HMB265H1 Lecture Notes - Lecture 16: Transposable Element, Transposase, P Element

• School: UTSG
• Department: Human Biology
• Course: HMB265H1
• Professor: Naomi Levy-Strumpf, Stephen Wright

Document Summary

Movement of small segments of dna (transposable elements) from one position to another (discovered by barbara mcclintock in late 1940s) This is odd; genes are usually thought of as fixed. Mcclintock"s experiments met with high degrees of skepticism, but slowly was accepted. Noticed in a particular strain of maize (ancestor of corn), chromosome 9 broke very frequently at a particular site. Chromosomes were very large and could be viewed under a light microscope (ie. could observe the chromosomes before there were molecular tools) At this time, we were just discovering dna stored genetic information. She hypothesized that there were genes (controlling elements) that could move around. Dissociation (ds) elements helps cause breaks (nonautonomous element) Activator (ac) elements required to activate break (autonomous element) However, she could not map the ac element to a specific loci; hypothesized that these were mobile elements.