1. Genomes and Their Evolution
Chapter 21
Genomes and Their Evolution

2. What you need to know: The major goals of the Human Genome Project
How prokaryotic genomes compare to eukaryotic genomes.
The activity and role of transposable elements and retrotransposons.
How evo-devo relates to our understanding of the evolution of genomes.
The role of homeotic genes and homeoboxes.

3. Bioinformatics
Use of computers, software, and math models to process and integrate data from sequencing projects

4. Human Genome Project
Purpose: _____________________________ _____________________________________
Completed in 2003
Genomes sequenced thus far*: 58,000 prokaryotes, 2700 eukaryotes, 5300 viruses
* Data as of 1/27/16

5. Human Genome Project

6. Comparing Genomes of Bacteria, Archaea, & Eukaryotes

7. Human DNA 3 billion base pairs ~20,000 genes
Only _______ codes for proteins (or RNA)
Mostly ____________ DNA: sequences present in multiple copies

8. Video Clip: What are SNPs?

9. Transposable Elements
Make up 75% of repetitive DNA
Stretches of DNA that can be moved from one location to another in genome
Discovered by Barbara McClintock – corn breeding experiments
2 Types:
__________________

10. Transposons Moves within genome via _____ intermediate
“cut & paste” or “copy & paste” mechanisms
Requires enzyme ___________________

11. Retrotransposons Move by means of ______ intermediate
Leaves copy at original site
Involves enzyme ______________________

12. Genome Evolution Insertion effects of transposons:
Can interrupt or alter gene function
Multiple copies of genes
Duplication  genes with related functions
Genes diverge by accumulating _________________
Some become nonfunctional ____________________
Eventually, new genes with new functions can occur

13. Multigene Families
Collections of 2 or more identical or very similar genes
Eg. _____________________: -globin and -globin gene families

14. Transpositions  chromosomal rearrangements

15. Transposable elements contribute to __________________
Promote recombination, disrupt genes or control elements, & carry genes to new locations
May be harmful or lethal, but can also have small beneficial effects
Provides raw material for ____________________________________

16. HHMI Short Film: The Birth & Death of Genes

17. Illustrative Example: Antifreeze Gene in Fish
Antifreeze proteins (AFP): produced by vertebrates, plants, fungi, bacteria to aid survival in sub-zero environments
Function: bind to ice crystals and prevent growth
Antarctic fish: old protein gene transformed into a new gene with new structure/function
Gene mutates  duplicated  divergent evolution

18. Evolutionary Development (Evo-devo)
Compares developmental processes to understand how changes can lead to evolution of organisms

19. __________________________: master regulatory genes
Control placement and spatial organization of body parts
___________________: widely conserved 180-nucleotide sequence within homeotic (Hox) genes
Found in many groups (fungi, animals, plants)
Hints at relatedness between all life forms

20. Conservation of homeotic genes