Genetics & Molecular Biology

Scientists have long known that sperm's activity level depends on their internal pH. And now researchers writing in Cell say they have found the channel that allows the tiny cells to rid themselves of protons. Once in the female reproductive tract, that proton release changes their internal environment from acidic to alkaline and begins their race to the finish line. The findings offer new insight into a critical event in human fertilization and may lead to new ways of controlling male fertility.

"The concentration of protons inside the [sperm] cell is 1,000 times higher than outside," said Yuriy Kirichok of the University of California, San Francisco. "If you just open a pore, protons will go outside. We identify the molecule that lets them out."
A new study published today in Nature suggests that approximately seven in every thousand morbidly obese people are missing a section of their DNA containing approximately 30 genes, which may be having a dramatic effect on their weight.

Researchers identified the missing genes in teenagers and adults who had learning difficulties or delayed development. They found 31 people who had nearly identical 'deletions' in one copy of their DNA. All of the adults with this genetic change had a BMI of over 30, which means they were obese.
The 'primordial soup' theory--which posits that early life began in a soup of organic molecules before evolving out of the oceans millions of years later--is fatally flawed, according to researchers writing in BioEssays. Instead the authors claim it was the Earth's chemical energy, from hydrothermal vents on the ocean floor, which kick-started early life.

In rejecting the soup theory the team turned to the Earth's chemistry to identify the energy source which could power the first primitive predecessors of living organisms: geochemical gradients across a honeycomb of microscopic natural caverns at hydrothermal vents. These
catalytic cells generated lipids, proteins and nucleotides giving rise to the first true cells.
This paper relates some neat work done at the University of Texas to understand signal processing by beta-adrenergic receptors:


In layman's terms:
Scientists from the University of Gothenburg, Sweden say they have discovered how aged yeast cells manage to form new and undamaged daughter cells. In a study published in Cell, two collaborating research groups at the Department of Cell and Molecular Biology have been able to show how newly formed yeast cells transport damaged and aged proteins back to the mother cell, guaranteeing that the new cell is born young and healthy.
 No vaccine currently exists for West Nile Virus, but a new therapeutic made from tobacco plants has been shown to arrest the infection, according to research conducted by Arizona State University scientists. The study, published this week in PNAS,  is the first to demonstrate a plant-derived treatment to successfully combat West Nile virus after exposure and infection.

"The goal of this research was twofold," said Arizona State University scientist Qiang Chen. "First, we wanted to show proof-of- concept, demonstrating that plant-made antibodies can work as effective post-exposure therapeutics. Secondly, we've sought to develop a therapeutic which can be made inexpensively so that the health care systems in developing countries can afford it."

Since when has systems biology been a synonym for genomics?

This is from a Perspective piece in the Oct. 2 issue of Science:

The relative value of discovery aimed at hypothesis generation versus hypothesis testing has been debated. High-profile journals publish systems biology studies, including the human genome sequence, but most papers focus on hypothesis-driven investigations.

A new study in Biological Chemistry suggests that Vitamin D, readily available in supplements or cod liver oil, may counter the effects of Crohn's disease.

Researchers from McGill University and the Université de Montréal found that Vitamin D acts directly on the beta defensin 2 gene, which encodes an antimicrobial peptide, and the NOD2 gene that alerts cells to the presence of invading microbes. Both Beta-defensin and NOD2 have been linked to Crohn's disease. If NOD2 is deficient or defective, it cannot combat invaders in the intestinal tract.
Photosynthesizing sea slugs take 'you are what you eat' to an extreme: by eating photosynthesizing algae, these "solar-powered" sea slugs are able to live off photosynthesis for months. How does this work? Is this just a straightforward case of symbiosis between algae and sea slugs?

It turns out that this is not a case of symbiosis: this is a case of the amazing and ubiquitous power of viruses to dramatically reshape the genetic landscape.

Cheap, powerful sequencing has enabled scientists to sample the viral world like never before. Our understanding of marine viruses, in particular, has exploded as researchers have sequenced whatever they can find in samples of seawater.