Genetics 3301

Chapter 13: Transposable Elements

Transposable elements in maize:

Ä Discovery of Ds and Ac elements associated with frequent chromosome breakage (13.2); Pigmentation phenotypes derived from Ds and unstable derivative strains (13-3);

Ä Autonomous (Ac) and non-autonomous (Ds) transposable elements in corn (13-4).

Bacterial transposable elements:

Ä Discovery of insertion sequences (IS) in gal using specialized transducing lambda phage (13-7); Different types of IS elements (T13-1); Relationship between IS elements and transposons (13-9); Antibiotic resistance and other genetic determinants (13-9, T13-2, 13-10).

Ä Mechanism of transposition (13-11); Transposable elements can move via replicative and conservative transposition (13-12); Replicative transposition generates another copy and conservative transposition moves the existing copy (13-13).

Eukaryotic transposable elements:

Ä Types (retrotransposons and DNA transposons).

Ä Retrotransposons are similar to retroviruses; retrovirus life cycle (13-14); Retrotransposon structure (13-15); Retrotransposons move via RNA intermediates (13-16, 13-17).

Ä Hybrid dysgenesis and the Drosophila P-element DNA transposon (13-18, 13-20); P-element structure (13-19); Use of P-elements for generating transgenic Drosophila and transposon tagged mutants (13-22); Transposition mediated by Ac in corn (13-21).

Genome size and transposable elements:

Ä C-value paradox is largely due to the number of transposable elements within a genome; Transposable elements within the human genome (13-23, 13-24).

Key terms: Know all of these except class I and class II elements, cosuppression, cut-and-paste, epimutation, HeT-A, junk DNA, negative selection, RNA element, safe haven, silenced, synteny, targeting, TART.

Problems: 1, 2, 3, 5.