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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.
orasa sukmark

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

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

adaptation fat metabolism key development human brain

shared by orasa sukmark on 15 Apr 12 - No Cached
  • orasa sukmark on 15 Apr 12
     
    Genetic adaptation for high production of Omega-3 and Omega-6 fatty acids is found only in humans can show genetic adaptation of human fat metabolism.
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
nidthamsirisup

Epigenetics Seeks Clues to Mental Illness in Genes' Life Story - Science in 2011 - NYTi... - 0 views

www.nytimes.com/...09brain.html

epigenetics DNA Genes disease

shared by nidthamsirisup on 15 Apr 12 - No Cached
  • epigenetics, the study of how people’s experience and environment affect the function of their genes.
  • Studies suggest that such add-on, or epigenetic, markers develop as an animal adapts to its environment, whether in the womb or out in the world — and the markers can profoundly affect behavior.
  • In studies of rats, researchers have shown that affectionate mothering alters the expression of genes, allowing them to dampen their physiological response to stress. These biological buffers are then passed on to the next generation: rodents and nonhuman primates biologically primed to handle stress tend to be more nurturing to their own offspring, and the system is thought to work similarly in humans.
  • ...3 more annotations...
  • the offspring of parents who experience famine are at heightened risk for developing schizophrenia, some research suggests — perhaps because of the chemical signatures on the genes that parents pass on.
  • in some people with autism, epigenetic markers had silenced the gene which makes the receptor for the hormone oxytocin. Oxytocin oils the brain’s social circuits, and is critical in cementing relationships; a brain short on receptors for it would most likely struggle in social situations.
  • In one large study of people with schizophrenia, researchers at Johns Hopkins are analyzing blood and other data to see whether the degree of epigenetic variation is related to the inherited risk of developing the disorder. In another, researchers at Tufts are studying the genes of animals dependent on opiates to see how epigenetic alterations caused by drug exposure affect the opiate sensitivity of the animals’ offspring.
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".
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