molecular biology

 

Synthetic Biology: Engineering Life To Examine It

Posted 6 January 2014 by Jalees Rehman

Two scientific papers that were published in the journal Nature in the year 2000 marked the beginning of engineering biological circuits in cells. The paper "Construction of a genetic toggle switch in Escherichia coli" by Timothy Gardner, Charles Cantor and James Collins created a genetic toggle switch by simultaneously introducing an artificial DNA plasmid into a bacterial cell. This DNA plasmid contained two promoters (DNA sequences which regulate the expression of genes) and two repressors (genes that encode for proteins which suppress... Read more

Cellular Alchemy: Converting Fibroblasts Into Heart Cells

Posted 11 May 2013 by Jalees Rehman

Medieval alchemists devoted their lives to the pursuit of the infamous Philosopher's Stone, an elusive substance that was thought to convert base metals into valuable gold. Needless to say, nobody ever discovered the Philosopher’s Stone. Well, perhaps some alchemist did get lucky but was wise enough to keep the discovery secret. Instead of publishing the discovery and receiving the Nobel Prize for Alchemy, the lucky alchemist probably just walked around in junkyards, surreptitiously collected scraps of metal and brought them... Read more

The ENCODE Controversy And Professionalism In Science

Posted 24 February 2013 by Jalees Rehman

The ENCODE (Encyclopedia Of DNA Elements) project received quite a bit of attention when its results were publicized last year. This project involved a very large consortium of scientists with the goal to identify all the functional elements in the human genome. In September 2012, 30 papers were published in a coordinated release and their extraordinary claim was that roughly 80% of the human genome was "functional". This was in direct contrast to the prevailing view among molecular biologists that the... Read more

Flipping the Switch: Using Optogenetics to Treat Seizures

Posted 24 January 2013 by Jalees Rehman

Optogenetics is emerging as one of the most exciting new tools in biomedical research. This method is based on introducing genes that encode for light-sensitive proteins into cells. A laser beam can then be used to activate the light-sensitive proteins. Many of the currently used optogenetic proteins respond to the laser activation by changing the membrane voltage potential inside the cells. This is the reason why neurons and other cells that can be excited by electrical impulses, are ideally suited... Read more

Immune Cells Can Remember Past Lives

Posted 9 January 2013 by Jalees Rehman

The generation of induced pluripotent stem cells (iPSCs) is one of the most fascinating discoveries in the history of stem cell biology. John Gurdon and Shinya Yamanaka received the 2012 Nobel Prize for showing that adult cells could be induced to become embryonic-like stem cells (iPSCs). Many stem cell laboratories now routinely convert skin cells or blood cells from an adult patient into iPSCs. The stem cell properties of the generated iPSCs then allow researchers to convert them into a... Read more

Can The Heart Regenerate Itself After A Heart Attack?

Posted 5 December 2012 by Jalees Rehman

Some cardiovascular researchers believe that the heart contains cardiac stem cells or progenitor cells which can become mature cardiomyocytes (beating heart cells) following an injury and regenerate the damaged heart. The paper "Mammalian heart renewal by pre-existing cardiomyocytes" published in the journal Nature by Senyo and colleagues (online publication on December 5, 2012), on the other hand, suggests that the endogenous regenerative potential of the adult heart is very limited. The researchers studied the regeneration of cardiomyocytes in mice using... Read more

Somatic Mosaicism: Genetic Differences Between Individual Cells

Posted 19 November 2012 by Jalees Rehman

The cells in the body of a healthy person all have the same DNA, right? Not really! It has been known for quite some time now that there are genetic differences between cells within one person. The expression to describe these between-cell differences is "somatic mosaicism", because cells can represent a mosaic of genetic profiles, even within a single organ. During embryonic development, all cells are derived from one fertilized egg and ought to be genetically identical. However, during every... Read more

Is the Analysis of Gene Expression Based on an Erroneous Assumption?

Posted 26 October 2012 by Jalees Rehman

The MIT-based researcher Rick Young is one of the world’s top molecular biologists. His laboratory at the Whitehead Institute for Biomedical Research has helped define many of the key principles of how gene expression is regulated, especially in stem cells and cancer cells. At a symposium organized by the International Society for Stem Cell Research (ISSCR), Rick presented some very provocative data today, which is bound to result in controversial discussions about how researchers should assess gene expression. It has... Read more