1. Chapter 13: transposable elements
Fig 13-1

2. Multiple IS elements can exist at diverse sites
in bacterial chromosomes and plasmids
Example: IS elements in an F factor
Fig 13-8

3. Various classes of Insertion Sequence (IS) elements
have been identified in E. coli
Element-specific inverted DNA sequence repeats flank each element

4. Transposons may be elaborate IS-type elements (simple)
or DNA fragments with IS elements at each end
Fig 13-9

5. Individual plasmids can contain multiple transposons
carrying multiple resistance genes
Mobility of the transposons provides extensive mobility of the R factors
Fig 13-10

6. Insertion of a bacterial transposons usually involves
duplication of DNA sequences flanking the insertion site
Resembles restriction
endonuclease cut
Fig 13-11

7. Two modes of transposition of a bacterial transposons
Fig 13-12

8. Replicative transposition involves cointegrate intermediate
Fig 13-13

9. One class of eukaryote transposable elements (retrotransposons)
appear to be related to retroviruses
Retrovirus life cycle
Fig 13-14

10. All contain vestiges of retroviral genes
Examples of
eukaryote
retrotransposons
All contain vestiges of retroviral genes
most retain pol
Fig 13-15

11. Retrotransposons such as yeast Ty1
transpose through an RNA intermediate
Fig 13-16

12. The first transposon system identified:
Ac-Ds system in corn
(B. McClintock)
Ac transposase can mobilize more than one transposon
Fig 13-21

13. Drosophila P elements were discovered
by study of a hybrid dysgenesis syndrome
Fig 13-18

14. P-M dysgenesis is due to presence of the P element transposon in P flies
Fig 13-19

15. P-M dysgenesis is due to presence of the P element transposon in P flies
Fig 13-19
Mobilization limited to germline cells:
Normal development of somatic tissue
degenerate germ cells due to massive
genetic damage
Fig 13-20

16. P element has been engineered as a transformation vector
Fig 13-22

17. Up to ½ of human genome is transposable elements and residues
Fig 13-23

18. The human HGO gene contains numerous repetitive elements
All elements are within introns
(exon insertions are presumably subject to negative selection)
Fig 13-24

19. Many mutations are caused by insertions
of transposable genetic elements

20. Retrotransposon abundance accounts for enormous differences in genome sizes in different grasses
Fig 13-25

21. Some transposons display insertion site specificities
that promote their accumulation in “safe havens”
Fig 13-

22. Fig 13-

23. Fig 13-