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Contents contributed and discussions participated by Sasicha Manupipatpong

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Sasicha Manupipatpong

Identical DNA codes discovered in different plant species - 2 views

www.sciencedaily.com/...120409164426.htm

plant species identical DNA sequences medicine

shared by Sasicha Manupipatpong on 16 Apr 12 - No Cached
  • found identical sequences of DNA located at completely different places on multiple plant genomes
  • Although the scientists found identical sequences between plant species, just as they did between animals, they suggested the sequences evolved differently.
  • find identical sequences in plant DNAs
  • ...9 more annotations...
  • identical sections weren't found at the same points
  • genomes of six animals (dog, chicken, human, mouse, macaque and rat)
  • six plant species (Arabidopsis, soybean, rice, cottonwood, sorghum and grape)
  • found long strings of identical code in different species of animals' DNA
  • expect to see convergent evolution, but we don't
  • Plants and animals are both complex multi-cellular organisms that have to deal with many of the same environmental conditions, like taking in air and water and dealing with weather variations, but their genomes code for solutions to these challenges in different ways
  • could help in the development of new medicines
  • used to find identical sequential patterns in an organism's entire set of proteins
  • lead to finding new targets for existing drugs or studying these drugs' side effects
  • Sasicha Manupipatpong on 16 Apr 12
     
    A computer algorithm found identical sequences of DNA in different places of various plant species' genomes. The same has been found in animals. This could prove to be beneficial in the development of new medicines (for testing drug side effects).
Sasicha Manupipatpong

Memory in adults impacted by versions of four genes - 2 views

www.sciencedaily.com/...120415151347.htm

genes alzheimer's hippocampus shrinking

shared by Sasicha Manupipatpong on 16 Apr 12 - No Cached
  • advanced understanding of the genetic components of Alzheimer's disease and of brain development.
  • understanding of the genetic components of Alzheimer's disease and of brain development
  • certain versions of four genes may speed shrinkage of a brain region involved in making new memories
  • ...12 more annotations...
  • hippocampus, normally shrinks with age, but if the process speeds up, it could increase vulnerability to Alzheimer's disease
  • two genes associated with intracranial volume -- the space within the skull occupied by the brain when the brain is fully developed in a person's lifespan
  • gene variants identified in the first study do not cause Alzheimer's, but they may rob the hippocampus of a kind of "reserve" against the disease
  • cause cell destruction and dramatic shrinkage of this key brain site
  • almost twice the Alzheimer's risk if he or she had these versions of the gene
  • if a person with one of these variants did get Alzheimer's, the disease would attack an already compromised hippocampus and so would lead to a more severe condition at a younger age than otherwise
  • Alzheimer's disease causes much of its damage by shrinking hippocampus volume
  • loses a greater-than-average amount of volume due to the gene variants we've identified, the hippocampus is more vulnerable to Alzheimer's
  • associations impacting intracranial volume, which is an indirect measure of the size of the brain at full development.
  • brain volume and intracranial volume are both highly heritable
  • no associations for brain volume
  • one of these genes has played a unique evolutionary role in human development, and perhaps we as a species are selecting this gene as a way of providing further advances in brain development
  • Sasicha Manupipatpong on 16 Apr 12
     
    The shrinking of the hippocampus, which occurs with age in normal people, was found to be accelerated by certain versions of four genes, which could increase susceptibility to Alzheimer's disease, which also affects the volume of the hippocampus.
Sasicha Manupipatpong

Gene switches do more than flip 'on' or 'off': Can exhibit much more complex binding be... - 1 views

www.sciencedaily.com/...120411131911.htm

genes switch on off more complex

shared by Sasicha Manupipatpong on 16 Apr 12 - No Cached
  • right genes for the job are turned on only in the specific cells where they are needed
  • molecular "clutch" that converts treadmilling to a stable bound state, moving the transcription process forward to completion to turn the gene on
  • act like a switch; they are either "on" (bound to DNA) or "off" (not bound)
  • ...12 more annotations...
  • can exhibit much more complex binding behavior
  • transcription factors' binding process is dynamic and involves more than just being bound or unbound
  • In addition to a stable binding state (on or off)
  • "treadmilling," where no forward transcription process is occurring
  • indicator of whether a gene was turned on or off
  • measure and calculate how long a protein is associated with all of the different genes it regulates
  • proteins that bind in the stable state are associated with high levels of gene transcription
  • if we can regulate the transition between treadmilling and stable binding, we can regulate the outcome in terms of gene expression
  • genetic medicine -- a new way to regulate the 'switches' that turn gene expression associated with disease on or off.
  • measured how long it took the competitor transcription factor to replace the resident protein and used this data to calculate the residence time at each location in the genome
  • specific proteins called "transcription factors" that control which genes are turned on or off in cells by binding to nearby DNA
  • new insights on how cells respond to developmental cues and how they adapt to changing environmental conditions
  • Sasicha Manupipatpong on 16 Apr 12
     
    Genes have been discovered to be more complex than we previously thought--rather than having only on and off states, there is an intermediate state called "treadmilling".
Sasicha Manupipatpong

New genes linked to brain size, intelligence - 2 views

www.sciencedaily.com/...120415150123.htm

genes linked brain size intelligence

shared by Sasicha Manupipatpong on 16 Apr 12 - No Cached
  • genes that increase your risk for a single disease that your children can inherit
  • factors that cause tissue atrophy and reduce brain size, which is a biological marker for hereditary disorders
  • schizophrenia, bipolar disorder, depression, Alzheimer’s disease and dementia
  • ...13 more annotations...
  • sample large enough to reveal clear patterns in genetic variation and show how these changes physically alter the brain
  • smaller brains
  • gene variants that deplete brain tissue beyond normal in a healthy person
  • unearth new genetic variants in people who have bigger brains as well as differences in regions critical to learning and memory
  • screened the genomes of people suffering from a specific brain disease and combed their DNA to uncover a common variant.
  • consistent relationship between subtle shifts in the genetic code and diminished memory centers
  • variations in their DNA that help boost or lower their brains’ susceptibility to a vast range of diseases
  • People also can take preventive steps through exercise, diet and mental stimulation to erase the effects of a bad gene
  • Once we identify the gene, we can target it with a drug to reduce the risk of disease
  • genes that explain individual differences in intelligence
  • gene called HMGA2 affected brain size as well as a person’s intelligence
  • People whose HMGA2 gene held a letter “C” instead of “T” on that location of the gene possessed larger brains and scored more highly on standardized IQ tests
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  • Sasicha Manupipatpong on 16 Apr 12
     
    Specific genes have been identified which affect brain size and intelligence--a difference of one nucleotide in the DNA sequence could determine how well you score on a standardized IQ test.
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
  • demonstrates how organisms have evolved in a different manner to achieve better adaptations and to have optimum protein translation efficiency
  • 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."
  • 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
  • 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
Sasicha Manupipatpong

DNA sequencing helps identify cancer cells for immune system attack - 1 views

www.sciencedaily.com/...120208152342.htm

shared by Sasicha Manupipatpong on 30 Mar 12 - No Cached
  • Sasicha Manupipatpong on 30 Mar 12
     
    DNA sequences from tumor cells can be used to direct the immune system to attack cancer, according to scientists. The immune system relies on an intricate network of alarm bells, targets and safety brakes to determine when and what to attack.
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