BEIJING, September 8, 2016: An examination of the ornamental fish market in southern China has led to the discovery of a new species and even a new genus of freshwater crab, researchers have reported.
Knowing about the growing demand for eye-catching freshwater crabs from southern China, the authors took a look at the ornamental fish market to eventually identify an individual with unusually structured male gonopod, which in crustaceans is a swimming appendage modified to serve as a reproductive organ.
O hi there i am a new genus and species of crab found in a pet market
Having their interest drawn by the peculiar crab, study leads author Chao Huang from Sun Yat-sen University in China managed to persuade the fish dealer to let them survey the collection site located in Guangdong, southern China.
Despite the superficial resemblance to an already existing freshwater crab genus, at second glance, the crab turned out to be quite distinct thanks to a unique set of features including the carapace, the monopod and the relatively long and slender legs.
Once the molecular analyses’ results were also in, the authors had enough evidence to assign the freshwater crab as a species and even a genus new to science.
Being a primarily aquatic species, the new crab prefers the pools of limestone hill streams, therefore its name Yuebeipotamon calciatile, where calciatile means ‘living on limestone’.
To adapt to the habitat, the species seems to have developed its characteristic slender legs, which make it easier for the crab to climb and move around whenever the short-lived limestone hill streams make it search for a new home, the researchers reported in the journal ZooKeys.
The carapace of the new crab is usually coloured in maroon to dark brown, while the claws and legs are reddish to purplish, the study said. (IANS)
Eliminating dead-but-toxic cells occurring naturally in the brains of mice designed to mimic Alzheimer’s slowed neuron damage and memory loss associated with the disease, according to a study published Wednesday that could open a new front in the fight against dementia.The accumulation in the body of “zombie cells” that can no longer divide but still cause harm to other healthy cells, a process called senescence, is common to all mammals.
Scientists have long known that these dead-beat cells gather in regions of the brain linked to old age diseases ranging from osteoarthritis and atherosclerosis to Parkinson’s and dementia.
Prior research had also shown that the elimination of senescent cells in ageing mice extended their healthy lifespan.
But the new results, published in Nature, are the first to demonstrate a cause-and-effect link with a specific disease, Alzheimer’s, the scientists said.
But any treatments that might emerge from the research are many years down the road, they cautioned.
In experiments, a team led by Tyler Bussian of the Mayo Clinic in Rochester, Minnesota used mice genetically modified to produce the destructive, cobweb-like tangles of tau protein that form in the neurons of Alzheimer’s patients.
The mice were also programmed to allow for the elimination of “zombie” cells in the same region.
“When senescent cells were removed, we found that the diseased animals retained the ability to form memories, and eliminated signs of inflammation,” said senior author Darren Baker, also from the Mayo Clinic.
The mice likewise failed to develop Alzheimer’s signature protein “tangles”, and retained normal brain mass.
Keeping zombies at bay
A closer look revealed that the “zombies” belonged to a class of cells in the brain and spinal cord, called glia, that provide crucial support and insulation to neurons.
“Preventing the build-up of senescent glia can block the cognitive decline and neuro-degeneration normally experienced by these mice,” Jay Penney and Li-Huei Tsai, both from MIT, wrote in a comment, also in Nature.
Bussian and his team duplicated the results with pharmaceuticals, suggesting that drugs could one day slow or block the emergence of Alzheimer’s by keeping these zombie cells at bay.
“There hasn’t been a new dementia drug in 15 years, so it’s exciting to see the results of this promising study in mice,” said James Pickett, head of research at Alzheimer’s Society in London.
For Lawrence Rajendran, deputy director of the Dementia Research Institute at King’s College London, the findings “open up new vistas for both diagnosis and therapy for neurodegenerative diseases, including Alzheimer’s.”
Up to now, dementia research has been mostly focused on the diseased neurons rather than their neighboring cells.
“It is increasingly becoming clear that other brains cells play a defining role,” Rajendran added.
Several barriers remain before the breakthrough can be translated into a “safe, effective treatment in people,” Pickett and other said.
The elderly often have lots of harmless brain cells that look like the dangerous senescent cells a drug would target, so the molecule would have to be good at telling the two apart.