How gene shaped human face

Researchers from KU Leuven (Belgium) and the universities of Pittsburgh, Stanford, and Penn State (US) have identified fifteen genes that determine human facial features. Human DNA determines what an individual look like, including facial features. That appeals to the popular imagination, as the potential applications are obvious. Doctors could use DNA for skull and facial reconstructive surgery, forensic examiners could sketch a perpetrator's face on the basis of DNA retrieved from a crime scene, and historians would be able to reconstruct facial features using DNA from days long gone.

In a new study conducted by KU Leuven in collaboration with the universities of Pittsburgh, Stanford and Penn State, the researchers adopted a different approach. "Our search doesn't focus on specific traits," lead author Peter Claes (KU Leuven) explains. "My colleagues from Pittsburgh and Penn State each provided a database with 3D images of faces and the corresponding DNA of these people. Each face was automatically subdivided into smaller modules. Next, we examined whether any locations in the DNA matched these modules. This modular division technique made it possible for the first time to check for an unprecedented number of facial features."

The scientists were able to identify fifteen locations in human DNA. The Stanford team found out that genomic loci linked to these modular facial features are active when human face develops in the womb. "Furthermore, we also discovered that different genetic variants identified in the study are associated with regions of the genome that influence when, where and how much genes are expressed," says Joanna Wysocka (Stanford). Seven of the fifteen identified genes are linked to the nose, and that's good news, Peter Claes (KU Leuven) continues. "

A skull doesn't contain any traces of the nose, which only consists of soft tissue and cartilage. Therefore, when forensic scientists want to reconstruct a face on the basis of a skull, the nose is the main obstacle. If the skull also yields DNA, it would become much easier to determine the shape of the nose. Age, environment, and lifestyle have an impact on what human face looks like, this could provide genetic insight into the shape and functioning of human brain, as well as in neurodegenerative diseases such as Alzheimer's."
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Viruses share gene with some organisms

A new study finds that viruses share some genes exclusively with cells that are not their hosts, viruses swap genes with a variety of cellular organisms and are agents of diversity. The study looked at protein structures in viruses and across all domains of life: from the single-celled microbes known as bacteria and archaea, to eukaryotes, a group that includes animals, plants, fungi and all other living things.

Viruses that infect archaea and bacteria, for example, are not known to infect eukarya. However, they may still interact in non harmful ways with organisms they do not infect. The team used a bioinformatics approach to analyze the genomes of organisms and the viruses that infect them. Rather than focusing on genetic sequences, which can change over the generations, the team examined the functional components of proteins, which they call folds.

 There are more than 1,400 of folds across all domains of life-has a unique 3-D structure that performs a specific operation. Because folds are critical to protein function, they remain stable even as the sequences that code for them change as a result of mutations or other processes.This makes protein folds reliable markers of evolutionary changes over vast time periods, especially for viruses that mutate notoriously fast.

The researchers found hundreds of folds that are present across all domaind of life and in all types of viruses, which suggests that they came from an ancient ancestor of all life forms. Some folds, however, occur only within a single domain and the viruses that infect it, suggesting a transfer of genetic material only between that group of viruses and their hosts. Out of a total of about 2,000 superfamilies of folds, the team found one that was exclusive to archaea and the viruses that infect archaea, 29 shared only by bacteria and the viruses that infect them, and 37 that are exclusive to eukaryotes and their viruses.

The data also point to other, as yet unknown, mechanisms that allow viruses to exchange genetic material with cells, many virus-hallmark genes in cellular organisms those viruses are not known to infect. People tend to think only about viruses that infect and kill their hosts, we have known for decades that a virus will sometimes enter into a cell and incorporate its genetic material into the cell without killing it. In the case of single-celled organisms, those genes are sometimes passed along to future generations. Human DNA, too, contains remnants of viruses.

Some retroelements and transposons are believed to have originated in ancient viruses. Retroelements are sequences copied from RNA viruses into DNA and inserted into the genomes of nonviral organisms. Transposons, also known as "jumping genes," can move from one part of the genome to another.The team also discovered a large subset of virus-specific protein folds that were not present in any cellular genomes. This suggests that viruses can create new genes and, potentially, transfer those genes to cellular organisms.
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Lung cancer genetic biomarkers

Single-nucleotide polymorphisms SNPs are variations in human DNA that determine human susceptibility to developing some diseases. Using the largest genome-wide SNP-smoking interaction analysis reported for lung cancer, researchers identified three novel SNPs. The results from their study reinforce that gene-smoking interactions play important roles in the etiology of lung cancer and responsible for part of the missing heritability of this disease.

Environmental and genetic risk factors contribute to development of lung cancer. Tobacco smoking is the most well-known environmental risk factor associated with lung cancer. They conducted a study to display that gene-smoking interactions play important roles in the etiology of lung cancer.

In their study, three novel SNPs (single-nucleotide polymorphisms), or variations in our DNA that underlie human susceptibility to developing disease, were identified in the interaction analysis, including two SNPs for non-small cell lung cancer risk and one SNP for squamous cell lung cancer risk. The three identified novel SNPs provide potential candidate biomarkers for lung cancer risk screening and intervention.

The genotype and phenotype data used in this analysis came from OncoArray Consortium. Genome-wide interaction scanning remains a challenge as most genome-wide association studies are designed for main effect association analysis and have limited power for interaction analysis.

The three SNPs, identified in the team's study, stratify lung cancer risk by smoking behavior. These three SNPs can be potential biomarkers used to improve the precision to which researchers can categorize an individual's risk of lung cancer disease by smoking behavior, which are helpful for individualized prognosis and prediction of treatment plan.
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