While it has long been known that embryonic stem cells have the ability to develop into any kind of tissue-specific cells, the exact mechanism as to how this occurs has heretofore not been demonstrated. Now, researchers at the Hebrew University of Jerusalem and elsewhere have succeeded in graphically revealing this process, resolving a long-standing question as to whether the stem cells achieve their development through selective activation or selective repression of genes.

The collaborative research group, which included Dr. Eran Meshorer of the Department of Genetics at the Silberman Institute of Life Sciences at the Hebrew University of Jerusalem, has revealed that the embryonic stem (ES) cells express large proportions of their genome “promiscuously.” This permissive expression includes lineage-specific and tissue-specific genes, non-coding regions of the genome that are normally “silent,” and repetitive sequences in the genome, which comprise the majority of the mammalian genome but are also normally not expressed. … Continue Reading »

Now that the genome (DNA) of humans and many other organisms have been sequenced, biologists are turning their attention to discovering how the many thousands of structural and control genes — the “worker bees” of living cells that can turn genes on and off — function.

To do that, they need to develop new techniques and tools. Scientists in the Optical Microscopy group at the National High Magnetic Field Laboratory at Florida State University, working in collaboration with researchers from the University of Alberta in Canada and the University of California, San Diego, have done just that, and in the process have produced back-to-back articles in the prestigious journal Nature Methods. … Continue Reading »

There’s no doubt about it … the platypus is one odd duck-billed, egg-laying, lactating mammal. With adaptations like webbed feet to fit its aquatic lifestyle and the poison spurs that decorate males, the platypus represents for many a patchwork of evolutionary development. But LSU’s Mark Batzer, along with an international consortium of scientists led by Wes Warren at Washington University in Saint Louis, Mo., has taken this theory to an entirely new level, proving that platypus looks aren’t only skin-deep – their DNA is an equally cobbled-together array of bird, reptile and mammalian lineages.

The consortium conducted the first analysis of platypus DNA in what was the largest platypus population genetics study to date. … Continue Reading »

An undergraduate student at Rensselaer Polytechnic Institute has learned very quickly that a spoonful of sugar really does help the medicine go down. In fact, with his invention, the sugar may actually be the medicine.

Among the most important and complex molecules in the human body, sugars control not just metabolism but also how cells communicate with one another. Graduating senior Jeffery Martin has put his basic knowledge of sugars to exceptional use by creating a lab-on-a-chip device that builds complex, highly specialized sugar molecules, mimicking one of the most important cellular structures in the human body — the Golgi Apparatus.

“Almost completely independently he has been able to come closer than researchers with decades more experience to creating an artificial Golgi,” said Robert Linhardt, the Ann and John H. Broadbent Jr. ’59 Senior Constellation Professor of Biocatalysis and Metabolic Engineering at Rensselaer and Martin’s adviser. “He saw a problem in the drug discovery process and almost instantly devised a way to solve it.” … Continue Reading »

Tumors have a unique vulnerability that can be exploited to make them more sensitive to heat and radiation, researchers at Washington University School of Medicine in St. Louis report.

The Washington University radiation oncology researchers found that tumors have a built-in mechanism that protects them from heat (hyperthermia) damage and most likely decreases the benefit of hyperthermia and radiation as a combined therapy.

By interfering with that protection, the researchers have shown that tumor cells grown in culture can be made more sensitive to hyperthermia-enhanced radiation therapy. The findings are reported in the May 1, 2008 issue of Cancer Research. … Continue Reading »

Analysis and diagnosis in a chip format are coming of age, but their practical application has been limited because until now, the sample usually had to be prepared separately and on a nonminiaturized scale. Jürgen Pipper and his team at the Institute of Bioengineering and Nanotechnology in Singapore want to change this. They have now developed a rapid test for genetic diagnosis that combines the preparation of biological samples with a polymerase chain reaction (PCR) on one chip. As they report in the journal Angewandte Chemie, the “laboratory device” for all steps in this system is a single drop containing magnetic nanoparticles, which is moved across the chip by a magnetic field.

PCR allows gene sequences to be duplicated and identified—to identify a disease trigger, for example. In this process, the sample must cycle through a specific sequence of temperatures. Because of the slow heating and cooling processes, laboratory PCR usually takes several hours. The new chip PCR requires only minutes, including for the sample preparation. … Continue Reading »

The tachykinin receptor 3 gene has been linked to alcohol and cocaine dependence

• The search for genes associated with alcohol dependence (AD) has recently been extended to the tachykinin receptor 3 gene (TACR3), located within a broad region on chromosome 4q.
• Researchers have found that seven of the nine single nucleotide polymorphisms – DNA sequence variations – in the 3’ region of TACR3 have a significant association with AD as well as cocaine dependence.

Previous family-based research had linked a broad region on chromosome 4q with alcohol dependence (AD). A new study has found that nine of the single nucleotide polymorphisms (SNPs) – DNA sequence variations – in the 3’ region of the tachykinin receptor 3 gene (TACR3), located within chromosome 4q, have a significant association with AD, particularly those with more severe AD, and co-existing cocaine dependence. … Continue Reading »

A person with dilated cardiomyopathy has an enlarged and stretched heart cavity, usually too weak to pump normally; most people will go on to develop heart failure. While clinicians know that up to 36 percent of all cases of dilated cardiomyopathy may be due to excessive drinking, it has been difficult to differentiate between alcohol-induced heart failure and heart failure due to idiopathic dilated cardiomyopathy. A first-of-its-kind study has found a way to both diagnose alcohol-induced heart failure and possibly reverse it through therapeutic interventions.

Results are published in the May issue of Alcoholism: Clinical & Experimental Research. … Continue Reading »