Classification Taxon TIger Lion Gray Wolf Domestic Cat Mountain Lion Kingdom Animalia Animalia Animalia Animalia Animalia Phylum Chordata Chordata Chordata Chordata Chordata Class Mammalia Mammalia Mammalia Mammalia Mammalia Order Carnivora Carnivora Carnivora Carnivora Carnivora Family Felidae X Canidae Felidae Felidae Genus Panthera Panthera Canis Felis Puma Species Panthera tigris Panthera leo Canis lupus Felis catus Puma Concolor
What is the scientific name of a gray wolf?
Which taxon includes the broadest characteristics?
Which taxon includes the most specific characteristics?
Which taxa do they all have in common?
Which taxon can interbreed and produce fertile offspring?
In the lion column, what name would you put instead of the X?
Which organisms in the chart is most closely related to Panthera Onca ?
The red fox classification is Animalia, Chordata, mammalia, Carnivora, Canidae, Vulpus, Vulpus vulpus. Is more related to a dog or big cat?
Chapter 26 Biotechnology and Genomics
1. DNA Cloning
First of all, what is the difference between gene cloning and cloning?
Production of identical copies of an organism through asexual means
Production of many identical copies of a single gene
A. Uses of gene cloning
Might want to produce large quantities of the gene ’s protein product
Learn how a cloned gene codes for a particular protein
Use the genes to alter the phenotypes of other organisms in a beneficial way
Produces transgenic organism
Gene therapy - cloned genes are used to modify a human
Example: Making Humulin
In 1982, the world ’s first genetically engineered pharmaceutical product was produced.
Humulin, human insulin, was produced by genetically modified bacteria.
B. Polymerase chain reaction (PCR)
Create billions of copies of a segment of DNA in a test tube in a matter of hours
Amplifies targeted DNA sequence
Your DNA sample
DNA polymerase (the enzyme involved in DNA replication)
a supply of DNA nucleotides
Figure 12.14 So a lot of DNA can be made from a tiny bit of DNA sample , such as a tiny blood sample taken from a crime scene
2. DNA analysis
The DNA is cut into fragments
Specific enzymes called restriction enzymes recognizes specific small DNA sequences and cut the DNA.
Fragments separated by gel electrophoresis
Smaller fragments move faster than larger fragments
Results in distinctive pattern of bands
How does gel electrophoresis work? DNA has negative charges, so it will migrate towards the positive charge Long fragments (move slower) Shorter fragments (Move Faster) - +
Use of DNA fingerprinting Murder, Paternity, and Ancient DNA
Has become a standard criminology tool .
Has been used to identify victims of the September 11, 2001, World Trade Center attack.
Can be used in paternity cases .
To study ancient pieces of DNA , such as that of Cheddar Man.
Bone marrow (gene transfer by implantation of modified stem cells)**
SCID (Severe Combined ImmunoDeficiciency)
* invivo ** ex vivo
Example: GENE THERAPY AND CANCER
Different approaches to treat cancer through gene therapy:
Replace missing or altered gene that can cause cancer
Improve patient’s immune response to cancer (enhance the natural ability of body to fight cancer cells)
Insert genes into cancer cells to make them more susceptible to chemotherapy/radiotherapy… or make normal cells more resistants
4 Genomics and Bioinformatics
Genomics: Study of the complete genetic sequences of humans and other organisms
Sequencing the human genome
Accomplished by 13-year effort of the Human Genome Project (HGP)
Humans have 20,000 25,000 genes
Most of the genes are expected to code for proteins
Found large area of Noncoding DNA , first called “junk DNA”, may have important functions
New genomes being sequenced all the time and at a much faster rate now
Compare genomes of organisms
Identify similarities between the sequence of human bases and those of other organisms
Offers a way to study changes in the genome through time
Track evolution of HIV
Understand the evolutionary relationships among organisms
Human and chimpanzee 98% alike
Human and mouse 85% alike
Comparative genomics Genome size does not correlate with evolutionary status, nor is the number of genes proportionate with genome size. Organism Homo sapiens (human) Mus musculus (mouse) Drosophila melanogaster (fruit fly) Arabidopsis thalania (flowering plant) C. Elegans (round worm) S. Cerevisia (yeast) Number of bases 3,000 millions 2,500 millions 180 millions 125 millions 97 millions 12 millions Number of genes 20,500 30,000 13,600 25,500 19,100 6,300 Number of chromosomes 46 40 8 10 12 32
knowing the sequence of the bases and how many genes we have
what does it code for (proteins)
Understand the function of the various genes discovered within each genomic sequence and how these genes interact
Help deduce the function of human genes by comparison to other genomes
Use of a microarray can tell what genes are turned on in a specific cell or tissue type in a particular organism at a particular point in time and under certain environmental circumstances