Gene splicing, Genetic engineering, recombinant DNA technology,genetic modification/manipulation (GM) is process of cutting a gene from one organism and pasting it into the DNA of another so that a characteristic can be transferred from one plant or animal to another
Restriction enzymes can be used to cut the DNA at different places making the DNA sticky ends so that it can be pasted into DNA from another organism
Splicing a gene into a plasmid
In this activity, you can cut out a gene from a chromosome of one organism and paste it into a plasmid.
To do this successfully:
Be careful not to cut up the gene you are working with
Cuts the DNa with jagged ends, not blunt ones, so that it can be pasted into the plasmid,
Make sure that cut ends of the plasmid match the cut ends of the DNA
The Splicing starts with identifying the correct Restriction enzyme for the Gene, if u choose wrong restriction enzyme it may cut Gene into half rather than isolating the whole gene, So care should be taken in identifying the restriction enzyme which isolates the whole gene (in this case HindIII),
After isolating gene we should cut Plasmid with corresponding restriction enzyme (HindIII) so that gene of interest can be inserted into the plasmid.
After inserting the gene we need to seal the plasmid with Ligase enzyme to achieve a recombinant DNA.
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Showing posts with label Genetic engineering. Show all posts
Showing posts with label Genetic engineering. Show all posts
Wednesday, December 17, 2008
Cloning
Clones are organisms that have identical genetic material. In other words, the sequence of bases n their DNA is exactly same. Long before the birth of Dolly the sheep, clones had bee observed in both nature and in the laboratory.When a couple has an identical twin or identical triplets, the children are clones of one another.A plant cutting can also be used to generate a clone.
Prior to 199, it was thought that cloning an entire animal could only be done with embryonic cells-cells present in the early stages of an organism’s development. In the 1950's, scientists generated entire frogs from embryonic frog cells.
After a small number of cell divisions, embryonic cells start to change into the different types of cells that form muscle, blood, liver, etc. This process is called differntiation. Although each of these cells has the same genetic material, each cell can only access the genes needed for its particular function.
Before the experiment at the roslin institute, it was thought that once cells differentiated, they could not be used to generate an entire organism, for instance, in sheep udder cells could generate other udder cells, but not an entire sheep.
The scientist of roslin institute solved this problem by growing sheep udder cells under starvation conditions, this put the cells in a state similar to embryonic cells. This is called the G0 state.
An egg cell was taken from another sheep. The nucleus (which contains the genetic material) was removed from the egg cell using fine needle. They then used electric shock to fuse one starved udder cell with one nucleus free egg cell. They made 277 of these fused cells.
Although the egg cell came from a black-faced sheep, notice that the nucleus with the genetic material came from the white-faced sheep.
The fused egg cell was then inserted into several different sheep. These surrogate mothers also black-faced.
Of the 277 fused cells, only one progressed to form a developed lamb. Dolly was born on July 5, 1996.Scientist found that dolly had same DNA as the udder cells she came from. She is a clone of these udder cells.Dolly has given birth to a lamb named Bonnie, produced the natural way.Other lambs have been born at the roslin institute through their cloning process, some carry genes that will produce usable human drugs.
A laboratory in Hawaii run by Dr.Ryuzo Yanagimachi was the second group to successfully clone an animal from an adult cell. They cloned mice using cumulus cells, a cell type found in the ovaries.
The cloning method used by the lab in Hawaii was different in two ways from the method used to clone Dolly. First, the cells used to clone the mice were not grown in culture, but instead were used immediately.
Second the nucleus was removed from the cumulus cell and then directly injected into the egg cell. This egg cell's nucleus had already been removed.
The yabagimachi lab used coat color to track genetic heritage. The cumulus cell comes from an agouti (brown) mouse, and the cell comes from a black mouse.
The egg cell now had the same genetic information as the nucleus donor mouse. The egg cell was then activated and implanted into a white host mother. On October 3, 1997 the host mouse gave birth to cumulina, named after the cumulus cells she was cloned from.
Cumulina is the same color as the mouse that donated the nucleus. The DNA fingerprinting confirmed that cumulina had the same DNA as the nucleus donor.
The scientist has taken cells from cumulina to make more clones. They have successfully made several generations of clones and all mice seem normal.Dolly the sheep died at the age of 6. Since the world said hello to Dolly, Several other animals have also been cloned.
Both Dolly and cumulina were cloned from cells in the female reproductive system; cows have also been cloned using ovary and cumulus cells with the same method that was used to clone Dolly.Pigs have been added to the cloned animal menagerie. Scientist hopes to use cloned pigs to grow organs that can be transplanted into humans.
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Email me : help.me.ishan@gmail.com
Prior to 199, it was thought that cloning an entire animal could only be done with embryonic cells-cells present in the early stages of an organism’s development. In the 1950's, scientists generated entire frogs from embryonic frog cells.
After a small number of cell divisions, embryonic cells start to change into the different types of cells that form muscle, blood, liver, etc. This process is called differntiation. Although each of these cells has the same genetic material, each cell can only access the genes needed for its particular function.
Before the experiment at the roslin institute, it was thought that once cells differentiated, they could not be used to generate an entire organism, for instance, in sheep udder cells could generate other udder cells, but not an entire sheep.
The scientist of roslin institute solved this problem by growing sheep udder cells under starvation conditions, this put the cells in a state similar to embryonic cells. This is called the G0 state.
An egg cell was taken from another sheep. The nucleus (which contains the genetic material) was removed from the egg cell using fine needle. They then used electric shock to fuse one starved udder cell with one nucleus free egg cell. They made 277 of these fused cells.
Although the egg cell came from a black-faced sheep, notice that the nucleus with the genetic material came from the white-faced sheep.
The fused egg cell was then inserted into several different sheep. These surrogate mothers also black-faced.
Of the 277 fused cells, only one progressed to form a developed lamb. Dolly was born on July 5, 1996.Scientist found that dolly had same DNA as the udder cells she came from. She is a clone of these udder cells.Dolly has given birth to a lamb named Bonnie, produced the natural way.Other lambs have been born at the roslin institute through their cloning process, some carry genes that will produce usable human drugs.
A laboratory in Hawaii run by Dr.Ryuzo Yanagimachi was the second group to successfully clone an animal from an adult cell. They cloned mice using cumulus cells, a cell type found in the ovaries.
The cloning method used by the lab in Hawaii was different in two ways from the method used to clone Dolly. First, the cells used to clone the mice were not grown in culture, but instead were used immediately.
Second the nucleus was removed from the cumulus cell and then directly injected into the egg cell. This egg cell's nucleus had already been removed.
The yabagimachi lab used coat color to track genetic heritage. The cumulus cell comes from an agouti (brown) mouse, and the cell comes from a black mouse.
The egg cell now had the same genetic information as the nucleus donor mouse. The egg cell was then activated and implanted into a white host mother. On October 3, 1997 the host mouse gave birth to cumulina, named after the cumulus cells she was cloned from.
Cumulina is the same color as the mouse that donated the nucleus. The DNA fingerprinting confirmed that cumulina had the same DNA as the nucleus donor.
The scientist has taken cells from cumulina to make more clones. They have successfully made several generations of clones and all mice seem normal.Dolly the sheep died at the age of 6. Since the world said hello to Dolly, Several other animals have also been cloned.
Both Dolly and cumulina were cloned from cells in the female reproductive system; cows have also been cloned using ovary and cumulus cells with the same method that was used to clone Dolly.Pigs have been added to the cloned animal menagerie. Scientist hopes to use cloned pigs to grow organs that can be transplanted into humans.
Hope You Like This Post, Let me know what you feel about this blog.
Email me : help.me.ishan@gmail.com
Sunday, December 14, 2008
Genetic Engineering
Genetic engineering, recombinant DNA technology, genetic modification/manipulation (GM) and gene splicing are terms that apply to the direct manipulation of an organism's genes.Engineering is different from traditional breeding, where the organism's genes are manipulated indirectly; genetic engineering uses the techniques of molecular cloning and transformation to alter the structure and characteristics of genes directly. Genetic engineering endeavors have found some success in improving crop technology, the manufacture of synthetic human insulin through the use of modified bacteria, the manufacture of erythropoietin in Chinese hamster ovary cells, and the production of new types of experimental mice such as the oncomouse (cancer mouse) for research.
Since a protein sequence is specified by a segment of DNA called a gene, novel versions of that protein can be produced by changing the DNA sequence of the gene.
Engineering
There are several ways through which genetic engineering is accomplished. Essentially, the process has four main steps:
1. Isolation of the genes of interest
2. Insertion of the genes into a transfer vector
3. Transformation of cells of organism to be modified
4. Separation of the genetically modified organism (GMO) from those that have not been successfully modified
Isolation is achieved by identifying the gene of interest that the scientist wishes to insert into the organism, usually using existing knowledge of the various functions of genes. DNA information can be obtained from cDNA or gDNA libraries, and amplified using PCR techniques. If necessary, i.e. for insertion of eukaryotic genomic DNA into prokaryotes, further modification may be carried out such as removal of introns or ligating prokaryotic promoters.
Insertion of a gene into a vector such as a plasmid can be done once the gene of interest is isolated. Other vectors can also be used, such as viral vectors, and non-prokaryotic ones such as liposomes, or even direct insertion using gene guns. Restriction enzymes and ligases are of great use in this crucial step if it is being inserted into prokaryotic or viral vectors. Daniel Nathans, Werner Arber and Hamilton Smith received the 1978 Nobel Prize in Physiology or Medicine for their isolation of restriction endonucleases.
Once the vector is obtained, it can be used to transform the target organism. Depending on the vector used, it can be complex or simple. For example, using raw DNA with DNA guns is a fairly straightforward process but with low success rates, where the DNA is coated onto particles such as gold and fired directly into a cell. Other more complex methods, such as bacterial transformation or using viruses as vectors have higher success rates.
After transformation, the GMO can be isolated from those that have failed to take up the vector in various ways.
Applications
The first genetically engineered medicine was synthetic human insulin, approved by the United States Food and Drug Administration in 1982. Scientists used bacteria in which they inserted plasmids containing the directions for insulin, they were then able to use the bacteria to produce and harvest artificial insulin. Another early application of genetic engineering was to create human growth hormone as replacement for a drug that was previously extracted from human cadavers. In 1987 the FDA approved the first genetically engineered vaccine for humans, for hepatitis B. Since these early uses of the technology in medicine, the use of GM has gradually expanded to supply a number of other drugs and vaccines. One of the best known applications of genetic engineering is the creation of genetically modified organisms (GMOs) such as foods and vegetables that resist pest and bacteria infection and have longer freshness than otherwise.
There are potentially momentous biotechnological applications of GM, for example oral vaccines produced naturally in fruit, at very low cost for most of the country.
Since a protein sequence is specified by a segment of DNA called a gene, novel versions of that protein can be produced by changing the DNA sequence of the gene.
Engineering
There are several ways through which genetic engineering is accomplished. Essentially, the process has four main steps:
1. Isolation of the genes of interest
2. Insertion of the genes into a transfer vector
3. Transformation of cells of organism to be modified
4. Separation of the genetically modified organism (GMO) from those that have not been successfully modified
Isolation is achieved by identifying the gene of interest that the scientist wishes to insert into the organism, usually using existing knowledge of the various functions of genes. DNA information can be obtained from cDNA or gDNA libraries, and amplified using PCR techniques. If necessary, i.e. for insertion of eukaryotic genomic DNA into prokaryotes, further modification may be carried out such as removal of introns or ligating prokaryotic promoters.
Insertion of a gene into a vector such as a plasmid can be done once the gene of interest is isolated. Other vectors can also be used, such as viral vectors, and non-prokaryotic ones such as liposomes, or even direct insertion using gene guns. Restriction enzymes and ligases are of great use in this crucial step if it is being inserted into prokaryotic or viral vectors. Daniel Nathans, Werner Arber and Hamilton Smith received the 1978 Nobel Prize in Physiology or Medicine for their isolation of restriction endonucleases.
Once the vector is obtained, it can be used to transform the target organism. Depending on the vector used, it can be complex or simple. For example, using raw DNA with DNA guns is a fairly straightforward process but with low success rates, where the DNA is coated onto particles such as gold and fired directly into a cell. Other more complex methods, such as bacterial transformation or using viruses as vectors have higher success rates.
After transformation, the GMO can be isolated from those that have failed to take up the vector in various ways.
Applications
The first genetically engineered medicine was synthetic human insulin, approved by the United States Food and Drug Administration in 1982. Scientists used bacteria in which they inserted plasmids containing the directions for insulin, they were then able to use the bacteria to produce and harvest artificial insulin. Another early application of genetic engineering was to create human growth hormone as replacement for a drug that was previously extracted from human cadavers. In 1987 the FDA approved the first genetically engineered vaccine for humans, for hepatitis B. Since these early uses of the technology in medicine, the use of GM has gradually expanded to supply a number of other drugs and vaccines. One of the best known applications of genetic engineering is the creation of genetically modified organisms (GMOs) such as foods and vegetables that resist pest and bacteria infection and have longer freshness than otherwise.
There are potentially momentous biotechnological applications of GM, for example oral vaccines produced naturally in fruit, at very low cost for most of the country.
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