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Scientists discovered a new retrovirus "fossil" found in the common vampire bat which is homologous to retroviruses in rodents and primates. The results suggest the recent circulation of an active infectious retrovirus and cross-species transmission. The study has been published in the scientific journal Journal of Virology.

Imagine something small enough to float on a particle of dust that holds the keys to understanding cancer, virology, and genetics. Luckily for us, such a thing exists in the form of trillions upon trillions of human, lab-grown cells called HeLa. But where did we get these cells? Robin Bulleri tells the story of Henrietta Lacks, a woman whose DNA led to countless cures, patents, and discoveries.

The most recent human retroviral infections leading to germ line integration took place with a subgroup of human endogenous retroviruses called HERVK(HML-2). The human genome contains ~90 copies of these viral genomes, which might have infected human ancestors as recently as 200,000 years ago. HERVs do not produce infectious virus: not only is the viral genome silenced - no mRNAs are produced - but they are littered with lethal mutations that have accumulated over time. A recent study revealed that HERVK mRNAs are produced during normal human embryogenesis. Viral RNAs were detected beginning at the 8-cell stage, through epiblast cells in preimplantation embryos, until formation of embryonic stem cells (illustrated). At this point the production of HERVK mRNA ceases. Viral capsid protein was detected in blastocysts, and electron microscopy revealed the presence of virus-like particles similar to those found in reconstructed HERVK particles. These results indicate that retroviral proteins and particles are present during human development, up until implantation.

4:33 video, For 10,000 years, humanity suffered from the scourge of smallpox. The virus killed almost a third of its victims within two weeks and left survivors horribly scarred. But Simona Zompi commends the brave souls -- a Buddhist nun, a boy, a cow, a dairymaid and physician Edward Jenner -- who first stopped the spread of this disastrous disease, to make us smallpox-free today.

This case study examines a variety of biological factors that may have been involved in the 2013 dolphin "unusual mortality event" (UME) on the East Coast of the United States. The story follows a news reporter and four different scientists who are preparing their notes for speaking at a public hearing about the dolphin die-off event. After reading the story, students assume the roles of these scientists and use the jigsaw method to gather, analyze, and share information.  Due to the interdisciplinary nature of environmental toxicology, this case study exposes students to four main topics: ecology of ecosystems, endocrine system/chemical messaging, immune system function, and virus biology.

Since 2003, the H5N1 influenza virus, more commonly known as the bird flu, has been responsible for the deaths of millions of chickens and ducks and has infected more than 650 people, leading to a 60 percent mortality rate for the latter. Luckily, this virus has yet to achieve human-to-human transmission, but a small number of mutations could change that, resulting in a pandemic. Now a team of investigators from St. Jude Children's Research Hospital, Stanford University Medical Center, and MacroGenics have developed an antibody which has proven 100 percent protective against the virus in two species of animal models.

Washington, D.C. - April 10, 2015 - Human norovirus may infect our canine companions, according to research published online April 1 in the Journal of Clinical Microbiology, a publication of the American Society for Microbiology. That raises the possibility of dog-to-human transmission, said first author Sarah Caddy, VetMB, PhD, MRCVS, a veterinarian and PhD student at the University of Cambridge, and Imperial College, London, UK. Norovirus is the leading cause of food-borne illness in the United States, according to the Centers for Disease Control and Prevention (CDC).