Investing in opposite outcomes—or bet hedging—is a common tool to cushion against huge monetary losses. While this strategy has earned a bad name for its role in the recent global financial crisis, bet hedging is key to survival in bacteria. But how microorganisms manage bet hedging at the molecular level is poorly understood. Now, new research in yeast shows that slow-growing cells resist stress better than fast-growing cells, thanks in part to higher levels of a stress-related protein… (more)

PLoS Biology, 2012

Silene latifolia’s female and male flowers, and X and Y chromosomes

Birds do it, bees do it—and now it appears that even plants do it. No, it’s not what you’re thinking. Sexual reproduction is obviously well-known in plants. Rather, the phenomenon in question is equalizing sex chromosome expression in males and females. In people, females inactivate one of their X chromosomes but such balancing was thought to be absent in plants.

Now researchers report the first evidence of sex chromosome balancing in the plant Silene latifolia, or white campion, along with insights into how this phenomenon evolves. (more)

PLoS Biology, 2012

Imbalanced gut bacteria can make mice obese, leading to diabetes

Obesity and type 2 diabetes have risen tremendously over the last 20 years, and  weight gain and insulin resistance are linked to gut bacteria that provide a source of extra calories by breaking down compounds that are otherwise indigestible.

Some mice are genetically protected against obesity-induced insulin resistance and, intriguingly, this may be due to alterations in their enteric microbe composition. Now, in this issue of PLoS Biology, Andréa Caricilli and colleagues present compelling evidence that gut bacteria can nullify genetic protections against diabetes … (more)

PLoS Biology, 2011

Nitrogen-fixing bacteria live in root nodules of legumes

There’s a surprisingly fine line between bacterial symbiosis and chronic infection. While one is beneficial and the other detrimental, recent findings suggest that they share mechanisms for sidestepping host defenses. Plants in the pea family (legumes) have symbiotic nitrogen-fixing bacteria that are closely related to bacteria that cause abortions in cattle and debilitating chronic infections in people… (more)

PLoS Biology, 2011

Some oomycetes feed off plants by extending hyphae between their cells

At first glance, diatoms, malaria parasites, and fungus-like plant pathogens called oomycetes look wildly different. But these organisms all have something in common: they belong to a group called the Chromalveolata that contains genes from algae. This diversity of lifestyles within a single group presents an opportunity to learn how some of them became obligate biotrophs, which require living hosts… (more)

PLoS Biology, 2011

Bacteria tumble in place when their flagella are unbundled

Bacteria can change course almost instantaneously, zipping towards food or away from toxins. How do such simple organisms do something so complex? It’s all in the flagella, a tail-like structure with rotating helical filaments… (more)

PLoS Biology, 2011

Networks of pyramidal cells help you remember things

No matter what you’re doing at any given moment, from walking to talking or even sleeping, your brain is doing its own thing. Networks of neurons constantly and often spontaneously generate rhythmic electrical activity in the cortex, the brain’s outermost layer and the seat of judgment, decision making, and other higher order functions.

What keeps these cortical networks humming along? New research shows that small changes in the electrical properties of pyramidal cells are key to maintaining the excitation-inhibition balance of networks… (more)

PLoS Biology, 2011

Tiny worms with simple genetics, nematodes have almost everything it takes to be a favored model system to study viral infections. Recent work has even shown that the nematode Caenorhabditis elegans has innate immune pathways against viruses much like those in vertebrates, including people.

So what’s missing? No viruses were known to infect nematodes naturally, limiting our view to only a small part of the complex life cycle of these pathogens… (more)

PLoS Biology, 2011

The maxim “you are what you eat” goes only so far. The bacteria inhabiting our guts, which outnumber our own cells by perhaps 10 to 1, are commonly thought to reflect our diets. But other factors can also affect gut microbes, and sorting out their provenance is critical because they can affect our health for good or ill, from enhancing immune function to increasing the risk of stomach cancer.

New research counters the prevailing view that diet shapes the makeup of gut microbes…(more)

PLoS Biology, 2010

Plants grow in a wondrous assortment of patterns, from simple to complex, with near mathematical precision. Honeysuckles sprout leaf pairs at regular intervals along their stems, for instance, whereas some succulents form double spirals turning in opposite directions.

The big question is how do they do this? New research reported in this issue of PLoS Biology suggests that mechanical stress is at the root of plant patterns, challenging the longstanding theory that the plant hormone auxin acts alone to direct this patterning… (more)

PLoS Biology, 2010