Genetic engineering is to traditional crossbreeding what the nuclear bomb was to the sword.
In order to begin to tease out environmental effects on gene expression, researchers used a variety of techniques to analyze B. subtilis cells grown in more than one hundred different environments. So I don't ever want to hear whinging about our labs being too much work!
Oetzi the Iceman's genome has been sequenced, revealing that (among other things) he was lactose intolerant and suffered from Lyme disease.
How long before DNA sequencing is cheap enough that people will be able to discover the same sorts of things about you, from a shed eyelash or flake of skin? Not long at all, if
What's black and white and causing a problem in Italian vineyards? A species of moth common in North America but unknown in Europe until a few years ago, one which surprisingly had no name. DNA barcoding identified it, now named Antispila oinophylla.
Sequencing the genome of a single cell in a complex mixture of field-collected organisms? Check.
Who says geneticists don't have a sense of humor? Not these guys, I'm guessing. (Warning: this is a YouTube video, so you probably don't want to click that link if you're in a quiet zone.)
A research group in Ireland has engineered bacteria to specifically target tumors, demonstrated by their (also-engineered) ability to bioluminesce.
There are also some good animations at the website of Molecular Medicine in Action; for one on PCR, click on Other in the tiny menu on the left side of the page.
Some genetic diseases are so uncommon in humans that it's effectively impossible to determine the genetic flaw responsible using affected individuals. Researchers have now succeeded in identifying a gene which leads to icthyosis when mutated by using highly inbred model organisms, in this case dogs (more specifically, golden retrievers).
Quelle horreur! The end times are approaching!
Another example of the interrelationship between genomic structure and function: a specific histone appears to play a role in gene activation with implications for triggering pluripotency in cells. Such "cellular reprogramming" has important implications for creating stem cells for disease research.
Canadian researchers have identified the genes for two non-heme dioxygenases in Papaver somniferum. Why is this news? Papaver somniferum is the opium poppy, and the products of those two genes are the enzymes which are responsible for the manufacture of codeine and morphine in the plant. Needless to say, this has far-reaching implications for the manufacture of pain relievers.
The genome sequence of the freshwater cnidarian Hydra magnipapillata has recently been reported. Surprisingly, researchers are claiming to be surprised that many human genes have homologs in this simpler eukaryote, including genes involved in diseases such as Alzheimer's and Huntington's.
Many of the 5' UTRs of eukaryotic genes contain introns — introns which are different from "normal" introns in their sequence and size. Recent research indicates that there is some correlation with such 5' UTR introns and the expression levels of the genes which have them. They are found particularly in regulatory genes, with interesting implications for evolution.
Plant breeding is a pain. (So is animal breeding, but that's not what I'm on about here.) Once you identify a plant with some characteristic you want, it takes several generations of crosses to get cultivars which breed true. Researchers at UC Davis have found a very fast, simple way to make haploid plants, which contain only one parent's chromosomes, significantly reducing the time it takes to create such true-breeding plants. What I particularly like about this story is that "The discovery came out of a chance observation in the lab that could easily have been written off as an error." — pay attention and think about what you're doing, that's one thing I keep telling you.…
How long before genetic testing forces a confrontation between inborn genetic advantage and competitive fairness? A recent report in PLoS ONE describes a the association between two variants of the myostatin gene in thoroughbred horses and their racing abilities: horses homozygous for the C version of the gene were much better sprinters, and those homozygous for the T version excelled in longer races, where stamina is more important. While this is in horses, not humans, we have the same gene: London 2012, anyone? Maybe Rio 2016? It's coming, that's for sure….
In a striking example of convergent evolution, geneticists have discovered that one of the proteins critical for echolocation has changed over time in almost identical ways in echolocating bats and dolphins.
As I've mentioned many times, there aren't a whole lot of genes on the Y chromosome — they've been shed pretty steadily over the course of evolution. Surprisingly, a team of researchers comparing the Male-Specific Region of the Y chromosome in chimps and men found that they are incredibly divergent in this region, contrary to expectations.
The approaches to sequencing DNA are multiplying rapidly; one of the most recent takes a purely chemical approach to determining DNA sequence. The authors claim that their method is cheaper than any currently available biologically-based method, but is complementary to, rather than a replacement for, whole-genome methods.
The shapes that RNA molecules adopt are very important to their function. Recent research from Prof. Hashim Al-Hashimi's group at the University of Michigan suggests that simple geometrical constraints limit the conformations which RNA molecules can take, with implications for studies of RNA-protein binding which is being increasingly recognized as important to both clinical and biological questions.
Using such next-generation methods, researchers have achieved extensive coverage (20x over 80% of the genome) of the genome of a 4000-year-old hair sample from a member of the ancient Saqqaq culture of Greenland. By examining some of the SNPs revealed by sequencing, they have been able to tentatively describe some of the phenotypic traits of this long-dead individual, and to confirm that this man's people derived from Siberian populations even longer ago.
In forensic news, molecular genetic analysis has shown that King Tutankhamun died over 3 millenia ago, at the age of 19, not from poison, septicemia, or inherited disease, but from malaria. This is the earliest confirmed case of malaria in history.
Here's a link to the story about that fascinating animal-plant hybrid, Elysia chlorotica.
Classes were held in Room 301 of PPHAC
Mondays, Wednesdays, and Fridays from 8:55 am to 9:45 am and again from 10:20 am to 11:10 am
Labs were held in Room 301, Collier Hall of Science
Mondays from 1:15 pm to 4:15 pm and Tuesdays from 12:45 pm to 3:45 pm
The text for this course was Introduction to Genetics: A Molecular Approach by Terry Brown, published by Garland Science.
Other readings were provided throughout the semester.
Our textbook has an associated website.