Concept 25 Some viruses store genetic information in RNA.

In 1959, David Baltimore was one of Cold Spring Harbor's first undergraduate research students.

Howard Temin, 1964.

Howard Temin in his office at the University of Wisconsin at Madison, 1973.

Howard Temin being interviewed after winning the 1976 Nobel Prize for Physiology or Medicine.

Howard Temin, 1987.

1 of 4) A series of electron micrographs showing the infection of H-9 cells with the MN strain of HIV-1 virus. Magnification including computer enhancements are approximately 100,000 times. A mature round virus particle is sitting next to the cell ready for infection. Note the visible inner core.

(2 of 4) Virus particle is fusing with the cell membrane and about to empty its contents into the cell. Note the visible inner core.

(3 of 4) Virus particle budding out from the cell. Although similar to the previous micrograph, the inner core is not as dense and therefore this is an "immature" viron budding out as opposed to a mature virus fusing in to infect a cell.

(4 of 4) Mature virus particles released from host cell.

HIV, the virus that causes AIDS, is a type of retrovirus. The virus itself has an extremely high mutation rate, which makes it very difficult to develop effective therapies against it.

In general, most viruses have a high mutation rate. Why do you think this is so?

Loading image. Please wait.

In 1959, David Baltimore was one of Cold Spring Harbor's first undergraduate research students.