Figure: GCK gene

Rasmus Hartmann-Petersen, Professor at the Department of Biology, explains:
– “The GCK gene, which codes for the enzyme glucokinase, regulates the secretion of insulin in the pancreas. GCK gene variants can therefore cause a form of hereditary diabetes. Although the connection between GCKand diabetes has been known for several years, we have, until now, only known the effect of a few percent of the possible variants of this gene”.

Together with colleagues at the PRISM centre, UCPH, who are currently studying the effects of genetic variations, the researchers measured the effect of all of the possible variants of GCK.

PhD student Sarah Gersing, who is the first author of the article, explains:
– “We used yeast cells to measure the activity of over 9000 different GCK variants. In this way, we were able to generate a list of the effects — both of already known variants, but also of variants that patients might carry, but that have not yet been discovered. This provides us with a reference for future GCK diagnostics”. 

Prof. Kresten Lindorff-Larsen, who heads the PRISM centre, continues:
– “Our results are quite unique; not only have we measured the effect of several thousand variants, but for many of the variants, we can now explain what they do to the glucokinase protein. In our centre, we have gathered researchers working across a range of research fields, bridging from data analysis and biophysics to cell biology and medicine, and it is now clear how this broad approach pays off in explaining how diseases arise”.

Gene variants of GCK can, among other things, cause a form of hereditary diabetes called “GCK maturity onset diabetes of the young” (GCK-MODY).

Professor of genetics, dr. med. Torben Hansen, who is also a member of the PRISM centre, says: – “Although GCK-MODY patients exhibit elevated blood glucose levels, this is often not associated with complications. Hence, unlike other forms of diabetes, most GCK-MODY patients might therefore not need to be treated with medication. However, due to missing or inaccurate genetic data, more than half of the GCK-MODY patients are classified with having either type 1 or type 2 diabetes – and are therefore unnecessarily medicated. We estimate that approx. 1% of those who have recently been diagnosed with type 2 diabetes in Denmark have a variant in the GCK gene, meaning that they don’t need treatment, or need to be treated differently. Our new map of GCK variants can hopefully help give these patients a more correct diagnosis.”

The next step for PRISM is to transfer these methods to other genes and diseases.
– “We are already well underway with genes involved in e.g., neurodegenerative diseases, and we are trying to develop precise methods that can provide us with insights on disease mechanisms”, says Rasmus Hartmann-Petersen.

 Kresten Lindorff-Larsen continues:
– “Our data gives us the opportunity to test and develop computational models for variant effects, which will then be transferable to other genes and diseases.”

– “Now, we have measured the effects of almost all variants of GCK, giving us knowledge on which variants that function, and which that do not. The next step is to understand why, and how the same underlying molecular mechanisms can give rise to a wide range of different diseases”, concludes Sarah Gersing.

A UCLA-led team of biologists wondered if those city-dwelling birds share common characteristics around the world that help them survive. In a paper published in Current Biology, they reveal the answer: Urban bird species tend to be smaller and less territorial and have greater ability to fly long distances. They also tend to have broader dietary and habitat niches, to lay more eggs at a time, to have longer lifespans and to live at a wider range of elevations than other species.

Several factors moderate the importance of those traits in how birds adapt to urban living, and the importance of those traits varies predictably across the planet.

The only trait that didn’t appear to be consistent globally among urban-dwelling birds, the resesarchers found, was the shape of their bills.

By 2030, the paper notes, the amount of urban land cover worldwide will have grown by 1.2 million square kilometers (or more than 463,000 square miles) since 2000 — roughly tripling over a 30-year period. That increase in urban space would be larger than the land area of California and Texas combined.

The authors write that a dramatic loss of biodiversity will accompany that urbanization unless there are practical plans to preserve it.

“Identifying traits that help wildlife adapt or even thrive in cities can help urban planners bolster biodiversity by, for example, increasing green spaces, planting more and taller trees, building more varied potential habitats, or reducing housing density,” said the paper’s lead author, Monte Neate-Clegg, a UCLA postdoctoral researcher. “It can also help conservation biologists to identify which types of species are most threatened by urbanization.”

Neate-Clegg and Morgan Tingley, a UCLA associate professor of ecology and evolutionary biology, combined data including records of more than 125 million individual bird sightings from the public science project eBird to calculate an “urban association index” that describes how closely each species is associated with living in urban settings.

They applied the measure to 3,768 bird species — around 35% of all bird species — in 137 cities across six continents.

The index takes into account factors like physical characteristics of the birds themselves and the geographic, population and landscape characteristics of the cities.

“Many of the most common urban birds globally are very familiar to us here in the U.S., including the house sparrow, barn swallow, osprey, and peregrine falcon,” Tingley said. “Although, interestingly, the species with the strongest associations with urban areas are actually three species of parakeet and a tanager from South America. Plus, of course, the feral pigeon.”

Interestingly, some of the species with the highest scores on the index — meaning that they were most closely associated with urban living — were not native to their regions, but such species made up less than 4% of the dataset, suggesting that invasive species might not have as big of an advantage as logic would suggest. Bird families with high average scores on the index — indicating that many species within that family were common in cities — included starlings, swifts, swallows, parrots, orioles and blackbirds.

Traits like smaller body size, lower territoriality, greater ability to fly longer distances — which scientists refer to as “dispersal ability” — broader dietary and habitat niches, larger clutch sizes, all tend to make it easier for city birds to find food and suitable nesting places, and to raise young that survive.

Bird species that generally build nests on the ground were not likely to live in cities, for fairly obvious reasons.

“In a city like Los Angeles, for example, the American crow is a cosmopolitan species whose broad diet, arboreal nesting habits and long lifespan favor life in the concrete jungle,” Neate-Clegg said. “In contrast, canyon wrens are highly territorial insectivores with low dispersal ability that shun cities and keep to steep, rocky terrain.”

But cities’ geographic properties — most notably their latitude — moderated the importance of those traits. For example, a broad diet was more important in temperate cities such as New York, while habitat generalists were more prevalent in tropical cities such as Bogotá, Colombia. The cities’ population sizes and surrounding terrain also played important roles: Anchorage, Alaska, with its small population and plentiful natural surroundings, is home to large birds like bald eagles that mostly feed on fish from rivers and lakes. Meanwhile, smaller birds that don’t require as much raw land and that can adapt to eating a variety of foods to survive would be more likely to inhabit sprawling, densely populated metropolises like Bangkok.

A joint research team led by Associate Professor Yan Xu of the Osaka Metropolitan University Graduate School of Engineering has succeeded in regulating the flow of single molecules in solution by opening and closing a nanovalve in a nanofluidic device by applying external pressure.

The research team fabricated a nanofluidic device with a thin, flexible glass sheet on the top, and a hard glass plate with small structures that forms nanochannels and nanovalve seats on the bottom. By applying external pressure to the flexible glass sheet to open and close the valve, they succeeded in directly manipulating and controlling the flow of individual molecules in solution. They also found that when they trapped single fluorescent molecules in the nanospace inside the valve, the fluorescence of the single molecules became brighter. This happened because the small space made it harder for the single molecules to move around randomly. Professor Xu said that “this effect of fluorescence signal amplification could help with detecting very small amounts of pathogens for early diagnosis of diseases such as cancers and Parkinson’s disease, without requiring expensive equipment.”

The findings of this study could be a significant step towards freely assembling materials using single molecules as building blocks in solution. This technology has the potential to be useful in various fields, such as developing personalized medicines for rare diseases and creating better displays and batteries. Its applications are limitless.

“We have been addressing various challenges by proposing and promoting the concept of ‘Single-Molecule Regulated Chemistry (SMRC),’ where molecules are treated as building blocks and all processes involved in chemical and biochemical reactions in solution are performed on a single-molecule basis. The single-molecule valve marks the first step towards the goal, which could one day revolutionize chemistry, biology, and materials science, as well as transform various industries,” said Professor Xu.