Genetics Final Flashcards
1860 Mendel
segregation/ independent assortment
1863 Miescher
isolation of nuclein
1885 Flemming
mitosis
1900 deVries
rediscovered Mendelian genetics
1902 Garrod
in born errors in metabolism “Allcaptonuria”
1903 Sutton & Bolveri
Meiosis; chromosome theory of inheritance
1905 Bateson & Punnett
genetic linkage
1910 Thomas Hunt Morgan
X-linked trait
1914 Sturterant
genetic mapping
1928 Griffith
transforming principle
1941 Beadle & Tatum
1 gene: 1 enzyme
1944 Avery, Macleod, & McClary
DNA transforming principle
1946 Lederberg & Tatum
bacterial conjugation
1950 Barbara McClintock
transportable elements
1952 Hershey & Chase
blender exp
1953 Watson & Crick
structure of DNA
1958 Meselson & Stahl
semi-conservative DNA replication
1966 Nirenberg & Khorana
genetic code; codons
1972 Boyer
recombinant DNA
1975 Sanger
DNA sequencing
1977 Phillip Sharp
intron spliced out
1986 Kary Mullis
PCR
2000 Venford Collins
Human Genome
2006 Mellow & Fire
discovery of RNA interference
Southern blot
Detect a DNA sequence in a DNA sample isolated from a cell
Steps for Southern blot
- Isolate gene
- Cut w/ Restriction Enzyme (like EcoR1)
- Agarose gel Electrophoresis
- Transfer to Paper (gel> buffer> paper> paper towels> heavy object)
- Add specific radioactive probe (oligonucleotide or other)
- Radioactive probe & selected gen hybridize show up on x-ray film
Northern blot
Tests for RNA; extract RNA from cell (mRNA) then follow the same steps as Southern blot
Western blot
run protein gel PAGE (polyacrylamide; smaller pores)
Steps of Western blot
- Run proteins
- transfer to paper (electrophoresis)
- SDS page: sodium dodecylsulfate (-), ionic detergent binds to proteins proportional to weight (separation caused by mass)
- Probe with specific antibody, bind specifically w/ foreign substance such as a specific inserted protein. The protein is thus an antigen.
1985-90 Human Genome Project (HGP)
US gov. and private funding awarded contracts to labs for sequencing a particular chromosome
Strategies of HGP
- To make a detailed map of markers
- Clone all humane DNA into vectors (BAC - bacterial artificial chromosome, 150,000 bp insert)
- Take all BACs and determine what markers they contain and position them on a chromosome
- Sequencing: take BAC and subclone its insert into plasmids to be sequenced using Sanger sequencing
Strategies for making a detailed map of DNA markers of the human genome
- VNTRs (variable nucleotide tandem repeat) DIS80: unique marker present at only one particular position on the chromosome
- ESTs (expressed sequence tags): take exon and find out where it maps to; give it a number; find out where it marks
Strategy for cloning all human DNA into vectors
use BAC (bacterial artificial chromosome) about 150,000 bp inserts, 500,000 BACs needed
contig
linked BACs into one sequence
Scaffolds
linked contigs after gaps are filled in
Paired-end read
ends of the same cloned insert (unknown in btw)
–compared w/ other inserts (long-insert vector) to determine what occurs in between
1998 Craig Venter - Celera Genomics
Raced the HGP to sequence the human genome
- Cloned all DNA
- Random sequencing
- Computer- intensive, assembly of fragments
Shotgun cloning & sequencing
cut your genome, map it, let a computer put it back together
How many bp in the human genome?
3x10^9
Unique seq
example: 50nts that only occur once
- Make up 50% of the Human Genome
- some genes are protein coding (1% of HG)
- Spacer seq (25% of HG) & Introns (24% of HG)
Spacer Sequences
The sequences in between genes
- -unique sequences
- -non-coding
Repetitive Sequences
sequences that appear multiple times (50% of human genome)
- gene gamilies
- telomeres
- centromers
- VNTRs
- RFLPs
- Dinucleotide Repeats
- Transposable Elements
Gene Families
tandem duplication of a region
- -A and A* are considered a gene form, derived from repeat of the same gene that has been mutated
- -Ex. globins, actins, myosins, tubulions… all related protein w/ similar function