Gene cloning is the process in which a gene of interest is located and copied (cloned) out of DNA extracted from an organism,” according to the Education Center of the University of Nebraska. DNA analysis is any technique used to analyze genes and DNA. Scientists catalogue an organism’s DNA in gene libraries in order to pick up a particular genome from thousands of different genes within a DNA. DNA analysis is extensively used to determine paternity, maternity and other biological relationships among people.
HISTORY OF GENE CLONING
Hans Dreisch was the first person to create cloned animals, in the late 18th century. He wanted to prove that during cell division the genetic material is not lost. Dreisch experimented with sea urchins, which grow independently, away from their mothers, and have large embryos. A two-celled sea urchin was put into a beaker of sea water and shaken until the cells separated. Each cell grew separately and formed a sea urchin.
CLONING AT CELLULAR LEVEL
It is only recently that cloning has been done at the cellular level in the animal kingdom. In November 1951, a team of scientists working at Robert Briggs Lab cloned a frog embryo. Mammals were first cloned in 1986 by two teams working independently and using similar methods. One team, led by Neal First in the United States, cloned a cow's embryo. The other team was led by Steen Willadsen in England, and cloned a sheep’s embryo.
SHEEP CLONING
In 1986, Ian Wilmut at the Roslin Institute in Scotland was assigned a project to clone sheep. He had to create sheep that could produce certain chemicals in their milk. He altered adult cells and then cloned them. He managed to produce sheep with the altered gene throughout their bodies. The paperwork was done in 1987 and the research in 1990. Wilmut’s team learned that by starving cells, they could be forced to the GO phase, which is similar to cell hibernation. This helped to increase the survival rate of cloned cells. On July 5, 1996, a lamb cloned from a frozen mammary cell of an adult sheep was born and named Dolly.
METHODS OF CLONING
There are three main methods of cloning. One is to transfer the nucleus. In this way, an embryo is created by fusing an adult animal cell. Cloning is also done by the microinjection method. This technique makes use of the adult cell nucleus. The third method of cloning is artificial twinning, which is a method in which the embryo is split into two or more embryos.
DNA ANALYSIS
Alec Jeffery, an English geneticist, was among the scientists who discovered DNA analysis technique. All living things have unique genetic codes. By analyzing its genetic sequences, you can identify any type of organism. DNA analysis helps scientists record an individual specimen's personality. With its use, scientists can conduct research on the evolution of a species and provide insight into our future health. DNA analysis has helped immensely in forensic science.
Transgenic organisms
Another important controversy is the possibility of unforeseen local and global effects as a result of transgenic organisms proliferating. The basic ethical issues involved in genetic research are discussed in the article on genetic engineering.Some critics have raised the concern that conventionally-bred crop plants can be cross-pollinated (bred) from the pollen of modified plants. Pollen can be dispersed over large areas by wind, animals, and insects. In 2007, the U.S. Department of Agriculture fined Scotts Miracle-Gro $500,000 when modified genetic material from creeping bentgrass, a new golf-course grass Scotts had been testing, was found within close relatives of the same genus (Agrostis) as well as in native grasses up to 21 km (13 miles) away from the test sites, released when freshly cut grass was blown by the wind.[59]GM proponents point out that outcrossing, as this process is known, is not new. The same thing happens with any new open-pollinated crop variety—newly introduced traits can potentially cross out into neighboring crop plants of the same species and, in some cases, to closely related wild relatives. Defenders of GM technology point out that each GM crop is assessed on a case-by-case basis to determine if there is any risk associated with the outcrossing of the GM trait into wild plant populations. The fact that a GM plant may outcross with a related wild relative is not, in itself, a risk unless such an occurrence has negative consequences. If, for example, an herbicide resistance trait was to cross into a wild relative of a crop plant it can be predicted that this would not have any consequences except in areas where herbicides are sprayed, such as a farm. In such a setting the farmer can manage this risk by rotating herbicides.The European Union funds research programs such as Co-Extra, that investigate options and technologies on the coexistence of GM and conventional farming. This also includes research on biological containment strategies and other measures to prevent outcrossing and enable the implementation of coexistence.If patented genes are outcrossed, even accidentally, to other commercial fields and a person deliberately selects the outcrossed plants for subsequent planting then the patent holder has the right to control the use of those crops. This was supported in Canadian law in the case of Monsanto Canada Inc. v. Schmeiser.
DNA TECHNOLOGY FOR FORENSIC INVESTIGATION
RFLP was one of the aboriginal applications of DNA assay to argumentative investigation. With the development of newer, added able DNA-analysis techniques, RFLP is not acclimated as abundant as it already was because it requires almost ample amounts of DNA. In addition, samples base by ecology factors, such as clay or mold, do not assignment able-bodied with RFLP.PCR AnalysisPolymerase alternation acknowledgment (PCR) is acclimated to accomplish millions of exact copies of DNA from a biological sample. DNA addition with PCR allows DNA assay on biological samples as baby as a few bark cells. With RFLP, DNA samples would accept to be about the admeasurement of a quarter. The adeptness of PCR to amplify such tiny quantities of DNA enables alike awful base samples to be analyzed. Great care, however, charge be taken to anticipate contagion with added biological abstracts during the identifying, collecting, and attention of a sample.STR AnalysisShort bike echo (STR) technology is acclimated to appraise specific regions (loci) aural nuclear DNA. Variability in STR regions can be acclimated to analyze one DNA contour from another. The Federal Bureau of Assay (FBI) uses a accepted set of 13 specific STR regions for CODIS. CODIS is a software affairs that operates local, state, and civic databases of DNA profiles from bedevilled offenders, baffling abomination arena evidence, and missing persons. The allowance that two individuals will accept the aforementioned 13-loci DNA contour is about one in a billion.Mitochondrial DNA AnalysisMitochondrial DNA assay (mtDNA) can be acclimated to appraise the DNA from samples that cannot be analyzed by RFLP or STR. Nuclear DNA charge be extracted from samples for use in RFLP, PCR, and STR; however, mtDNA assay uses DNA extracted from addition cellular organelle alleged a mitochondrion. While earlier biological samples that abridgement nucleated cellular material, such as hair, bones, and teeth, cannot be analyzed with STR and RFLP, they can be analyzed with mtDNA. In the assay of cases that accept gone baffling for abounding years, mtDNA is acutely valuable.All mothers accept the aforementioned mitochondrial DNA as their offspring. This is because the mitochondria of anniversary new antecedent comes from the mother's egg cell. The father's agent contributes alone nuclear DNA. Comparing the mtDNA contour of anonymous charcoal with the contour of a abeyant affectionate about can be an important address in missing-person investigations.Y-Chromosome AnalysisThe Y chromosome is anesthetized anon from ancestor to son, so assay of abiogenetic markers on the Y chromosome is abnormally advantageous for archetype relationships amid males or for allegory biological affirmation involving assorted macho contributors.
fingerprinting
DNA fingerprinting, also known as DNA typing, is a method of isolating and making images of sequences of DNA. The technique was developed in 1984 by the British geneticist Alec Jeffreys, after he noticed the existence of certain sequences of DNA (called minisatellites) that do not contribute to the function of a gene but are repeated within the gene and in other genes of a DNA sample. Jeffreys also determined that each organism has a unique pattern of these minisatellites, the only exception being multiple individuals from a single zygote (e.g., identical twins). The procedure for creating a DNA fingerprint consists of first obtaining a sample of cells containing DNA (e.g., from skin, blood, or hair), extracting the DNA, and purifying it. The DNA is then cut at specific points along the strand with substances called restriction enzymes. This produces fragments of varying lengths that are sorted by placing them on a gel and then subjecting the gel toan electric current (electrophoresis): the shorter the fragment the more quickly it will move toward the positive pole (anode). The sorted, double-stranded DNA fragments are then subjected to a blotting technique in which they are split into single strands and transferred to a nylon sheet. The fragments undergo autoradiography in which they are exposed to DNA probes—pieces of synthetic DNA that have been made radioactive and that bind to the minisatellites. A piece of X-ray film is then exposed to the fragments, and a dark mark is produced at any point where a radioactive probe has become attached. The resultant pattern of these marks can then be analyzed. An early use of DNA fingerprinting was in legal disputes,notably to help solve crimes and to determine paternity. The technique was challenged, however, overconcerns about sample contamination, faulty preparation procedures, and erroneous interpretation of the results. Efforts were made to improve reliability, and today the technique has been refined through the use of more specific and more sensitive probes and better blotting membranes. It also has been recognized that DNA fingerprinting, similar to other DNA analysis techniques, is limited by the quality of the sample obtained. DNA samples that are degraded or collected postmortem typicallyproduce less reliable results than do samples that are obtained from a living individual. If only a small amount of DNA is available for fingerprinting, PCR may be used to create thousands of copies of a DNA segment. Once an adequate amount of DNA has been produced, the exact sequence of nucleotide pairs in a segment of DNA can be determined using one of several biomolecular sequencing methods. Automated equipment has greatly increased the speed of DNA sequencing and has made available many practical applications, including pinpointing segments of genes that cause genetic diseases, mapping the human genome, engineering drought-resistant plants, and producing biological drugs from genetically altered bacteria.
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