Stem cells produced in vivo

WIKIMEDIA, RAMAIt wasn’t what they had initially planned for the transgenic mice they were studying, but Spanish scientists have created induced pluripotent stem cells (iPSCs) within diverse tissues of the live rodents. The in vivo-reprogrammed murine iPSCs the team described in Nature this week are not like other stem cells: not only can they form cells of all three germ layers, but also trophoblast-like cells, progenitors that help form the placenta, which embryonic stem cells typically do not form. Study coauthor Manuel Serrano from the Spanish National Cancer Research Center said that these iPSCs “are more primitive than the cells produced in vitro, and even more primitive that the cells taken from embryos.”

“What’s really remarkable is we’re still learning the ways the earliest embryonic cells segregate themselves to different lineages,” the Harvard Stem Cell Institute’s George Daley, who was not involved in the...

Serrano and his colleagues are now working to better understand the basic biology of the de-differentiated cells.

Parasitic, with a mutualistic twist

ANDERS ILLUMMegalomyrmex ants storm the gardens of fungus-growing species, feeding on resident broods and clipping the wings of virgin queens. It might seem that these socially parasitic critters do irreparable harm to the colonies they invade, but it turns out that the presence of Megalomyrmex visitors can actually do the host ants good. When the host species is attacked by another species of ant, Megalomyrmex defend the fungus-growing colony, using the alkaloid venom that helped them invade in the first place to fight the raiders and defend the fungal turf.

The Smithsonian Institution (SI)’s Natasha Mehdiabadi pointed out that such behaviors demonstrate “how ‘parasitic’ or ‘mutualistic’ relationships are not so clear-cut.”

Rachelle Adams of SI and her colleagues published their findings in the Proceedings of the National Academy of Sciences this week. Adams likened the Megalomyrmex ants to the Medieval mercenaries that protected cities for pay. “They’re still parasites because they’re extracting resources,” she said. “But [they] use the same chemical weaponry that helps them to invade the host colony against this other raiding species.”

Reasons for high tropical amphibian diversity

SXC.HU, MIHAI TAMASILAScientists have long recognized the latitudinal diversity gradient, in which biodiversity is greatest in the tropics and less flush in temperate zones. This week, Alex Pyron from George Washington University and the University of Arizona’s John Wiens described in the Proceedings of the Royal Society B: Biological Sciences their use of a big data approach to study the diversity among tropical amphibian species, combining climatic and phylogenetic information to address a long-standing question.

Overall, Wiens and Pyron identified rapid speciation and reduced extinction rates within the tropics as the major reasons for increased amphibian diversity there. Gary Mittelbach, a professor of zoology at Michigan State University’s Kellogg Biological Station who was not involved in the study, told The Scientist that the pair’s analysis “is remarkable in its reach to examine a diverse set of hypotheses for the generation of the latitudinal diversity gradient and to treat these hypotheses synthetically.”

Studies such as this, he added, “point to the tropics as the engine of biodiversity, both as a cradle for the generation of new species and as a museum for the preservation of diversity.”

Changes needed in cancer drug R&D

FLICKR, _TAWCANA mix of preclinical research problems and clinical trial issues is stunting the translation of basic cancer research discoveries into new treatments for patients, Virginia Commonwealth University’s Masoud Manjili argued this week in an opinion piece. “Because of our current approach to translational research, there is still significant discordance between preclinical findings and clinical results,” he wrote. “Such discordance has hindered the clinical impact of academic research, despite sizeable investments made in it.”

Manjili noted that in order to move translational research forward, a “radically new approach”—a collaborative effort involving academia, industry, and government—will be required.

Other news in life science

Expeditious TB Tests
New rapid tests for extensively drug-resistant tuberculosis appear highly accurate.

Toward a MERS Vaccine
Researchers generate an infectious cDNA clone of the Middle East respiratory syndrome coronavirus genome that could inform vaccine design.

Lasker Winners Announced
Discoveries related to rapid neurotransmitter release are among those recognized by the Albert and Mary Lasker Foundation this year.

Right Under Their Noses
Biology students discover a new species of beetle in the giant city of Manila.

Putting Bad Memories to Bed
Researchers selectively erase methamphetamine-related memories in mice and rats.

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