BIOL 118 Lecture Notes - Lecture 36: Antigenic Shift, Natural Selection, Zoonosis

• School: University of San Diego
• Department: Biology Courses
• Course: BIOL 118
• Professor: Terry Bird

Document Summary

Mutations that can alter the proteins ha & na. Ha needed to bind to host cell, na to break away from old host cell. In terms of antigenic shift, target for immune system (antigens) Gradual changes over time can allow the cell to escape from immunity within a population. Can only occur in influenza bc it has multiple subunits to its genome* Two diff subtypes of the same virus that can infect the same host cell. Natural selection; diff combinations of the two viruses that went in. Packaging diff combinations of the diff subunits ha & na mixed. Antigenic drift happens all the time host cell. Shift happens rarely, resulting in an unsee virus that can cause & undergo a pandemic. Shift only occurs bc it has diff rna subunits unlike variola major which only has 1 genome. Consequence of the unique structure of the influenza virus *** be. Results of two diff subtypes infecting one host.