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VATIS Update Biotechnology is published 6 times a year to keep the readers up to date
of most of the relevant and latest technological developments and events in the field of
Biotechnology. The Update is tailored to policy-makers, industries and technology
transfer intermediaries. |
Co-Publisher
Biotech Consortium India Ltd.
Editorial Board
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Yeast genomes reveal clues
to boost bioethanol production |
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Two studies published online recently in Genome Research have analysed the genome structures of bioethanol-producing yeasts, uncovering genetic clues that will be critical in developing new technologies needed to implement production on a global scale. The two joint studies, both by researchers from Brazil and the United States, take a major step towards this goal, identifying genomic properties of industrial fuel yeasts that likely gave rise to more robust strains.
In one of the studies, Dr. Lucas Argueso from Duke University Medical Centre, the United States, and co-researchers have sequenced and analysed the structure of the entire genome of strain PE-2, a prominent industrial strain in Brazil. The groups work revealed that portions of the genome are plastic compared with other yeast strains, specifically the peripheral regions of chromosomes, where several sequence rearrangements were observed. These chromosomal rearrangements amplified genes involved in stress tolerance, helping the strain adapt to the industrial environment. As PE-2 is amenable to genetic engineering, the authors believe that their work on PE-2 will open the door to development of new technologies to boost bioethanol production.
Dr. Boris U. Stambuk from Stanford University, the United States, and his colleagues studied the genome structure of industrial bioethanol yeasts, searching for variations in the number of gene copies in five strains used in Brazil, including PE-2. They found that all five industrial strains have amplifications of genes involved in the synthesis of vitamins B6 and B1 compounds critical for efficient growth and utilization of sugar. The group demonstrated that the gene amplifications confer robust growth in industrial conditions, indicating that these yeasts likely adapted to limited availability of vitamins in the industrial process to gain a competitive advantage. The authors suggest that this knowledge can be utilized to engineer new strains of yeast capable of even more efficient bioethanol production, from a wider range of agricultural stocks.
Source:
www.eurekalert.org
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New cancer gene discovered |
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A new cancer gene has been discovered by a research group at the Sahlgrenska Academy, Sweden. The gene causes an insidious form of glandular cancer adenoid cystic carcinoma usually in the head and neck, and in women in the breast also. The researchers showed that the gene is found in 100 per cent of these tumours, which could lead to quicker and better diagnosis and more effective treatment.
The newly discovered cancer gene is what is called a fusion gene, created when two healthy genes join as a result of a chromosome change. One of the two genes that form the fusion gene is known as MYB. Among other things, this gene controls cell growth and makes sure that the body gets rid of cells that are no longer needed. MYB has long been known as a highly potent cancer gene in animals. However, there was no evidence of the gene being involved in the development of tumours in humans.
Previously it was thought that fusion genes pretty much only caused leukaemia, but our group can now show that this type of cancer gene is also common in glandular cancer, says Prof. Gran Stenman, who heads the research group at the Lundberg Laboratory for Cancer Research at the Sahlgrenska Academy.
The research group also looked at the mechanism behind the transformation of the normal MYB gene into a cancer gene. Genes can be compared to blueprints for proteins. Carefully controlled regulating systems then determine when and how much of each protein is formed. One such regulating system is microRNA, which can turn genes on and off. When this cancer gene forms, this important control system is put out of action, leading to activation of the gene and massive overproduction of an abnormal MYB protein with carcinogenic properties.
Source:
www.lifesciencesworld.com
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Genomes of two
E. coli strains sequenced |
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An international team of researchers from the United States, Republic of Korea and France has sequenced and analysed the genomes of two important laboratory strains of Escherichia coli bacteria. The benign strains K-12 and B, the two most important laboratory types, have been indispensable tools for biomedical and biotechnology research. The genome sequence of K-12, isolated in 1922 in the United States, has been known since 1997. Strain B was isolated in 1918 in France, as the current study discovered. The genomes of the two B strains were sequenced at the Korea Research Institute of Bioscience and Biotechnology and at Genoscope, the French centre for genome sequencing. The two B genomes each contain, like K-12, about 4.6 million nucleotide base pairs (Ts linked with As or Gs linked with Cs).
The new developments allow complete genomes of these two laboratory workhorses to be compared for the first time. Although the B and K-12 strains came into the laboratory half a world apart, their genome sequences show that they are closely related, said Dr. William Studier, a biophysicist at the Brookhaven National Laboratory (BNL) of the United States Department of Energy. The scientists found that B and K-12 genomes have non-random distribution of single base-pair differences between them.
The genome comparisons also turned up some interesting differences between the two B strains. The two B strains REL606 and BL21(DE3) have had separate laboratory histories since 1959. Apparently, as scientists at different labs shared strains for their research, one sample got mislabelled. The current detailed genomic analysis uncovered this long-buried mix-up. With this mystery solved, every difference between the two B genome sequences could be understood in terms of the different laboratory manipulations used on the ancestral strains, Dr. Studier said. This information provided new insights into the types of changes to the genome caused by standard laboratory treatments, including exposure to chemicals, irradiation with ultraviolet light and DNA transfer between genomes.
Source: www.sciencedaily.com
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Scientists identify genetic marker for intelligence |
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At Trinity College Dublin (TCD), Republic of Ireland, scientists have identified one of the first genetic indicators of intelligence. People who carry the genetic variant within a gene called NOS1 recorded lower IQ scores than those who do not carry the variant. The same test was also carried out among patients with schizophrenia and yielded the same result. Significant differences were also found in the working memory of those who carried the genetic variation and those who did not.
Dr. Gary Donohoe, a TCD clinical psychologist, said the genetic variant they have discovered is significant because it has been so difficult to make the connection between an individuals genetic make-up and their intelligence. In all, 600 people in Ireland and 1,700 in Germany participated in the study. It is hoped that the research will help better understand the nature of intelligence and mental health disorders such as schizophrenia.
Source:
www.irishtimes.com
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A new dimension
for genome studies |
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A new study in the United States from scientists at MIT, the Broad Institute of MIT and Harvard, University of Massachusetts Medical School and Harvard University reveals the 3-D structure of the human genome and answers the thorny question of how each of our cells stows some three billion base pairs of DNA. The work, reported in Science, may also explain how cells control which stretches of DNA are transcribed and which remain silent. Furthermore, the new technique could allow researchers to study how gene expression changes. The new structural data reveal that the human genome is organized into two separate compartments, keeping active genes accessible while sequestering unused DNA in a denser storage compartment. Each chromosome alternates between regions of active, gene-rich DNA and inactive, gene-poor stretches.
The scientists established that the genome adopts an unusual organization known in mathematics as a fractal. This architecture, called a fractal globule, enables the cell to pack DNA incredibly tightly while avoiding the knots and tangles that might interfere with the cells ability to read its own genome. The DNA can easily unfold and refold during gene activation, gene repression and cell replication. Key to deciphering the structure of genome was the development of the new Hi-C technique, which permits genome-wide analysis of the proximity of individual genes.
Source: web.mit.edu
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