A group of scientists at Boston College, Chestnut Hill, has reconstructed the natural history of a specific retrovirus lineage — ERV-Fc — that disseminated widely between 33 and 15 million years ago (Oligocene and early Miocene).
Retrovirus particles budding from rhesus macaque placenta cells. Image credit: Dorothy Feldman, via aacrjournals.org.
Retroviruses are abundant in nature and include human immunodeficiency viruses (HIV 1 and HIV 2), human T-cell leukemia viruses (HTLV 1 and 2), and the well-studied oncogenic retroviruses of mice and other model organisms, among many others.
The team’s findings, reported online on March 8, 2016, in the journal eLife , show that an ancient group of retroviruses known as ERV-Fc infected the ancestors of at least 2… Read more
Researchers at the University of California have uncovered in detail the dynamic process that allows the hydra — a simple freshwater animal famous for its regenerative capabilities — to open and close its mouth.
The white hydra ( Hydra vulgaris ). Image credit: Corvana / CC BY-SA 3.0.
Hydra looks like a column with a ring of tentacles at one end. The other end adheres to a rock or other surface, sticking the animal in place while it waits for unsuspecting prey to swim by.
When a live animal brushes against its tentacles, the hydra shoots out poisoned barbs to sting and paralyze its prey.
Then the hydra contracts its tentacles, a special group of cells splits apart to display a black maw, and it sucks the prey in.
Once the meal is digested, the hydra rips open its mouth to spit out a… Read more
Japanese tits combine their calls using specific rules to communicate important compound messages, says an international group of ornithologists led by Rikkyo University scientist Toshitaka Suzuki.
New study provides the first experimental evidence for compositional syntax in a wild animal species, the Japanese tit ( Parus minor ). Image credit: Toshitaka Suzuki.
“Language is one of humans’ most important defining characteristics,” said Dr. Suzuki and his colleagues from Sweden and Switzerland.
“It allows us to generate innumerable expressions from a finite number of vocal elements and meanings, and underlies the evolution of other characteristic human behaviours, such as art and technology. The power of language lies in combining meaningless sounds… Read more
A team of researchers led by Michigan State University biochemist and molecular biologist Amy Ralston has discovered a new kind of stem cell — induced extraembryonic endoderm stem (iXEN) cells.
Morphology of iXEN cells is similar to that of blastocyst-derived XEN cells. Image credit: Anthony Parenti et al.
“Other scientists may have seen these cells before, but they were considered to be defective, or cancer-like. Rather than ignore these cells that have been mislabeled as waste byproducts, we found gold in the garbage,” said team member Anthony Parenti, also from Michigan State University.
A great deal of stem cell research focuses on new ways to make and use pluripotent stem cells.
Pluripotent stem cells can be created by reactivating embryonic genes to reprog… Read more
Long-legged wading birds that nest above resident American alligators ( Alligator mississippiensis ) for protection from mammalian nest predators may also provide a source of food for the alligators living in the Everglades, Florida, says a team of researchers led by University of Florida scientist Lucas Nell.
An American alligator ( Alligator mississippiensis ) attempting to catch a raccoon ( Procyon lotor ) on a bait station in southwest Florida. Image credit: Florida Fish and Wildlife Conservation Commission.
For many bird species nest predation is the greatest threat to reproductive success.
Long-legged wading birds, like herons, egrets, ibises, storks, and spoonbills may choose nesting sites above resident American alligators, likely to take advan… Read more
A new study in rats led by Dr. Beth Allison of the University of Cambridge, UK, suggests that the aging clock begins ticking even before we are born and enter this world.
This false-color image shows human chromosomes (green) capped by telomeres (red). Image credit: U.S. Department of Energy Human Genome Program.
Dr. Allison and co-authors also found that providing mothers with antioxidants during pregnancy meant that their offspring aged more slowly in adulthood.
Our DNA is ‘written’ onto chromosomes, of which humans carry 23 pairs. The ends of each chromosome are known as telomeres and act in a similar way to the plastic that binds the ends of shoelaces, preventing the chromosomes from fraying.
As we age, these telomeres become shorter and shorter, and hence their… Read more
A new species of the plant genus Rafflesia – R. consueloae — has been described from the Philippine Island of Luzon by a team of scientists led by Prof. Edwino Fernando of the University of the Philippines.
Rafflesia consueloae . Image credit: Edwino S. Fernando.
Rafflesia is a genus of endophytic, holoparasitic plants, well-known for producing the largest flowers in the world.
“ Rafflesia flowers are unique in that they are entirely parasitic on roots and stems of specific vines in the forests and have no distinct roots, stems, or leaves of their own,” Prof. Fernando said.
“Thus, they are entirely dependent on their host plants for water and nutrients.”
When in bloom, all Rafflesia flowers emit a repulsive odor, similar to that of rotting flesh.
The best known of Raffl… Read more
According to a new study in the Zoological Journal of the Linnean Society , an extinct bird known as the dodo ( Raphus cucullatus ) was in fact relatively smart.
The dodo ( Raphus cucullatus ) by Frederick William Frohawk, 1905.
The dodo is an extinct flightless bird that lived on the Indian Ocean island of Mauritius. It was discovered by European sailors in 1598, and was extinct by 1680.
The bird was about 1 m tall, weighed 10-23 kg, and had blue-gray plumage, a big head, a long bill, small useless wings, stout yellow legs, and a tuft of curly feathers high on its rear end.
Even though the dodo has become an example of stupidity, oddity, obsolescence, and extinction, most aspects of its biology are still unknown.
To examine the brain of the dodo, a team of researchers from Denmar… Read more