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Sasicha Manupipatpong

Divergent evolution illuminated: Light shed on reasons behind genome differences betwee... - 0 views

www.sciencedaily.com/...120329124607.htm

trna dna evolution genome differences proteins biotechnology

shared by Sasicha Manupipatpong on 01 Apr 12 - No Cached
  • divergent evolution of the genomes of different groups of species
  • three large domains: Archaea, Bacteria and Eukarya
  • genomes of each group have evolved towards distinct structures that have favored their separation
  • ...15 more annotations...
  • connection between the function of enzymes and the composition of the genomes shed light on the evolution and structure of genes
  • analyzed the distribution and abundance of transfer RNA genes
  • structure of genomes was adapted to the activity of some enzymes, which differ for Bacteria and for Eukarya and are absent in Archaea
  • activity of these enzymes modifies tRNAs, allowing them to recognize up to three distinct codons
    • Sasicha Manupipatpong
      Sasicha Manupipatpong on 01 Apr 12
       
      Prior to the study, it was understood that tRNA's have a specific anti-codon sequence which would recognize a single mRNA codon with the complementary sequence. Does this mean that the tRNA also attaches to different amino acids as well? How does the tRNA differentiate between the different amino acids it is at that moment carrying and the codon it matches with on the mRNA--does it change shape according to which amino acid is attached to it?
  • activity of the bacterial and eukaryal enzymes is different, which explains why the genomes and the gene composition of bacteria, eukarya, and archaea have diverged
  • relation between genome structure and the speed of protein synthesis from its genes
  • greater the abundance of a protein in a cell the higher the number of triplets found in its gene sequence that can be read by modified tRNAs
  • biotechnology as the discovery of the relevance of these modifications will allow an improvement in the industrial production of proteins
  • another parameter with which to optimize the synthesis of proteins from a gene
  • human insulin is "manufactured" in bacteria and our discovery would allow this production to be increased if we take into account the activity of these enzymes
  • relevant for the study of cancer: "it is possible that these modification enzymes are over-represented in some kinds of cancer. In fact, this would be logical because cancer cells are highly efficient in producing proteins."
  • demonstrates how organisms have evolved in a different manner to achieve better adaptations and to have optimum protein translation efficiency
  • don't exactly know why these enzymes appear or why they are different in bacteria and in eukaryotes but it's clear that they contribute to the separation of genomes of these two groups
  • genetic code is the same
  • what has changed is the relative importance of different codons of the code
  • Sasicha Manupipatpong on 01 Apr 12
     
    A recent study uncovers the reasons for the divergent evolution of the genomes of different species. The findings provide information about tRNA modifications which may prove useful in the field of biotechnology, specifically in the industrial production of proteins
Sea Maskulrath

Changes in gene expression causes high BP in pregnancy - 1 views

zeenews.india.com/...igh-bp-in-pregnancy_16515.html

epigenetics DNA human

shared by Sea Maskulrath on 16 Apr 12 - No Cached
  • Washington: Researchers have discovered that changes in the gene expression of a key enzyme may contribute to high blood pressure and increase susceptibility to forming blood clots in pregnant women with preeclampsia.
  • Epigenetics refers to changes in gene expression that are mediated through mechanisms other than changes in the DNA sequence.
  • The VCU team reported that thromboxane synthase – an important inflammatory enzyme – is increased in the blood vessels of expectant mothers with preeclampsia.The thromboxane synthase gene codes for this enzyme, which is involved in several processes including cardiovascular disease and stroke. This enzyme results in the synthesis of thromboxane, which increases blood pressure and causes blood clots.
  • ...5 more annotations...
  • According to Walsh, one of the main epigenetic mechanisms is methylation of the DNA, which controls the expression of genes. The increase of
  • his enzyme in the blood vessels is related to reduced DNA methylation and the infiltration of neu
  • enzyme
  • trophils
  • trophils into the blood vessels. Neutrophils are white blood cells that normally help fight infection.
Pop karnchanapimonkul

Sight Seen: Gene Therapy Restores Vision in Both Eyes: Scientific American - 0 views

www.scientificamerican.com/article.cfm

gene therapy vision disease enzyme

shared by Pop karnchanapimonkul on 13 Apr 12 - No Cached
  • gene therapy to treat blindness in 12 adults and children with Leber's congenital amaurosis (LCA), a rare inherited eye disease that destroys vision by killing photoreceptors—light-sensitive cells in the retina at the back of the eye.
  • genetic mutations in retinal cells. One mutated gene that causes the disorder is named RPE65. An enzyme encoded by RPE65 helps break down a derivative of vitamin A called retinol into a substance that photoreceptors need to detect light and send signals to the brain.
  • injected a harmless virus carrying normal copies of RPE65
  • ...8 more annotations...
  • subsequently began producing the enzyme
  • proved so much they no longer met the criteria for legal blindness
  • injected the functional genes into the previously untreated eye
  • improved as soon as two weeks after the operation: They could navigate an obstacle course, even in dim light, avoiding objects that had tripped them up before, as well as recognize people's faces and read large signs
  • brains were much more responsive to optical input as well.
  • second round of gene therapy further strengthened the brain's response to the initially treated eye as well as the newly treated one
  • that neuroplasticity plays a role
  • visual cortex responding to the newly flowing channel of information from the second eye bolster activity in areas of the visual cortex responding to the initially treated eye.
  • Pop karnchanapimonkul on 13 Apr 12
     
    Article about how the enzyme produced from gene therapy is used to cure blindness in an eye genetic disease.
Kantham Hongdusit

Improved Understanding Of Cancer Progression - 0 views

www.medicalnewstoday.com/...244086.php

shared by Kantham Hongdusit on 15 Apr 12 - No Cached
  • Kantham Hongdusit on 15 Apr 12
     
    Researchers in IMIM have discovered the function of the enzyme LOXL2, which is one of the factor causing cancer. The enzyme interacts with histone H3, and changes the DNA sequence around that histone, eliminating the lysine 4 amino acid group, which favors tumor development
Kantham Hongdusit

Key enzyme involved in protecting nerves from degeneration identified - 0 views

www.sciencedaily.com/...120330164852.htm

enzyme protecting key genetics

shared by Kantham Hongdusit on 02 Apr 12 - No Cached
  • Kantham Hongdusit on 02 Apr 12
     
    Fly's enzyme is used to cure diseases such as Parkinson's, and aid nerve damage and spinal cord
wasin kusakabe

Direct transfer of plant genes from chloroplasts into the cell nucleus: Gene function p... - 0 views

www.sciencedaily.com/...120413121916.htm

Genes Chloroplasts Cell Nucleus DNA

shared by wasin kusakabe on 14 Apr 12 - No Cached
  • Chloroplasts, the plant cell's green solar power generators, were once living beings in their own right.
  • This changed about one billion years ago, when they were swallowed up but not digested by larger cells.
  • either direct transport in the form of DNA fragments from the chloroplasts to the nucleus or transport in the form of mRNA, which is then transcribed back into DNA.
  • ...5 more annotations...
  • Genes consist of several modules, separated by non-coding DNA regions (introns).
  • It was found that the transfer takes place without the involvement of RNA and that the DNA apparently jumps directly from the cell's chloroplasts into its nucleus.
  • t is thought that the introns even help the splicing enzymes by folding themselves into stable RNA structures, thus directing the enzymes to the right locations.
  • Since the introns obstruct protein synthesis, they need to be removed from the mRNA, a procedure described as splicing.
    • wasin kusakabe
      wasin kusakabe on 14 Apr 12
       
      The Chloroplasts was an different entity before they were swallowed up by larger cells to corporate with each other.
  • wasin kusakabe on 14 Apr 12
     
    The differences between the genes in the chloroplasts and the genes in the nucleus being researched.
nidthamsirisup

Mysterious Noncoding DNA: 'Junk' or Genetic Power Player? | PBS NewsHour - 0 views

www.pbs.org/...junk-dna.html

noncoding DNA gene

shared by nidthamsirisup on 15 Apr 12 - No Cached
  • Genes represent only a tiny fraction -- 1 percent -- of our overall genetic material. Then there's the other 99 percent of our DNA -- the stuff that doesn't make protein
  • Researchers have found that some of this noncoding DNA is in fact essential to how our genes function and plays a role in how we look, how we act and the diseases that afflict us.
  • Embedded in this 99 percent is DNA responsible for the mechanics of gene behavior: regulatory DNA. Greg Wray of Duke University's Institute for Genome Sciences and Policy describes the regulatory DNA as the software for our genes, a set of instructions that tells the genome how to use the traditional coding genes.
  • ...5 more annotations...
  • "It's like a recipe book," Wray said. "It tells you how to make the meal. You need to know the amounts. You need to know the order. The noncoding DNA tells you how much to make, when to make it and under what circumstances."
  • common diseases are probably more influenced by regulatory differences, Harismendy said. These include Type 2 diabetes, Crohn's disease, Alzheimer's Disease and a variety of cancers, including breast, colon, ovarian, prostate and lung.
  • According to Wray, research has shown that diseases like bipolar syndrome and clinical depression may be associated with noncoding mutations that determine whether the brain is producing too much or not enough of a particular neurotransmitter. One noncoding mutation gives a person almost complete protection against the nasty malaria parasite, plasmodium vivax.
  • Another piece of noncoding DNA regulates the enzyme responsible for lactose tolerance, the ability to digest milk. Research by Wray and other scientists has shown that in four populations where dairy consumption is a vital part of the diet, new mutations have appeared that essentially keep the gene that produces the lactase enzyme from switching off.
  • And recent research done by evolutionary biologists suggests that differences in regulatory DNA may represent a major part of what separates us from chimpanzees.
Pop karnchanapimonkul

Genetic adaptation of fat metabolism key to development of human brain - 0 views

www.sciencedaily.com/...120412133056.htm

adaptation fat metabolism brain human gene

shared by Pop karnchanapimonkul on 13 Apr 12 - No Cached
  • 300,000 years ago humans adapted genetically to be able to produce larger amounts of Omega-3 and Omega-6 fatty acids. This adaptation may have been crucial to the development of the unique brain capacity in modern humans.
  • higher risk of developing disorders like cardiovascular disease.
  • investigated the genes for the two key enzymes that are needed to produce Omega-3 and Omega-6 fatty acids from vegetable oils.
  • ...7 more annotations...
  • genetic adaptation for high production of Omega-3 and Omega-6 fatty acids is found only in humans
  • 300 000 years ago in the evolutionary line that led to modern humans
  • important factor for human survival in environments with limited dietary access to fatty acids
  • In today’s life situation, with a surplus of nourishment, this genetic adaptation contributes instead to a greater risk of developing disorders like cardiovascular disease
  • first study to show a genetic adaptation of human fat metabolism
  • thrifty gene
  • adaptation that contributed to enhanced survival in an earlier stage of human development, but in a life situation with an excess of food instead constitutes a risk factor for lifestyle diseases
  • Pop karnchanapimonkul on 13 Apr 12
     
    This article explains how earlier genetic adaptations that help our survival is now harming us.
pet-chompoo sa-ngarmangkang

BBC News - 'Tipsy' alcohol gene 'could help curb alcoholism' - 0 views

www.bbc.co.uk/...health-11572894

shared by pet-chompoo sa-ngarmangkang on 07 Apr 12 - No Cached
  • people who react strongly to alcohol are less likely to become addicted
  • the gene we have found tells us a lot about how alcohol affects the brain
  • Most of the alcohol people consume is broken down in the liver, but some is metabolised in the brain by an enzyme which the CYP2E1 gene
  • ...2 more annotations...
  • "tipsy" version of CYP2E1 break down alcohol more readily, which explains why they feel the effects of alcohol much quicker than others
  • CYP2E1 on chromosome 10 appears to dictate whether a person can hold their drink better than others.
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