Academic journal article Science and Children

In the News: SHORT ITEMS OF INTEREST TO THE SCIENTIFIC COMMUNITY

Academic journal article Science and Children

In the News: SHORT ITEMS OF INTEREST TO THE SCIENTIFIC COMMUNITY

Article excerpt

TROPICAL SEA SNAKE USES ITS HEAD TO "BREATHE"

Researchers have found a sea snake that uses a complex system of blood vessels in its head to draw in extra oxygen when it dives and swims underwater.

During submersion, the bluebanded sea snake (Hydrophis cyanocinctus) is now thought to use an extensive vascular network across the top of its head to absorb oxygen from the surrounding water.

"For the first time, we describe this modified cephalic vascular network (MCVN) that provides this sea snake with a complementary supply of oxygen to the brain during submersion," says lead researcher Alessandro Palci.

The highly venomous blue-banded sea snakes, which live in tropical waters of Southeast Asia, are found on coral reefs and warm coastal waters. Sea snakes must surface regularly to breathe but are among the most completely aquatic of all air-breathing vertebrates.

The vascular network, located just under the skin of the snout and forehead of the snake, surprised researchers in their new study.

ARC Future Fellow Kate Sanders, from the University of Adelaide School of Biological Sciences, says the latest study expands understanding of the unusual cutaneous respiratory anatomy of sea snakes.

--Flinders University (www.eurekalert.org/pub_releases/2019-09/fu-tss090119.php)

NEW INSIGHTS INTO BIRD MIGRATION

A gene newly associated with the migratory patterns of golden-winged and blue-winged warblers could provide further information into the longstanding question of how birds migrate across such long distances.

A new study is the first to combine whole genome sequencing and migration tracking technology to pinpoint a single gene associated with the complex suite of traits that determine migratory behavior. These findings may have important conservation implications for the declining populations of golden-winged warblers.

Migration programming in birds is incredibly complex, encompassing a suite of neurological, physiological, and behavioral traits. Researchers have known for a few decades that there is a genetic component to migration. Recent studies in birds have identified large regions of the genome, encompassing hundreds of genes, associated with migration, but it has been more difficult to pinpoint the specific roles of any single gene.

The researchers studied migration patterns in golden-winged warblers and blue-winged warblers, genetically similar species that breed in the Midwest and northeastern United States. Some birds of each species migrate to wintering grounds in Central America, from Panama to Guatemala, while others travel farther to South America, primarily Venezuela. Birds will usually return to similar breeding grounds and wintering sites each year.

Members of the research team from the University of Toledo previously determined the specific locations where these birds were wintering. They placed geolocators, essentially small backpacks with light sensors, on birds caught at breeding grounds in the United States. The geolocators recorded light levels of their environment, which the researchers analyzed when the birds were captured the next year at their breeding sites.

Importantly, the team from Toledo took genetic samples from the migrating birds, which allowed the group to investigate genetic differences between birds that winter in Central America and those that winter in South America. The majority of these differences occurred in a small region on the bird's Z chromosome, a sex-determining chromosome like the X and Y chromosomes in humans. Only one gene, called VPS13A, was present in this region.

Although the gene does not yet have any known function in birds, in humans it is associated with the neurodegenerative disorder chorea-acanthocytosis, which affects movement.

According to the researchers, the gene appears to be a target of natural selection in birds that winter in South America. …

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