Joe Raedle/Getty

Vast stores of DNA samples and data have been produced by the increasing pace of genetic sequencing.

Early last year, three researchers set out to create one genetic data set to rule them all. The trio wanted to assemble the worlds most comprehensive catalogue of human genetic variation, a single reference database that would be useful to researchers hunting rare disease-causing genetic variants.

Unlike past big data projects, which have involved large groups of scientists, this one deliberately kept itself small, deploying just five analysts. Nearly two years in, it has identified about 50million genetic variants points at which one persons DNA differs from anothers in whole-genome sequence data collected by 23other research collaborations. The group, called the Haplotype Reference Consortium, will unveil its database in San Diego, California, on 20October, at the annual meeting of the American Society of Human Genetics.

Geneticists have not always been so willing to share data. But that seems to be changing. Its been surprisingly easy to bring all these data sets together, says Jonathan Marchini, a statistical geneticist at the University of Oxford, UK, and one of the consortiums leaders. There is a lot of goodwill between the people in the field; they all understand the benefits of doing this and have worked hard to make their data available.

In the past five years, there has been an explosion in rates of sequencing human genomes thanks to the falling cost of the technology. At the same time, geneticists have realized that linking genes to diseases and traits will require much bigger sample sizes than any one research centre can assemble.

It was once assumed that common diseases and traits could be traced to a few common genetic variants that would be relatively easy to find. But that has turned out not to be the case. It is now clear that thousands of different variants each play a small part in determining a persons height or risk of schizophrenia, for example. And finding those thousands of variants means looking at a daunting number of people. At the same time, the increased pace of genetic sequencing has made it possible to collect enough genomes to uncover those variants.

Here are a bunch of data sets that individually cost millions of dollars to generate, and you have people willing to make that data available to a shared resource, which is amazing, says geneticist Daniel MacArthur of Massachusetts General Hospital in Boston.

MacArthur is part of the Exome Aggregation Consortium, another attempt to create a supersized library of human genetic variation. On 20October, MacArthur and his colleagues plan to unveil their own public database containing the protein-coding portions, or exomes, of 63,000 human genomes originally gathered by other researchers. We can say from looking at a very large cohort of peoplethis is what the distribution of rare variation looks like, says MacArthur. And that is very powerful.

MacArthur is developing tools to comb the data for mutations that disable genes. Only some of these loss-of-function mutations cause harm; predicting which are pathogenic will require knowing more about which ones regularly occur in healthy people.

See more here:

Giant gene banks take on disease

Human genetics : gel electrophoresis

By: Petchploy Rungkamoltip

Follow this link:

Human genetics : gel electrophoresis - Video

Human Genetics Molecular Biology of Gene
Human Genetics Molecular Biology of the Gene.

By: GEBRI usc

Visit link:

Human Genetics Molecular Biology of Gene - Video

PUBLIC RELEASE DATE:

9-Oct-2014

Contact: Kevin Jiang kevin.jiang@uchospitals.edu 773-795-5227 University of Chicago Medical Center @UChicagoMed

The National Institute on Drug Abuse (NIDA) has awarded the University of Chicago a $12 million, five year grant to establish a national Center of Excellence to study drug abuse-associated behaviors by conducting research with rats.

Led by Abraham Palmer, PhD, associate professor of human genetics, the NIDA Center for Genome-Wide Association Studies in Outbred Rats will combine complex behavioral studies with recent technological advances in rat genetics to help scientists shed light on the genes behind drug addiction.

Rats have a long and storied history as an important animal model for research, especially in behavioral studies. But in recent decades, the use of rats has given way to mice because of innovations in the manipulation of mouse genomes. This shift has affected certain research fields, particularly the study of drug abuse and addiction, where behavioral tasks are often too complex for mice to perform. That's led to a slowdown in research aimed at revealing the genetics thought underlie drug abuse-related behaviors.

"The odds of permanently recovering from drug addiction are low and there is currently very little understanding of why that is," Palmer said. "With an animal system, we have a powerful advantage in that once we've found a genetic location or pathway, we can easily manipulate the gene and measure the resulting effects. The use of rats is critical because many of the behaviors we will study have proven difficult or impossible to adapt for mice."

A rat revival

To shed light on the genetics behind complex traits such as drug abuse behavior, the researchers will utilize genome-wide association studies (GWAS) an examination of the entire genomes of different individuals to reveal genetic variants linked with particular traits. Research groups around the country will perform experiments exploring separate behaviors, and send samples to UChicago for genetic analysis. This allows the center to study the genetics of multiple aspects of drug abuse efficiently and at a much more rapid pace than previously possible.

While most animal studies use almost genetically identical subjects, GWAS studies require large numbers of unrelated individuals. The center will support a comprehensive breeding program that provides researchers with a unique population of rats that have been bred to maintain as much genetic diversity as possible. Studies will be performed on both male and female rats to explore the relationship between gender, drug abuse behavior and genetics.

Read more:

University of Chicago establishes national center to study genetics of drug abuse in rats

PUBLIC RELEASE DATE:

9-Oct-2014

Contact: Mary Beth O'Leary moleary@cell.com 617-397-2802 Cell Press @CellPressNews

Neurodevelopmental disorders such as Down syndrome and autism-spectrum disorder can have profound, lifelong effects on learning and memory, but relatively little is known about the molecular pathways affected by these diseases. A study published by Cell Press October 9th in the American Journal of Human Genetics shows that neurodevelopmental disorders caused by distinct genetic mutations produce similar molecular effects in cells, suggesting that a one-size-fits-all therapeutic approach could be effective for conditions ranging from seizures to attention-deficit hyperactivity disorder.

"Neurodevelopmental disorders are rare, meaning trying to treat them is not efficient," says senior study author Carl Ernst of McGill University. "Once we fully define the major common pathways involved, targeting these pathways for treatment becomes a viable option that can affect the largest number of people."

A large fraction of neurodevelopmental disorders are associated with variation in specific genes, but the genetic factors responsible for these diseases are very complex. For example, whereas common variants in the same gene have been associated with two or more different disorders, mutations in many different genes can lead to similar diseases. As a result, it has not been clear whether genetic mutations that cause neurodevelopmental disorders affect distinct molecular pathways or converge on similar cellular functions.

To address this question, Ernst and his team used human fetal brain cells to study the molecular effects of reducing the activity of genes that are mutated in two distinct autism-spectrum disorders. Changes in transcription factor 4 (TCF4) cause 18q21 deletion syndrome, which is characterized by intellectual disability and psychiatric problems, and mutations in euchromatic histone methyltransferase 1 (EHMT1) cause similar symptoms in a disease known as 9q34 deletion syndrome.

Interfering with the activity of TCF4 or EHMT1 produced similar molecular effects in the cells. Strikingly, both of these genetic modifications resulted in molecular patterns that resemble those of cells that are differentiating, or converting from immature cells to more specialized cells. "Our study suggests that one fundamental cause of disease is that neural stem cells choose to become full brain cells too early," Ernst says. "This could affect how they incorporate into cellular networks, for example, leading to the clinical symptoms that we see in kids with these diseases."

###

The American Journal of Human Genetics, Chen et al.: "Molecular convergence of neurodevelopmental disorders."

The rest is here:

Multiple neurodevelopmental disorders have a common molecular cause

Contact Information

Available for logged-in reporters only

Newswise To reduce false positives when identifying genetic variations associated with human disease through genome-wide association studies (GWAS), Dartmouth researchers have identified nine traits that are not dependent on P values to predict single nucleotide polymorphisms (SNP) reproducibility as reported in Human Genetics on October 2, 2014.

Reproducibility rates of SNPs based solely on P values is low. Dartmouth authors analysis of GWAS studies published in Nature Genetics showed a 1-5 percent replication rate.

It is important to improve our ability to select SNPs for validation using a formalized process. In this paper, we propose a combination of traits that improve replication success, said first author Ivan P. Gorlov, PhD, DSC, associate professor of Community and Family Medicine, Geisel School of Medicine at Dartmouth.

The team assigned a value of zero or one to nine different predictors. To compute the Replication Score (RS), one totals the individual scores for all significant predictors. The predictors include Online Mendelian Inheritance in Man (OMIM, a list of genetically caused diseases), receptors, kinases, growth factors, transcription factors, tissue specific, plasma membrane localization, nuclear localization and conversation index. The authors provided detailed information to construct the RS in supplementary material to the paper.

An RS score is not disease specific but shows the potential for impact on human disease. The disease-associated genes have something in common, said Gorlov. And we know what specific characteristics should be present to ensure the SNP is likely to be replicated

Gorlov says the empirical model can be used to select SNPs for validation and prioritization. We believe that RS-based SNP prioritization may provide guidance for more targeted and powered approach to detecting the disease-associated SNPs with small effect size, he concluded.

This work was supported in part by the National Institutes of Health U19 CA148127 Grant and the National Institutes of Health Grants 5 P30 CA016672, LM009012, LM010098 and GM103534. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

About Norris Cotton Cancer Center at Dartmouth-Hitchcock Norris Cotton Cancer Center combines advanced cancer research at Dartmouth and the Geisel School of Medicine with patient-centered cancer care provided at Dartmouth-Hitchcock Medical Center, at Dartmouth-Hitchcock regional locations in Manchester, Nashua, and Keene, NH, and St. Johnsbury, VT, and at 12 partner hospitals throughout New Hampshire and Vermont. It is one of 41 centers nationwide to earn the National Cancer Institutes Comprehensive Cancer Center designation. Learn more about Norris Cotton Cancer Center research, programs, and clinical trials online at cancer.dartmouth.edu.

Here is the original post:

Dartmouth Researchers Develop Reproducibility Score for SNPs Associated with Human Disease in GWAS

PUBLIC RELEASE DATE:

8-Oct-2014

Contact: Robin Dutcher robin.Dutcher@hitchcock.org 603-653-9056 The Geisel School of Medicine at Dartmouth

Lebanon, NH, 10/8/14 To reduce false positives when identifying genetic variations associated with human disease through genome-wide association studies (GWAS), Dartmouth researchers have identified nine traits that are not dependent on P values to predict single nucleotide polymorphisms (SNP) reproducibility as reported in Human Genetics on October 2, 2014.

Reproducibility rates of SNPs based solely on P values is low. Dartmouth authors' analysis of GWAS studies published in Nature Genetics showed a 1-5 percent replication rate.

"It is important to improve our ability to select SNPs for validation using a formalized process. In this paper, we propose a combination of traits that improve replication success," said first author Ivan P. Gorlov, PhD, DSC, associate professor of Community and Family Medicine, Geisel School of Medicine at Dartmouth.

The team assigned a value of zero or one to nine different predictors. To compute the Replication Score (RS), one totals the individual scores for all significant predictors. The predictors include "Online Mendelian Inheritance in Man" (OMIM, a list of genetically caused diseases), receptors, kinases, growth factors, transcription factors, tissue specific, plasma membrane localization, nuclear localization and conversation index. The authors provided detailed information to construct the RS in supplementary material to the paper.

An RS score is not disease specific but shows the potential for impact on human disease. "The disease-associated genes have something in common," said Gorlov. "And we know what specific characteristics should be present to ensure the SNP is likely to be replicated"

Gorlov says the empirical model can be used to select SNPs for validation and prioritization. "We believe that RS-based SNP prioritization may provide guidance for more targeted and powered approach to detecting the disease-associated SNPs with small effect size," he concluded.

###

View post:

Researchers develop reproducibility score for SNPs associated with human disease in GWAS

Contact Information

Available for logged-in reporters only

Newswise (PHILADELPHIA) Transfer RNAs (tRNAs) are ancient workhorse molecules and part of the cellular process that creates the proteins, critical building blocks of life that keep a cell running smoothly. A new discovery suggests that the number of human genomic loci that might be coding for tRNAs is nearly double what is currently known. Most of the newly identified loci resemble the sequences of mitochondrial tRNAs suggesting unexpected new links between the human nuclear and mitochondrial genomes, links that are not currently understood.

Transfer RNAs (tRNAs) represent an integral component of the translation of a messenger RNA (mRNA) into an amino acid sequence. TRNAs are non-coding RNA molecules and can be found in all three kingdoms of life i.e., in archaea, bacteria and eukaryotes.

At the DNA level, a triplet of consecutive nucleotides known as the codon is used to encode an amino acid. Frequently, a given amino acid can be encoded by more than one codon: in fact, there are 61 distinct codons encoding the 20 standard human amino acids. During translation, each of the codons contained in the coding region of the mRNA at hand is recognized by its matching tRNA and the corresponding amino acid added to the nascent amino acid sequence. It has been known for many years that each of these 61 tRNAs has multiple copies spread throughout the genome that is found in the human nucleus. The presence of multiple genomic loci from which the same molecule can be made is a fairly standard trick of genomic organization: processing these loci in parallel can ensure that adequate amounts of each tRNA can be generated quickly enough to meet the high demand that the amino acid translation process imposes on the cell. In addition to the 61 tRNAs that are found in the human nuclear genome, 22 more tRNAs are encoded in the genome of the cellular organelle known as the mitochondrion: the mitochondrion, originally a bacterium itself, uses these 22 tRNAs to make proteins out of the just-over-a-dozen mRNAs that are encoded in its genome.

Recent research efforts have shown that tRNAs can have other roles, which go beyond their involvement in protein synthesis. For example, tRNAs can affect the physiology of a cell, they can modulate the abundance of important molecules, etc. These and other unexpected findings have revived interest in looking at tRNAs, this time under a different prism. But, how many tRNAs are actually encoded by the human genome and could be potentially involved in amino acid translation and other processes?

A team led by Isidore Rigoutsos, Director of the Computational Medicine Center at Thomas Jefferson University (TJU), set out to tackle this question and they have reported their findings in a study that was just published in the journal Frontiers in Genetics. What we found, frankly, surprised us, said Rigoutsos.

The team searched the 3 billion base pairs of the human genome for DNA sequences that resembled the 530 known nuclear and mitochondrial tRNAs. Even though they used very stringent criteria in their searches, they found 454 lookalike loci, i.e., sequences that look like tRNA, but havent yet been experimentally confirmed as such. The researchers found nearly as many as the known ones with which they started: 81% of these tRNA-lookalikes had not been reported previously. Rather unexpectedly, the team found that most of these new loci resembled some of the 22 mitochondrial tRNAs.

Interestingly, the discovered tRNA lookalikes are not spread uniformly across the 24 chromosomes. Instead, they have penetrated preferentially some chromosomes and have avoided others. For example, chromosomes 1, 2, 7, 8 and 9 claim the lions share of the discovered tRNA-lookalikes. On the other hand, chromosome 18 contains no lookalikes. Also, some of the codons are particularly over-represented among the lookalikes whereas other codons are absent.

The surprises did not stop there. The team also discovered that in the chromosomes where the tRNA-lookalikes are found their locations are not accidental either. Instead, the lookalikes are positioned in close proximity to known nuclear tRNAs. This of course begs the question whether the tRNA-lookalikes are transcribed, just like the known tRNAs. By examining public repositories, the team found evidence of transcription for more than 20% of the discovered tRNA-lookalikes: the transcriptional profiles appear to depend on cell type, which suggests that more of the look-alikes will be found to be transcribed as data from more cell types become available. On several occasions, the public data revealed evidence for molecules whose endpoints matched exactly the endpoints of the tRNA-lookalikes discovered by the team. This is certainly exciting, but it is currently unclear whether these molecules participate in translation as tRNAs, or have entirely different roles, said Rigoutsos.

Originally posted here:

Conspicuous tRNA Lookalikes Riddle the Human Genome

To reduce false positives when identifying genetic variations associated with human disease through genome-wide association studies (GWAS), Dartmouth researchers have identified nine traits that are not dependent on P values to predict single nucleotide polymorphisms (SNP) reproducibility as reported in Human Genetics on October 2, 2014.

Reproducibility rates of SNPs based solely on P values is low. Dartmouth authors' analysis of GWAS studies published in Human Genetics showed a 1-5 percent replication rate.

"It is important to improve our ability to select SNPs for validation using a formalized process. In this paper, we propose a combination of traits that improve replication success," said first author Ivan P. Gorlov, PhD, DSC, associate professor of Community and Family Medicine, Geisel School of Medicine at Dartmouth.

The team assigned a value of zero or one to nine different predictors. To compute the Replication Score (RS), one totals the individual scores for all significant predictors. The predictors include "Online Mendelian Inheritance in Man" (OMIM, a list of genetically caused diseases), receptors, kinases, growth factors, transcription factors, tissue specific, plasma membrane localization, nuclear localization and conversation index. The authors provided detailed information to construct the RS in supplementary material to the paper.

An RS score is not disease specific but shows the potential for impact on human disease. "The disease-associated genes have something in common," said Gorlov. "And we know what specific characteristics should be present to ensure the SNP is likely to be replicated."

Gorlov says the empirical model can be used to select SNPs for validation and prioritization. "We believe that RS-based SNP prioritization may provide guidance for more targeted and powered approach to detecting the disease-associated SNPs with small effect size," he concluded.

Story Source:

The above story is based on materials provided by The Geisel School of Medicine at Dartmouth. Note: Materials may be edited for content and length.

Original post:

Reproducibility score for SNPs associated with human disease in GWAS

Contact Information

Available for logged-in reporters only

Newswise The Gordon and Betty Moore Foundation today announced the University of Chicagos Matthew Stephens as the recipient of a Moore Investigator in Data-Driven Discovery award. Stephens, a professor in statistics and human genetics, is among 14 scientists from academic institutions nationwide who will receive a total of $21 million over five years to catalyze new data-driven scientific discoveries. Stephens grant is for $1.5 million.

These Moore Investigator Awards are part of a $60 million, five-year Data-Driven Discovery Initiative within the Gordon and Betty Moores Science Program. The initiativeone of the largest privately funded data scientist programs of its kindis committed to enabling new types of scientific breakthroughs by supporting interdisciplinary, data-driven researchers.

Science is generating data at unprecedented volume, variety and velocity, but many areas of science dont reward the kind of expertise needed to capitalize on this explosion of information, said Chris Mentzel, program director of the Data-Driven Discovery Initiative. We are proud to recognize these outstanding scientists, and we hope these awards will help cultivate a new type of researcher and accelerate the use of interdisciplinary, data-driven science in academia.

Stephens is a data scientist who develops statistical and computational analysis tools for the large datasets being generated in the biological sciences. Over the last 15 years, Stephens and his collaborators have made seminal contributions to several problems in population genetics, including identifying structure (clusters) in genetic data, and modeling correlations among genetic variants.

The methods for identifying structure, which Stephens developed with his collaborators (Jonathan Pritchard, Peter Donnelly and Daniel Falush), have driven scientific discoveries in hundreds of organisms. Science papers in 2002, 2003, and 2004 used their method to elucidate the genetic structure of human populations, the Heliobacter pylori stomach bacterium, and domestic dog breeds, respectively. The original paper of Stephens and his collaborators has been cited more than 11,000 times. And, in an example of the potential for cross-fertilization of ideas across disciplines, similar methods have also become popular in machine learning to identify structure in large collections of text documents.

Stephenss work modeling correlations among genetic variants began with a paper in 2003, with graduate student Na Li, PhD03. At the time scientists were grappling with a problem: they had an elegant model (based on work by UChicagos Richard Hudson, professor in ecology & evolution) relating these correlations to the underlying recombination process, which mixes a parents genetic material before transmission to an offspring, but these models were computationally intractable for even small datasets.

Li and Stephens solved this problem by simplifying the model enough to make it computationally tractable. This new simplified model has found widespread application in the last 10 years: Stephens, Li and their collaborators used their model to demonstrate that most recombination in human genes occurs in relatively narrow channels (``hotspots) rather than being spread uniformly. And thousands of scientists conducting genomic studies now make regular use of these models to impute missing genotype data to substantially improve the efficacy of their studies.

Stephenss recent focus has been on developing methods for data integration combining information on multiple related processes. An important application of these methods which he has been pursuing with collaborators, including Yoav Gilad, Jonathan Pritchard and Anna DiRienzo - is to combine information measured on cellular processes, such as gene expression, and transcription factor binding, to help understand the mechanisms of genetic regulation within living cells.

Link:

Moore Foundation Selects Matthew Stephens for Data-Driven-Discovery Grant

Icelanders love keeping track of how they're related, which has made them "the world champions of human genetics.

A commercial for an Icelandic phone company from a few years ago depicted a couple waking up after a one-night stand. They both pick up their smart phones. They both log into a family-tree website, Islendingabok. And thats where things get awkward.

There are only 320,000 people who live in Iceland, and most are descended from a small clan of Celtic and Viking settlers. Thus, many Icelanders are distant (or close) relatives. Sometimes too close.

The desire to avoid unwitting incestuous pairings at one point even spawned an app, created by a group of engineering students at the University of Iceland, that allows its users to bump their phones together to determine whether they share a common ancestor. (Tag line: Bump in the app before you bump in bed.")

Concerns about wading into the shallow end of the gene pool are just a small part of the Icelandic obsession with genealogy. As Iva Skoch explained in Global Post, when two Icelanders meet, the first question is usually, "Hverra manna ert bu?" (Who are your people?) Bookstores are stocked with thick volumes on the histories of Icelandic families.

For nearly a millennium, careful genealogical records had been kept in the Islendingabok, or Book of Icelanders. In 1997, Icelandic neurologist Kri Stefnsson created a web-based version of Islendingabok in order to offer his countrymen 24/7 access to their family trees. Along with developer Fridrik Skulason, he scoured census data, church records, and family archives in order to encompass what he claims is 95 percent of Icelanders who have lived within the past three centuries. It has since become one of the most popular sites in the country.

If you take the old Icelandic sagas, they all begin with page after page of genealogy, Stefnsson told me. It assures that the common man won't be forgotten.

For Stefnsson, the national preoccupation with heredity has yielded an unexpected professional benefit: Having the genealogy of the entire nation is one of the things that has turned us into the world champions of human genetics.

Because Icelanders do such a good job of tracing their family histories, Stefnsson and his colleagues at Decode, the genetics firm he founded, have a rich trove of data for experiments. So far, hes discovered how specific genetic mutations affect a person's chances of having everything from Alzheimers to blond hair. Hes identified a certain cancer-causing mutation thats much more common in Iceland than in America, and he's uncovered a genetic component to longevity. Most recently, he and many co-authors found that a certain mutation introduced in Iceland in the 15th century is the primary driver of Icelanders risk of hypertrophic cardiomyopathy, a disease in which the heart muscles thicken.

Having the genealogy gives us an opportunity to figure out how everyone is related to everyone else, he said. If you are tracing genes to figure out disease, it is important to figure out, how does this mutation travel from one generation to the next?

Visit link:

How Iceland's Genealogy Obsession Leads to Scientific Breakthroughs

The worlds largest study into the genetics behind human height has discovered the traits vast complexity.

Researchers at The University of Queensland took a leading role in the analysis of more than a quarter of a million samples, finding hundreds of new genes that play a role in determining height.

Co-senior investigator Professor Peter Visscher, from UQs Queensland Brain Institute (QBI), said the discovery would help provide a model for genetic studies of other human traits and of diseases such as psychiatric disorders and dementia.

Just as neuroscientists use experimental organisms as a model to study brain function, geneticists use human height as a model trait to study genetic variation, he said.

The study involved more than 300 organisations across the world and found 697 DNA variants which influence height.

Joint-lead author and QBI researcher Dr Jian Yang said the findings were significant because they proved exactly how complicated human height is.

The DNA variant with the largest effect on height only has an impact of about five millimetres, and most of the other variants have a much smaller effect, Dr Yang said.

Taken together, all DNA variants we discovered account for height differences spanning approximately 11 centimetres.

This shows that the genetic basis for height isnt controlled by a single gene or small group of genes there are thousands of genes involved.

Its estimated that about 80 per cent of a normal healthy individuals height is controlled by heritable genetic factors, and weve only discovered around one-fifth of those genes.

The rest is here:

Genetic building blocks of height revealed

Oct. 5 (UPI) -- Scientists believe they now have a better understanding of what determines height in humans. An international group of researchers came together and studied a group of over 250,000 people from different regions of the world. They located over 400 genome regions that appear to be related to determining height, and they found almost 700 genetic variants.

The research, published in Nature Genetics, claims that around 80 percent of human height is based on genes, while the remaining 20 percent is based on external factors like diet. The researchers involved believe these findings could help treat diseases that can be related to height, like osteoporosis. The study further supports the concept that height is largely based on genetics, as is seen by tall parents bearing taller children. The found genes might help scientists study rare syndromes that cause children to grow unusually tall or unusually little.

2014 United Press International, Inc. All Rights Reserved. Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.

Continued here:

Scientists are closer to understanding human height, new study reports

Human genetics of malaria has uncovered some new clues about susceptibility to severe malaria
Human genetics of malaria has uncovered some new clues about susceptibility to severe malaria. Subscribe this channel to watch more motivational, inspiration...

By: Health, Mind, Body, Spirit

Read the original here:

Human genetics of malaria has uncovered some new clues about susceptibility to severe malaria - Video

PUBLIC RELEASE DATE:

3-Oct-2014

Contact: Noah Brown nbrown9@partners.org 617-643-3907 Massachusetts General Hospital @MassGeneralNews

It has become common for people who have pets to refer to themselves as "pet parents," but how closely does the relationship between people and their non-human companions mirror the parent-child relationship? A small study from a group of Massachusetts General Hospital (MGH) researchers makes a contribution to answering this complex question by investigating differences in how important brain structures are activated when women view images of their children and of their own dogs. Their report is being published in the open-access journal PLOS ONE.

"Pets hold a special place in many people's hearts and lives, and there is compelling evidence from clinical and laboratory studies that interacting with pets can be beneficial to the physical, social and emotional wellbeing of humans," says Lori Palley, DVM, of the MGH Center for Comparative Medicine, co-lead author of the report. "Several previous studies have found that levels of neurohormones like oxytocin which is involved in pair-bonding and maternal attachment rise after interaction with pets, and new brain imaging technologies are helping us begin to understand the neurobiological basis of the relationship, which is exciting."

In order to compare patterns of brain activation involved with the human-pet bond with those elicited by the maternal-child bond, the study enrolled a group of women with at least one child aged 2 to 10 years old and one pet dog that had been in the household for two years or longer. Participation consisted of two sessions, the first being a home visit during which participants completed several questionnaires, including ones regarding their relationships with both their child and pet dog. The participants' dog and child were also photographed in each participants' home.

The second session took place at the Athinoula A. Martinos Center for Biomedical Imaging at MGH, where functional magnetic resonance imaging (fMRI) which indicates levels of activation in specific brain structures by detecting changes in blood flow and oxygen levels was performed as participants lay in a scanner and viewed a series of photographs. The photos included images of each participant's own child and own dog alternating with those of an unfamiliar child and dog belonging to another study participant. After the scanning session, each participant completed additional assessments, including an image recognition test to confirm she had paid close attention to photos presented during scanning, and rated several images from each category shown during the session on factors relating to pleasantness and excitement.

Of 16 women originally enrolled, complete information and MR data was available for 14 participants. The imaging studies revealed both similarities and differences in the way important brain regions reacted to images of a woman's own child and own dog. Areas previously reported as important for functions such as emotion, reward, affiliation, visual processing and social interaction all showed increased activity when participants viewed either their own child or their own dog. A region known to be important to bond formation the substantia nigra/ventral tegmental area (SNi/VTA) was activated only in response to images of a participant's own child. The fusiform gyrus, which is involved in facial recognition and other visual processing functions, actually showed greater response to own-dog images than own-child images.

"Although this is a small study that may not apply to other individuals, the results suggest there is a common brain network important for pair-bond formation and maintenance that is activated when mothers viewed images of either their child or their dog," says Luke Stoeckel, PhD, MGH Department of Psychiatry, co-lead author of the PLOS ONE report. "We also observed differences in activation of some regions that may reflect variance in the evolutionary course and function of these relationships. For example, like the SNi/VTA, the nucleus accumbens has been reported to have an important role in pair-bonding in both human and animal studies. But that region showed greater deactivation when mothers viewed their own-dog images instead of greater activation in response to own-child images, as one might expect. We think the greater response of the fusiform gyrus to images of participants' dogs may reflect the increased reliance on visual than verbal cues in human-animal communications."

Co-author Randy Gollub, MD, PhD, of MGH Psychiatry adds, "Since fMRI is an indirect measure of neural activity and can only correlate brain activity with an individual's experience, it will be interesting to see if future studies can directly test whether these patterns of brain activity are explained by the specific cognitive and emotional functions involved in human-animal relationships. Further, the similarities and differences in brain activity revealed by functional neuroimaging may help to generate hypotheses that eventually provide an explanation for the complexities underlying human-animal relationships."

View post:

Massachusetts General study suggests neurobiological basis of human-pet relationship

The Hidden | To Kill Them is My Cause
Next: Coming Soon Previous: http://www.youtube.com/watch?v=SLUILzthLzE The Hidden Playlist: http://www.youtube.com/playlist?list=PLWsLbuUWZNdaGZdfg_qufToYdtV3KOUXr -------------------- If...

By: Erik Martin

Read the rest here:

The Hidden | To Kill Them is My Cause - Video

PUBLIC RELEASE DATE:

2-Oct-2014

Contact: Katherine Unger Baillie kbaillie@upenn.edu 215-898-9194 University of Pennsylvania @Penn

It's an early lesson in genetics: we get half our DNA from Mom, half from Dad.

But that straightforward explanation does not account for a process that sometimes occurs when cells divide. Called gene conversion, the copy of a gene from Mom can replace the one from Dad, or vice versa, making the two copies identical.

In a new study published in the American Journal of Human Genetics, University of Pennsylvania researchers Joseph Lachance and Sarah A. Tishkoff investigated this process in the context of the evolution of human populations. They found that a bias toward certain types of DNA sequences during gene conversion may be an important factor in why certain heritable diseases persist in populations around the world.

Lachance is a postdoctoral fellow at Penn in Tishkoff's lab and will be starting his own lab at Georgia Tech in January. Tishkoff is a Penn Integrates Knowledge Professor with appointments in the Perelman School of Medicine's Department of Genetics and the School of Arts & Sciences' Department of Biology.

The study pins on the question of why humans have a genetic predilection for certain diseases. Some reasons have become clear to scientists. The Amish, for example, have a higher risk of several genetic diseases due in part to a phenomenon called founder effects, whereby certain genes rise to prevalence in populations that originated with a relatively small number of individuals.

Other genetic diseases can become relatively common if some aspect about them is advantageous.

"The classic example is sickle-cell anemia," Lachance said. "It's an evolutionary trade-off because people with one copy of a sickle-cell mutation are highly protected from malaria."

See the article here:

DNA 'bias' may keep some diseases in circulation, Penn biologists show

It's an early lesson in genetics: we get half our DNA from Mom, half from Dad.

But that straightforward explanation does not account for a process that sometimes occurs when cells divide. Called gene conversion, the copy of a gene from Mom can replace the one from Dad, or vice versa, making the two copies identical.

In a new study published in the American Journal of Human Genetics, University of Pennsylvania researchers Joseph Lachance and Sarah A. Tishkoff investigated this process in the context of the evolution of human populations. They found that a bias toward certain types of DNA sequences during gene conversion may be an important factor in why certain heritable diseases persist in populations around the world.

Lachance is a postdoctoral fellow at Penn in Tishkoff's lab and will be starting his own lab at Georgia Tech in January. Tishkoff is a Penn Integrates Knowledge Professor with appointments in the Perelman School of Medicine's Department of Genetics and the School of Arts & Sciences' Department of Biology.

The study pins on the question of why humans have a genetic predilection for certain diseases. Some reasons have become clear to scientists. The Amish, for example, have a higher risk of several genetic diseases due in part to a phenomenon called founder effects, whereby certain genes rise to prevalence in populations that originated with a relatively small number of individuals.

Other genetic diseases can become relatively common if some aspect about them is advantageous.

"The classic example is sickle-cell anemia," Lachance said. "It's an evolutionary trade-off because people with one copy of a sickle-cell mutation are highly protected from malaria."

Less is known, however, about gene conversion events, which became the focus of Lachance and Tishkoff's study. Previously, researchers have found that during gene conversion DNA is more likely to be retained and copied if the allele that differs contains either a guanine (G) or a cytosine (C) nucleotide. Conversely, the DNA is more likely to be converted, or replaced, if the allele contains an adenine (A) or thymine (T).

"This bias is very small," Lachance said. "It's like a very slightly weighted coin. But over generations and across huge amounts of the genome, flipping the coin over and over again, we thought we would start to see an effect at the population level.

To see if this genetic preference, known as the GC bias, was having an effect, Lachance and Tishkoff analyzed the genomic sequences of 25 people -- five from each of five groups representing diverse populations. They identified 7.5 million single nucleotide polymorphisms, or SNPs, which are mutations involving a single nucleotide, and grouped them according to whether a change represented a shift from a G or C to an A or T or the reverse.

More here:

DNA 'bias' may keep some diseases in circulation, biologists show

The bond between humans and dogs is strong and ancient. From being the protector of the first herds in a faithful pet, dogs and people share many aspects of life. The relationship between the two species has been studied by psychologists, anthropologists, ethnologists and also by genetic and molecular biologists. In this sense, dogs are a great model for understanding the causes of human diseases, especially cancer.

Unlike other mammals used in research, dogs develop cancer spontaneously as humans do and cancer is the most common cause of death in this species. The dog genome has been obtained in recent years, but we still don't know how is controlled and regulated, what we call the epigenome.

This week the team led by Manel Esteller, director of the Program for Epigenetics and Cancer Biology (PEBC) at Bellvitge Biomedical Research Institute (IDIBELL), Professor of Genetics at the University of Barcelona and ICREA researcher, has characterized the dog's epigenome and transferred the results to human cancer to understand the changes in appearance of tumors. The finding is published this week in the journal Cancer Research.

"We have characterized the epigenome level of each nucleotide of DNA of cells from the cocker species spaniel. In these canine cells we induced a morphological change similar to what happens in cancer progression and we have seen displayed significant alterations in the modulation of genes, called epigenetic lesions "says Manel Esteller.

"The interesting thing is that when we looked the same dog genes in human breast cancer, epigenetic aberrations occur in the same regions of DNA. Data suggests the existence of common epigenetic mechanisms in both species that have been evolutionarily conserved to change the shape and consistency of our cells and tissues, "concludes the researcher.

Study results suggest that act pharmacological action on these epigenetic alterations may be helpful in slowing disease progression.

Story Source:

The above story is based on materials provided by IDIBELL-Bellvitge Biomedical Research Institute. Note: Materials may be edited for content and length.

View post:

Dog's epigenome gives clues to human cancer

LEIPZIG, Germany, Oct. 1 (UPI) -- Throughout human history monogamy has been a sexual philosophy largely eschewed by men, yet demanded of women. This was especially so for men of early human societies, who preferred the company of numerous wives.

We know this much thanks to the research skills of several generations of anthropologists. And now, this understanding has been confirmed by DNA analysis and the work of researchers in the field of human evolution. As a recent study of human DNA revealed, humanity has absorbed the genetics of many more mothers than fathers -- further proof the men of early societies fathered children with multiple women.

"[Historically] more of the women were reproducing than the men," Mark Stoneking, a biological anthropologist at Germany's Max Planck Institute for Evolutionary Anthropology, told Live Science. "This often happens in human societies, because not all men are able to afford wives, or sometimes a few men will have many wives."

Stoneking and his colleagues used a new technique for observing the variances within the paternally inherited Y chromosome, passed down from father to son, and the mitochondrial DNA, the genes inherited from mothers. After collecting DNA samples of 623 males sourced from 51 populations around the world, including Australian, European, and American populations, researchers were able to show that females not only reproduced more frequently than males, but that women also migrated more often.

Because women of early societies often traveled for marriages, moving in with their husbands in a faraway village, females spread their DNA around geographically, resulting in fewer variances from population to population. Men and their sons, on the other hand, tended to stay put, enabling male DNA to remain more distinct from place to place.

Researchers hope these new DNA analysis techniques can continue to be used to learn more about the history of humanity's fathers and mothers.

The study was published last week in the journal Investigative Genetics.

2014 United Press International, Inc. All Rights Reserved. Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.

See the original post:

DNA suggests humanity has more mothers than fathers