The document discusses the human genome and endogenous retroviruses. It notes that while viruses make up about 8% of our genome, they are no longer able to make copies of themselves. However, some virus elements have been found to influence gene expression in stem cells and parts of the placenta appear derived from viruses. Overall, the document suggests that while once threats, endogenous retroviruses may now play regulatory roles in human biology and evolution through gene expression changes.

1. T H E E N E M Y W I T H I N …
G U I L L A U M E B O U R Q U E , M C G I L L U N I V E R S I T Y

2. • Who knows a bit about biology?
• … about genetics?
• … about the human genome?

3. H U M A N
G E N O M E
• Each cell of the body contains a
copy of the human genome
• The genome consists of
3,200,000,000 bases of information
(A, C, G or T)
• The genome encodes genes that
are the blueprint to make proteins,
which are the active molecules in
the cells
• Different types of cells (e.g. blood,
skin) activate different sets of
genes
ck12.org

4. H O W M A N Y G E N E S A R E T H E R E
I N T H E H U M A N G E N O M E ?
L E N G T H G E N E S
Y E A S T 1 2 , 1 0 0 , 0 0 0 6 , 2 9 4
F R U I T F LY 1 6 5 , 0 0 0 , 0 0 0 1 3 , 6 0 0
H U M A N 3 , 2 0 0 , 0 0 0 , 0 0 0
wikipedia.org
L E N G T H G E N E S
Y E A S T 1 2 , 1 0 0 , 0 0 0 6 , 2 9 4
F R U I T F LY 1 6 5 , 0 0 0 , 0 0 0 1 3 , 6 0 0
H U M A N 3 , 2 0 0 , 0 0 0 , 0 0 0 1 8 , 8 2 6
wpclipart.com

5. Other stuff
98%
Genes
2%
H U M A N G E N O M E

6. lookfordiagnosis.com
phys.org

7. E V O L U T I O N I S
A C O M P E T I T I O N
vs

8. L I F E - C Y C L E O F A V I R U S
Nicolle Rager Fuller, National Science Foundation

9. H I V V I R U S
wikipedia.org

10. quantamagazine.org

11. E N D O G E N O U S V I R U S E S
quantamagazine.org

12. Other stuff
98%
Genes
2%
H U M A N G E N O M E

13. Viruses
8%
Other stuff
90%
Genes
2%
H U M A N G E N O M E
• ~100,000 virus
elements
• Each between
100 and 7,000
basepairs
• “Tiny insertions”

14. E V O L U T I O N I S
A C O M P E T I T I O N
vs

15. E V O L U T I O N I S
A C O M P E T I T I O N
vs

16. A R E W E D Y I N G ?
• No, at least not because of that…
• The viruses that are embedded in our genome are no
longer able to make copies of themselves… Ouf!
• But, what are they doing there?
• Are they just junk DNA?

17. PA R T S O F T H E P L A C E N TA I S
D E R I V E D F R O M V I R U S E S !
bloodjournal.org

18. – B A R B A R A M C C L I N T O C K ( N O B E L P R I Z E , 1 9 8 3 )
“Transposable elements are controlling elements.”

19. V I R U S E S H AV E C H A N G E D T H E G E N E S T H AT
A R E E X P R E S S E D I N H U M A N S T E M C E L L S
bloodjournal.org
bloodjournal.org
Kunarso et al. 2010

20. E V O L U T I O N I S
A C O M P E T I T I O N
vs

21. E V O L U T I O N I S
A C O M P E T I T I O N
vs
toonpool.com

22. Viruses
8%
Other stuff
90%
Genes
2%
H U M A N G E N O M E

23. T H A N K Y O U
guil.bourque@mcgill.ca

24. Viruses
8%
LINE
17%
Alu
11%
Other repeats
9%
Other stuff
53%
Genes
2%
H U M A N G E N O M E