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Archive - Nov 2013

November 3rd

Transmitting Stress Response Patterns Across Generations

Children of survivors of extremely stressful life events face adjustment challenges of their own, as has been most carefully studied among the children of Nazi Death Camp survivors. This "intergenerational" transmission of stress response has been studied predominantly from the psychological perspective. However, recent research points to biological contributions as well. Indeed, a new study published in the November 1, 2013 issue of Biological Psychiatry demonstrates that offspring born to stressed mothers show stress-induced changes at birth, with altered behavior and gender-related differences that continue into adulthood. "The notion that biological traits that are not coded by the sequence of DNA can be transmitted across generations is the focus of a field of research called epigenetics. This new paper implicates epigenetic regulation of a well-studied contributor to stress response, CRF1 (corticotropin-releasing factor type 1), in the intergenerational transmission of patterns of stress response," said Dr. John Krystal, Editor ofBiological Psychiatry, who was not involved in the study. The researchers, led by Dr. Inna Gaisler-Salomon at University of Haifa in Israel, were interested in how stress modulates behavior and gene expression across generations. Previous studies in both humans and animals have shown that females exposed to stress even before they conceive can affect their children and even grandchildren. In this study, the researchers looked for a possible mechanism for these effects, focusing on the CRF1 gene. They studied adolescent female rats that went through a mild stress procedure before mating. Stress led to an increase in CRF1 expression in the frontal cortex, a brain region involved in emotional regulation and decision-making.

November 2nd

“Zone in with Zon”—DNA Sequencing on Mars?

Dr. Gerald Zon’s latest “Zone in with Zon” blog post, dated October 21, 2013, and published by TriLink BioTechnologies of San Diego, addresses the stimulating possibility of sequencing DNA on Mars. Although initially skeptical about this “far-out” idea, Dr. Zon did a little research and concluded that it might not be so far-fetched after all. He began by mentioning the long history of theories and research on how life, as we know it, began and evolved, noting that the subject has received considerable attention since 1924 when Soviet biologist Alexander Oparin proposed a theory of the origin of life on earth through the gradual chemical evolution of molecules that contain carbon in the “primordial soup.” Research continued, Dr. Zon said, with Stanley Miller’s now classic article “A Production of Amino Acids Under Possible Primitive Earth Conditions” in Science in 1953. Dr. Zon noted that recent identification of nucleobase analogs 2,6-diaminopurine and 6,8-diaminopurine has been reported by Dworkin and coworkers and suggested to strongly support extraterrestrial origin. In discussing what might be the origin of Martian genomes, Dr. Zon mentions the “common ancestry hypothesis” that proposes the natural transfer of viable microbes in space, such as from Mars to Earth and Earth to Mars. Scientists who have investigated this theory have concluded that “if microbes existed or exist on Mars, viable transfer to Earth is not only possible, but also highly probable, due to microbes’ impressive resistance to the dangers of space transfer and to the dense traffic of billions of Martian meteorites that have fallen on Earth since the dawn of our planetary system. Earth-to-Mars transfer is also possible but at a much lower frequency.” Dr.