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Archive - Jan 2, 2014

Pacific Plant Has Absorbed Six “Foreign” Genomes into Its Mitochondria

Amborella trichopoda, a sprawling shrub that grows on just a single island in the remote South Pacific, is the only plant in its family and genus. It is also one of the oldest flowering plants, having branched off from others about 200 million years ago. Now, researchers from Indiana University, with the U.S. Department of Energy Joint Genome Institute (DOE JGI), Penn State University, and the Institute of Research for Development in New Caledonia, have determined a remarkable expansion of the genome of the plant's critical energy-generating structures. Its mitochondria, the plant's energy-producing organelles, in an epic demonstration of horizontal gene transfer, have acquired six genome equivalents of foreign DNA -- one from a moss, three from green algae, and two from other flowering plants. It is the first time that an organelle has captured entire "foreign" genomes, those from other organisms, and the first description of a land plant acquiring genes from green algae. "It swallowed whole genomes from other plants and algae as well as retained them in remarkably whole forms for eons," said Indiana's Dr. Palmer, the senior author of the findings published December 20, 2013 in the journal Science. This work reports on the extent of Amborella's genomic gluttony. The work n the mitochondrial genome is accompanied by a report of the Amborella trichopooda nuclear genome by the Amborella Genome Project, the establishment of a high-quality Amborella trichopoda genome sequence by another group, and a Perspective piece linking the reports together. The DOE JGI Plant Program focuses on fundamental biology of photosynthesis, the conversion of solar to chemical energy, and the role of terrestrial plants and oceanic phytoplankton in global carbon cycling.

More Evidence Suggests Type 2 Diabetes Is an Inflammatory Disease

As people's waistlines increase, so does the incidence of type 2 diabetes. Now scientists have a better understanding of exactly what happens in the body that leads up to type 2 diabetes, and what likely causes some of the complications related to the disease. Specifically, scientists from Denmark have found that in mice, macrophages (see image of isolated macrophage), a specific type of immune cell, invade the diabetic pancreatic tissue during the early stages of the disease. Then, these inflammatory cells produce a large amount of pro-inflammatory proteins, called cytokines, which directly contribute to the elimination of insulin-producing beta cells in the pancreas, resulting in diabetes. This discovery was published in the January 2014 issue of the Journal of Leukocyte Biology. "The study may provide novel insights allowing development of tailor-made anti-inflammatory based therapies reducing the burden of type 2 patients," said Alexander Rosendahl, Ph.D., a researcher involved in the work from the Department of Diabetes Complication Biology at Novo Nordisk A/S, in Malov, Denmark. "These novel treatments may prove to complement existing therapies such as insulin and GLP-1 analogues." To make their discovery scientists compared obese mice that spontaneously developed diabetes to healthy mice. The mice were followed from a young age when the obese mice only showed early diabetes, to an age where they displayed systemic complication in multiple organs. Presence of macrophages around the beta cells in the pancreas and in the spleen was evaluated by state-of-the-art flow cytometric technology allowing evaluation on a single cell level. At both the early and late stages, the diabetic mice showed significant modulations compared to healthy mice.