Physics Nobel for Optical Tweezers, Enabled Single Molecule DNA Work

The 2018 Nobel Prize for Physics has been awarded to Arthur Ashkin of Bell Labs, Gérard Mourou, École Polytechnique, Palaiseau, France
and the University of Michigan, Ann Arbor and Donna Strickland, University of Waterloo, Canada for work on laser pulses that led to the development of “optical tweezers” that use lasers to manipulate small objects. 

The invention of optical tweezers made it possible for UC Davis biologists led by Professor Stephen Kowalczykowski and the late Professor Ron Baskin to design experiments where they could manipulate and observe single DNA molecules being copied in real time. In 2001, they used optical tweezers to move a tiny bead with a piece of DNA attached under a microscope, where they could watch a helicase enzyme unwind the DNA — the first step to copying or repairing it.

“Cellular Memory” of DNA Damage in Oocyte Quality Control

By Sofie Bates

Females are born with a finite number of eggs that are steadily depleted throughout their lifetime. This reserve of eggs is selected from a much larger pool of millions of precursor cells, or oocytes, that form during fetal life. So there is a substantial amount of quality control during the process of forming an egg cell, or ovum, that weeds out all but the highest quality cells. New research from Neil Hunter’s laboratory at UC Davis reveals the surprising way that this critical oocyte quality control process works.

Breakthrough in Designing a Better Salmonella Vaccine

By Trina Wood

UC Davis researchers announce in the Proceedings of the National Academy of Sciences this week a breakthrough in understanding which cells afford optimal protection against Salmonella infection—a critical step in developing a more effective and safe vaccine against a bacterium that annually kills an estimated one million people worldwide.

Salmonella bacteria (red) invading human cells. Salmonella infections can cause severe disease and current vaccines are inadequate. New work in mouse models shows which cells are responsible for immunity to Salmonella and may lead to improved vaccines. Photo credit: Rocky Mountain Laboratories, NIAID, NIH

How Do You Make an Earth-like Planet?

Astronomers have spotted many Earth-like worlds around other stars, but are these exoplanets really similar to our home, and could they support life? The CLEVER Planets project, including UC Davis professor Sarah Stewart, has received a $7.7 million NASA grant to explore how rocky planets like Earth acquire, sustain, and nurture the chemical conditions necessary for life.

Recipe for a planet

Credit: Courtney Dressing, Harvard-Smithsonian Center for Astrophysics

Agricultural Index Insurance Pairs Economics, Natural Sciences For Climate Resilience in East Africa

By Alex Russell

For poor and subsistence farmers in developing countries, a severe drought, flood or other catastrophe can cost them everything. In response to these kinds of climate-related risks, farmers often choose to minimize their exposure to loss. They might avoid higher-cost improved seeds that promise bigger harvests or riskier but profitable cash crops. Both of these strategies can keep them poor.

Maize farmers in Tanzania. Agricultural index insurance could help small farmers like these invest in higher-value crops and increase their income.

Newly Discovered Enzyme is “Firing Pin” for Plant Immunity

SIK1 Gene Opens Possibilities for Treating Disease, Breeding Resistant Crops

Just like humans, plants have an immune system that helps them fight off infections. Plant immunity has some important differences: they don’t make antibodies and can’t fight off the same bug more quickly months or years later. However, plant cells can identify pathogens and react to them, often by producing a burst of reactive oxygen which is toxic to bacteria or fungi. Cells around an infected site will go into programmed cell death to seal off the disease.

“Grit in the Gears” Costs Energy in Modular Information Systems

Digital information may appear to exist as abstract ones and zeroes, flipping effortlessly from one to another. But in fact there is a minimum amount of energy required to run any computation system, regardless of how “energy efficient” are its component parts. A recent paper from Jim Crutchfield and Alex Boyd at the UC Davis Complexity Sciences Center with Dibyendu Mandal at UC Berkeley shows that there is some inescapable friction, or “grit in the gears” between the levels of organization in an information system.

There and Back Again: Mantle Xenon Has a Story to Tell

By Talia Ogliore

The Earth has been through a lot of changes in its 4.5 billion year history, including a shift to incorporating and retaining volatile compounds such as water, nitrogen and carbon from the atmosphere in the mantle before spewing them out again through volcanic eruptions.

This transport could not have begun much before 2.5 billion years ago, according to researchers at UC Davis and Washington University in St. Louis, published Aug. 9 in the journal Nature.

Markers of Cellular Aging Improve During Insight Meditation Retreat

By Anahita Hamidi

Telomeres are repetitive nucleotide sequences that act as protective “caps” at the end of DNA strands. As cells age, either as a function of time or as a result of stress and poor health, telomeres tend to shorten. As such, telomere length can be used as a crude biological marker of health and well-being.

Telomeres are caps at the end of a chromosome. They become shorter with aging. (Getty Images)

A recent study by researchers at the University of California Davis, Center for Mind and Brain, measured changes in telomere length, telomerase (the enzyme which replenishes telomeres), and telomere-regulating genes in a group of individuals who participated in a month-long Insight meditation retreat.

Defend Against Predators or Run? Evolutionary Tradeoffs in Butterflyfish

How does a fish avoid being eaten by a bigger fish? Evolution could build up defenses such as spines or armor, or favor avoidance strategies such as quick reactions, swimming away and hiding. The rules of evolution are tough, so you cannot really have both, the argument goes.

But this hypothesis has been difficult to test in practice. Now Jennifer Hodge, a postdoctoral researcher working with Professor Peter Wainwright and colleagues in the UC Davis Department of Evolution and Ecology, College of Biological Sciences, has carried out a survey of hundreds of specimens of butterflyfish, carefully measuring their physical traits and defenses compared to feeding style.