News tagged with genetic changes
Researchers have identified four genes newly associated with severe childhood obesity. They also found an increased burden of rare structural variations in severely obese children.
Genetics Apr 07, 2013 | not rated yet | 0 |
Working with mice, Johns Hopkins researchers have established a link between elevated levels of a stress hormone in adolescence—a critical time for brain development—and genetic changes that, in young adulthood, cause ...
Neuroscience Jan 17, 2013 | 5 / 5 (5) | 3 |
Nearly half of the 700,000 cancer patients who undergo surgical removal of a primary tumor each year suffer a recurrence of their disease at some point, and many of those patients will eventually die from their disease. The ...
Cancer Dec 27, 2012 | not rated yet | 1 |
Bugs without borders: Researchers track the emergence and global spread of healthcare associated Clostridium difficile
Researchers show that the global epidemic of Clostridium difficile 027/NAP1/BI in the early to mid-2000s was caused by the spread of two different but highly related strains of the bacterium rather than one as was previo ...
Genetics Dec 09, 2012 | not rated yet | 0 |
(Medical Xpress)—One small change to the DNA sequence can cause more weighty changes to the human body, according to a new study released today.
Genetics Sep 17, 2012 | not rated yet | 0 |
Genetic variations that are linked with the onset of Barrett's oesophagus (BE), a pre-cancerous condition of the lower end of the gullet, have been identified for the first time. The discovery of variations in regions on ...
Genetics Sep 09, 2012 | not rated yet | 0 |
(Medical Xpress) -- Ten more DNA regions linked to type 2 diabetes have been discovered by an international team of researchers, bringing the total to over 60.
Genetics Aug 12, 2012 | 5 / 5 (2) | 0 |
A team led by investigators at the Stanford University School of Medicine has found that the most common genetic risk factor for Alzheimer's disease disrupts brain function in healthy older women but has little impact on ...
Alzheimer's disease & dementia Jun 12, 2012 | 5 / 5 (1) | 0 |
Changes to just three genetic letters among billions led to evolution and development of the mammalian motor sensory network, and laid the groundwork for the defining characteristics of the human brain, Yale ...
Genetics May 30, 2012 | 4 / 5 (6) | 1 |
In the largest study of its kind, researchers have profiled genetic changes in cancer with drug sensitivity in order to develop a personalised approach to cancer treatments. The study is published in Nature on Thursday 29 Mar ...
Cancer Mar 28, 2012 | 5 / 5 (2) | 0 |
Scientists have discovered a genetic cause of extreme thinness for the first time, in a study published today in the journal Nature.
Genetics Aug 31, 2011 | 4.8 / 5 (4) | 0 |
A team led by researchers at the National Institutes of Health is the first to systematically survey the landscape of the melanoma genome, the DNA code of the deadliest form of skin cancer. The researchers ...
Genetics Apr 15, 2011 | 5 / 5 (3) | 0 |
Scientists said Wednesday that flu infections were rising among pigs raised for slaughter on farms in south and southeastern China, also plagued by bird flu.
Diseases, Conditions, Syndromes May 07, 2013 | 5 / 5 (2) | 0
A different view of cancer cells: New study measures physical changes in tumor cells as they become metastatic
Most cancer deaths are caused by metastatic tumors, which break free from the original cancer site and spread throughout the body. For that to happen, cancer cells must undergo many genetic and physical changes.
Cancer Apr 23, 2013 | not rated yet | 0 |
Scientists from King's College London have identified patterns of epigenetic changes involved in autism spectrum disorder (ASD) by studying genetically identical twins who differ in autism traits. The study, published in ...
Autism spectrum disorders Apr 23, 2013 | 3 / 5 (1) | 1 |
In biology, mutations are changes to the nucleotide sequence of the genetic material of an organism. Mutations can be caused by copying errors in the genetic material during cell division, by exposure to ultraviolet or ionizing radiation, chemical mutagens, or viruses, or can be induced by the organism itself, by cellular processes such as hypermutation. In multicellular organisms with dedicated reproductive cells, mutations can be subdivided into germ line mutations, which can be passed on to descendants through the reproductive cells, and somatic mutations, which involve cells outside the dedicated reproductive group and which are not usually transmitted to descendants. If the organism can reproduce asexually through mechanisms such as cuttings or budding the distinction can become blurred. For example, plants can sometimes transmit somatic mutations to their descendants asexually or sexually where flower buds develop in somatically mutated parts of plants. A new mutation that was not inherited from either parent is called a de novo mutation. The source of the mutation is unrelated to the consequence, although the consequences are related to which cells were mutated.
Mutations create variation within the gene pool. Less favorable (or deleterious) mutations can be reduced in frequency in the gene pool by natural selection, while more favorable (beneficial or advantageous) mutations may accumulate and result in adaptive evolutionary changes. For example, a butterfly may produce offspring with new mutations. The majority of these mutations will have no effect; but one might change the color of one of the butterfly's offspring, making it harder (or easier) for predators to see. If this color change is advantageous, the chance of this butterfly surviving and producing its own offspring are a little better, and over time the number of butterflies with this mutation may form a larger percentage of the population.
Neutral mutations are defined as mutations whose effects do not influence the fitness of an individual. These can accumulate over time due to genetic drift. It is believed that the overwhelming majority of mutations have no significant effect on an organism's fitness. Also, DNA repair mechanisms are able to mend most changes before they become permanent mutations, and many organisms have mechanisms for eliminating otherwise permanently mutated somatic cells.
Mutation is generally accepted by the scientific community as the mechanism upon which natural selection acts, providing the advantageous new traits that survive and multiply in offspring or disadvantageous traits that die out with weaker organisms.
For more information about Mutation, read the full article at
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