There is no ET in Human DNA

Well after all the hulllaba about the presence of extraterrestrial DNA in human genome and lots of blogs and articles later inlcuding the ones from mine which talked about the unusual presence and shift in genetic codon makeup in human DNA. More plausible evidence has started to emerge for what can be termed as ET DNA  in Human genome, triggered  by the completion of the genome sequencing of the marsupial opposum

An international team, led by researchers at the Broad Institute of MIT and Harvard, and supported by the National Institutes of Health (NIH), have announced the publication of the first genome of a marsupial, belonging to a South American species of opossum (Monodelphis domestica ). In a comparison of the marsupial genome to genomes of non-marsupials, including human, published in the journal Nature, the team found that most innovations leading to the human genome sequence lie not in protein-coding genes, but in areas that until recently were referred to as “junk” DNA. Genome of the marsupial Monodelphis domestica reveals innovation in non-coding sequences the study helps to explain the evolutionary origins of human DNA and the role played by transposons,  

The study reveals a surprising role in human evolution for “jumping genes”

So how does the marsupial genome sequencing explains what has been refered as the presence of extraterrestrial gene or well of course we dont have any ET DNA

In the words of  Broad Institute director Eric Lander “Evolution is tinkering much more with the controls than it is with the genes themselves,”. “Almost all of the new innovation … is in the regulatory controls. In fact, marsupial mammals and placental mammals have largely the same set of protein-coding genes. But by contrast, 20 percent of the regulatory instructions in the human genome were invented after we parted ways with the marsupial.”

It showed that an important source of genetic innovation comes from bits of DNA, called transposons, that make up roughly half of our genome and that were previously thought to be genetic “junk.”

The research shows that this so-called junk DNA is anything but, and that it instead can help drive evolution by moving between chromosomes, turning genes on and off in new ways.

 “The official textbook picture of how genes work really didn’t appear to be right,” Lander said. “There was much more of the genome standing around shouting instructions than actually producing proteins.”

That raised a question of how evolution actually works on the genome, Lander said. With so much of the genome devoted to regulation, it became apparent that evolution could work by simply changing the instructions rather than changing the protein-coding genes themselves.

Now that perhaps explain all the articles you may have come across about the discovery of extraterrestrial genes in human DNA

Thus, the mobile elements that are typically thought of as “junk DNA” have played a creative role in genome evolution – spreading key genetic innovations involved in the control of gene expression across the genome.

 

A tiny opossum’s genome has shed light on how evolution creates new creatures from old, showing that change primarily comes by finding new ways of turning existing genes on and off

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‘Personalized Medicine’ Goal of Human Genetics Initiative

Oregon Health & Science University effort, launched 25-April 2007 during National DNA Day, will meld genetics and clinical care

OHSU today is launching the Human Genetics Initiative (HGI), an effort that brings together the university’s vast array of genetics research resources and brainpower, and applies them in a health care setting. It will allow the university to seek new ways of understanding the role of genetics in common disorders like obesity, hypertension, osteoporosis and diabetes.

The goal of HGI is to accelerate the translation of scientific knowledge to patient care by recruiting new geneticists, building a campuswide bank of advanced technology, developing new educational programs for the next generation of health care providers, and, eventually, establishing a novel delivery model for genetics health care.

Gene splicing, SNP, Jumping genes, Transposons

I was looking for an easy way to explain DNA, Gene splicing, SNP, Jumping genes, Transposons and such to a non biologist without using too much technical jargons. And then I came across a study by University of Cambridge about how human mind reacts and learns written text , JUst see if you can read the following text, They are sure not spelling mistkes but made by rearranging text  in word by retaining the first and last letter in such a way that your mind still can read it

 

*I CAN READ IT! CAN YOU*

 

Cna yuo raed tihs? fi yuo cna raed tihs, yuo hvae a mnid to udrtsand DNA and why it is poisbssle for DNA to Evovle.

 

i cdnuolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg. The phaonmneal pweor of the hmuan mnid, aoccdrnig to a rscheearch at Cmabrigde inervtisy, it dseno’t mtaetr in waht oerdr the ltteres in a wrod are, the lny iproamtnt tihng is taht the frsit and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it whotuit a pboerlm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Azanmig huh? yaeh and I awlyas tghuhot slpeling was ipmorantt! now you can raed tihs

Did you read the text and were you able to understand the meaning and the message it contained, If so think about it if you can read the message even when the order at which it is written is changed, Our DNA is also evolving in a similar fashion,now go on read about Gene splicing, SNP, Jumping genes, Transposons you would understand them better.

I guess perhaps we can use the same to explain to students or non biologists many other features of DNA especially how it is possible for HSP genes to create different proteins from different structural arrangement or how more than one DNA can code for one protein

Theranostics-Genetics Testing for Clinical Diagnostics for Personalized Medicine

Theranostics is the term used to describe the proposed process of diagnostic therapy for individual patients – to test them for possible reaction to taking a new medication and to tailor a treatment for them based on the test results or in plain english Personalized Medicine.

Personalized medicine is the use of detailed information about a patient’s genotype or level of gene expression and a patient’s clinical data in order to select a medication, therapy or preventative measure that is particularly suited to that patient at the time of administration

The test results are used to tailor treatment, usually with a drug that targets a particular gene or protein.

Seen the movie Gattaca it shows glipses of the what to come.

This method is looked as the possible end result of new advances made in Pharmacogenomics, Drug Discovery using Genetics, Molecular Biology and Microarray chips technology

The technology is set to grow by leaps as new companies are introducing new microarray chip which are getting cheaper day by day

Already there are microarraychips approved by FDA for clinical diagnostics

its not so much of junk DNA- University of Oxford Scientists discoveres Cancer cure with it

 Junk DNA is not junk after all

Recently, scientists at the University of Oxford have discovered that ‘junk’ genetic material can switch off cancer tumours, preventing them from growing.

By using RNA to switch off a gene involved in controlling cell division, Oxford University scientists may have found a role for RNA in developing new cancer therapies. RNA is the mirror image of DNA, and is used to pass on instructions to the cell to build the proteins that run every body function.

The Human Genome Project found that human DNA carries approximately 34,000 genes that produce proteins. The remaining majority of the genome constituted what was considered to be junk DNA as it had no obvious function. However, this is set to change.

‘‘There has been a quiet revolution taking place in biology in past few years,’’ said Dr Alexandre Akoulitchev, a Senior Research Fellow at Oxford. ‘‘Scientists have begun to see ‘junk’ DNA as having an important function. The variety of RNA types produced from this so called ‘junk’ is staggering and the functional implications are huge.”

Akoulitchev studied the RNA that regulates a gene called DHFR. This gene produces an enzyme that controls the production of molecules called tetrahydrofolate and thymine that cells need to divide rapidly.

“Switching off the DHFR gene could help prevent ordinary cells from developing into cancerous tumour cells, by slowing down their replication. In fact, one of the first anti-cancer drugs, Methotrexate, acts by binding and inhibiting the enzyme produced by this gene. Targeting the gene itself would cut the enzyme out of the picture altogether. Understanding how we can use RNA to switch off or inhibit DHFR and other genes may have important therapeutic implications for developing new anti-cancer treatments.”

This research was funded by The Wellcome Trust and the Medical Research Council.

Original paper: Repression of the human dihydrofolate reductase gene by a non-coding interfering transcript was published in Nature on 22nd January 2006.

Microarray based Bio Detection Technologies

DNA microarray detection of antimicrobial resistance genes in diverse bacteria

Study published at http://cat.inist.fr/?aModele=afficheN&cpsidt=17459830
High throughput genotyping is essential for studying the spread of multiple antimicrobial resistance. A test oligonucleotide microarray designed to detect 94 antimicrobial resistance genes was constructed and successfully used to identify antimicrobial resistance genes in control strains. The microarray was then used to assay 51 distantly related bacteria, including Gram-negative and Gram-positive isolates, resulting in the identification of 61 different antimicrobial resistance genes in these bacteria. These results were consistent with their known gene content and resistance phenotypes. Microarray results were confirmed by polymerase chain reaction and Southern blot analysis. These results demonstrate that this approach could be used to construct a microarray to detect all sequenced antimicrobial resistance genes in nearly all bacteria.

The Insider -Code inside Codes : Scientists Discover Parallel Codes in Genes

Researchers from The Weizmann Institute of Science report the discovery of two new properties of the genetic code. Their work, which appears online in Genome Research, shows that the genetic code—used by organisms as diverse as reef coral, termites, and humans—is nearly optimal for encoding signals of any length in parallel to sequences that code for proteins. In addition, they report that the genetic code is organized so efficiently that when the cellular machinery misses a beat during protein synthesis, the process is promptly halted before energy and resources are wasted.

DNA sequences that code for proteins need to convey, in addition to the protein-coding information, several different signals at the same time. These “parallel codes” include binding sequences for regulatory and structural proteins, signals for splicing, and RNA secondary structure. Here, we show that the universal genetic code can efficiently carry arbitrary parallel codes much better than the vast majority of other possible genetic codes. This property is related to the identity of the stop codons. We find that the ability to support parallel codes is strongly tied to another useful property of the genetic code—minimization of the effects of frame-shift translation errors. Whereas many of the known regulatory codes reside in nontranslated regions of the genome, the present findings suggest that protein-coding regions can readily carry abundant additional information.

“Our findings open the possibility that genes can carry additional, currently unknown codes,” explains Dr. Uri Alon, principal investigator on the project. “These findings point at possible selection forces that may have shaped the universal genetic code.”

The genetic code consists of 61 codons—tri-nucleotide sequences of DNA—that encode 20 amino acids, the building blocks of proteins. In addition, three codons signal the cellular machinery to stop protein synthesis after a full-length protein is built.

While the best-known function of genes is to code for proteins, the DNA sequences of genes also harbor signals for folding, organization, regulation, and splicing. These DNA sequences are typically a bit longer: from four to 150 or more nucleotides in length.

 

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