biotechnology exploring the source and exploitation of genetic alterations
TRANSCRIPT
Biotechnology
Exploring the source and exploitation of genetic alterations
Directions:1) Carefully read through ALL slides of this tutorial (60
slides total). TAKE NOTES on the back of this sheet on the Biotech information. These should be ‘K.I.S.S.’ format … ‘Keep it Short & Simple’ … stick to the key facts presented. Check vocab. definitions against your list from Ch. 13 if needed. Make sure you understand each slide before moving on to the next one!
The process by which desired traits of certain plants and animals are selected and passed on to their future generations is called selective breeding.
Selective Breeding
Genetics and Biotechnology
German shepherdService dog
HuskySled dog
Saint BernardRescue dog
13.1 Applied Genetics
Chapter 13
Hybridization
Genetics and Biotechnology
Hybrid organisms can be bred to be more disease-resistant, to produce more offspring, or to grow faster.
A disadvantage of hybridization is that it is time consuming and expensive.
13.1 Applied Genetics
Chapter 13
Inbreeding
Genetics and Biotechnology
The process in which two closely related organisms are bred to have the desired traits and to eliminate the undesired ones in future generations
Pure breeds are maintained by inbreeding.
A disadvantage of inbreeding is that harmful recessive traits also can be passed on to future generations.
13.1 Applied Genetics
Chapter 13
A test cross involves breeding an organism that has the unknown genotype with one that is homozygous recessive for the desired trait.
Genetics and Biotechnology
Test Cross
13.1 Applied Genetics
Chapter 13
Genetic Engineering
Technology that involves manipulating the DNA of one organism in order to insert the DNA of another organism, called exogenous DNA.
Genetics and Biotechnology
13.2 DNA Technology
Chapter 13
Genetically engineered organisms are used
Genetics and Biotechnology
to study the expression of a particular gene. to investigate cellular processes.
to study the development of a certain disease.
to select traits that might be beneficial to humans.
13.2 DNA Technology
Genetically engineered bollworm
Chapter 13
DNA Tools
Genetics and Biotechnology
An organism’s genome is the total DNA in the nucleus of each cell.
DNA tools can be used to manipulate DNA and to isolate genes from the rest of the genome.
13.2 DNA Technology
Chapter 13
Genetics and Biotechnology
Scientists use restriction enzymes as powerful tools for isolating specific genes or regions of the genome.
13.2 DNA Technology
Chapter 13
Restriction enzymes recognize and bind to specific DNA sequences and cleave the DNA within the sequence.
Genetics and Biotechnology
The ends of the DNA fragments, called sticky ends, contain single-stranded DNA that is complementary.
13.2 DNA Technology
Chapter 13
EcoRI specifically cuts DNA containing the sequence GAATTC.
Genetics and BiotechnologyChapter 13
Genetics and Biotechnology
An electric current is used to separate DNA fragments according to the size of the fragments in a process called gel electrophoresis.
When an electric current is applied, the DNA fragments move toward the positive end of the gel.
The smaller fragments move farther faster than the larger ones.
13.2 DNA Technology
Chapter 13
Genetics and Biotechnology
The unique pattern created based on the size of the DNA fragment can be compared to known DNA fragments for identification.
13.2 DNA Technology
Gel electrophoresis
Chapter 13
Genetics and Biotechnology
The newly generated DNA molecule with DNA from different sources is called recombinant DNA.
13.2 DNA Technology
Chapter 13
Genetics and Biotechnology
To make a large quantity of recombinant plasmid DNA, bacterial cells are mixed with recombinant plasmid DNA. Some of the bacterial cells take up the recombinant plasmid DNA through a process called transformation.
13.2 DNA Technology
Chapter 13
Genetics and Biotechnology
Large numbers of identical bacteria, each containing the inserted DNA molecules, can be produced through a process called cloning.
13.2 DNA Technology
Chapter 13
Genetics and Biotechnology
To understand how DNA is sequenced, scientists mix an unknown DNA fragment, DNA polymerase, and the four nucleotides—A, C, G, T in a tube.
13.2 DNA Technology
Chapter 13
Genetics and Biotechnology
Each nucleotide is tagged with a different color of fluorescent dye.
Every time a modified fluorescent-tagged nucleotide is
incorporated into the newly synthesized strand, the reaction stops.
13.2 DNA Technology
Chapter 13
Genetics and Biotechnology
The sequencing reaction is complete when the tagged DNA fragments are separated by gel electrophoresis.
13.2 DNA Technology
Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
PCR Analysis
Chapter 13
A technique called the polymerase chain reaction (PCR) can be used to make millions of copies of a specific region of a DNA fragment.
Genetics and Biotechnology
13.2 DNA Technology
Chapter 13
Genetics and BiotechnologyChapter 13
Genetics and Biotechnology
Biotechnology
Organisms, genetically engineered by inserting a gene from another organism, are called transgenic organisms.
13.2 DNA Technology
Chapter 13
Genetics and Biotechnology
Transgenic Animals
Scientists produce most transgenic animals in laboratories for biological research. Mice, fruit flies, and the roundworm Caenorhabditis elegans
13.2 DNA Technology
Chapter 13
Genetics and Biotechnology
Transgenic Plants
Genetically engineered cotton resists insect infestation of the bolls.
Sweet-potato plants are resistant to a virus that could kill most of the African harvest.
Rice plants with increased iron and vitamins could decrease malnutrition.
13.2 DNA Technology
Chapter 13
Gene Splicing
The Human Genome Project
The goal of the Human Genome Project (HGP) was to determine the sequence of the approximately three billion nucleotides that make up human DNA and to identify all of the approximately 20,000–25,000 human genes.
Genetics and Biotechnology
13.3 The Human Genome
Chapter 13
Sequencing the Genome
Each of the 46 human chromosomes was cleaved.
Genetics and Biotechnology
These fragments were combined with vectors to create recombinant DNA, cloned to make many copies, and sequenced using automated sequencing machines.
Computers analyzed the overlapping regions to generate one continuous sequence.
13.3 The Human Genome
Chapter 13
Genetics and Biotechnology
Decoding the sequence of the human genome can be compared toreading a book that was printed in code.
13.3 The Human Genome
Chapter 13
Less than two percent of all of the nucleotides in the human genome code for all the proteins in the body.
Genetics and Biotechnology
The genome is filled with long stretches of repeated sequences that have no direct function.
These regions are called noncoding sequences.
13.3 The Human Genome
Chapter 13
DNA Fingerprinting
Genetics and Biotechnology
Protein-coding regions of DNA are almost identical among individuals.
The long stretches of noncoding regions of DNA are unique to each individual.
DNA fingerprinting involves separating these DNA fragments to observe the distinct banding patterns that are unique to every individual.
13.3 The Human Genome
Chapter 13
Identifying Genes
Genetics and Biotechnology
Researchers have identified genes by scanning the sequence for Open Reading Frames (ORFs).
ORFs contain at least 100 codons that begin with a start codon and end with a stop codon.
13.3 The Human Genome
Chapter 13
Bioinformatics
Genetics and Biotechnology
Creating and maintaining databases of biological information
Finding genes in DNA sequences of various organisms and developing methods to predict the structure and function of newly discovered proteins
13.3 The Human Genome
Chapter 13
DNA Microarrays
Genetics and Biotechnology
Tiny microscope slides or silicon chips that are spotted with DNA fragments
Help researchers determine whether the expression of certain genes is caused by genetic factors or environmental factors.
13.3 The Human Genome
Visualizing Microarray Analysis
Chapter 13
Genetics and Biotechnology
Variations in the DNA sequence that occur when a single nucleotide in the genome is altered are called single nucleotide polymorphisms or SNPs.
13.3 The Human Genome
Chapter 13
Regions of linked variations in the human genome are known as haplotypes.
Genetics and Biotechnology
Assembling the HapMap involves identifying groups of SNPs in a specific region of DNA.
13.3 The Human Genome
Chapter 13
The HapMap will enable geneticists to take advantage of how SNPs and other genetic variations are organized on chromosomes.
Genetics and Biotechnology
13.3 The Human Genome
Chapter 13
Genetics and Biotechnology
The benefits of pharmacogenomics include more accurate dosing of drugs that are safer and more specific.
13.3 The Human Genome
Chapter 13
The study of how genetic inheritance affects the body’s response to drugs is called pharmacogenomics.
Genomics is the study of an organism’s genome.
A technique aimed at correcting mutated genesthat cause human
diseases is called gene therapy.
Genetics and Biotechnology
Scientists insert a normal gene into a chromosome to replace a dysfunctional gene.
13.3 The Human Genome
Chapter 13
Genes are the primary information storage units, whereas proteins are the machines of a cell.
Genetics and Biotechnology
13.3 The Human Genome
Chapter 13
The large-scale study and cataloging of the structure and function of proteins in the human body is called proteomics.
13.3 The Human Genome
Genetics and BiotechnologyChapter 13
Can we modify the genetic code of living things? (& should we?)
Means of genetic manipulation Selective breeding
Of dissimilar individuals, called hybridization Of similar individuals, called inbreeding
Increasing genetic variation Mutation caused by mutagen (radiation or
chemicals) Use of drugs to produce polyploids
Genetic engineering!!! (direct manipulation of an organism’s genes)
Genetic Engineering
Also known as… Genetic modification or
manipulation Recombinant DNA technology Gene splicing
Genetic Engineering
Uses two main techniques or processes:
1. Gene cloning (makes copies)
2. Transformation (take up new DNA)
Tools of genetic engineering Restriction enzymes cut DNA at
a specific place in the code Gene splicing recombines DNA
from different sources Vectors & plasmids harvest
DNA for cloning
How’s it done?As easy as 1, 2, 3…
Rabbit DNA
+
Crab DNA
=
Crabbit !!
How to genetically engineer DNA1. Begin with the source DNA you want
2. Cut out a DNA fragment from the source DNA with restriction enzyme
3. Cut out a sequence from the plasmid with the same restriction enzyme
4. The source DNA is inserted into plasmid
How to genetically engineer DNA5. Bacteria have to take up the
foreign DNA. This is called transformation.
6. Bacteria becomes a cloning vector, making copies of recombinant DNA
Applications Genetic screening identifies
“broken” DNA Gene therapy uses
recombinant DNA technology to replace an absent or faulty gene with a normal, working gene
( - 1) Try your hand at gene therapy – click here)
Applications Gene splicing uses
recombinant DNA technology to produce transgenic organisms (organisms with other organisms’ genes) that help make better medicines, treatments, and supplements (Example: Transgenic Corn from our ‘Virtual Corn Lab’ 1st Qtr.!)
Polymerase chain reaction (PCR) copies DNA
Gel electrophoresis makes a picture of DNA called a DNA fingerprint
Other tools of genetic engineering
How to make a DNA fingerprint1. Small amounts of DNA are extracted
from blood, saliva, hair, urine, etc ( - 2) Click here for Virtual DNA extraction Lab)
2. If the amount of DNA is too small, the polymerase chain reaction, or PCR, can be used to increase the quantity of DNA ( - 3) Click here for Virtual PCR lab)
How to make a DNA fingerprint3. DNA is cut into fragments of specific
sizes by restriction enzymes
4. DNA is put in a slab of gel and an electrical current moves DNA to the + electrode (
- 4) Click here for Virtual Gel Electrophoresis lab)
Bigger pieces move more slowly & travel shorter distances
How to make a DNA fingerprint5. The banding pattern in the gel is
analyzed
Applications
DNA fingerprinting identifies differences between individuals’ genetic makeup to establish identity or relationships
Stem cells have the ability to develop into different cell types
What is a stem cell? ( - 5) Click here for helpful animation) Types of stem cells( - 6) Click here for helpful animation) Embryonic stem cells ( - 7) Click here for helpful animation) Somatic cell nuclear transfer ( - 8) Click here for Virtual Cloning Lab)
Other tools of genetic engineering
Applications Cloning DNA
enables rapid, large-scale production of useful genes, cells, tissues
Watch Nova scienceNow: Stem Cells (click here)
Problem…How would you apply this
technique to make a vaccine?
Hint: How do vaccines work? What does your immune system use to
target foreign cells? Can your immune system be “tricked” into
thinking it is infected with a virus?
Is there a need for a cure? Should “broken” genes be fixed?