First synthetic bacterial cell created
ROCKVILLE, Md., May 20 (UPI) — U.S. scientists announced Thursday they have constructed the world’s first self-replicating, synthetic bacterial cell.
Researchers at the J. Craig Venter Institute, a not-for-profit genomic research organization, said they synthesized the 1.08 million base pair chromosome of a modified Mycoplasma mycoides genome. The scientists said their synthetic cell is the proof of principle that genomes can be designed by computer, chemically made in a laboratory and transplanted into a recipient cell to produce a new self-replicating cell controlled only by the synthetic genome.
Writing in the opinion section of the journal Nature, one leading synthetic biology scientist — University of Pennsylvania Professor of bioethics Arthur Caplan — called the accomplishment “one of the most important scientific achievements in the history of mankind.” But former University of Florida Professor Steven Benner, creator of the Foundation for Applied Molecular Evolution, cautioned the technique could resurrect long extinct ancestral bacteria.
“For nearly 15 years Ham Smith, Clyde Hutchison and the rest of our team have been working toward this publication today — the successful completion of our work to construct a bacterial cell that is fully controlled by a synthetic genome,” said J. Craig Venter, the institute’s founder and senior author on the research.
“We have been consumed by this research, but we have also been equally focused on addressing the societal implications of what we believe will be one of the most powerful technologies and industrial drivers for societal good,” he added. “We look forward to continued review and dialogue about the important applications of this work to ensure that it is used for the benefit of all.”
The historic research is reported in the online journal Science Express and will appear in an upcoming print issue of the journal Science.
Belly-fat linked to later dementia risk
BOSTON, May 20 (UPI) — U.S. researchers have linked increased abdominal fat at middle-age with greater dementia risk later.
Researchers at Boston University School of Medicine said their preliminary findings indicated an association of excess abdominal fat in middle-age in otherwise healthy people to greater later risk of Alzheimer’s disease and other forms of dementia.
The study, published in the Annals of Neurology, also confirmed a finding of smaller studies that obesity is associated with lower total brain volume
“Our findings, while preliminary, provide greater understanding of the mechanisms underlying the link between obesity and dementia,” Dr. Sudha Seshadri said in a statement. “Further studies will add to our knowledge and offer important methods of prevention.”
Seshadri and colleagues looked at data — including magnetic resonance imaging scans of the brain — for 730 participants recruited from the Framingham Heart Study Offspring Cohort. The average age of a participant was age 60 years and about 70 percent were women.
Fish looking at themselves become fearful
STANFORD, Calif., May 20 (UPI) — U.S. biologists say fish looking at themselves in a mirror become feisty but fearful, suggesting more brain activity than had been suspected.
Stanford University Professor Russell Fernald, postdoctoral researcher Julie Desjardins and colleagues said the behavior suggests the fish are encountering something so far outside their realm of experience, it results in an emotional response.
The scientists compared the behavior and brain activity of male African cichlids during and after one-on-one encounters with either a mirror or other another male of about the same size.
Territorial male cichlids usually react to another male by trying to fight with it in a sort of tit-for-tat manner. Desjardins suspects the fish fighting their own reflections become fearful because the enemy in the mirror doesn’t exhibit the reactions they expect from another fish.
“In normal fights, they bite at each other, one after the other … but it is always slightly off or even alternating in timing,” Desjardins said. “But when you are fighting with a mirror, your opponent is perfectly in time. So the subject fish really is not seeing any sort of reciprocal response from their opponent.”
The discovery that fish can discern a difference so subtle “opens the door for us to better understand what is going on in the brain of non-mammalian animals,” Desjardins said.
The study is to appear in the journal Biology Letters.
Did end of smallpox vaccinations hike HIV?
FAIRFAX, Va., May 20 (UPI) — U.S. scientists suggest the end of widespread small pox vaccinations toward the end of the 20th century might have resulted in the rapid spread of HIV.
Dr. Raymond Weinstein of George Mason University and a team of researchers from UCLA and George Washington University said the vaccine given to prevent the spread of smallpox produces a five-fold reduction in HIV replication in the laboratory. That, they said, suggests ending smallpox vaccinations might have caused a loss of protection against the human immunodeficiency virus.
The researchers said they looked at the ability of white blood cells taken from people recently immunized against smallpox to support HIV replication compared to unvaccinated controls. They found significantly lower viral replication in blood cells from vaccinated individuals.
“There have been several proposed explanations for the rapid spread of HIV in Africa, including wars, the reuse of unsterilized needles and the contamination of early batches of polio vaccine. However, all of these have been either disproved or do not sufficiently explain the behavior of the HIV pandemic,” Weinstein said. “Our finding that prior (smallpox) immunization … may provide an individual with some degree of protection to subsequent HIV infection suggests the (widespread) withdrawal of such vaccination may be a partial explanation.”
The study is reported in the journal BMC Immunology.
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