Genetics & Molecular Biology

Preventing mosquitoes from urinating as they feed on blood could prevent the spread of dengue fever, yellow fever and other diseases, say researchers writing in the American Journal of Physiology.

When mosquitoes consume and process blood meals, they must urinate to prevent fluid and salt overloads that can kill them. The research team found that blocking a protein in the renal tubules of Aedes aegypti mosquitoes prevents them from relieving themselves. The work may lead to the development of new insecticides to disrupt the mosquito's renal system, which contributes to a mosquito's survival after feeding on blood.
Modern humans are generally monogamous while exhibiting tendencies toward polygamy over the course of evolutionary history, say scientists who analyzed genomic data from three population samples of African, Asian and European origin. The findings, published in the American Journal of Human Genetics, are consistent with studies in evolutionary psychology and anthropology that depict contemporary human populations.
Scientists writing in the FASEB Journal say a genetically modified strain of tobacco can help temper the damaging effects of toxic pond scum, known as microcystin-LR (MC-LR), which makes water unsafe for drinking, swimming, or fishing. The plant could serve as a major tool for helping keep water sources safe to use, especially in developing nations.

The new strain was developed by inserting genes which code for the production of an antibody called MC-LR. With the genes in place, the new strain of tobacco produced the antibody in its leaves and secreted it from its roots into the surrounding hypotonic growth medium.
Why do some people who experience traumatizing events develop Post-Traumatic Stress Disorder while others don't? Scientists know that, in general, the more traumatic events a person experiences the higher their likelihood of developing PTSD, but even under extreme stress not all individuals develop the disorder. Now, researchers writing in Biological Psychiatry say that survivors of the 1994 Rwandan Genocide may help explain how genetic factors influence this relationship.
Who's Ernesto Di Mauro? He is Professor of Molecular Biology at the Department of Genetics and Molecular Biology, Sapienza University of Rome, Italy. I caught his recent research in The Journal of Biological Chemistry, which "publishes papers based on original research that are judged to make a novel and important contribution to understanding the molecular and cellular basis of biological processes." Here are two recent abstracts by Di Mauro and colleagues. (1)
Many people, including me, are concerned about potential harm to crop biodiversity from gene flow. Most people's concern focuses on transgenics. There is a certain probability, albeit small, that transgenes will end up in the progeny of non-transgenic plants, weedy relatives of the crop, or wild relatives that grow nearby due to pollen flow. Transgenes can also be moved from place to place by accidental or purposeful movement of seeds.

How much transgene flow is actually happening is a subject of some controversy, but what about gene flow between non-transgenic plants?
A new study of the IGF1 gene in BMC biology has found that small domestic dogs probably originated in the Middle East more than 12,000 years ago. Researchers traced the evolutionary history of IGF1, finding that the version of the gene that is a major determinant of small size probably originated as a result of the domestication of the Middle Eastern gray wolf.
Most science talks I listen to, even good ones, leave me dissatisfied because the stories I hear never come to a complete resolution. The issue is this: we can get from traits to genes, and from genes to molecular biology. But we have largely failed at getting from molecular biology back to the characteristics of organisms. We don't do a good job explaining organismal traits with molecular biology.
UCL (University College London) scientists studying face recognition in identical twins say the essential skill is largely determined by our genetics. Published today in the Proceedings of the National Academy of Sciences, the study found that identical twins were twice as similar to each other in terms of their ability to recognize faces, compared to non-identical twins.

Researchers also found that the genetic effects that allow people to recognize faces are linked to a highly specific mechanism in the brain, unrelated to other brain processes such as the ability to recognize words or abstract art.
A new RNA molecule created by University of Colorado scientists can catalyze a key reaction needed to synthesize proteins. The discovery may have significant implications, researchers say, because it further substantiates the 'RNA World' hypothesis, which proposes that life on Earth evolved from early forms of RNA. The research is detailed this week in the Proceedings of the National Academy of Sciences.