BLG 400 Lecture Notes - Lecture 8: Wild Type, Transposable Element, Chromosome
29 Dec 2019
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Document Summary
Transposable/mobile/ elements or transposons:- a dna sequence that can change its position in the same chromosome or in different chromosomes. Made a discovery studying the coloured kernels of maize corn: mazie corn has 10 chromosomes. Mcclintock notices that there is a constant breakage in chromosome 9 that occurs. She determined that the breakage of the chromosome was due to a transposable/mobile element called ds (dissociation element) which was located at the sight of the break. She also discovered that there was another unlinked gene called ac (activator) that was responsible for turning on the activity of ds gene. Mcclintock suspected that ac and ds are both transposable elements because she found it impossible to map the ac gene since it was constantly moving when she looked at chromosome. In some plants it mapped in one position, in another plant it mapped to another position. Different phenotypes were created when the ac was found in different positions.
