Molecular Biology: a field of science concerned with the way in which the molecules of life (DNA, RNA, and proteins for the most part) interact, regulate each other, and are modified within a cell. Not merely a subject but also a toolkit of techniques to gather information about biomolecules: the polymerase chain reaction (PCR), blotting, … Continue reading
Tag Archives: DNA
Inheriting Is a Complex Business: Penetrance, Dominance, and Sex Linkage
To the uninitiated, genetics may sound simple. You have a particular trait because your parents had it. Real-world genetics, however, is anything but simple. To assert that a child has a trait (blond hair, asthma, a predilection for being overweight) because one of the parents had it is to presume that there is only one … Continue reading
Read: 23andMe, Which Bypasses Physicians to Sell Genetic Testing to the Public, Is Told by the FDA to Stop Selling Its DNA Tests
Via @NatureNews, a very interesting article about the fight in the United States over how to best administer genetic testing. The company 23andMe has been selling a 99-dollar service in which your DNA profile reveals your carrier status for a slew of genetic diseases (including cystic fibrosis and Tay-Sachs disease), your expected drug response (e.g. … Continue reading
Jargon: Polymorphism (a common variation in the DNA sequence)
Polymorphism: a common and localized variation in the DNA code. For example, if the sequence inside a gene typically reads “…GATTACA…” but many individuals are shown to have “…GATCACA”, the “C” that is normally a “T” is a polymorphism. Polymorphisms occur frequently in the human genome: some are neutral in their effect, some are beneficial, … Continue reading
Death: Frederick Sanger (Father of Genomics)
Anyone who works in molecular biology has heard of “Sanger sequencing”, which is a really useful method of sequencing DNA, one base at a time, using “chain terminators”. This method is named after Frederick Sanger, who recently passed away. Here’s a cool video which explains Sanger sequencing. Check out the BBC’s obituary for more details. Continue reading
More Than Meets the Eye: The Genetics of Eye Colour
So, I saw this show where this guy deduced that a girl’s claimed parents were not her biological mom and dad because they had blue eyes but the girl had brown eyes. Ah, yes, you saw an episode of Jonathan Creek. A really good show, despite some occasionally ludicrous twist endings. And Jonathan Creek made … Continue reading
I Have a Genetic Disease That Neither of My Parents Have. What Gives?
So, here’s something I don’t understand. I have sickle-cell disease and I’m told it’s a genetic condition, but neither my dad nor my mom have it. Well, genetic inheritance is a bit more complex than most people imagine it to be. There are different “modes” of inheritance. Sickle-cell disease, for example, is transmitted from parents … Continue reading
Supplement for Biologists: The Mitochondrial DNA Mutation Rate
Warning: Not for the general public. I make an exception to my usual rule of writing to the curious lay public for this supplement. I recently wrote about the use of mitochondrial DNA (or mtDNA) in identifying bodies more than a decade old. While researching the topic, I found a lot of seemingly contradictory information … Continue reading
DNA in the Trenches: How Missing Soldiers Get ID’d Decades After Their Deaths
Did you know that over 73,000 American soldiers who fought during World War II are still missing in action1? These are Armed Forces personnel who were sent by their government to fight a war but who never came back. They became prisoners of war (POWs) or were listed as missing in action (MIA). 1,643 U.S. … Continue reading
Jargon: Gene (A stretch of DNA that can be transcribed into a functional RNA molecule)
Gene: a stretch of DNA that can be transcribed into a functional RNA molecule. This RNA molecule is frequently, though not always, translated into a protein. Genes are always referred to as “functional units of inheritance”, which is not a fantastically intuitive concept. This one was given to us by a German who used the … Continue reading
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