1. Regulation of transcription in eukaryotes

2. Regulation of transcription is usually complex in eukaryotes

3. Example: Activation of transcription by Gal4 in yeast

4. Reporter genes can be used to study transcription factors and their binding sites

5. Eukaryotic transcription activators have DNA binding domains similar to their bacterial counterparts
Homeodomain
Zinc finger domain
Helix-loop-helix
Leucine zipper

6. Multiple targets of an activator

7. Activation of transcription by tethering the mediator
to the DNA

8. Activator-induced chromatin and nucleosome remodeling
(similarly a repressor can induce changes in chromatin)

9. Elongation factors help RNA polymerase to overcome a stall

10. Insulators restrict enhancer function to specific regions

13. Some gene clusters are regulated by locus control regions

14. Cooperative binding of transcription factors

15. Control of HO gene expression in budding of yeast
Recruits nucleosome modifiers
Recruits mediator

16. The ß-interferon enhanceosome
Activated upon viral infection
Architectural protein
Chromatin and nucleosome modifiers

17. Structure of the ß-interferon enhanceosome

18. Combinatorial control of gene expression

19. Combinatorial control of mating type gene expression in yeast

20. Mechanisms of gene repression in eukaryotes

21. Gal1 gene repression by Mig1

22. Signal transduction pathways and control of
transcription factors in mammals

23. Indirect unmasking of the Gal4 activating region by galactose

24. Heterochromatin DNA is not accessible for transcription
DAPI staining of heterochromatin in Arabidopsis

25. Heterochromatin DNA is not accessible for transcription

26. Heterochromatin formation is done by recruitment of chromatin modifying complexes. Those complexes are recruited by histone modification or DNA methylation.

27. Formation of heterochromatin at telomeres in yeast
Histone methylation

28. Positional effect of gene expression
Location in heterochromatin
Position variegation in Drosophila
Histone methylation

29. Repression by Polycomb
PRC: polycomb repressive complex PRE: polycomb response element
Histone methylation

30. Gene silencing by DNA methylation

31. Maintenance and de novo DNA methylation

32. Methylation of upstream sequences silences downstream genes

33. Imprinting is mediated by DNA methylation

34. Epigenetic regulation of gene expression
Self-maintained repression of gene expression in bacteriophage lambda

35. Epigenetic maintenance methylation in vertebrates

36. De novo methylation is required for development