Week in Review: March 9–13

Modifying mouse memories; mitochondria-disrupting antibiotics; horizontal gene transfer across animals; T cells target dengue; optogenetics without the genetics

Mar 13, 2015
Tracy Vence

False memories in mice

KARIM BENCHENANE, GAETAN DE LAVILLEON, MARIE LACROIX, CNRSThrough behavioral experimentation and neuronal manipulation, investigators from the French National Center for Scientific Research and their colleagues have created false memories in sleeping mice, leading the animals, after they’ve awoken, to seek out a place they once feared. Their results were published in Nature Neuroscience this week (March 9).

“The study shows that the emotional value of a particular [location] can be modified, and what is most critical is that this can happen in a subconscious, sleep state,” neuroscientist György Buzsáki of the New York University Neuroscience Institute who was not involved with the work told The Scientist.

“Scientists had thought that during sleep, representations of waking experiences get reactivated, and this finding clearly suggests this is the case,” said Kate Jeffery, a behavioral neuroscientist at University College London who also was not involved in the study.

Tetracyclines disrupt mitochondria

ECOLE POLYTECHNIQUE FEDERALECommonly used antibiotics can disrupt mitochondrial function in plants, fruit flies, worms, mice, and human cells in culture, researchers from the École Polytechnique Fédérale in Lausanne, Switzerland, and their colleagues showed in Cell Reports this week (March 12). The researchers noted their findings could have implications for, among other things, the use of these antibiotics, called tetracyclines, in livestock.

“This is a straightforward and clear story,” said Cole Haynes, who studies mitochondrial dysfunction at Memorial Sloan Kettering Cancer Center in New York City but was not involved in the work. “It’s a nice job by the authors showing that tetracyclines really have mitochondrial consequences [that scientists] have not thought about seriously.”

“What surprises me is the extent of the effects and that the scientific community has not considered the off-target effects of this class of compounds in their experimental design,” said Jodi Nunnari, a professor of molecular and cellular biology at the University of California, Davis, who did not participate in the research.

Finding “foreign” genes

NHGRIExamining the genomes of fruit flies, worms, primates, and humans, among other animals, a team led by scientists at the University of Cambridge uncovered evidence that horizontal gene transfer—wherein a species acquires genetic material from another species—is a hallmark of several species. The results were published this week (March 12) in Genome Biology.

“The study makes a compelling case presenting more evidence of lateral gene transfer from bacteria into eukaryotes,” said microbiologist Julie Hotopp of the University of Maryland who was not involved with the work. “Redoing this type of analysis has been needed for quite some time. People continue to cite the papers from 2000 and 2001 as examples that there is no lateral gene transfer, particularly in humans.”

Optogenetics sans genetics

FLICKR, STEVE JURVETSONResearchers from the University of Chicago have developed an approach to stimulate neurons in culture using light and gold nanoparticles. The method, described in Neuron this week (March 12), could help speed up neuroscience research.

“Exciting cells in the nervous system without going through all the difficulty of creating a transgenic animal. . . . It’s a shortcut,” explained study coauthor Francisco “Pancho” Bezanilla, a biophysicist at the University of Chicago.

“It’s an exciting new technique and certainly could have lots of applications,” said Michael Sasner, a mouse model expert at the Jackson Laboratory in Bar Harbor, Maine, who was not involved in the study. “You have the huge variety of antibodies available to conjugate a gold nanoparticle to; you could very quickly and relatively easily study stimulation in a hippocampal slice, for example.”

Dengue-targeting T cells

CDC, JAMES GATHANYT cells that recognize dengue virus and express a specific surface marker home to the skin during infection, scientists at the National University of Singapore (NUS) and their colleagues have found. The results, published this week (March 11) in Science Translational Medicine, could point to improved vaccine design.

“When you vaccinate, you want to generate not only cells that recognize the particular pathogen but also that are going to the right place,” study coauthor Laura Rivino of NUS told The Scientist.

“The concept that T cells are really going to be important for controlling natural dengue infection, and now in the context of dengue vaccination, is really big for the field,” said Sujan Shresta of the La Jolla Institute for Allergy and Immunology who was not involved in the research.

Punchcard microfluidics

PLOS ONE, G. KORIR AND M. PRAKASHInspired by a children’s toy, Stanford bioengineers have created a programmable microfluidic system operated by hand crank. The team described its device in PLOS ONE last week (March 4).

“The tool has exactly the same specs as any of these other microfluidic technologies that are out there that are all automated and run by computers,” study coauthor Manu Prakash of Stanford told The Scientist.

“This paper is the most clever use of an inexpensive programmable toy to produce useful microfluidic systems at low cost,” said Paul Yager, a professor of bioengineering at the University of Washington in Seattle who was not involved in the study.

Nanocrystals behind chameleon color

NATURE COMMUNICATIONS, J. TEYSSIER ET AL. Guanine nanocrystals are at the root of chameleons’ dramatic color changes, researchers from the University of Geneva and their colleagues reported in Nature Communications this week (March 10).

“People generally assume that color change in chameleons is well understood, and I don’t think it is at all,” said Randall Morrison of McDaniel College in Maryland who was not involved with the research. “This whole notion of the tunable photonic crystals is a new way to look at physiological color change in animals.”

Other news in life science:

Judge: PubPeer Users Remain Anonymous
A Michigan judge denies a request to reveal the identities of commenters on the post-publication review website.

Human Brain Project Reviewed
After weathering serious criticism last year, the European Commission–backed effort to map the brain’s neural connections must reform or die, a review panel says.

23andMe Enters Drug Development
The personal genomics firm announced it plans to make medicines.

Herpes Vax Shows Promise
A vaccine candidate against herpes simplex virus type 2 provides complete protection against infection in mice, with no evidence of latent virus.

Bird Flu Spreads in China and the U.S.
China reports new H7N9 bird flu infections in humans while other strains are detected in US commercial turkey farms.