Archive for the ‘PLoS Genetics’ Category


Workflow for 3D face scan processing, including the A) original surface, B) trimmed to exclude non-face parts, C) reflected to make mirror image, D) anthropometric mask of quasi-landmarks, E) remapped, F) reflected remapped, G) symmetrized and H) reconstructed.

By Philip Ross

Could a single hair be used to make an accurate 3D model of a criminal suspect’s face? Researchers from the U.S. and Belgium have developed a computer program that renders a crude genetic “mugshot” from a small sample of DNA.

Forensics can already predict eye and hair color relatively easily. Io9 notes that criminal investigators can even use maggots to extract a victim’s DNA from their unidentifiable body or find hidden faces by zooming into hi-res photos of eyes. But the face is a complex structure that’s more difficult to map from just one DNA sample.

According to New Scientist, researchers used a stereoscopic camera to make 3D images of roughly 600 volunteers with mixed European and West African ancestry. They identified more than 7,000 distinct points on the face to see how sex and racial ancestry affect the position of these points. The variations were used to develop a statistical model that reconstructs the overall shape of a person’s face.

The team also isolated 24 genetic variants, called single nucleotide polymorphisms, which play a role in shaping a face, such as those that shape the head during embryonic development. Lastly, researchers had volunteers rate the 600 faces on perceived ethnicity as well as on a scale of masculinity and femininity.

The new study, published in the journal PLOS Genetics, says this process could allow investigators to make computer-generated mugshots from genetic material left at a crime scene.

“We show that facial variation with regard to sex, ancestry, and genes can be systematically studied with our methods, allowing us to lay the foundation for predictive modeling of faces,” the authors note. “Such predictive modeling could be forensically useful; for example, DNA left at crime scenes could be tested and faces predicted in order to help to narrow the pool of potential suspects. Further, our methods could be used to predict the facial features of descendants, deceased ancestors, and even extinct human species. In addition, these methods could prove to be useful diagnostic tools.”

Any 3D renderings created using the new technology wouldn’t be used in a court of law – any person identified via the DNA mugshots would still have his DNA compared to the crime scene sample – but it could at least narrow the search for a suspected criminal. And there are still a few kinks to work out in the process before the technology is ever used in the field.

“I believe that in five to 10 years’ time, we will be able to computationally predict a face,” Peter Claes of the Catholic University of Leuven in Belgium told New Scientist.

http://www.ibtimes.com/dna-mugshot-how-crime-fighting-computer-sketch-program-can-predict-face-your-genes-1563049

Thanks to Da Brayn for bringing this to the attention of the It’s Interesting community.

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An Indiana man’s nasty injury led scientists to discover a new type of bacteria that sheds light on symbiotic microbes in insects.

Two years ago, Thomas Fritz cut down a dead crab apple tree in his yard. He fell while hauling away the woody debris and a branch from the tree impaled his right hand between the thumb and index finger.

Fritz, a 71-year-old retired inventor, engineer and volunteer firefighter, bandaged the gash himself. He waited a few days to see a doctor and by the time of his appointment, the puncture wound became infected. The doctor took a sample of the cyst that formed at the site of the cut and sent it to a lab.

After an abscess, swelling and more pain, Fritz’s wound eventually healed. But the sample from his infection puzzled scientists at the lab who couldn’t identify what type of bacteria they were looking at. The sample was eventually sent to ARUP Laboratories, a national pathology reference library operated by the University of Utah, where scientists named the new strain human Sodalis or HS.

Colin Dale, a biologist at the University of Utah, said that genetic analyses of HS showed it is related to Sodalis, a genus of bacteria that he discovered in 1999 and has been found to live symbiotically in 17 insect species, including tsetse flies, weevils, stinkbugs and bird lice. In such symbiotic relationships, both the host and the bacteria gain — for example, while Sodalis bacteria get shelter and nutrition from their insect hosts, they also provide the insects vital B vitamins and amino acids.

Though symbiotic relationships between microorganisms and insects are common, their origins are often a mystery. The new evidence provides “a missing link in our understanding of how beneficial insect-bacteria relationships originate,” Dale said, adding that the findings show that these relationships arise independently in each insect.

As the strain of Sodalis in this case likely came from a tree, the discovery suggests that insects can get infected by pathogenic bacteria from plants or animals in their environment, and the bacteria can evolve to become less virulent and to provide symbiotic benefits to the insect. Then, instead of spreading the bacteria to other insects by infection, mother insects pass down the microbes to their offspring, the researchers said.

“The insect picks up a pathogen that is widespread in the environment and then domesticates it,” Dale explained in a statement from the National Science Foundation, which funded the research. “This happens independently in each insect.”

The research was detailed earlier this month online in the journal PLoS Genetics.

http://www.livescience.com/25035-wound-leads-to-bacteria-discovery.html