research finds that a level of "healthy" inflammation is necessary to prevent metabolic diseases, such as fatty liver.


Mitochondria are cell organelles located within animal and human cells. They produce energy for the organism, possess their own genetic material - mitochondrial DNA (mtDNA) - and are transmitted exclusively by the mother.

Depending on their activity and tasks, different numbers of mitochondria are present in a cell - usually a few hundred to a thousand per body cell.


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.