Sunday, November 23, 2014

Viruses and Diversity

Viruses are known to range in severity, and an experiment in mice was conducted to find out more about them. More specifically, five genetically identical mice were infected with a virus that was much more virulent than when the same virus infected five genetically diverse mice one at a time. One reason for this is that the virus wasn't able to adapt to the different genetic makeups of the different mice, and therefore was less effective. However, this has only been able to be experimentally proven with mice, plants, and insects. Research in this field was done by biologists Jason Kubinak and Wayne Potts.

Since viruses tend to be less virulent in a more diverse population, researchers encourage the diversification of cattle to lessen the probability of disease spreading. Potts and Kubinak use their study to show that the "sex-against virulence hypothesis." This hypothesis states that sexual reproduction evolved in order to increase genetic diversity, which in turn decreased the chance of viral infection.Therefore, the group of mice that had the same genetic makeup showed what would happen if mice reproduced asexually, and this reiterates the importance of diversification as an effect of sexual reproduction. Sexual reproduction enables organisms to gain resistance to viruses and diseases that they may have be vulnerable to otherwise. In the experiment, the virus used is mouse leukemia combined with a virus that causes a drastic increase in the number of red blood cells. Together, the virus is called the "Friend virus complex." The red blood cell count is increased in the spleen, and the more there are, the more likely the spleen will be inflamed, endangering the mouse's life. With the help of this combination of viruses, a virus in the spleen is able to replicate itself.


To start, a healthy mouse was injected with infected spleen tissue from another mouse. The previously healthy mouse was tested for how well it was fitted to the virus (i.e. if it allowed the virus to replicate easily). This was done by weighing the spleen because an enlargement of the spleen yields a more harmful virus.

Although there has been no experimental proof of this in other vertebrates, plants and insects have shown that genetic similarity allows a virus to adapt to a host more efficiently, and thus become more detrimental. Being able to replicate itself faster is lethal to the organism, as well as the rest of the organisms with its identical genetic makeup.

Article: http://www.sciencedaily.com/releases/2014/11/141118072528.htm
Supporting Article: http://www2.estrellamountain.edu/faculty/farabee/BIOBK/biobookdiversity_1.html

1 comment:

  1. I find this article very interesting because it explains the relationship between diversity and the effectiveness of a virus. It seems to be shown that the more diverse a population is, the less effective a virus will be. This makes sense because one individual may be susceptible to a virus while another may be resistant to it. This also shows the importance of diversity, as a group of individuals who are not diverse will all be susceptible to the same virus.

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