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Updated: 51 weeks 3 days ago
Sometimes evolution proceeds much more rapidly than we might think. Genetic analysis makes it possible to detect the earliest stages of species formation and to gain a better understanding of speciation processes. For example, a study just published in PLOS Genetics by researchers from Eawag and the University of Bern - investigating rapid speciation in threespine stickleback in and around Lake Constance - shows that a species can begin to diverge very rapidly, even when the two daughter species breed alongside one another simultaneously.
Dr. David Gangitano is an associate professor in the Department of Forensic Science at Sam Houston State University. Sam Houston State University is advancing the field of forensic botany with the publication of two recent studies that use marijuana DNA to link drug supplies and pollen DNA to aid in forensic investigations.
A novel HIV-based lentiviral vector can introduce a gene to pancreatic tumor cells that makes them more sensitive to the chemotherapeutic drug gemcitabine, without integrating into cellular DNA. This integrase-defective lentiviral delivery system greatly reduces the risk of insertional mutagenesis and replication-competent lentivirus production, as describe in a new study published in Human Gene Therapy, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers. The article is available free to read on the Human Gene Therapy website until March 31, 2016.
Left: Hexameric rings form a tube of viral capsid. Right: view from the other side of the protein oligomer. Bank voles are small rodents that are not dangerous by themselves, but their excreta can contain one of the dangerous hantaviruses. While bank voles are unaffected by the infection, hantaviruses can cause potentially fatal diseases in humans for which no treatments exist. In central and northern Europe, infection is accompanied by fever, headache, or even renal failure. The strain that occurs in East Asia -- the Hantaan virus -- is even more dangerous: up to five percent of infected patients die of hemorrhagic fever, renal failure, or severe respiratory disorders.
Electron micrograph of the marine bacteria Marinomonas mediterranea is shown. Scientists from The University of Texas at Austin, the Stanford University School of Medicine and two other institutions have discovered that bacteria have a system that can recognize and disrupt dangerous viruses using a newly identified mechanism involving ribonucleic acid (RNA). It is similar to the CRISPR/Cas system that captures foreign DNA. The discovery might lead to better ways to thwart viruses that kill agricultural crops and interfere with the production of dairy products such as cheese and yogurt.
Japanese bioengineers have tweaked Escherichia coli genes so that they pump out thebaine, a morphine precursor that can be modified to make painkillers. A common gut microbe could soon be offering us pain relief. Japanese bioengineers have tweaked Escherichia coli genes so that they pump out thebaine, a morphine precursor that can be modified to make painkillers. The genetically modified E. coli produces 300 times more thebaine with minimal risk of unregulated use compared to a recently developed method involving yeast.
A parasite in a trout gill is coated with IgT, labeled green. IgT both responds to pathogens and appears to control the commensal bacteria in the gills. Oriol Sunyer, a professor at the University of Pennsylvania School of Veterinary Medicine, has described fish as "an open gut swimming." Their mucosal surfaces -- their skin, digestive tract and gills -- are in constant contact with water, including any pathogens that that water may contain.
This is Tariq Rana, Ph.D. Researchers at University of California, San Diego School of Medicine have discovered that HIV infection of human immune cells triggers a massive increase in methylation, a chemical modification, to both human and viral RNA, aiding replication of the virus. The study, published February 22, 2016 in Nature Microbiology, identifies a new mechanism for controlling HIV replication and its interaction with the host immune system.
__IMAGE_1 The mitochondrion isn't the bacterium it was in its prime, say two billion years ago. Since getting consumed by our common single-celled ancestor the "energy powerhouse" organelle has lost most of its 2,000+ genes, likely to the nucleus. There are still a handful left--depending on the organism--but the question is why. One explanation, say a mathematician and biologist who analyzed gene loss in mitochondria over evolutionary time, is that mitochondrial DNA is too important to encode inside the nucleus and has thus evolved to resist the damaging environment inside of the mitochondrion. Their study appears February 18 in Cell Systems.
These bloodsuckers originally parasitized bats. The bed bug (Cimex lectularius) has been a familiar human parasite for more than 3,000 years. After a significant decrease in its population density in the middle of the last century, we have seen a dramatic increase again around the world over the past 20 years. In Australia, for instance, there is an increase of 4,500%.
A team of researchers led by scientists at St. Jude Children's Research Hospital is looking at ways to improve how blood-forming stem cells can be used for therapeutic interventions. The work has uncovered a group of genes that regulate how hematopoietic stem cells start to grow and thrive in mice. The function of many of these genes was previously unknown. Reconstitution of a robust blood-forming system is essential for recovery from many catastrophic diseases as well as from chemotherapy treatments. A report on this study appears today in the Journal of Experimental Medicine.
This is a dormant mouse blastocyst. After a gestation period of around ten months, fawns are born in early summer - when the weather is warm and food is plentiful for the mother. Six months would actually be enough for the embryo's development, but then offspring from mating in the later portion of summer would be born in winter. Therefore, nature prolongs the gestation period by a hormone-regulated pause in the development of the early embryos. Many animal species use this process, called diapause, to adjust their reproduction to environmental conditions.
Recurrent DSB clusters in neural stem/progenitor cells are shown. The genome of developing brain cells harbors 27 clusters or hotspots where its DNA is much more likely to break in some places than others, researchers from the Program in Cellular and Molecular Medicine (PCMM) at Boston Children's Hospital, Harvard Medical School, and the Howard Hughes Medical Institute report in the journal Cell. Those hotspots appear in genes associated with brain tumors and a number of neurodevelopmental and neuropsychiatric conditions, raising new questions about these conditions' origins, as well as how the brain generates a diversity of circuitry during development.
Graphic of microtubules, the 'railway network' within every cell of the human body Researchers from the University of Warwick have discovered how cells in the human body build their own 'railway networks', throwing light on how diseases such as bowel cancer work. The results have just been published in Nature Scientific Reports.
A new imaging technique has allowed researchers at North Carolina State University, the University of North Carolina at Chapel Hill, and the University of Pittsburgh to see how DNA loops around a protein that aids in the formation of a special structure in telomeres. The work provides new insights into the structure of telomeres and how they are maintained.