Tiny Genetic Differences Have Huge Consequences (1/20/2008)
 |
| The interaction of messenger RNA (mRNA) in a cell. Majewski and his colleagues have demonstrated that the natural processing of mRNA, via a process called splicing, is genetically controlled by single nucleotide polymorphisms (SNPs). (Credit: NHGRI/Talking Glossary of Genetics) |
A study led by McGill University researchers has demonstrated that small differences between individuals at the DNA level can lead to dramatic differences in the way genes produce proteins. These, in turn, are responsible for the vast array of differences in physical characteristics between individuals.
This study solves in part the mystery of how a relatively small number of differences within DNA protein coding sequences could be responsible for the enormous variety of phenotypic differences between individuals. It had previously been shown that individual differences reside in simple, relatively small variations in the DNA sequence called single nucleotide polymorphisms (SNPs, often pronounced "snips"), which exist primarily in the "junk code" of the DNA not previously known to have any profound genetic effect.
"There are many SNPs," explained Dr. Jacek Majewski of McGill University. "If you add them all together, you'd expect that two individuals would differ at more than a million of those positions. So we have a million or more small differences that distinguish you and me, and yet it would be very hard to explain all the phenotypic differences in the way we look, grow, and behave just by the handful of these protein coding differences."
Majewski and his colleagues have demonstrated that the natural processing of messenger RNA (mRNA), via a process called splicing, is genetically controlled by these SNPs. The SNPs in certain individuals lead to changes in splicing and result in the production of drastically altered forms of the protein. These out-of-proportion consequences may lead to the development of genetic diseases such as cystic fibrosis and Type 1 diabetes.
The study, part of the Genome Regulators in Disease (GRID) Project funded by Genome Canada and Genome Quebec, was led by Dr. Jacek Majewski of McGill University's Department of Human Genetics and the McGill University and Genome Quebec Innovation Centre, and first-authored by his research associate Dr. Tony Kwan. It was published January 13 in the journal Nature Genetics.
The study was originally initiated by Dr. Tom Hudson, former director of the McGill University and Genome Quebec Innovation Centre, and drew upon the data collected by the vast HapMap (Haplotype Map) Project, a global comparative map of the human genome, which Hudson and his colleagues were instrumental in completing.
Note: This story has been adapted from a news release issued by McGill University
Post Comments:
| 
Subscribe
Tiny water creepy crawlies from South Korea and the Russian Far East
NASA satellite data helps pinpoint glaciers' role in sea level rise
Weather on the outer planets only goes so deep
Shattering the endurance record for small electric UAV
But what does it do?
Artificial forest for solar water-splitting
Sea level influenced tropical climate during the last ice age
World's smallest droplets
Using clay to grow bone
Grammar errors? The brain detects them even when you are unaware
Principles of locomotion in confined spaces could help robot teams work underground
Researchers perform fastest measurements ever made of ion channel proteins
Ultraresponsive magnetic nanoscavengers for next generation water purification
Do potatoes grow on vines? A review of the wild relatives of some favorite food plants
New discovery of ancient diet shatters conventional ideas of how agriculture emerged
Untangling the tree of life
More effective, cheaper concrete manufactured with ash from olive residue biomass
Seahorse's armor gives engineers insight into robotics designs
New quantitative analysis for open source software projects
High-volume Bitcoin exchanges less likely to fail, but more likely breached, says study
Computer scientists develop video game that teaches how to program in Java
Do palm trees hold the key to immortality?
Researchers show how we can do math problems unconsciously
Keep moving and have fun
New strategy for fingerprint visualization developed at Hebrew University
Children's bicycle helmets shown to be effective in impact and crush tests
How Usain Bolt can run faster -- effortlessly
Enhancing cognition in older adults also changes personality
DNA-guided assembly yields novel ribbon-like nanostructures
Carnivorous plant throws out 'junk' DNA
What is the role of double-stranded RNA in antiviral host defense systems?
Mining the botulinum genome
Sacred lotus genome sequence enlightens scientists