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Genomics - Coggle Diagram
Genomics
Genomics
Study of entire genome
Human genome = 3.2x10\(^9\) bp (3.2millionKb)
Human Genome Project (HGP)
Strategies
Genetic linkage map
Co-inheritance
First markers were genes
Useful markers have alleles
Easily distinguishable phenotypes e.g. wing shape, eye colour in fruit flies
Molecular marker
Known disease genes
Blood groups
RFLPs + VNTRs
Microsatellites
Resolution of ~1.6cM
Physical map
Markers onto chromosome
Sequence-tagged sites
Short PCR-able sequences detected within other genomic sequences
Ideally heterozygous
Produces ordered + overlapping fragments
Can be stored in clone libraries
Resolution of ~100kb
Sequencing, collection + annotation
Sanger-sequencing
Parallel development of improved sequencing methods
Identification of gene sequences + gene function
Resolution to 1 base
50% human genes discovered have unknown function
1.5% nuclear genome is encoded
Mitochondrial genome - mostly encoded or conserved
Gene rich areas high GC% content
Discovery of CpG islands scattered between genes
CpG islands help gene regulation
2 x no. genes as in flies and worms
More complex - alternative mRNA splicing
Share 223 genes with bacteria not in worms, yeast or flies
ELSI
Ethical, legal and social issues
Privacy + confidentiality of genetic information
Fairness in use of genetic info.
Insurers
Employers
Psychological impact, stigmatisation + discrimination
Reproductive issues
Genetic counselling
Clinical issues
Standards + quality control
Concerns over commercialisation
Improved sequencing technologies
Fluorescent sequencing methods
PAGE capacity increase 4x
Capillary sequencing
Robotic pipetting + plasmid preparation
Enhanced reliability + throughput
Celera project
Smash genome into small fragments
Sequence fragments using Sanger method
Rebuild whole genome with huge computing power
Worked well with small genomes - never attempted with big genomes
Post-genomic era
Proteomics
Location of SNPs
Human diversity
Determine all human polymorphisms
Pharmacogenomics
Genetic component of all human diseases
Bioinformatics
Development of computer-based tools to analyse sequence data
Pseudogenes
Can be used to trace evolutionary history
Duplicate genes - one copy may become mutated over time until it is inactivated
This is not a problem because the other copy is still encoded
One copy becomes a pseudogene
Repeat sequences - transposable elements (TEs)
Retrotransposons
Class 1 via RNA intermediate
Transcribe into mRNA then encode reverse transcriptase + mRNA - DNA
LTR - long terminal repeat
LINES - long interspersed nuclear elements
SINES