(The new DNA sequencer. Image: Ion Torrent.)

The time and cost of DNA sequencing process have been reduced in recent years, and the holy grail of genomics, the $ 1,000 genome is getting closer. That is the goal to which scientists are directed reporting in Nature on a new sequencing technology.

More than 40 members of a U.S. biotechnology company signed a paper in which they present a sequencing device, unlike others, does not depend on optical media to capture the information in DNA, but instead uses a system of semiconductors or chips ion .

“Though far from a complete human genome sequencing for $ 1,000, together is a very positive development,” values ​​SINC Fernando Carrasco, technical director of the Center for Genomics Service of Molecular Biology “Severo Ochoa” (CSIC-UAM ).

Semiconductors detected protons (hydrogen ions with positive electric charge) emitted during chemical sequencing reaction. Applying this principle chips are used, the production scale is very cheap because they are disposable, inexpensive and do not require optical reading.

Click to continue »

Some inherited diseases are caused by mutations “recessive”, which causes decreased production of a protein or production of a defective protein unable to perform correctly. Gene therapy aims to cure these diseases by introducing genes “healthy” so they can replace the function of genes “defective”. To introduce these genes in healthy cells affected by the disease need appropriate vehicles, called “vectors” which, in most cases, are devoid of virus more pathogenic components.

The success of this type of gene therapy depends on adequate distribution of the healthy gene to a sufficient number of cells affected and to ensure the persistence of gene expression “healthy” in these cells. The latter has proven to be particularly more difficult than initially expected. Thus, in many cases, the gene “healthy” was introduced into a cell, over time, remained “silent”, ie left to give the correct instructions for protein production, which back the disease again.

It is believed that this “silence” may be due to the use of a number of elements “artificial” first, not the gene actually used but a simplified version, called cDNA, which contains the coding of protein but lacks many elements required for regulation of their production and, secondly, they used a “promoter” of viral origin to ensure the expression of this gene. It seems that in the body over time, these elements are somehow recognized as “foreign” and produces its “silencing.” As an alternative to the use of these elements may resort to the natural version of the gene in its fullness. This is technically more complicated, since genes are typically very large, and do not fit into most viral vectors are commonly used in gene therapy trials (such as adenovirus, retrovirus and lentivirus). An interesting exception is the herpesviral vectors, derived from herpes simplex virus (HSV-1), capable of accommodating up to 150 kb of genetic material.

Click to continue »

Myelin is necessary to properly propagate nerve impulses between neurons and to run the commands of the brain that make movement possible. In childhood, these diseases tend to be genetic and affects a single gene. In adulthood, are inflammatory diseases such as multiple sclerosis. “In the case of childhood diseases, each one in particular is rare or very rare, but if you look at all as a group, then, the incidence is high, a hit for every thousand people,” says Raúl Estévez, leader pofesor study and the Department of Physiology II in the Health Sciences campus de Bellvitge, University of Barcelona (UB), “On the other hand, a high percentage of children with involvement of the myelin, the diagnosis is not clear and can not reach any conclusion, “the expert, ICREA Academy Award and a member of the Center for Biomedical Research Network on Rare Diseases (CIBERER).

In recent years, thanks to the application of patterns of abnormalities in magnetic resonance imaging of the brain, new diseases have been defined. Thus, in 1995, identified a disease of myelin called autosomal recessive leukoencephalopathy megalencefálica with subcortical cysts (MLC).

Click to continue »

Genetic diseases, such as color blindness, Duchenne muscular dystrophy, cystic fibrosis and others, are due to one or more abnormalities in DNA, which alter its functioning. In most cases, an error in a gene, such a mutation leads to a defect in the protein that is encoded so abnormal. Thus, in the case of sickle cell disease (a type of anemia), a substitution of one nucleotide in the gene for b-globin (a component of hemoglobin) results in the replacement of one amino acid for another in the protein. Consequently, red blood cells are less flexible and more fragile: they are easily destroyed, hence the anemia. This type of mutation, which is the genetic information encoding the protein that is altered, is just one of many. Patrick Edery, Central Research Neurosciences de Lyon (INSERM / CNRS / Université de Lyon) and his colleagues come to discover a new one, which involves a snRNA, that is to say a “small nuclear RNA .

Click to continue »

Pass nanochannels DNA sequences 1,000 times narrower than a human hair to take the figure of a tiny spaghetti is the technique known as DNA stretching (Deployment of DNA). It is also one of the lines microGUNE CIC Research, who has already published two papers and soon plans to file a patent.

To display the DNA molecules, it is necessary to make them go through tiny channels dimensions. The micro and nano-engineering unit microGUNE CIC, based on a technology known as nanoimprint lithography, optical devices containing sealed channels 50 nanometers.

The devices made by CIC microGUNE part of a particular set of Lab-on-a-chip (Lab on a chip), and are called single molecule devices, Which allows a multitude of tasks from a tiny amount of DNA, almost the contents in a single cell.

Click to continue »

From a genetic standpoint, the wild strawberry (Fragaria vesca), is similar to but less complex cultivated strawberry, which makes their study by scientists. Its chromosome-14 has one of the smallest genomes of economically important plants, but still contains approximately 240 million base pairs.

The consortium that has sequenced the genome includes two researchers at the Georgia Institute of Technology (Mark Borodovsky and Paul Burns). The pool manager is Kevin folta, a professor at the Institute of Food and Agricultural Sciences University of Florida.

When the consortium obtained the genomic sequence of the wild strawberry, Borodovsky and Burns worked to identify protein-coding genes in the sequence. An innovative pattern recognition program, called GeneMark.hmm-ES +, Borodovsky and Burns identified 34,809 genes, of which 55 percent were assigned to gene families.

Click to continue »

Researchers at UBC and Center for Genome Sciences of the Cancer Agency of British Columbia conducted a detailed analysis of the genome and have identified genes Grosmannia clavigera allowing the fungus to circumvent the natural fungicides pine and use as carbon sources for its own growth. “We found that the fungus can not only survive, but thrive when exposed to chemicals in the resin normally fungicides” said Joerg Bohlmann, professor and researcher at UBC’s Michael Smith. “In some ways, it’s as if these genes gave the fungus the ability to turn poison into nectar.”

“Our study helps clarify how the fungus infects pine successfully, and gives us a better understanding of the complex chemical interaction between the tree, the beetle and the fungus,” says Bohlmann. “This new knowledge could shed light on strategies to prevent future infections, such as selection of trees with improved resistance to beetles and their associated pathogens.”

Click to continue »