BIOL 200 Lecture Notes - Lecture 9: Noncoding Dna, Transposable Element, Prokaryote
Document Summary
Transposable elements, transposons, or mobile dna elements are interspersed repeated. Dna sequences that can move in the genome: transposons are also referred to in lay terms as jumping genes , dispersed sometimes randomly, sometimes speci cally. Barbara mcclintock rst described transposons; received nobel prize for discovery. Transposons are found in both prokaryote and eukaryotes. Transposons can be classi ed into two basic types based on their mode of mobility: cut and paste (transposons) Dna transposons move through a cut and paste mechanism: rna intermediate (retrotransposons) - copy and paste mechanism; copy is an rna intermediate. Mobile elements that transpose directly as dna. Structure of insertion sequence (is) element (prokaryotes) // dna transposon (eukaryotes): transposase gene - region that encodes transposase, inverted repeats or terminal inverted repeats (tirs) are present at each end. The 5" > 3" sequence on one strand is repeated on the other strand: target-site direct repeats or target site duplication (tsd)
