Genetics & Molecular Biology

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  …

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…

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. To switch the gene on and off, melanopsin is used, a protein found in the retina which…

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. In many migratory animals, the light-sensitive chemical reactions in the flavoprotein cryptochrome (CRY) are thought to play an important role in the ability to sense the Earth's magnetic field…

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. Sigh...

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…

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.  (Source: http://www.dna-sequencing-service.com/dna-sequencing/mrna-dna/) Protein production…

You may have heard that doves mate for life but they are a rarity in bird species.   In most, infidelity is a widespread phenomenon even though for females the costs are high because the cuckolded partners often reduce their parental care and extra lovers also may transmit diseases. Yet female birds are just as promiscuous as males and researchers from the Max Planck Institute for Ornithology in Seewiesen set out to investigate why.   In a genetic long-term study of zebra finches they found that females inherit the disposition for their infidelity from their fathers. So men get the…

In 2009, Elizabeth. H. Blackburn, Carol W. Greider and Jack W. Szostak were awarded the Nobel Prize in Physiology or Medicine for their discovery of telomerase, an enzyme that replenishes the telomeres (see figure 1), DNA sequences at the endings of the chromosomes which appear to play a very important role in the aging process. This process, however, is far from being completely elucidated. Figure 1: Human chromosomes, with the telomeres highlighted. (Source: National Institute of General Medical Sciences) A new study seems to provide another step forward in our understanding. Researchers…

Recombination, the process by which a molecule of (usually) DNA is broken and joined to another one, is one of the main sources of genetic diversity in sexual organisms. Meiotic recombination takes place during the meiotic division (which gives rise to the gametes), and through the process chromosomes show crossover (see figure 1). Figure 1: An illustration of crossing over during the meiotic division.  (Source: http://www.britannica.com) Previous research has shown that the rate of this meiotic recombination exhibits a fair amount of variation between different species, and even…