Biotechnological+Applications

Humans have been manipulating plant and animal populations for 10, 000 years.

In farmers language it means choosing which stock are the breeding stock. Think about it, if you are one of the rams not chosen to be a stud, your genes are not passed on to the next generation. The farmer gets to choose which types of sheep characteristics are the ones he wants for the flock. We have really changed a lot of wild species, have a look at this original corn.

This is an image of Teosinte Corn, next to the modern corn. Teosinte Corn has been bred for a range of characteristics, creating it into our modern corn, so that it is now unrecognisable and much better tasting.

.

This process is called **Selective Breeding**. Farmers and breeders have been used this technique for generations and generations.

There is a new strategy which we will study as well. **Transgenic organisms** are changing the way industry and commercial users of crops and stock are planning the next generations of their product. With the growth in technologies based on DNA and protein synthesis, scientists are interested in transferring the actual gene from one species into a more user friendly species!

This is an image of Golden Rice, a species of Rice that has Vitamin A, a vitamin often deficient in Asian populations dependent on Rice.

It was invented by transferring two genes from two other species into a rice plant. This process is called Transgenesis.

But there are implications for the normal rice once this technology is commercially available.

both types of human manipulation have affects on the genes available for the next generation. There are implications for - genetic biodiversity of the population, - the health of individual organisms. -the health of ecosystems. -the survival of populations and the evolution of populations.

Students will need to have a background knowledge of:
 * the basic principles of gene expression, gene technology, genetic engineering, and genetic modification
 * techniques used in gene technology, e.g. restriction enzymes, ligation, polymerase chain reaction, [|gel electrophoresis], tissue culture, DNA sequencing, etc.
 * an understanding of the ethics relating to gene technology.

The Achievement Standard asks us to understand the implications of how humans manipulate the genes being passed on to the next generation, by comparing techniques human use. We will be comparing Selective Breeding and Transgenesis.

We will also have to discuss the effects these applications have on future gene pools, so there is another link for this information. To go to resources for Effects that Human Manipulations have on Gene Pools click here.

Selective breeding
What is it? Simple powerpoint to introduce ideas. http://www.slideshare.net/hannahreed/selective-breeding-powerpoint

How do farmers do it? Traditional way (recording phenotypes) and modern way (using Marker Assisted Selection) What examples do we know? What are the implications for the next generation if humans use Selective Breeding techniques? How will this affect the genes being passed on to the next generation?

Selective breeding is more than just pick a good looking parent and breed it with the same. Breeders need to know the genotype for the characteristics they are selecting in the offspring. They prove whether the parent is heterozygous or homozygous by using a test cross. A pure breeding individual will be homozygous for the gene, thus always passing on the same allele. If they are bred with another homozygous parent the offspring is going to receive a known genotype, creating the desired phenotype. By keeping records of each generation farmers have good predictors for the offspring.

Scientists have entered the discussion using Marker Assisted Selection technology. Scientists are tracking the desired phenotype using DNA sequences that occur commonly in the offspring with the phenotype. They can establish a marker gene (DNA sequence) that co-relates to the characteristic farmers are selecting for. By testing and keeping accurate records it is possible to predict more certainly what the offspring will inherit. A simple DNA test will confirm that the offspring has the alleles. The farmer doesn't have to wait for the baby to grow until it expresses the alleles. This is an advantage when looking at features that happen after sexual maturity, like flowering or fruiting in apples. If a test can tell the breeder which offspring to keep for the required years to cropping it speeds up the process ad reduces the risk for the farmer.

DNA markers are also very useful for predicting the inheritance of recessive genes, and characteristics controlled by more than one gene (polygenic characteristics). Apple tree breeders are using Marker Assisted technology more,although the technology is expensive and not widespread yet. (http://www.doiserbia.nb.rs/img/doi/0534-0012/2010/0534-00121002359M.pdf) As the apple genome is more and more identified the marker sequences will be more available. There is a simple explanation at the Biotech Learning Hub. (http://www.biotechlearn.org.nz/focus_stories/breeding_red_fleshed_apples/video_clips/dna_markers_and_apple_breeding). This picture shows the phenotypes of apple for the red flesh, and the DNA sequences, which show an additional DNA band in individuals with the red flesh, visit the actual page at http://www.biotechlearn.org.nz/focus_stories/breeding_red_fleshed_apples/images/marker_assisted_selection_in_apples.

The DNA marker will be present in the seeds DNA, so farmers can select which plants to grow, well before the actual phenotype of the red flesh in the fruit is expressed.

Check out the series of videoclips at eTV, shows wild apple forest in kazakstan, and the anthocyanin gene pathway research. http://www.etv.org.nz/programme.php?id=86316

http://www.etv.org.nz/programme.php?id=86317 Under the Skin of the red apple you may have to register with eTV,

Transgenesis
What is it? How do scientists do it? What examples do we know? What are the implications for the next generation if humans use transgenic organisms? How will this affect the genes being passed on to the next generation?

Making a transgenic organism requires -identifying the useful protein in its normal organism, identifying the gene that creates that protein, separating that gene from the DNA of the normal animal, making lots and lots of copies of that gene, then inserting the desired gene into a useful host.

A simple example is the protein chymosin. This is an enzyme that coagulates milk, used by newborn calves to allow them to feed on milk. The liquid milk turns into semi solid lumps in their stomach. People use chymosin to turn milk into cheese, but they had to sourced their chymosin from dried stomachs of calves that had been killed. By cutting the gene out of the DNA of the cells in the stomach of the calves, and inserting it into the plasmid DNA of //Kluveromyces lactis// ,the fungi K lactis then releases the enzyme during its fermentation. Farmers can collect the enzyme, which is pure protein, uncontaminated and made to order.

There are a number of tools available to move the genes from one species to another.

Restriction Enzymes
These are enzymes found in nature that cut DNA into sections. The chopped up sections can be used for a wide range of applications. Enzymes are specific to known sites called recognition sites.

Ligation
This uses the naturally found enzyme called Ligase which joins a section of DNA on to another section of DNA. Once a section of DNA has been cutout by the Restriction Enzyme it can be joined back in by the Ligase enzyme. The process of joining on is called annealing. The new DNA is called recombinant DNA.

Polymerase Chain Reaction
This process mimics the natural cell process that replicates DNA. At the end of the process the target DNA has been amplified.

http://www.dnalc.org/view/15924-Making-many-copies-of-DNA.html.

http://www.youtube.com/watch?v=GLgt-EGkhZs This video lasts 7 minutes and is a mini lesson, just like mine but on youtube!!

====It is called PCR because it uses the polymerase enzyme in the process. Polymerase is the enzyme that make the bases bind on naturally in the nucleus. If you want to make new DNA artificially then I guess you want the raw materials that make it in nature, like sets of nucleotide bases, and the enzyme, and the instruction code from the original DNA. Scientists control the temperature to split the double stranded DNA, add in the raw materials and voila (French for so there) the new DNA is the same as the old DNA.====

What sort of things could people use this technology for?

Gel electrophoresis
This process separates sections of DNA into different length samples so that scientists can use those lengths. Scientists have a sample of DNA or of protein, they cut it up(or digest it) with restriction enzymes, and then want to identify the different cut bits. They might be wanting to use different fragments to investigate the genes in that bit, or might be using the final pattern to show differences between species or individuals.

The first step is to make an agarose gel. The DNA fragments move through the gel at different speeds, depending on how big the fragments are. http://www.biotechlearn.org.nz/themes/dna_lab/video_clips/gel_electrophoresis_making_the_gel_v0083

The next step is to load the DNA mixture into the gel. http://www.biotechlearn.org.nz/themes/dna_lab/video_clips/gel_electrophoresis_loading_and_running_the_gel_v0084

This link shows what the end product looks like, where the different fragments end up, so scientists can see which bits of DNA (or which proteins in this case) are present. http://www.biotechlearn.org.nz/themes/dna_lab/images/protein_electrophoresis

http://www.youtube.com/watch?v=yaWOFaliJro

http://www.youtube.com/watch?v=QEG8dz7cbnY This video describes what happens when a gel electrophoresis is run.

http://www.youtube.com/watch?v=6QYgN-toA1A

Transgenesis
Literally this means transferring a gene from one species to another, it requires the gene to be isolated from the original species, amplified, then inserted into a nucleus of cells in another species.

New Zealand research leads the world on transgenesis in some species. http://www.biotechlearn.org.nz/focus_stories/transgenic_cows

Review the language

For extracting DNA at home, try this http://www.youtube.com/watch?v=hOpu4iN5Bh4

[] Battleships to practice using the terms you have learned in this topic.

DNA Profiling
In this application a sample of DNA can be used to identify either and individual or a species from another individual or species.This benefits humans in a number of ways.Prior to this technology scientists had to rely on external identification or on fingerprints or blood types. it is hard to identify a snake species once it is a shoe, or apiece of fish once it is filleted, so to be able to use DNA from a part of a sample is very useful.

Paternity testing
This series of clips (1 minute each ish) shows how PCR and gel electrophoresis are used in paternity testing. http://www.youtube.com/watch?v=Ab3fO726pik video 1 http://www.youtube.com/watch?v=ibyKootm9Bw video 2 http://www.youtube.com/watch?v=k5j-Brx7KVE video 4 http://www.youtube.com/watch?v=PgrAc7WMDTY video 5

This is a simple game or animation to model the way DNA can be used to identfy parents or suspects. http://www.biotechnologyonline.gov.au/popups/int_dnaprofiling.html

This isa lesson(about 5 minutes long) that covers gel electrophoresis and restriction enzymes used in DNA profiling. Very clear explanation. http://www.youtube.com/watch?v=ZEidsjaLSGg

Forensics This application is made famous by CSI Miami, CSI New York ..... This New Zealand resource is easy to follow. http://www.biotechlearn.org.nz/focus_stories/forensics

or

International website applications The examples from this page are all interesting, at different levels. Try all four tabs to get the most information. The modern Disney movie Anastasia is based on the Romanovs. http://www.dnai.org/d/index

http://www.amnh.org/explore/ology/genetics is one of my old favourites for using in the junior school, so the ideas are straight forward., The most useful game for year 13 students to play is the Scientist at work tab. Can you identify the endangered species through their DNA sample?

Gene Therapy
A gene makes a polypeptide. A polypeptide is part of a protein. Proteins are implicated in a wide range of diseases in humans. If scientists can change the gene in a cell they can change the protein the cell makes, thus affecting the disease being caused by the dysfunctional protein.

Stem Cells
These are cells that have not become specialised yet, the term for specialised is Differentiated. Once differentiated cells will only use the genes that they need to do their specialist function. Undifferentiated cells are useful because all of their genes are still available to be used. Thus stem cells can be turned into any other cell.

http://abpischools.org.uk/page/modules/stemcellnew/.cfm?coSiteNavigation_allTopic=1