New Research In Genetic Cloning Late February example essay topic

New Developments or Research in Genetic Cloning: Summary Since genetic cloning is a very wide topic, the focus of my paper lies mainly on the new discoveries which might be beneficial to human beings. The focus of the first section of the paper is on the various cloning techniques geneticists use nowadays. They techniques included range from the simplest and suitable for all situations, to complicated and suitable for certain areas. The second section of the paper, the longest section, discusses five of the many researches performed over the last five years. The researches a rearranged in descending chronological order, dating from February 1997, to April 1992. These researches are discussed because they all have one thing in common: they may be beneficial to human beings later on.

For example, the newest entry in my paper, and perhaps the one that shocked the whole world, was the report about the first successful clone mammal from non-embryonic cells. This will be helpful in the future for patients waiting for organ transplants. Scientists will be able to clone a fully functional organ, and replace it with the damaged one. The report on the cloning of the human's morphine receptor is advantageous to us because this helps scientists to develop new analgesics. The third section of the paper contains a brief discussion about the advantages and the disadvantages of genetic cloning. It speculates how our future will improve due to the technologies we are developing, and also the biggest drawbacks which might come from it.

The last part of the paper, is the explanation of complicated terms used in this paper. The terms which will be explained are printed in bold terms throughout the paper. This section, the glossary, is like the ones which appears in textbooks. New Developments or Research in Genetic Cloning Genetic cloning is one of the many aspects which has been recently introduced to improve our quality of live.

Researchers are trying to improve our lives everyday applying genetic engineering onto our everyday lives. Cows can be genetically altered to produce more milk, receptors in our body could be cloned to improve our health. The techniques and new research reported in this paper is just one tree out of the whole forest of genetic engineering. Part I: Techniques of Genetic Cloning Geneticists use different cloning methods for different purposes. The method used to identify human diseases are different than the method used to clone a sheep. The following are used techniques in genetic cloning.

Recombinant DNA In recombinant DNA, the desired segment is clipped from the surrounding DNA and copied millions of times. Each restriction enzyme recognizes a unique nucleotide sequence wherever it occurs along the DNA spiral. This nucleotide sequence, known as the recognition site is a short, symmetric sequence of bases repeated on both strands of the double helix. After the segment is removed, the ragged, or 'sticky' ends that remain after cleavage by the restriction enzyme allow a DNA restriction fragment from one organism to join to the complementary ends. This method allows a foreign DNA to be cloned in a bacteria. The result will be identical clones of the original recombinant molecule in hundreds of copies per cell.

Polymerase Chain Reaction (PCR) The PCR is a method of gene amplification. It is a better method than bacterial cloning because of its greater sensitivity, selectivity, and speed. Moreover, it does not require bacterial vectors and rapidly amplifies the chosen segment of DNA in the test tube without the need for living cells. In this process, the DNA sequence to be amplified is selected by primers, which are short pieces of nucleic acid that correspond to sequences flanking the DNA to be amplified. After an excess of primers is added to the DNA, together with a heat-stable DNA polymerase, the strands of both the genomic DNA and the primers are separated by heating and allowed to cool. A heat-stable polymerase lengthens the primers on either strand, therefore generating two new, identical double-stranded DNA molecules and doubling the number of DNA fragments.

Positional Cloning This method is used when scientists need to identify human disease genes. The overall strategy is to map the location of a human disease gene by linkage analysis and to then use the mapped location on the chromosome to copy the gene. There are two essential requirements for mapping disease genes. Firstly, there must be sufficient numbers of families to establish linkage and, second, adequate informative DNA markers.

Once suitable families are identified, the investigators determine if diseased people in the family have particular DNA sequences at specific locations that healthy family members do not. Particular DNA marker is said to be 'linked' to the disease if, in general, family members with certain nucleotides at the marker always have disease and family members with other nucleotides at the marker do not have the disease. The marker and the disease gene are so close to each other on the chromosome that the likelihood of crossing-over is very small. Once a suspected linkage result is confirmed, researchers can then test other markers known to map close to the one found, in an attempt to move closer and closer to the disease gene of interest. The gene can then be cloned if the DNA sequence has the characteristics of a gene and it can be shown that particular mutations in the gene confer disease. Cloning by Nuclear Transfer This method has been used in mammals to provide a valuable tool for embryonic study and as a method to multiply 'elite' embryos.

In this method, two different cells are involved: an unfertilized egg and a donor cell. The donor cells are obtained by culture of cells from a mammalian embryos over a period of several months. This enabled the culture to consist of many genetically identical cells. To illustrate this method, sheep are used as an example.

An all white breed sheep gave the donor embryo, while the Scottish Blackface ewes provided the recipients eggs. By micro manipulation the chromosomes were removed from the eggs before the nucleus of the donor cell was introduced by cell fusion. An electric current is used to trigger the egg to begin development. These new embryos were then transferred to recipient sheep to discover if they were able to develop to lambs.

When the lambs were born, they were genetically identical female white lambs. Complementation Cloning by Retroviral Technique An efficient mammalian c DNA (complementary DNA) cloning process has been developed that utilizes retro viral c DNA expression libraries. Complentationcloning of bacterial and yeast genetic systems has produced a lot of information for researchers. This system, in addition to cloning genes, is also helpful the structure-function relationship of known proteins.

One advantage this system has over others is that with the retrovirus expression system, because of its wide range of target cells, allows it to clone surface molecules genes. Part II: New Research In Genetic Cloning Late February, 1997: First Cloned Mammal In late February, Dr. Ian Wilmut and his research team from the Roslin Institute in Edin borough made a major scientific breakthrough: they cloned a sheep from non-embryonic cells. To create this cloned sheep the research team focused on stopping the cell cycle. They then take the cells from the udder of Finn Dorset ewe. In order to stop the cells from dividing, the scientists put these cells in a culture with very low nutrition concentration. While this was happening, Dr. Wilmut and his team used the nuclear transfer technique (mentioned in part I) to continue.

An unfertilized egg cell is taken from a Scottish Blackface ewe. The first step is to remove the egg's nucleus, while leaving the cytoplasm intact. They then place the nucleus alongside the cell from the Finn Dorset ewe. An electric pulse was used to fuse them together, and a second one to imitate the burst of energy at fertilization, triggering cell division. About five to seven days later, the embryo was implanted into the uterus of another Blackface ewe. September 1996: Purification and Molecular Cloning of Plx 1 Cdc 2, a protein which controls mitosis in a cell, is negatively regulated 1 by on its threonine-14 and tyrosine-15 residues.

Cdc 25, a protein which these residues, undergoes act i vat ion by multiple kinase's at mitosis. Plx 1, a kinase that associates with and the NH 3 (amino) end of Cdc 25, was purified extensively from Xenopus egg extracts. Dr. Kumagai and his colleagues in C.I.T. (California Institute of Technology) found that cloning its c DNA revealed that Plx 1 is related to the Polo family 2 of protein kinase's. Cdc 25 by Plx 1 reacted strongly with MPM-2, a monoclonal antibody to mitotic phosphoproteins. The team concluded that Plx 1 may be a mechanism for coordinating the regulation of Cdc 2 with the progression of mitotic processes such as separating chromosome. November, 1995: Positional Cloning of Clock Gene, timeless In November, 1995, Michael W. Young and his colleagues from the Laboratory of Genetics in Rockefeller University used positional cloning to clone timeless (tim) in the fly Drosophila.

The Drosophila's gene timeless (tim) and period (per) interact, and both are required for production of circadian rhythms. Tim is a clock gene which controls circadian 3, such as the sleep-wake cycle in humans and insect locomotor activity cycles. The molecular cloning of the gene tim has allowed the detection of circadian cycles in tim RNA expression. The research revealed a strong relationship between per and tim and suggest a rudimentary intracellular biochemical mechanism 4 regulating circadian rhythms in the fly Drosophila. January, 1995: Genetically Altered Bacteria Which Makes Ethanol From Xylose Researchers have achieved a key step in efforts to develop genetically engineered bacteria that can produce ethanol efficiently from plant biomass for use in alternative transportation fuels. Scientists at the Department of Energy's National Renewable Energy Laboratory in USA have genetically modified the bacterium Zymomonas mobil is so that it also makes ethanol from the five-carbon sugar.

In its natural form, this bacterium produces ethanol from the six-carbon sugars glucose fructose and sucrose. Right now, ethanol is produced by yeast fermentation of glucose. These. mobil is bacterium makes ethyl alcohol in five to 10% yield than yeast. The team which made this discovery, molecular biologist Stephen Picataggio and his colleagues, spliced two operon's from an E-coli into the genome of the Z...

One of these operon's encodes assimilation, while the other encodes the pentose metabolism enzymes. The modified bacteria grows on ferments it efficiently to ethyl alcohol. The teams work will also improve the ethanol-producing abilities of E. coli because it is now able to produce ethanol from pentose sugars and hexose sugars. July 1993: Morphine Receptor Cloned In July, 1993, a team led by Dr. Lei Yu, associate professor of medical and molecular genetics at Indiana University School of Medicine, decoded the amino acid sequence for the morphine receptor that is located on the surface of nerve cells.

The group isolated the sequence from a rat brain c DNA library, and since homology between the rat and human sequence is expected to be high, Dr. Yu performed straightforward biological technique 5 to isolate the human sequence from the genome. The most promising application of this work will be the ability to design new analgesics that are more potent than morphine but lack the side effects caused by it. From this research, another possibility is to find a powerful analgesic that does not become quickly tolerated by the body as morphine does. This could bring relief to people who suffer from chronic pain. However, the most immediate advantage of this discovery is the ability to screen new pharmacologic compounds for their similarity to the u receptor far more quickly and accurately than conventional methods. The research could also have serious significance for the understanding of narcotic addition and how to treat people efficiently who have become addicted to these drugs.

August 1992: The Cloning of a Family of Genes that Encode MelanocortinReceptors Proopiomelanocortin (POM C) is expressed primarily in the pituitary and in limited regions in the brain and periphery. It is processed into a large and complex family of peptides with different biological activities. The three major activities include the regulation and production of a hormone called adrenal and aldosterone, control growth and pigment production, and analgesia. Roger Cone of Oregon Heath Sciences University cloned the murine and human stimulating hormone receptors (MSH-Rs) and a human ACTH receptor (ACTH-R). The cloning of these receptors allowed the researchers to define the receptors as a subfamily of receptors coupled to guanine nucleotide-binding proteins that may include the receptor. Also, from the information they found in their experiment, they found that receptor is the smallest guanine coupled receptor identified to date. (in 1992) April 1992: Cloning of the Interleukin-1 Converting Enzyme Interleukin-1 mediates a wide range of immune and inflammatory responses.

The active cytosine is generated by proteolytic cleavage of an inactive precursor. A complementary DNA encoding a protease that carries out this cleavage has been cloned. Recombinant expression in cells enabled the cells to process precursor IL-1 to the mature form. Sequence analysis indicated that the enzyme itself may undergo proteolytic processing. The gene encoding the protease was mapped to a site frequently involved in rearrangement in human cancers. This discovery, by Douglas Cerretti and his team provides new insight in this field of biology and offers a new target for the development of therapeutic agents.

Part : Brief Discussion about the Advantages and Disadvantages of Gene Cloning Advantages The most appealing aspect of genetic cloning is that it will improve our lifestyle. Fatal diseases such as AIDS could be cured by genetics. Through X-ray crystallography, new drugs could be manufactured to stop mutation of proteins. Our quality of food will increase, because farmers will only sell produces of the highest quality.

Disadvantages There are a few disadvantages that will be the result of genetic cloning. The problems will mainly arise in the agricultural area. Since might be cloned, that means that they will have identical immune systems. If an epidemic spread through the animals, most of the animals, if not all, will be killed by the disease or virus in which they are not immune to.

Huge improvements of our lifestyles have been made possible because of technological advancements. Biotechnology, such as genetic cloning, could have dramatic impacts on human beings in the near future. Millions of people will if these knowledge is put into good use. Part IV: Glossary of Terms primers: An already existing DNA chain bound to the template DNA to which nucleotides must be added during DNA synthesis. restriction enzyme: A degradative enzyme that recognizes and cuts up DNA that is foreign to a cell. c DNA (complementary DNA): DNA that is identical to a native DNA containing a gene of interest except that the c DNA lacks non coding regions because it is synthesized in the laboratory using m RNA templates. operon: A unit of genetic function common in bacteria and phages and consisting of regulated clusters of genes with related functions. genome: The complete complement of an organism's genes; an organism's genetic material. homology: Similarity in characteristics resulting from a shared ancestry. analgesia: The insensibility to pain without loss of consciousness. proteolytic processing: the hydrolysis of proteins or peptides with formation of simpler and soluble products (as in digestion) Notes 1 Akiko Kumagai.

'Purification and Molecular Cloning of Plx, a Cdc 25-Regulatory Kinase from Xenopus Egg Extracts. ' Science 273 (1996): 1377.2 Akiko Kumagai. ' Science 273 (1996): 1377.3 Michael Young. 'Positional Cloning and Sequence Analysis of the Drosophila Clock Gene, timeless. ' Science 270 (1995): 805.4 Michael Young. ' Science 270 (1995): 805 5 Lei Yu. 'u Receptor Cloned From Rat Brain c DNA Library.

' Molecular Pharmacol: (44) 1993: 8-12.