Transcript Diapositive 1 - Master 1 Biologie Sant&#233

Reference books:
Molecular Biology of the Cell, 4th edition, by B. Alberts et al.,
2002.
Molecular Cell Biology, 5th edition, by H. Lodish et al., 2004.
Molecular Biology of the gene, 5th edition, J. Watson et al, 2004
Planches à voir Tazi 1. PPT
METHODOLOGIE.PDF
Watson & Crick – “…the secret of life”
•
Watson: a zoologist, Crick: a
physicist
•
“In 1947 Crick knew no biology and
practically no organic chemistry or
crystallography..” – www.nobel.se
•
Applying Chagraff’s rules and the Xray image from Rosalind Franklin,
they constructed a “tinkertoy” model
showing the double helix
•
Their 1953 Nature paper: “It has not
escaped our notice that the specific
pairing we have postulated
immediately suggests a possible
copying mechanism for the genetic
material.”
Watson & Crick with DNA model
Rosalind Franklin with X-ray image of DNA
Replication
DNA
Transcription
DNA pol fidelity
Error rate of ~ 10-9 to 10-12.
RNA pol fidelity
Error rate of ~ 10-4 to 10-5.
RNA
Translation
Post-transcriptional regulation
Protein
GENOMICS
Discovering
TRANSCRIPTOMICS
PROTEOMICS
BIOINFORMATICS
DNA
(Genome)
Pre-mRNA
mRNA
mRNA
Proteins
(Transcriptome)
(Proteome)
Metabolites (Metabolome)
Steps in DNA Sequencing and Genotyping
• Selecting part of genome to sequence
or genotype
• Amplifying nucleic acid
• Determine sequence of one or a
succession of nucleic acids:
– Chemical reaction format
– Read out format
• Resequencing vs de novo sequencing
Sequence Tagget sites (STSs)
Short segments of unique DNA sequence along every
chromosome
Dideoxynucleoside Sequencing
Dideoxynucleoside Sequencing
Dideoxynucleoside Sequencing
Séquençage par des ddNTP Fluorescents
Genome Sequencing Approaches
https://www.roche-applied-science.com/sis/sequencing/flx/
Multimedia presentation
Pyrosequencing
Ronaghi M. Pyrosequencing sheds light on DNA sequencing. Genome Res 2001
Pyrosequencing - Solid Phase
Ronaghi M. Pyrosequencing sheds light on DNA sequencing. Genome Res 2001
Pyrosequencing - Liquid Phase
Ronaghi M. Pyrosequencing sheds light on DNA sequencing. Genome Res 2001
Pyrogram
Ronaghi M. Pyrosequencing sheds light on DNA sequencing. Genome Res 2001
454 LifeSciences Sequencer
454 LifeSciences Sequencer Process Overview
454 LifeSciences Sequencer Process Overview
454 LifeSciences Sequencer
454 LifeSciences Sequencer
454 LifeSciences Sequencer
Applications of Ultra-Low-Cost Sequencing
• Sequencing individual human genomes as component of
preventive care.
• Genotype-phenotype associations
• Comprehensive gene expression profiling in vitro and in
situ at all stages of development of a multicellular
organism
• Comprehensive analysis of mutations present in cancer
clones.
• Mitochondrial heteroplasmy
• Microbial diversity (metagenomic studies)
Shendure N. Advanced sequencing technology: methods and goals. Nat Rev Gen 2004
3 billion bases
20,000 – 30,000 genes
3000 nucleotide/gene (on average)
99,9% nucleotide similarity to each other
99% nucleotide similarity to chimpanzees
Less than 2 % codes for proteins
Chromosome 1 has the most genes
Chromosome Y has the fewest genes
Variations in human genome
Microsatelitte sequences and variation
"Microsatellites" are defined as loci (or regions within DNA sequences)
where short sequences of DNA are repeated in tandem arrays. This means
that the sequences are repeated one right after the other. The lengths of
sequences used most often are di-, tri-, or tetra-nucleotides.
Single Nucleotide polymorphisms
* Protein Coding sequences represent less than 2% of human genome
* More than 50% of human genome sequences are repetitive sequences
CpG islands density on each chromosome