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The Human Genome Project. Public: International Human Genome Sequencing Consortium (aka HUGO) Private: Celera Genomics, Inc. (aka TIGR). The HGP. 1st proposed in 1986 In addition to humans, the effort included E. coli, yeast, C. elegans, Drosophila, and mouse. Funded in 1988 - PowerPoint PPT Presentation
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The Human Genome Project
Public: International Human Genome Sequencing Consortium (aka HUGO)
Private: Celera Genomics, Inc. (aka TIGR)
The HGP1st proposed in 1986
In addition to humans, the effort included E. coli, yeast, C. elegans, Drosophila, and mouse
Funded in 1988Estimated cost: $3 billion Final cost: $2.6 billionGot underway in 1990
1st genome sequenced in 1995 (TIGR)
Yeast sequenced in 1996
E. coli sequenced in 1997
C. elegans sequenced in 1998
Drosophila sequenced in 2000 (Celera)
The Human Sequence
The genome was sequenced about 4 times over
Contained errors and gaps
The finished sequence, released in April of 2003, was sequenced 8 times over, had 1 error in 10,000 bases and did not contain significant gaps
Gaps can exist:1) within unfinished sequence clones2) between sequenced BACs3) between mapped BACs
Human draft sequence released in Jan. 2001 (HUGO & Celera)
The “Typical” Human Gene
Size of exons 145 bp
# of exons 8.8
Size of introns 3,365 bp
Size of 3’ UTR 770 bp
Size of 5’ UTR 300 bp
Coding sequence size 1,340 bp
CDS 447 aa
Genomic extent 27 kb
The Number of Human Genes
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000
Earlyestimates
Laterestimates
Draft sequence
Final sequence
# of Genes in Other Organisms
0
5000
10000
15000
20000
25000
M. g E. c S. c D. m C. e H. s A. t
Orthologs of Human Proteins
Where did the prokaryotic orthologs come from?
One possibility is horizontal transfer
41 genes may have been transferred in this way
For example: MAOs, monoamine oxidases
These enzymes deactivate neurotransmittersAnother possibility is the loss of these genes over time so that most eukaryotes lack them
Functional Categories of Proteins
Families of Transcription Factors
Some surprises from the HGP Not every gene has its own promoter Not every gene encodes a protein The number of genes in our genome
Promoters: a number of adjacent genes are transcribed simultaneously. These genes were shown to share a promoter, much like prokaryotes control gene expression.
Genes that do not encode proteins tRNA rRNA snRNAs (small nuclear RNAs) snoRNAs (small nucleolar RNAs) ncRNAs (non-coding RNAs)These are untranslated genes such as the
let-7 gene in C. elegans. It encodes a 21-base RNA that binds to another gene
How Can We Have So Few Genes? Combinatorial Control
Alternate Splicing
We are not just 1.5 times as complex as flies, even though we have about 1.5 times the number of genes.
If each gene has 2 states: on or off, then
there are 213,600 different combinations in Drosophila but 221,000 different combinations in humans.
Epigenetic Control