"Another dogma in cell biology seems about to be toppled: If a mutation in a gene doesn't change the basic sequence of building blocks, then it has no effect." This introduces Beckman's news report of some recent research. A silent mutation is a single letter change in a codon that nevertheless produces the same amino acid. According to co-author Kimchi-Sarfaty: "We were all educated that silent mutations should be ignored, and people really don't pay attention to them." However, this entered education because of the dominance of theory rather than the strength of evidence. The new paper provides enough data to show that many areas of molecular biology need to be revisited. "This may be a generalizable phenomenon that may lead to changes in function we haven't been thinking about" said co-author Gottesman.
The authors draw attention to possible medical implications, "raising the possibility that mutations that do not change coding sequence may contribute to disease by a similar mechanism". But the findings are also relevant to genome similarity measures (particularly humans and chimps) and also the detection of signatures of natural selection in genome sequences (based on the neutral theory of molecular evolution). They allow us to anticipate some revisions to previously reported findings.
Perhaps the most interesting comment comes from Pearson: "Biologists have realized that the genetic code harbours a layer of information that they have largely ignored. Again." This needs to be digested. Why has this layer of information been ignored? Why did it become a "dogma in cell biology"? The answer seems to be that the mindset of molecular biologists is to assume simplicity rather than complexity in the genetic code. This mindset is driven by the thought that cellular information is ultimately mindless and a product of natural forces. This new research allows us once again to ask whether it is time to assume complexity rather than simplicity because design inferences allow us to recognise intelligent agency in the genetic code.
A "Silent" Polymorphism in the MDR1 Gene Changes Substrate Specificity
Chava Kimchi-Sarfaty, Jung Mi Oh, In-Wha Kim, Zuben E. Sauna, Anna Maria Calcagno, Suresh V. Ambudkar, Michael M. Gottesman.
Science Online December 21, 2006, DOI: 10.1126/science.1135308
Abstract: Synonymous Single Nucleotide Polymorphisms (SNPs) do not change the coding sequences, and, therefore, are not expected to change the function of the protein in which they occur. Here, we report that a synonymous SNP in the Multidrug Resistance 1 (MDR1) gene, part of a haplotype previously linked to altered function of the MDR1 gene product, P-glycoprotein (P-gp), nonetheless results in P-gp with altered drug and inhibitor interactions. Similar mRNA levels and protein, but altered conformations were found for wild-type and polymorphic P-gp. We hypothesize that the presence of a rare codon, marked by the synonymous polymorphism, affects the timing of co-translational folding and insertion of P-gp into the membrane, thereby altering the structure of substrate and inhibitor interaction sites.
Choi, C.Q. "Silent" mutations are not always silent, The Scientist, 21st December 2006.
Pearson, H. Silent mutations speak up, email@example.com: 21 December 2006; | doi:10.1038/
Beckman, M. The Sound of a Silent Mutation, ScienceNOW Daily News, 22 December 2006
Amato, I. Silent No Longer, Chemical & Engineering News, January 22, 2007, Volume 85, Number 04, pp. 38-40.
"The more scientists study the genetic code, the more it reads like poetry. In a poem, every word, every line break, even every syllable can carry more than a literal meaning. So too can the molecular letters, syllables, and words of the genetic code carry more biologically relevant meanings than they appear to at first.
Now, a cadre of researchers is discovering intriguing depths of meaning in "synonyms" in the genetic code - very short wordlike sequences, or codons, that translate into exactly the same amino acids during the construction of a protein. Scientists are finding that synonymous codons influence the temporal pattern by which a messenger RNA (mRNA) molecule bearing genetic specifications from a cell's nucleus is translated by machinelike ribosomes into protein molecules." [snip]
|<< <||> >>|
Evolution has become a favorite topic of the news media recently, but for some reason, they never seem to get the story straight. The staff at Discovery Institute's Center for Science and Culture started this Blog to set the record straight and make sure you knew "the rest of the story".
A blogger from New England offers his intelligent reasoning.
We are a group of individuals, coming from diverse backgrounds and not speaking for any organization, who have found common ground around teleological concepts, including intelligent design. We think these concepts have real potential to generate insights about our reality that are being drowned out by political advocacy from both sides. We hope this blog will provide a small voice that helps rectify this situation.
Website dedicated to comparing scenes from the "Inherit the Wind" movie with factual information from actual Scopes Trial. View 37 clips from the movie and decide for yourself if this movie is more fact or fiction.
Don Cicchetti blogs on: Culture, Music, Faith, Intelligent Design, Guitar, Audio
Australian biologist Stephen E. Jones maintains one of the best origins "quote" databases around. He is meticulous about accuracy and working from original sources.
Most guys going through midlife crisis buy a convertible. Austrialian Stephen E. Jones went back to college to get a biology degree and is now a proponent of ID and common ancestry.
Complete zipped downloadable pdf copy of David Stove's devastating, and yet hard-to-find, critique of neo-Darwinism entitled "Darwinian Fairytales"
Intelligent Design The Future is a multiple contributor weblog whose participants include the nation's leading design scientists and theorists: biochemist Michael Behe, mathematician William Dembski, astronomer Guillermo Gonzalez, philosophers of science Stephen Meyer, and Jay Richards, philosopher of biology Paul Nelson, molecular biologist Jonathan Wells, and science writer Jonathan Witt. Posts will focus primarily on the intellectual issues at stake in the debate over intelligent design, rather than its implications for education or public policy.
A Philosopher's Journey: Political and cultural reflections of John Mark N. Reynolds. Dr. Reynolds is Director of the Torrey Honors Institute at