Genetics Today Flashcards
The human genome project
1990-2003
Aims- sequence all 3.3 billion bases, identity all 20500 genes (gene maps), sequencing tools and put info in database, transfer to private sector, ethics (gen info nondiscrimination act) and compare by sequencing others species
Results of Human Genome Project
- avg gene is 3000 bases
- 20000-25000 total genes
- <2% code for proteins
- 50% gene functions unknown
- repeated sequences make up 50%
- humans have same protein families as other species but # gene family members greater in humans for dev and immunity
- humans have 3x more proteins b/c splicing
Transitions
Change purine for another purine (AG) or pyrimidine for another pyrimidine
Transversions
Substitute purine for pyrimidine
Missense
Change single AA
Nonsense
Insertion of stop codon
RNA Splicing
Exon skipping (coding mutation)
Exon skipping/intron retention (non coding mutation)
Regulatory Mutation
Changes in protein modifications
Insertion
Change in reading frame
1 or 2 base pairs
Deletion
Loss of function of protein
Repeat expansion
Altered structure of protein (coding mutation)
Altered expression (noncoding mutation)
Promoter
Transcription is altered –> inc or dec in protein levels
SNP
Single nucleotide polymorphism
Single base difference
Make up 90% genetic variation
Caused by sub/deletion/insert of 1 base
Halpotype
Linear array of consecutive SNPs that define a particular chromosomal region
HapMap
Project to develop a map of human variants (chromosomal regions and genes associated w disease and response to drugs)
Mapped 1 million SNPs to find types of variation, where they occur and distribution among races/populations
