Genetics & Molecular Biology

Retinitis pigmentosa are a diverse group of hereditary diseases that lead to incurable blindness and affect two million people worldwide. Though the causes are diverse, the manifestation of the disease is similar: highly sensitive rod photoreceptors, which allow us to see at dusk, die first  and the cones that operate during daylight and are responsible for high-resolution color vision follow.  Scientists from the Friedrich Miescher Institute for Biomedical Research (FMI)say they have restored vision in retinitis pigmentosa using an archaebacterial protein, halorhodopsin.  …

This is what your next doctor's visit will sound like after you get your genome sequenced: "Analysis of 2·6 million single nucleotide polymorphisms and 752 copy number variations showed increased genetic risk for myocardial infarction, type 2 diabetes, and some cancers. We discovered rare variants in three genes that are clinically associated with sudden cardiac death—TMEM43, DSP, and MYBPC3. A variant in LPA was consistent with a family history of coronary artery disease. The patient had a heterozygous null mutation in CYP2C19 suggesting probable clopidogrel resistance, several variants…

Scientists from the Institute of Biochemistry and Molecular Biology and Collaborative Research Center 746 of the University of Freiburg say they have discovered a new mechanism which plays an essential role in the assembly and growth of mitochondria, the 'power plants' of the cell. These organelles make energy stored in food ready for use by the cell. The generators in the cellular power plants are biological membranes located inside the mitochondria. Even minute errors in the composition of the inner mitochondrial membrane can lead to severe metabolic derangements, which can have an…

During pregnancy, many women experience remission of autoimmune diseases like multiple sclerosis and uveitis and scientists have described a biological mechanism they say is responsible for changes in the immune system that helps explain that remission. The expression of an enzyme known as pyruvate kinase is reduced in immune cells in pregnant women compared to non-pregnant women, says biophysicist Howard R. Petty from the University of Michigan Kellogg Eye Center, and Roberto Romero, M.D., of the National Institutes for Health. Their study coming in the August issue of the American Journal…

Regarding the recent Nature News article (Transcription: Enhancer makes non-coding RNA. Nature 465, 173-174; 2010) about the discovery of enhancer RNAs (eRNAs) and their apparent link with neuronal activity, an initial question that arises is whether these eRNAs are really a new class of small RNAs. The question stems from the striking similarities between eRNAs and microRNAs. MicroRNAs are a class of regulatory small RNA sequences that inhibit protein translation by first binding specific messenger RNA (mRNA) transcripts at the 3’ untranslated region through sequence complementation, which…

If you take a look at a marimba, a marimba has different tones in each pad.  Also, when you hit its volume and timber is slightly differently, in a concave design that is uneven to prevent reflection send back the geometric corrdinants to a processor that generates nerve signals and you have a replaceable eye.  Senses can be regenerated accurately, if they are complicated enough.  You can not have an overwhelming signal and must be celebrated sensitively.  

Researchers have come a long way from initially cracking the DNA code since the time of Watson and Crick, to now unveiling the complex layers of molecular codes that make up the cell’s molecular fingerprint. These codes are no longer restricted to the 4 nucleotide codes of the DNA sequence, but rather a complex web of coding systems that regulate every stage of gene expression, including the epigenetic codes (transcriptional), microRNA codes (translational), as well as codes derived from alternative splicing of RNA transcripts (post-translational). While the existence of these codes are now…

Hummingbirds require an enormous amount of energy to beat their wings fast enough to hover and maneuver. In many ways they appear to retain  some of the flight patters of insects, but they have an enormous amount of mass in comparison. Many changes in cell structure must occur to allow this high metabolism rate, and most specifically in mitochondria to be able to provide such large quantities of energy. Quite a few changes in cell morphology and physiology might be expected to help deal with these large metabolism rates. Greater oxygen and carbon dioxide diffusion rates in the lungs…

A new study published in Genome Research has identified intrinsic properties of DNA that influence mutation rate, shedding light on an area of biology that still needs to be investigated - the mechanisms involved in genome maintenance . Some DNA mutations are subject to natural selection, either conferring a biological advantage that is selected for, or a negative effect that is selected against. Mutations not under selection are said to be neutral, and the rate at which neutral mutations accumulate is reflective of the true DNA mutation rate. Researchers can estimate this mutation rate…

Scientists have long wondered what is happening at the cellular and molecular level to bring about the amazing coordination that occurs when birds migrate or fish gather in schools. A team of researchers writing in Science has found evidence that this collective behavior can arise in cells that initially may not be moving at all, but are prodded into action by an external agent such as a chemical. Their study has shown that food-deprived amoebae are prodded into their coordinated clumping by the chemical cyclic adenosine monophosphate (cAMP), effectively changing the parameters of the cell…