HMB265H1 Lecture Notes - Lecture 17: Transposase, Wild Type, Transposable Element

• School: UTSG
• Department: Human Biology
• Course: HMB265H1
• Professor: Maria Papaconstantinou

Document Summary

Saw particular breaks in dna on chromosome 9. Postulated that there are small breaks of dna that move from one position to another. Frequent break in the maize was on chromosome 9. Ds (dissociation) factor element causes break (on the site) Ac (activator) factor - unlinked genetic factor necessary to activate the break at the ds locus. Could not map ac to a specific area. Published in the 50s but wasn"t accepted until 80s-90s after more research was done. Loss of wild-type allele on one side of the ds locus. Heterozygotes facing loss in some cells would cause recessive phenotype to be expressed. Unusual phenotypes can then be seen where it"s a combination of the two. The spotting below is caused by the ac-ds activities which cause re-expression of wild-type. Autonomous elements encode info req for own movement and for movement of nonautonomous elements. This excises the ds to give rise to the wild-type allele.