Viruses

Discovering Ancient Viruses

In 2000, scientists drilled a hole into the Siberian permafrost to collect old soil and look for ancient predators. In fact, these soil samples were estimated to be around 30,000 years old. These viral predators may be even older. Ten years later, the researchers added portions of these samples to amoebae colonies to see if any of the viruses from the soil would infect the amoebae. They were basically “fishing” by using amoebae as bait. The scientists found a virus new to science and named it Pithovirus sibericum. It was giant, measuring about 1.5 micrometers long. After 30,000 years, P. sibericum had been thawed and brought back to life.

Viruses are a large part of the planet’s biomass. Bacteriophages, or phages, are specific viruses that infect bacteria. Phages are the most abundant organism on Earth, with an estimated number of ten million trillion trillion (10^31). If phages were the size of an average beetle, they would completely cover the entire surface of the Earth several miles deep. They are abundant, but we know so little. Groups of student researchers are exploring this unknown realm.

This past semester, scientists at Mitchell Community College collected soil samples from Iredell County, then extracted, purified, and amplified new phages. The research was done in partnership with Howard Hughes Medical Center’s SEA-PHAGES program. SEA-PHAGES is seeking to find, characterize, and sequence phages that infect bacteria from the Actinobacterial family. The goal is to better understand the diversity within and between these phages. Instead of amoebae, Mitchell researchers used a bacteria, Microbacterium foliorum, as bait to catch the viruses.

Mitchell scientists discovered seven new viruses (seen here), and chose two phages for DNA sequencing. Next semester, the students will learn more about these phages by exploring their genome. The diversity of phages that inhabit Iredell County soil will become a little less blurry.

Mitchell CC Phages 2018


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A Planet of Viruses- Book Review

A Planet of Viruses by Carl Zimmer

“Viruses are unseen but dynamic players in the ecology of Earth.”

Carl Zimmer originally wrote the essays contained in this book as an educational tool to help people understand more about viruses. This newly released second edition certainly educates.

The Introduction traces the history of viruses as well as viral research by intertwining the story of the Tobacco Mosaic Virus. The second section of the book, “Old Companions” highlight several viruses that have accompanied humans throughout history. You will learn interesting things about Rhinoviruses, Influenza, and Human Papillomavirus (HPV). For example, HPV can speed up the cell cycle without allowing the cell to kill itself for protection (p.30). This could, in fact, cause cancer.

The next section shows just how prevalent viruses are throughout ecosystems. Our genomes contain viral genes (p.57). Virus genes carry out nearly 10% of all the photosynthesis on Earth (p.51). Finally, Zimmer discusses the future of viruses. The following show some very interesting facts:

  • HIV is so well studied that we know the molecular steps it took to adapt to us (p.68). Can this help in treating this virus?
  • The West Nile virus can survive inside 62 species of mosquitoes. 150 different bird species in America have been found to carry it (p.75).
  • There are giant viruses that can actually be infected by smaller viruses (p.106).

Zimmer tells a great story in this book. He leaves the reader with something to think about: Should viruses be considered a “deadly venom” or a “life-giving” substance?