CANCER GENES - 'METHYL MAGNET'
The researchers, from the University of New South Wales (UNSW), believe a tiny spelling mistake involving a single letter in the DNA sequence near the start of the genes is what attracts the biochemical tag – known as methylation.
This biochemical tag directly impacts on our DNA, by switching genes off.
"Methylation sits on top of our DNA, and provides the instructions to turn the gene off," explains study co-leader, Dr Megan Hitchins, from UNSW's Lowy Cancer Research Centre.
In one well-known cause of hereditary cancer, changes in the cancer-prevention gene MLH1 are passed from parent to child creating up to 80 percent risk of developing bowel, uterine and other cancers. However, some families with hereditary cancer have no spelling mistakes in MLH1, but instead have methylation sitting on the gene.
"When the methylation attaches to the MLH1 gene in these families, it causes it to be completely switched off and as a consequence cancer develops," says study co-leader and head of the adult cancer program at the Lowy Cancer Research Centre, Professor Robyn Ward. "But until now, we did not understand how these methylation tags were being passed from parent to child."
In the study the researchers looked at three generations of a large family, who had cancer at a young age, but in whom no spelling mistakes typical of this hereditary cancer syndrome had been found. Strikingly several members of the family from all generations had methylation tags on their gene.
"In this family, biochemical tags attached to the MLH1 gene were present in all three generations. This was intriguing since these markers are usually removed during the production of eggs and sperm," Dr Hitchins said.
"What we found was that a subtle change near the gene was acting like a magnet to attract methylation. So it was not the methylation itself that was being passed from parent to child, but rather the DNA change, and this acted as a methyl magnet," she said.
The methylation was cleared away in the sperm and eggs and then recreated in each new generation, the researchers said.
Professor Ward said the discovery pinpointed the cause of cancer in this family and it offered new options for genetic diagnosis, counselling and early interventions in other families at risk of hereditary cancers.
The team is also exploring the use of certain drugs to clear away the methylation in cancer to switch the anti-cancer genes back on again. In the future these drugs may be used to create a more targeted approach to cancer treatment and possibly prevention.
GENOMIC CODE CRACKING - ATOMIC LEVEL GENE DECODING RESULTS
Hi... Today we seen some information regarding genomic code cracking that is atomic level gene decoding results that is revealed.Freinds Dr. Paul F. Agris, professor of biochemistry at NC State, and academic colleagues from England and Poland show clear evidence for 1966 “Wobble Hypothesis” offered by Francis Crick who was the co-founder of the DNA molecule and its double-helix structure, and Dr. Agris’ own “Modified Wobble Hypothesis” posed in 1991.
The scientists used x-ray crystallography of the cell’s protein-manufacturing unit, the ribosome, to provide a visual snapshot of the decoding process.
This research is published in the December 2004 edition of Nature Structural and Molecular Biology.
The Wobble Hypothesis was Crick’s attempt to make sense of how the cell decodes the genetic information of DNA – the molecule that constitutes all the genetic information in a cell – and then, from that information the biologically active proteins comes to an existence, Dr. Agris results.
The term DNA has 61 three-letter codes that are translated by transfer RNA (tRNA) into amino acids; also proteins are made of amino acids. But the facts is that there are only 20 natural amino acids. Squaring the disparity between the number of codes and the number of amino acids – there are three times as many codes as there are amino acids – became a hurdle for Crick and other early geneticists, Dr. Agris explanation.
Also Crick attempted to clear this hurdle with the Wobble Hypothesis. He based this theory on the first report of a tRNA molecule’s chemical structure discovered by Robert Holley in 1963. Normally, RNA molecules are composed of four nucleosides: adenosine, guanosine, cytosine and uridine (A,G,C,U). But the tRNA molecule which Holley studied included a modified nucleoside called inosine (I), Dr. Agris says. By seeing this inosine in an important area of the tRNA molecule – an area that read the three-letter DNA codes when the cell synthesizes proteins – led Crick to believe that a single tRNA used inosine to read more than one code, and that therefore the 61 codes were decoded by fewer than 61 tRNAs.
Example, Dr. Agris used the amino acid alanine, which has four codes. Crick’s hypothesis would allow that only the two tRNA molecules could be capable to decode all four alanine codes.By using the modified nucleoside I in place of A, G, C or U, one tRNA may be able to read three codes, effectively “wobbling” the reading.
Twenty-five years after the Wobble Hypothesis, Dr. Agris proposed his Modified Wobble Hypothesis. It stated that modified nucleosides other than inosine would in some cases expand tRNAs ability to translate codes by wobbling to greater numbers of three-letter codes, whereas other modified nucleosides would restrict the wobble to only one or two codes.
According to the recent paper,Dr. Agris and colleagues already proved that Agris’ alteration to Crick’s hypothesis was correct: Cellular modification of tRNA alters chemistry and also structure in a manner critical for tRNA to decode more than one three-letter code.
And by using atomic-level resolution – in which researchers can distinguish atom from atom – and working with a tRNA specific for the amino acid lysine,Dr. Agris and his colleagues show modified nucleosides enabling tRNA to decode genomic information on the ribosome, the cell’s protein synthesis machinery.
Thus Specifically, it shows modifications enabling the decoding of two codes. One modification acts like a platform on which decoding takes place, and the other allows a novel chemical and physical interaction to occur between tRNA and the code,Dr. Agris said.
“This is the first visualization that modifications are critical for decoding the genome through wobble,” Said by Dr. Agris.
Dr. Agris says that 15 to 20 percent of tRNAs in all organisms require modified chemistries in order for codes to be properly read and protein synthesis to be successful.
“An understanding of how modified nucleosides enable and improve wobble recognition of the three-letter codes for protein synthesis opens the possibility of using modified nucleosides to expand the cells’ use of tRNA to make new proteins, or in new ways to target the protein synthesis machinery in pathogens,” Said by Dr. Agris.
http://www.supremesolutions.in/
WHAT IS RIBOSOMAL RNA (RRNA) ????
There are 4 kinds. In eukaryotes, these are
18S rRNA. One of these molecules, forth with some 30 altered protein molecules, is acclimated to accomplish the baby subunit of the ribosome.
28S, 5.8S, and 5S rRNA. One anniversary of these molecules, forth with some 45 altered proteins, are acclimated to accomplish the ample subunit of the ribosome.
The S cardinal accustomed anniversary blazon of rRNA reflects the amount at which the molecules debris in the ultracentrifuge. The beyond the number, the beyond the atom (but not proportionally).
The 28S, 18S, and 5.8S molecules are produced by the processing of a distinct primary archetype from a array of identical copies of a distinct gene. The 5S molecules are produced from a altered array of identical genes.
http://www.supremesolutions.in/
WHAT IS MRNA (MESSENGER RNA) ????
A atom of RNA that serves as a arrangement for protein synthesis. mRNA is transcribed from a gene and again translated by ribosomes in adjustment to accomplish a protein. Each set of three bases, alleged codons, specifies a assertive protein in the arrangement of amino acids that comprise the protein. The arrangement of a fiber of mRNA is based on the arrangement of a commutual fiber of DNA.
Messenger RNA comes in a advanced ambit of sizes absorption the admeasurement of the polypeptide it encodes. Best beef aftermath baby amounts of bags of altered mRNA molecules, anniversary to be translated into a peptide bare by the cell.
Many mRNAs are accepted to best cells, encoding "housekeeping" proteins bare by all beef (e.g. the enzymes of glycolysis). Other mRNAs are specific for alone assertive types of cells. These encode proteins bare for the action of that accurate corpuscle (e.g., the mRNA for claret in the precursors of red claret cells).
http://www.supremesolutions.in/
DNA GENE DECODING SITES
While these adaptation sites accommodate the befalling for DNA Acceptance Networking, that seems to be a by-product of their capital function, which is to break your DNA. For the acceptance world, casework like this accept amazing implications, including:
(i) In the majority of adoptions in the world, there is little or no advice about the bearing father. This includes calm adoptions, as able-bodied as adoptions from added genitalia of the world. Adaptation your child's DNA will accommodate you with cogent advice about the bearing ancestor and the bearing mother. The websites affirmation they acquiesce you to attending 20 or 40 years into the approaching at cogent DNA markers that will affect your child's bloom (such as pre-disposition to assertive diseases).
(ii) Once registered with some sites, you will be automatically brash over the abutting 10, 20 or 30 years, as medical science makes new discoveries and advances.
(iii) In some situations DNA adaptation may become accessible as allotment of pre-adoption medical and amusing advice about the child. Currently, parents accept bound medical information, photographs, and sometimes a video. Perhaps in the approaching a DNA besom will become allotment of this pre-adoption advice package.
(iv) As countries become added careful about whom may accept their accouchement (such as China) will they demand DNA tests of the adopting parents? Adopting Parents already accept to accumulation medical and lab letters as allotment of a abstracts for all-embracing adoption. Are DNA letters next?
These websites will accompany abundant opportunities, but additionally abundant quandaries. We will no best accept the botheration of not knowing, but instead accept the accountability of whether we demand to apperceive in the aboriginal place. We will apperceive whether our accouchement are agreeable to assertive ancestry or talents, athletics, music or languages, and we'll animate them to accompany assertive paths. I accept afresh declared these websites to clients, accompany and relatives. It is absorbing how abounding bodies accept said, "But do you absolutely demand to apperceive this information?". Clearly, some bodies would rather not apperceive and aloof let the approaching unfold.
This is a web-based account that helps you accept your DNA. Send in a sample of your child's saliva and see how the decoded genes announce your child's future. This armpit is partly adjourned by Google. The amount for a DNA assay is $999, and you will accept a address allegory about 600,000 DNA checkpoints.
At this time their account is alone accessible in the USA, Europe and Canada, although it will aggrandize in the approaching to added countries. In acknowledgment to my catechism to this armpit as to whether adopting parents could use it to accept the DNA decoded for a adolescent proposed to them for adoption, the acknowledgment was "Our account is not advised to be acclimated for abiogenetic screening purposes."
Doug Chalke
Executive Director
Sunrise Family Services Society
Vancouver, February, 2008
www.SunriseAdoption.com
http://www.supremesolutions.in/
