Genetics & Molecular Biology

The naked mole rat (or Heterocephalus glaber) (see figure 1) is a strange mammal. As their name already implies, they have little hair. Furthermore, their eyes are very small and their visual abilities are mediocre at best. This naked rat is one of only two eusocial mammals (the other one being the Damaraland mole rat, or Fukomys damarensis), with a lifestyle similar to social insects. Living in underground colonies, ruled by the only reproductive female (the ‘queen’), the work is performed by non-reproductive females. A few males hang around, mating with the queen. They live in a huge network of burrows, where they browse around in search of plant tubes, which they eat (see video).

The image of a stoner always having the munchies is a stereotype because it's true - and it's true, say researchers, because it has a basis in biology.

Daniele Piomelli, Nicholas DiPatrizio and colleagues found that fats in foods like potato chips and french fries trigger a biological mechanism - and that is driven by natural marijuana-like chemicals in the body called endocannabinoids.

In their study, they discovered that when rats tasted something fatty, cells in their upper gut started producing endocannabinoids but sugars and proteins did not have this effect.

Botany: A Blooming History

And now we come to part three of this series

Parental stress seems to influence the progeny of organisms. For example, studies have shown that, if mice are stressed, their offspring will show signs of anxiety, even if they receive the usual levels of maternal care. Such epigenetic effects do not alter the DNA sequence, but leave genetic ‘marks’ on genes that influence how active these are. There are some ideas that health issues such as obesity or mental illness could be the result of stress on the parents.

But the changes in the inherited DNA that might give rise to these effects have proved difficult to identify. Now, research  on fruit flies appears to have elucidated a mechanism that allows the effects of stress to be passed on without having to alter genes.

An innovative gene therapy technique, known as genome editing, ‘searches’ a specific mutated gene and fixes it. Now, for the first time, it has been shown to work in living animals. In the study, the researchers used two versions of a genetically engineered virus (AAV, or adeno-associated virus). One of these versions carried the enzyme that cut the DNA in the right spot, and the other one transported the gene meant to replace the mutated one.

All this was done in liver cells of living mice that suffered from the blood-clotting disorder hemophilia, which is caused by a single-gene mutation and comes in two forms: hemophilia A and hemophilia B, caused by, respectively a lack of clotting factor VIII and IX. In this study, the mice suffered from the B variant.

A fairly new method in genetic research, known as optogenetics (selected as Method of the Year in 2010 by Nature Methods, see video for a great explanation), uses light to control gene expression. Now, researchers form EHT Zürich have engineered human cells (implanted in mice) so that the expression of a gene that plays a role in diabetes can be controlled by light. Instead of creating a whole new genetic network, they combined existing signal pathways, one from the immune system, and one from the eye.

Researchers say that a protein expressed in the human retina, human cryptochrome 2 protein (hCRY2), can sense magnetic fields when implanted into Drosophila, leading to an interesting topic in sensory biology; perhaps humans have an innate magnetic sense.

Migratory birds and sea turtles do, and that ability to sense the Earth's magnetic field is how they navigate long-distance voyages during migration.
This video has become quite popular recently (so if you've already seen it, my apologies). It's about a preacher who claims that (hold on to your seatbelts) becoming christian changes your DNA. 
Say what? Yes, you've heard that correctly. Becoming christian changes your DNA. Oh my...

It's quite disturbing to see that there are actually people who buy this.

Wanna commit a crime and get away with it? Well, do so and afterwards become a born-again christian. Apparently, this'll greatly help you get away with it.

Noah and Alexis Beery were diagnosed with cerebral palsy at age 2, but knowing that was only the first step on a journey to find an answer to the children's problems.  Yet a determined mother determination and the high tech world of next-generation sequencing in the Baylor Human Genome Sequencing Center were able to solve the case.

Writing in Science Translational Medicine, Baylor College of Medicine researchers, along with experts in San Diego and at the University of Michigan in Ann Arbor, describe how the sequencing of the children's whole genome along with that of their older brother and their parents zeroed in on the gene that caused the children's genetic disorder, which enabled physicians to fine-tune the treatment of their disorder.

DNA codes for proteins, and, in doing so, is responsible for many processes that take place in our bodies. An important player in the processes that turn a DNA sequence into a functional protein (see figure 1), is messenger RNA, or mRNA. A recent study, published in Nature, has found a way to artificially modify this mRNA. This changes the ‘building instructions’ of the protein and results in a different protein than the one that was originally coded for.

Figure 1: From DNA to protein.