Visualizing “Unfurling” Microtubule Growth

Living cells depend absolutely on tubulin, a protein that forms hollow tube-like polymers, called microtubules, that form scaffolding for moving materials inside the cell. Tubulin-based microtubule scaffolding allows cells to move, keeps things in place or moves them around. When cells divide, microtubule fibers pull the chromosomes apart into new cells. Cells with defects in tubulin polymerization die.

Microtubule fibers are hollow rods made of much smaller tubulin subunits that spontaneously assemble at one end of the rod, but exactly how they do this inside the crowded environment of living cells has been a mystery. Now researchers at UC Davis have uncovered the mechanism that puts these blocks in place, illustrated in a new animation.

The Whole Tooth: New Method to Find Biological Sex From a Single Tooth

A team led by UC Davis researchers have come up with a new way to estimate the biological sex of human skeletal remains based on protein traces from teeth.

Tooth of a European-American buried in San Francisco in the 1850s. A new technique developed at UC Davis allows archaeologists
to find a person’s biological sex based on a single tooth. (Jelmer Eerkens)

Estimating the sex of human remains is important for archaeologists who want to understand ancient societies and peoples. Researchers can measure features of bones that differ between males and females, usually the pelvis. But skeletons of children and adolescents don’t show these structural changes, and often sites may only yield a few pieces of bone.

Exploring the Role of Redox and Bioelectric Players in Tissue Regeneration

Regeneration of a lost limb is arguably one of the seven wonders of biology. While you can’t grow a new arm, a humble tadpole can grow a new tail in a week. Seeking a better understanding of limb regeneration, Min Zhao, professor of dermatology and ophthalmology at the University of California, Davis, and graduate student Fernando Ferreira (also at University of Minho, Portugal) are studying the relationship of redox players, like oxygen and hydrogen peroxide, with bioelectricity, including membrane potential and electric currents, to pinpoint how a tadpole can regrow an amputated tail.

Detecting E.coli Strains Using Molecular Electronics

New technology developed by Josh Hihath and colleagues at UC Davis uses atomically fine electrodes to suspend a DNA probe that binds target RNA. The device is able to detect as little as a one-base change in RNA, enough to detect toxic strains of E. coli.

By Aditi Risbud Bartl

Finding a fast and inexpensive way to detect specific strains of bacteria and viruses is critical to food safety, water quality, environmental protection and human health. However, current methods for detecting illness-causing strains of bacteria such as E. coli require either time-intensive biological cell cultures or DNA amplification approaches that rely on expensive laboratory equipment.

Grant to Improve Poultry Production Worldwide

USAID awards second phase of funding to Genomics to Improve Poultry Innovation Lab 

By Diane Nelson

Throughout Africa, chickens are vital to family nourishment, income and food security. But African poultry production is threatened by an extremely virulent Newcastle disease virus that can decimate entire flocks within days.

UC Davis Animal Science Professor Huaijun Zhou with white leghorn chickens at a UC Davis facility. Zhou uses genetic and genomic techniques to breed chickens that are more resistant to disease and heat stress for developing world farmers. (Gregory Urquiaga)

Study Explores How Fruit Flies Navigate Unstable Convective Air

By Greg Watry

Drosophila melanogaster

The fruit fly Drosophila melanogaster lives in deserts and also urban environments with many hot surfaces and resulting air currents. (Photo: Sanjay Acharya)

When insects migrate over vast distances, many take advantage of a natural phenomenon called thermal convection, which causes flow movement when air at different temperatures interact. Hitching a ride on invisible rollercoasters called convection cells, insects—like aphids and spiders—follow the flow of warm air upwards and cold air downwards.

“They are floating up to 3,000 feet,” said Victor Ortega-Jimenez, an assistant project scientist in the Combes Lab at UC Davis, of this movement. “All these clouds of insects are floating up there and moving in these convection cell patterns.”

Seeing Plants in Three Dimensions

Scientists are taking a new look at the inner workings of plants by imaging and modeling them in three dimensions.

“We’ve realized tremendous advances in technology for 3-D imaging of leaves,” said Tom Buckley, assistant professor of plant sciences at UC Davis.

Plant scientists are getting new insight by imaging and modeling leaves in three dimensions. (Image: University of Sydney)

Recent developments are summarized in an article in Trends in Plant Sciences, which sprang from a 2017 workshop at the University of Sydney organized by Buckley and Professor Margaret Barbour, University of Sydney.

From Lab Fruit Flies to Mosquito Extermination in 30 Years

Louis Pasteur famously compared science and its application to a tree and it’s fruit. The path from a fundamental discovery to application can be a long and winding one, but rewarding none the less.

Mosquito

Discoveries in basic genetics have now enabled scientists to wipe out lab populations of the malaria mosquito, Anopheles gambiae. (Anthony Cornel)

Professor Ken Burtis, faculty advisor to the Chancellor and Provost, recently came across an exciting example. Burtis was looking for a study for his first year seminar class when he found a paper from Andrea Crisanti’s lab at Imperial College London. Crisanti’s team was able to wipe out a lab population of Anopheles gambiae mosquitoes by introducing a disrupted gene for sex determination and using CRISPR “gene drive” technology to spread it through the population. Within eight generations, there were no female mosquitoes left for breeding.

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.

Open Source Data Base of Non-Human Primate Brain Imaging

An international team, including researchers at the California National Primate Research Center at UC Davis,  has released the first open-source data sets of non-human primate brain imaging. Details of the PRIMatE Data Exchange (PRIME-DE) consortium are published today (Sept. 27) in the journal Neuron.

The project will greatly augment progress on in vivo brain imaging of non-human primates, said John Morrison, director of the CNPRC and Professor of Neurology at the UC Davis School of Medicine.

MRI images

PRIME-DE collects MRI images of brains of non-human primates. It will be a global resource for researchers. (PRIME-DE)