Download Genome Dark Matter v.2

DARK MATTER IN THE GENOME
Shin-Han Shiu
Plant Biology / Genetics / EEBB
Cell, nucleus, and chromosomes
DNA
A
G
G
C
G
T
A
G
A
G
A
G
A
T
C
C
T
T
G
A
T
T
C
C
G
C
A
A
C
T
C
T
C
A
A
G
G
A
A
C
A
A
DNA and Genome

How many A's, T's, G's, and C's are there in the human
genome?
3,038,000,000 letters

A sizable book, say, the most recent Harry Potter book
~1,516,000 characters in 758 pages*

The book of our life
1,519,000 pages
~1,000 of the Deathly Hallows

How fast can you read?
Say, 1/day, take about 3 years
No vacation, no social life, no going anywhere else.
And the worse of all, it looks like this...
TTGGCTATCCTTTATATTTTAAGGGTTATTAGGATATTTTTTATTATGACTACATGGGATAAATGTTTAAAAAAAATAAAAAAAAACCTTTCTACGTTTGAGTATAAGACGTGGATAAAGCCTATCCATGTGGAGCAAAA
TAGTAACTTATTCACAGTTTACTGTAACAATGAATATTTCAAAAAACATATAAAATCTAAGTATGGAAATCTTATTTTATCAACAATCCAAGAGTGTCATGGTAATGATTTAATTATTGAATATTCTAATAAAAAATTCT
CTGGCGAAAAAATTACTGAGGTTATCACAGCTGGACCACAAGCTAATTTTTTTAGCACAACAAGTGTTGAGATAAAAGATGAATCAGAAGATACAAAAGTAGTACAAGAACCTAAAATATCAAAGAAGTCTAATAGTAAA
GACTTTTCTTCATCACAAGAGTTATTCGGTTTTGACGAAGCTATGCTAATTACAGCAAAAGAAGATGAGGAATACTCTTTTGGTTTACCGTTAAAAGAAAAATATGTTTTTGATAGTTTTGTTGTTGGAGATGCTAACAA
AATTGCTAGAGCAGCGGCTATGCAGGTATCGATAAATCCAGGTAAATTACATAACCCTTTATTCATTTATGGTGGTAGTGGTTTAGGTAAAACTCACTTAATGCAAGCAATAGGTAATCATGCAAGAGAAGTTAATCCTA
ATGCCAAAATTATTTATACAAATTCAGAACAATTTATTAAAGATTATGTAAATTCTATTCGTTTACAAGATCAAGATGAGTTTCAAAGAGTTTATAGATCTGCGGATATACTTTTGATTGATGATATTCAATTTATCGCT
GGTAAAGAGGGTACTGCTCAGGAGTTTTTCCATACTTTTAATGCATTGTATGAAAATGGTAAACAGATAATTCTAACTAGTGATAAGTATCCAAATGAAATAGAAGGGCTTGAAGAAAGACTAGTTTCGCGTTTTGGTTA
TGGTTTAACAGTTTCTGTTGATATGCCAGATTTAGAAACCAGAATTGCTATCTTGCTCAAAAAAGCTCATGATTTAGGTCAGAAATTACCTAACGAAACAGCAGCTTTTATTGCTGAGAATGTACGTACTAATGTCAGAG
AACTAGAAGGTGCTCTAAATAGGGTTCTTACTACCTCTAAATTTAATCATAAAGATCCTACTATCGAAGTAGCACAAGCTTGCTTAAGAGATGTTATAAAAATACAAGAAAAGAAAGTAAAAATAGATAATATCCAAAAG
GTTGTTGCTGATTTTTATAGAATCAGGGTAAAAGATTTAACTTCTAATCAAAGAAGTAGAAATATAGCTAGACCAAGACAGATAGCAATGAGTTTAGCACGTGAACTAACATCACATAGTTTGCCAGAAATAGGCAATGC
TTTTGGTGGTAGAGACCATACGACAGTTATGCATGCTGTCAAAGCTATAACTAAATTAAGACAAAGCAATACTTCAATATCGGATGATTATGAGTTGCTTTTAAATAAAATTTCTCGTTAAATAAAATTAGTAACTTTAT
CAAAGGGGTTTTAAAAAATGAATTTTGTACTAAATAGAGATGACTTACTAAAGCCTTTGCAATCTATGCTCTCAGTTGCAAATAGTAAGAGTACAATGCCTTTATTATCATGTATCTTATTTGATATTGATAATAATAAT
CTCAAAATTACGGCTTCGGATCTTGATACAGAGATATCATGCAATATAGCAGTTAGTTGTAACACAACTATTAAGTTAGCATTAAATGCTGACAAAATTTATAACATTGTCAGAAGCTTAAATGAAAATTCAATGATTGA
TTTTAGAATTAATGAAAATAAGGTAACTATTGTTTCTAATAATAGTACTTTTAACCTTATATCACTAAATGCTGACAACTATCCTCTTATTGATAGTAATATCAATGAGCAAGCAAGTTTTGATCTTTCTCAACAAGATT
TTCATCATATTATTTCAAAAGTAGATTTCTCAATGGCTAATGATGATACTCGATATTTCTTAAATGGGATGTTTTGGGAAATCAACGCAAATCTACTAAGAGCAGTATCTACAGATGGTCATAGAATGTCTATCACAGAG
GCTATAATTGATAGTAAAGTGTTAGATAGTGCTTCTCAGTCGATAATTCCAAAAAAAGCGATTTTAGAGCTTAAAAAGATAGTTGGCAAAACAGAAGAAAATATCAAAATTTGTCTTGGCAAAAATTATCTAAAAGCGAT
TTTTGGTAATTATGCTTTTATATCAAAGCTTATAGATGGTCGCTATCCTGATTACCAAAAAGTAATCCCTAAAAATAATACAAAACTATTAGCAGTTGATAAGCAGTTTTTCAAAAATTCATTATTAAGAACATCAATAC
TTGCTAATGATAAATATAAAGGTGTTCGTCTTAACATATCTCAAAATCAATTACTTCTATCAGCTAATAACCCTGATAATGAAAAGGCTGAAGATAAAATCGAAGTTCAATATAATGATCAACCAATGGAAATTTGTTTT
AATTACAAATATCTTTTGGATATTATAAATGTACTTAGTGAAGAAACTATGTCTATCTACCTTGATAATCCAAATATGAGTGCTTTAGTTAAAGATGAGAAAGATAATAGTTTGTTTATTATTATGCCAATGAAAATTTA
AGTAATAAGTAGTTTTAGGAAATAACTATTTTTATAAGCCTTTTGGAATGAATAATAAAGCAATAAAAAAAGGTATGCATAAAAACATTATATAGAAAGCTGGGATTAGATAATTTCCAGTAGTAGTAATTAATAAAGTC
ATAAGAAAGGCAACAGTACCTCCAAATAAAGAAACGCTTATATTAAAACTTATTCCAAAACCAGTATTTCTATTTCTAACAGGAAATAGCCCTGCCGTATTTGCAAATATAGGTCCTATTACAGCACCACTTATAATAGC
AAGAGAAAAAATAGCTATAGATACTAATTGATGATTTTTTATAATAATTTGGTATATTGGTAAAACAGCTATAAATAAGACTATACAAGAATACATCAGAACTTTTTTACCACCAATTCTATCAGCAATATATCCAAATA
TAATTGAAGAAAGCATTAATACTATAGTTAATCCGAGAGTATTTTGTTAAACACATAAGAGATAGCATCACAAAATTTTTCAAAACTATTATTCACTTTTCTAAATATTTTTTTAAAGTTAGCCCAAACCTTTTCAATAG
GATTTAAATCTGGAGAATACGGAGGTAGATATAATATTTGTACATCAAATTTATTGGCTATTTCAATCAGCTTAGAGGATTTATGGAAACTAGCATTATCCATTACTATAGTAGTTTTAGGTTTTAATGATGGGCATAAG
TGTTCCTCAAACCATTGATTAAAAATTTCAGTATTGGTATATCCACTGTACTCTAATGGAGCTATAATCTTTTTATCTGCATAATTATATCCAGCAACAATACTTCTTCTTTGTGTTTGATATGCTAAAACCTCACCATA
ACTAGGCTCACCAATTAGTGACCATCCTCTTAGGATAGAAAGCTTATTGTCACACCCCATCTCATCTATATAAAATAACAAGTTTTGAGCTATTTCTTTTAGTTTTTCTATATACTCCAACCTTTCATGTTCTTTTCTTT
GCTTATATTTTGGAGTCTTTTTTTAAAACTAAAACCAAGTCTATTAAGACAATCATAAAATGTACTTCTTGGAATATCAGGGGCTAATGCTTCTTTTATATCTAATGCACTTGCATCTGGATGATCTATCAAATACTGTT
CAATCAATGTTTTATCGGTAAAGCTAGCGACTCTGCCACAACCAACTCCTTGCTTTGAACTATAATCTCCGGTTCTTTTATAAAACTCTATCCATGAAACAACTGTACGCTTATCTATGTTAAAAAACTTACTCAGCTCG
AACTCCGTCATACCTTCTTCATATTTATTAATTACGATGTCTCTAAAATATTGGCTATATGATGGCATTTTTATTAGACATTATAACATTTCTACAAATATCTTTTTCTACAAATATCTTTCGGATTAACTATATAAGTA
GAGTCAACAACCATCCAAATCACCCAATTATCTATAATTTTCTGCTTGCTAAAAAAACGCATACCAATGATGCTACACTTGTAAAACCATCCATATATGGCGTTGTTGAATCAGTATAAAATATAAGTAGTTGCGAAACT
AGTAACCCAAATACTACAATGCTTACTAGAACTTTTAACCAACCAATGATTTTAAGTCTATGAACAACTATCTTTTTGTGACTAAAGTTGGGTTGCCAACTATACCAACCGTATCCAAAGCTAAATAAAAGAATCATCTG
CAATATAGCATCGGCATATAGTCCACTAACAGAAAATAAACCCGCACTCATGATCAAACCAACTATCTCCACAGGCCAACCAATGACATAAAGCCTTGCCAGCAAAAAGGTACACAAAAGATTAACAATCATTGTACAAA
AATCAAAAATATGCAGCATATTTATTTTACTAATCAAAGTATTATAAATATTATAATAACTTTGAAGTTGGCGTATTAAAGCCATAAACTTTAGTAGGTTAGTGTTTATACCAATATTTTGAGATGCTTTCTGCAAGCTA
ATAACATTTAGCTATCTAGCCTAAATAATTAATATACAAAACTTTCAAGCTTATTGAATTTTTCAACAGATACAGCGCGTTATAACAAATAAGTAATTGACTAAATTAAAAAGCAAGTATAATATCGATTGTGTTTATTA
CATAATATAAAACGAGGATAAAAAAAATATGAAATTAAGAAAAGTATTAATCGCGACATTATTAGGAGCTTCTGCTTTATCTTTAAGTAGTTGTTGGTTACTTGTTGGTGCAGCTGTTGGTGGTGGAACTGCTGCGTATA
TTTCTGGTGAGTATTCAATGAATATGAGTGGCAGTGTAAAAGATATTTACAATGCTACTTTAAAAGCTGTTCAAAGCAATGATGATTTTGTAATTACTAAAAAATCTATTACTTCTGTTGATGCAGTTGTTGATGGTAGT
ACTAAGGTAGACTCAACAAGTTTCTATGTTAAAATAGAAAAACTTACTGATAATGCTTCAAAAGTTACAATTAAGTTTGGTACTTTTGGTGACCAAGCAATGTCAGCAACATTAATGGATCAAATCCAAAAGAATCTTTA
ATTAAATAGGTAATTACTATAATGACTTTTCTAAAGAAAGCTTTTATTGCAACTATAGTTTCTATTTCAGCATTAGTTCTAAATAGTTGTATTGTTGCAGCAATAGCTGTTGGTGGTGGAACAGTTGCCTATATTGATGG
AAATTATTTTATGAATATAGAAGGCAACTATAAAGCTGTCTATAAAGCTACTCTTAAAGCTATTAATGATAATAATGACTTTGTTCTAGTATCAAAAGATCTTGATCAAACAAAGCAAAATGCCGACATTGAAGGTGCTA
CTAAAATTGATAGTACGAGTTTTAGTGTCAAAATTGAAAGACTGACAGATCAGGCTACTAAAGTGACAATCAAATTTGGTACTTTTGGCGATCAAGCAATGTCATCAACATTAATGGATCAGATCCAGGCAGCTGTACAT
AAAGCTTCTTAGAAATGTACAAAAAACTCTACTTAATTATATTATCCACAATAATCGCAATCTCTCTTAATAGTTGTGTTGTTGCCGCTGTTTTAATTGGTACAGCAGTTGTTGCTGGAGGTACAGTATATTACATCAAT
GGTAACTATATAATCGAAGTCCCTAAAGATATTAGAAGTGTATACAATGCTACAATCAAGACTATACAGATGGATAGTCAAAATAAACTAATAAGTCAAACCTATAATACTAAATCTGCTATAATTAAAGCTTTACAAAA
AGGTGAAAAAATTAGTATAGATTTAAGCAATATTGATAGTCGTTCAACAGAGATAAAAATTCGTATAGGTGTACTTGGCGATGAGAAAAAATCTGCTGATTTAGCAAACTCAATAACAAAAAATATCACCTAAGCAATAT
TTCTCGAACTTTGGTTAACTTTTTCTTTTTAAAAACTTTCAAAAATGTATAATTTGTGTTAGTTTGCAAACTACCCTTATATCCATAATGAGTAATAAGGTATTAGATACATATTATAAAAACAATCGACATATTTGGGT
GCTAGTACTATCTGGTGCTGTTATAGGCACAATGATTGGTCTTCTAGCAACAGCATTTCAGCTACTCCTAGACTTTATTTTTAAAATTAAGCTGGCTCTTTTTTCTTTCAGTGGTGGTAATCTTTTTATCGAAATCGCTA
TGTCAATATCATTAAGTATTGTGATGGTATTAATTTCGATTTTTATTGTTAAAAAATTTGCGAAAGAGGCTGGTGGTAGCGGTATCCAAGAGGTTGAGGGTGCTTTAAAAGGCTGCCGCAAAATACGTAAAAGAGTTATG
CCCGTGAAGTTTATAAGTGGACTTTTTTCGTTAGGCTCAGGTTTAAGTTTAGGTAAAGAGGGACCATCAATTCATATGGCTGCTGCATTAGCGCAGTTTTTTGTTGATAAATTTAAACTTACTACAAAATATGCTAATGC
GGTTATCTCTGCTGGGGCTGGAGCTGGACTAGCAGCTGCTTTTAATACCCCACTTTCTGGGATTATCTTTGTTATTGAAGAGATGAATAGAAAGTTTAGATTTAGTGTTTCGGCAATAAAGTGTGTGCTAGTAGCATGTA
TCATGAGTACAGTTATCTCTAGAGCTATTATGGGTAATCCTCCAGCAATACGCGTAGAAACTTTCAGCTCAGTACCACAAAATACTCTTTGGTTATTTATGGTATTAGGGATTATATTTGGTTATTTTGGTTTACTATTT
AACAAATCCTTAATCAAAGTGGCAAACTTTTTCTCAGAAGGCTCCAAGAAGAGGTATTGGACTTTAGTTATAATTGTTTGCATAATTTTTGGTATTGGTGTTGTTCTATCTCCAAATGCTGTTGGCGGTGGCTATATTGT
CATAGCAAATACTCTTGATTATAACTTATCAATCAAGATGCTTTTAGTGCTTTTTGTACTTCGTTTTGCTGGAGTTATTTTCTCATATGGCACCGGCGTTACTGGTGGGATATTCGCACCAATGATTGCGCTTGGTACTG
Our research interest
TTGGCTATCCTTTATATTTTAAGGGTTATTAGGATATTTTTTATTATGACTACATGGGATAAATGTTTAAAAAAAATAAAAAAAAACCTTTCTACGTTTGAGTATAAGACGTGGATAAAGCCTATCCATGTGGAGCAAAA
TAGTAACTTATTCACAGTTTACTGTAACAATGAATATTTCAAAAAACATATAAAATCTAAGTATGGAAATCTTATTTTATCAACAATCCAAGAGTGTCATGGTAATGATTTAATTATTGAATATTCTAATAAAAAATTCT
CTGGCGAAAAAATTACTGAGGTTATCACAGCTGGACCACAAGCTAATTTTTTTAGCACAACAAGTGTTGAGATAAAAGATGAATCAGAAGATACAAAAGTAGTACAAGAACCTAAAATATCAAAGAAGTCTAATAGTAAA
GACTTTTCTTCATCACAAGAGTTATTCGGTTTTGACGAAGCTATGCTAATTACAGCAAAAGAAGATGAGGAATACTCTTTTGGTTTACCGTTAAAAGAAAAATATGTTTTTGATAGTTTTGTTGTTGGAGATGCTAACAA
AATTGCTAGAGCAGCGGCTATGCAGGTATCGATAAATCCAGGTAAATTACATAACCCTTTATTCATTTATGGTGGTAGTGGTTTAGGTAAAACTCACTTAATGCAAGCAATAGGTAATCATGCAAGAGAAGTTAATCCTA
ATGCCAAAATTATTTATACAAATTCAGAACAATTTATTAAAGATTATGTAAATTCTATTCGTTTACAAGATCAAGATGAGTTTCAAAGAGTTTATAGATCTGCGGATATACTTTTGATTGATGATATTCAATTTATCGCT
GGTAAAGAGGGTACTGCTCAGGAGTTTTTCCATACTTTTAATGCATTGTATGAAAATGGTAAACAGATAATTCTAACTAGTGATAAGTATCCAAATGAAATAGAAGGGCTTGAAGAAAGACTAGTTTCGCGTTTTGGTTA
TGGTTTAACAGTTTCTGTTGATATGCCAGATTTAGAAACCAGAATTGCTATCTTGCTCAAAAAAGCTCATGATTTAGGTCAGAAATTACCTAACGAAACAGCAGCTTTTATTGCTGAGAATGTACGTACTAATGTCAGAG
AACTAGAAGGTGCTCTAAATAGGGTTCTTACTACCTCTAAATTTAATCATAAAGATCCTACTATCGAAGTAGCACAAGCTTGCTTAAGAGATGTTATAAAAATACAAGAAAAGAAAGTAAAAATAGATAATATCCAAAAG
GTTGTTGCTGATTTTTATAGAATCAGGGTAAAAGATTTAACTTCTAATCAAAGAAGTAGAAATATAGCTAGACCAAGACAGATAGCAATGAGTTTAGCACGTGAACTAACATCACATAGTTTGCCAGAAATAGGCAATGC
TTTTGGTGGTAGAGACCATACGACAGTTATGCATGCTGTCAAAGCTATAACTAAATTAAGACAAAGCAATACTTCAATATCGGATGATTATGAGTTGCTTTTAAATAAAATTTCTCGTTAAATAAAATTAGTAACTTTAT
CAAAGGGGTTTTAAAAAATGAATTTTGTACTAAATAGAGATGACTTACTAAAGCCTTTGCAATCTATGCTCTCAGTTGCAAATAGTAAGAGTACAATGCCTTTATTATCATGTATCTTATTTGATATTGATAATAATAAT
CTCAAAATTACGGCTTCGGATCTTGATACAGAGATATCATGCAATATAGCAGTTAGTTGTAACACAACTATTAAGTTAGCATTAAATGCTGACAAAATTTATAACATTGTCAGAAGCTTAAATGAAAATTCAATGATTGA
TTTTAGAATTAATGAAAATAAGGTAACTATTGTTTCTAATAATAGTACTTTTAACCTTATATCACTAAATGCTGACAACTATCCTCTTATTGATAGTAATATCAATGAGCAAGCAAGTTTTGATCTTTCTCAACAAGATT
TTCATCATATTATTTCAAAAGTAGATTTCTCAATGGCTAATGATGATACTCGATATTTCTTAAATGGGATGTTTTGGGAAATCAACGCAAATCTACTAAGAGCAGTATCTACAGATGGTCATAGAATGTCTATCACAGAG
GCTATAATTGATAGTAAAGTGTTAGATAGTGCTTCTCAGTCGATAATTCCAAAAAAAGCGATTTTAGAGCTTAAAAAGATAGTTGGCAAAACAGAAGAAAATATCAAAATTTGTCTTGGCAAAAATTATCTAAAAGCGAT
TTTTGGTAATTATGCTTTTATATCAAAGCTTATAGATGGTCGCTATCCTGATTACCAAAAAGTAATCCCTAAAAATAATACAAAACTATTAGCAGTTGATAAGCAGTTTTTCAAAAATTCATTATTAAGAACATCAATAC
TTGCTAATGATAAATATAAAGGTGTTCGTCTTAACATATCTCAAAATCAATTACTTCTATCAGCTAATAACCCTGATAATGAAAAGGCTGAAGATAAAATCGAAGTTCAATATAATGATCAACCAATGGAAATTTGTTTT
AATTACAAATATCTTTTGGATATTATAAATGTACTTAGTGAAGAAACTATGTCTATCTACCTTGATAATCCAAATATGAGTGCTTTAGTTAAAGATGAGAAAGATAATAGTTTGTTTATTATTATGCCAATGAAAATTTA
AGTAATAAGTAGTTTTAGGAAATAACTATTTTTATAAGCCTTTTGGAATGAATAATAAAGCAATAAAAAAAGGTATGCATAAAAACATTATATAGAAAGCTGGGATTAGATAATTTCCAGTAGTAGTAATTAATAAAGTC
ATAAGAAAGGCAACAGTACCTCCAAATAAAGAAACGCTTATATTAAAACTTATTCCAAAACCAGTATTTCTATTTCTAACAGGAAATAGCCCTGCCGTATTTGCAAATATAGGTCCTATTACAGCACCACTTATAATAGC
AAGAGAAAAAATAGCTATAGATACTAATTGATGATTTTTTATAATAATTTGGTATATTGGTAAAACAGCTATAAATAAGACTATACAAGAATACATCAGAACTTTTTTACCACCAATTCTATCAGCAATATATCCAAATA
TAATTGAAGAAAGCATTAATACTATAGTTAATCCGAGAGTATTTTGTTAAACACATAAGAGATAGCATCACAAAATTTTTCAAAACTATTATTCACTTTTCTAAATATTTTTTTAAAGTTAGCCCAAACCTTTTCAATAG
GATTTAAATCTGGAGAATACGGAGGTAGATATAATATTTGTACATCAAATTTATTGGCTATTTCAATCAGCTTAGAGGATTTATGGAAACTAGCATTATCCATTACTATAGTAGTTTTAGGTTTTAATGATGGGCATAAG
TGTTCCTCAAACCATTGATTAAAAATTTCAGTATTGGTATATCCACTGTACTCTAATGGAGCTATAATCTTTTTATCTGCATAATTATATCCAGCAACAATACTTCTTCTTTGTGTTTGATATGCTAAAACCTCACCATA
ACTAGGCTCACCAATTAGTGACCATCCTCTTAGGATAGAAAGCTTATTGTCACACCCCATCTCATCTATATAAAATAACAAGTTTTGAGCTATTTCTTTTAGTTTTTCTATATACTCCAACCTTTCATGTTCTTTTCTTT
GCTTATATTTTGGAGTCTTTTTTTAAAACTAAAACCAAGTCTATTAAGACAATCATAAAATGTACTTCTTGGAATATCAGGGGCTAATGCTTCTTTTATATCTAATGCACTTGCATCTGGATGATCTATCAAATACTGTT
CAATCAATGTTTTATCGGTAAAGCTAGCGACTCTGCCACAACCAACTCCTTGCTTTGAACTATAATCTCCGGTTCTTTTATAAAACTCTATCCATGAAACAACTGTACGCTTATCTATGTTAAAAAACTTACTCAGCTCG
AACTCCGTCATACCTTCTTCATATTTATTAATTACGATGTCTCTAAAATATTGGCTATATGATGGCATTTTTATTAGACATTATAACATTTCTACAAATATCTTTTTCTACAAATATCTTTCGGATTAACTATATAAGTA
GAGTCAACAACCATCCAAATCACCCAATTATCTATAATTTTCTGCTTGCTAAAAAAACGCATACCAATGATGCTACACTTGTAAAACCATCCATATATGGCGTTGTTGAATCAGTATAAAATATAAGTAGTTGCGAAACT
AGTAACCCAAATACTACAATGCTTACTAGAACTTTTAACCAACCAATGATTTTAAGTCTATGAACAACTATCTTTTTGTGACTAAAGTTGGGTTGCCAACTATACCAACCGTATCCAAAGCTAAATAAAAGAATCATCTG
CAATATAGCATCGGCATATAGTCCACTAACAGAAAATAAACCCGCACTCATGATCAAACCAACTATCTCCACAGGCCAACCAATGACATAAAGCCTTGCCAGCAAAAAGGTACACAAAAGATTAACAATCATTGTACAAA
AATCAAAAATATGCAGCATATTTATTTTACTAATCAAAGTATTATAAATATTATAATAACTTTGAAGTTGGCGTATTAAAGCCATAAACTTTAGTAGGTTAGTGTTTATACCAATATTTTGAGATGCTTTCTGCAAGCTA
ATAACATTTAGCTATCTAGCCTAAATAATTAATATACAAAACTTTCAAGCTTATTGAATTTTTCAACAGATACAGCGCGTTATAACAAATAAGTAATTGACTAAATTAAAAAGCAAGTATAATATCGATTGTGTTTATTA
CATAATATAAAACGAGGATAAAAAAAATATGAAATTAAGAAAAGTATTAATCGCGACATTATTAGGAGCTTCTGCTTTATCTTTAAGTAGTTGTTGGTTACTTGTTGGTGCAGCTGTTGGTGGTGGAACTGCTGCGTATA
TTTCTGGTGAGTATTCAATGAATATGAGTGGCAGTGTAAAAGATATTTACAATGCTACTTTAAAAGCTGTTCAAAGCAATGATGATTTTGTAATTACTAAAAAATCTATTACTTCTGTTGATGCAGTTGTTGATGGTAGT
ACTAAGGTAGACTCAACAAGTTTCTATGTTAAAATAGAAAAACTTACTGATAATGCTTCAAAAGTTACAATTAAGTTTGGTACTTTTGGTGACCAAGCAATGTCAGCAACATTAATGGATCAAATCCAAAAGAATCTTTA
ATTAAATAGGTAATTACTATAATGACTTTTCTAAAGAAAGCTTTTATTGCAACTATAGTTTCTATTTCAGCATTAGTTCTAAATAGTTGTATTGTTGCAGCAATAGCTGTTGGTGGTGGAACAGTTGCCTATATTGATGG
AAATTATTTTATGAATATAGAAGGCAACTATAAAGCTGTCTATAAAGCTACTCTTAAAGCTATTAATGATAATAATGACTTTGTTCTAGTATCAAAAGATCTTGATCAAACAAAGCAAAATGCCGACATTGAAGGTGCTA
CTAAAATTGATAGTACGAGTTTTAGTGTCAAAATTGAAAGACTGACAGATCAGGCTACTAAAGTGACAATCAAATTTGGTACTTTTGGCGATCAAGCAATGTCATCAACATTAATGGATCAGATCCAGGCAGCTGTACAT
AAAGCTTCTTAGAAATGTACAAAAAACTCTACTTAATTATATTATCCACAATAATCGCAATCTCTCTTAATAGTTGTGTTGTTGCCGCTGTTTTAATTGGTACAGCAGTTGTTGCTGGAGGTACAGTATATTACATCAAT
GGTAACTATATAATCGAAGTCCCTAAAGATATTAGAAGTGTATACAATGCTACAATCAAGACTATACAGATGGATAGTCAAAATAAACTAATAAGTCAAACCTATAATACTAAATCTGCTATAATTAAAGCTTTACAAAA
AGGTGAAAAAATTAGTATAGATTTAAGCAATATTGATAGTCGTTCAACAGAGATAAAAATTCGTATAGGTGTACTTGGCGATGAGAAAAAATCTGCTGATTTAGCAAACTCAATAACAAAAAATATCACCTAAGCAATAT
TTCTCGAACTTTGGTTAACTTTTTCTTTTTAAAAACTTTCAAAAATGTATAATTTGTGTTAGTTTGCAAACTACCCTTATATCCATAATGAGTAATAAGGTATTAGATACATATTATAAAAACAATCGACATATTTGGGT
GCTAGTACTATCTGGTGCTGTTATAGGCACAATGATTGGTCTTCTAGCAACAGCATTTCAGCTACTCCTAGACTTTATTTTTAAAATTAAGCTGGCTCTTTTTTCTTTCAGTGGTGGTAATCTTTTTATCGAAATCGCTA
TGTCAATATCATTAAGTATTGTGATGGTATTAATTTCGATTTTTATTGTTAAAAAATTTGCGAAAGAGGCTGGTGGTAGCGGTATCCAAGAGGTTGAGGGTGCTTTAAAAGGCTGCCGCAAAATACGTAAAAGAGTTATG
CCCGTGAAGTTTATAAGTGGACTTTTTTCGTTAGGCTCAGGTTTAAGTTTAGGTAAAGAGGGACCATCAATTCATATGGCTGCTGCATTAGCGCAGTTTTTTGTTGATAAATTTAAACTTACTACAAAATATGCTAATGC
GGTTATCTCTGCTGGGGCTGGAGCTGGACTAGCAGCTGCTTTTAATACCCCACTTTCTGGGATTATCTTTGTTATTGAAGAGATGAATAGAAAGTTTAGATTTAGTGTTTCGGCAATAAAGTGTGTGCTAGTAGCATGTA
TCATGAGTACAGTTATCTCTAGAGCTATTATGGGTAATCCTCCAGCAATACGCGTAGAAACTTTCAGCTCAGTACCACAAAATACTCTTTGGTTATTTATGGTATTAGGGATTATATTTGGTTATTTTGGTTTACTATTT
AACAAATCCTTAATCAAAGTGGCAAACTTTTTCTCAGAAGGCTCCAAGAAGAGGTATTGGACTTTAGTTATAATTGTTTGCATAATTTTTGGTATTGGTGTTGTTCTATCTCCAAATGCTGTTGGCGGTGGCTATATTGT
CATAGCAAATACTCTTGATTATAACTTATCAATCAAGATGCTTTTAGTGCTTTTTGTACTTCGTTTTGCTGGAGTTATTTTCTCATATGGCACCGGCGTTACTGGTGGGATATTCGCACCAATGATTGCGCTTGGTACTG
Now, 1366 genomes are sequenced or being
sequenced
Evolution of genome sizes

In Mb

Thale cress (Arabidopsis thaliana):
150

Fruit fly (Drosophila melanogaster):
160

Pufferfish (Takifugu rubripes):
400

Human (Homo sapiens):
3,000

Onion (Allium cepa):
16,750

Tiger salamander (Ambystoma tigrinum):
32,000

Marbled lungfish (Protopterus aethiopicus):
132,000
http://www.rbgkew.org.uk/
What's in the genome
Genome
Exon
UTR
Annotated genes
Intron
Cis-regulatory elements
Selfish elements
Dead genes (pseudogenes)
Novel genes
"Non-genic": repetitive elements

E.g. Human genome
 Exons take up?
 Introns account for?
 Repetitive elements occupy?
 Unknown?
A
B
C
1%
24%
25%
24%
1%
25%
35%
60%
45%
40%
15%
5%
Venter et al. (2001) Science 291:1304
What are in the unknown regions?
 Investigate with tiling array
cDNA array
Tiling array
Gap size: 10bp
Probe size: 25bp
 Number of features:
 Arabidopsis, 135Mb, 1 chip, ~6x106 features
 Human, 3Gb, 7 chips, ~4.2x107 features
"Non-genic": unannotated genes

Tiling array analysis of human Chr 21, 22
Kapranov et al., 2002. Science
Tiling array analysis of human transcriptome

Human Chr 21, 22

What do you think these expressed regions represent??
Kapranov et al., 2002. Science
Difficulties for coding gene prediction
 Training data
 You need to know something...
 “Biased” toward the properties of the majority.
 Real genes that are shorter tend to be much harder to
predict.
Table 3 Accuracy of GISMO, Glimmer and CRITICA in
predicting short genes (<300 bp)
Gene finder
Cor
Sn
Snfk (%)
Sp
GISMO
0.64
63.0
86.4
69.0
Glimmer
0.54
72.0
83.7
44.0
CRITICA
0.60
46.0
67.4
84.0
Snfk denotes the sensitivity in detecting function-known genes.
Krause et al., 2006. Nucleic Acid Res. 35:540
Novel coding sequence identification

Arabidopsis thaliana as an example
 135Mb, ~50% occupied by annotated
genes.
 Focus on coding sequences 90-300bp
long.

What would you do next to eliminate
ORFs that are likely false predictions?
133,090 sORFs
Criterion 1: Codon usage bias

Some codons are used more frequently than others
http://www.cbs.dtu.dk/services/GenomeAtlas/
Criterion 1: Codon usage bias


For example: codons for proline
NCDS
CDS
CCT
0.25
0.12
CCC
0.25
0.49
CCA
0.25
0.06
CCG
0.25
0.33
Suppose you have the following 2 sequences both code for
poly-leucine, which one is more likely to be real coding
sequence?
Seq1
CCT CCA CCT
p(CDS | Seq1)  0.12  0.06  0.12  8.6 104
Seq2
CCC CCG CCC
p(CDS | Seq 2)  0.49  0.33  0.49  7.9 102
Posterior probability of coding sequence

Compare known non-coding and coding sequences
Hanada et al., 2007. Genome Res.
Posterior probability of coding sequence

Scanning Arabidopsis genome
Hanada et al., 2007. Genome Res.
After applying the first criterion
7,442 coding sORFs
How good is the CDS finding measure

For the training data

For 18 Arabidopsis small protein genes
 All 18 are predicted as CDS.

For 84 yeast small protein genes
 All 84 are predicted as CDS.
So what does this mean?

If a sequence is a true coding sequence
 Our approach can predict them with high accuracy.
 So, the sensitivity is very good.

Is this good enough??

What about specificity?
 Namely, how good is the criteria in excluding false positives?
Criterion 2: Expression
 Which of the following distribution more likely
depicting the expression level distribution of true CDS
compared to that of false CDS?
Tiling array
Frequency
Gap size: 10bp
Probe size: 25bp
Expression level
Low
High
Comparison of expression levels

Exon, intron, tRNA, rRNA, our predictions
A: Exon
B: Intron
C: Prediceted novel CDS
D: tRNA
E: rRNA
Applying the second criterion

Prediction significantly enriched in expressed sequences
2,996 transcribed
sORFs
Criterion 3: Purifying selection

Compare known coding and non-coding sequences
Ka
w
Ks
K a : non - synonymous substituti on rate
K s : synonymous substituti on rate
w  1 : negative (purifying ) selection
w  1 : selectivel y neutral
w  1 : positive selection
Criterion 3: Purifying selection

Compare known coding and non-coding sequences
In the end,

We found a large number (941) small ORFs have the
following three properties:
 They have nucleotide composition similar to known coding
sequences.
 They are expressed.
 They are subjected to selection in a fashion a protein sequence
would be selected.

Take home message:
 We don't know the functions of all any of these.
 The view that most of the "intergenic" region is junk DNA may
be wrong.
Acknowledgement

Current and past lab members
Kousuke Hanada
Melissa Lehti-Shiu
Cheng Zou

TIGR
 Chris Town
 Hank Wu

University of Chicago
 Wen-Hsiung Li
 Justin O. Borevitz
 Xu Zhang

Funding