Chapter 13 Applied GeneticsAdvances in technology
What is Applied Genetics?s Applying theoretical concepts of genetics to practical areas.s For example plants, animals, and medicine.
Selective Breedings Produces organisms with desired traits.s For example large heads of grain, juicy berries, disease resistant plants, calves that produce the most milk.
Inbreedings Mating between closely related individuals--develops pure blood lines. Insures offspring are homozygous for traits.s Disadvantage: also brings out harmful recessive traits. Ex. Boxers tend to get cancer. The Pharaohs disfiguration.
What is a Breed?s A selected group of organisms within a species that have been bred for particular characteristics.s German shepherdss Boxerss Klydesdale Horsess Himalayan Cats
What is a Hybrid?s Offspring of parents with different forms of a trait.s Ex. Crossing a disease resistant plant with one that produces a lot of yield = a plant that is disease resistant and productive.s Examples wheat, corn, rice, garden vegetables
How do we determineGenotypes?s Perform test crosses: cross an individual of known genotype with one of unknown genotype and observe offspring.s Known genotype is always the recessive.
Example of a Test cross D D D d Dd Dd Dd ddd dd Dd Dd Dd d dd All offspring are 1/2 offspring are Dominant dominant 1/2 offspring are recessive
Genetic Engineerings A faster and more reliable method for increasing the frequency of a specific allele in a population.s Involves cutting (or cleaving) DNA from 1 organism into fragments and inserting the fragments into a host organism.
Recombinant DNAs Is made by connecting or recombining fragments of DNA from different organisms.s Transgenic Organisms: contain foreign DNA ( or recombinant DNA)
How to Produce a TransgenicOrganisms First: isolate the foreign DNA fragment and cleave the DNA with restriction enzymes.s Second:Attach the fragment to a vehicle called a vector so it can be transported into the host cell.s Third:Transfer the vector to the host and reconnect the vector with the host DNA by gene splicing (rejoining DNA)
How to Produce TransgenicOrganisms.s Fourth: After the DNA is transferred now it can replicate every time the host DNA replicates making clones (identical copies) of the recombinant DNA.
Restriction Enzymess Used to cleave DNA at certain sites.s ECORI cleaves at 5’GAATTC3’s BAMHI cleaves at 5’GGATCC3’s HINDIII cleaves at 5’AAGCTT3’s Palendrome: words or sentences that read the same forwards and backwardss Ex. Mom, DAD
Restriction Enzymess If DNA is cut straight through both strands you have blunt ends Ex. 5’TTAT3’ 5’AATA3’s If DNA is cut stagerdly the ends are said to be “sticky” 5’GATCCGAGGA3’ 5’TCCTAGGC3’
Types of Vectorss Vectors transport foreign DNA to a hosts Biological vectors are viruses, and plasmids (small rings of DNA found in bacteria cells)s Mechanical Vectors: micropipette or small metal bullets
Why is cloning possible?s Because foreign pieces of DNA introduced into the host cell has been so completely, the foreign DNA is replicated as if it were the host’s DNA.s Advantage to using bacteria in cloning is it replicates quickly.s Cloning Animals: to produce healthy, productive animals that increase yield.
Sequencing DNAs Once pure DNA has been cloned then the sequence of DNA can be determined by:s separating the strandss the single strands are mixed with enzymes, radioactive nucleotides and dyes.
Sequencing DNAs The mixture produces complementary strands of varying lengths.s They are separated according to size by gel electrophoresis, producing a pattern of dyed bans which can be read with a X-ray
The process of GelElectrophoresiss Restriction enzymes either one or several restriction enzymes is added to a DNA sample. The enzymes cut the DNA into fragments.s The gel: a gel similar to gelatin, is formed so that small wells are left at one end. Into the wells, small amounts of the DNA sample are placed.
The Process of GelElectrophoresiss The electrical Field : the gel is placed in a solution, and an electrical field is set up so that one end of the gel is positive and the other is negative.s The fragments Move: the negatively charged DNA fragments travel toward the positive end. The smaller fragments, the faster it moves through the gel.
The Process of GelElectrophoresiss Fragments that are the farthest from the well are the smallest.
The Human Genomes It is approximately 80,000 genes on 46 chromosomes.s There are 3 billion base pairs of DNA
Linkage Mapss The genetic map that shows the location of genes on chromosomess Genes that cross over frequently must be farther apart than genes that rarely cross over.
Uses of the Human Genomes Diagnosis of genetic disorderss Gene therapy: the insertion of normal genes into human cells to correct genetic disorders. (Used with CF patients)s DNA fingerprinting
DNA Fingerprintings Small DNA samples can be obtained from blood, hair, skin, or semen and copied millions of times using a technique called PCR (polymerase chain reaction)s The individuals DNA is cleaved with restriction enzymes and run through gel electrophoresis.
DNA Fingerprintings The DNA fragments that separate in the gel can be compared with another sample to see if there is a match.s DNA is very distinct like a fingerprint.s No two individuals have the same DNA except Identical twins.s In looking a child’s DNA half of the bands will match the mother and the other half will match the father.