Genetic technology is used in all sorts of instances. Cloning is a process in which a specific gene is taken and duplicated. there are two main reasons for this: scientists want to study either the copies of this gene, the proteins it produces, or both. The process of gene cloning is relatively simple. First, a DNA vector and the gene of interest are separated from the bacterial cell and the chromosomal DNA respectively. Then the gene of interest is inserted into the vector. The function of the vector is to carry the gene, and ensure it is replicated. The recombinant vector is then inserted into a host cell that doesn't already have the vector, and it is reproduced with the cell. Many copies of the gene of interest are then formed. Several enzymes are used in this process: restriction enzymes are used to cut the DNA into small fragments. This allows the vectors to be cut apart, and then put back together, allowing genes to be inserted at certain times. Genomic libraries and cDNA libraries are constructed differently, genomic libraries contain vectors with genes derived from chromosomal DNA. cDNA libraries are when mRNA is used instead of DNA, but reverse transcriptase is used to make DNA from the starting material. These fragments can be separated by gel electrophoresis. DNA molecules are negative, and can be pulled to the positive side of the container; their size will determine how quickly they reach the other side (charge/length/mass). Endogenous replication is different from PCR, vectors are not used in this form. The combination of two primers, four deoxynucleoside triphosphates and a heat stable Taq polymerase replicate the DNA.
Genomics is the study of the genome of a certain species, whereas functional genomics is the study of the expression of those genes. There are several methods used to sequence DNA. PCR is one method, described above. Another is the dideoxy chain-termination method: where the binding of dNTPs helps polymerase synthesize the target strand. DNA microarrays are chips used to monitor express of up to a thousand genes simultaneously. The small chip is dotted with many sequences, and it uses those to determine which genes in the genome are expressed by the organism. These can be used to determine which genes are disease causing.
Proteins such as insulin are important to diabetics. Insulin is created by inserting the alpha and beta chains next to the coding sequence of E. coli, which then allows them to replicate. Products such as factor VIII are created by using sheep as the host. A cloned hormone gene is inserted into a plasmid vector next to the sheep beta lactoglobulin promoter. The vector is inserted into the sheep oocyte, and when it is fertilized it is implanted into a female sheep. The protein is obtained from the offsprings milk, and is then purified. There are three applications of this technology include bettering the production of food products, livestock and increasing the effectiveness of medicine. Genetically modified organisms are also known as transgenic organisms; who undergo either gene addition or gene replacement. Their DNA is beneficially modified. A transgenic organism is different from an organism that has experienced a gene knockout. A gene knockout is when an organism undergoes a mutation that renders a certain gene nonfunctional. There are different recombinant technology techniques in plants than in bacteria. There are also differences between gene cloning and reproductive cloning. Gene cloning is just copying a gene, whereas reproductive cloning is reproducing the entire organism
B. Useful Materials
This video talks about the basic process of gel electrophoresis. In this case, we are comparing a blood sample found at the crime scene to a suspect's DNA. The fragments of DNA are measured by size, mass and length.
This video talks about the method of DNA sequencing. It goes over the old method, but now the new automated method provides scientists an easier and much more time effective solution (fluorescently labeling the nucleotides).
This article is about the side effects of genetic cloning. The length of Dolly's telomeres was below that of a sheep her age. Scientists reason that because the process started before Dolly was actually born (cultivating the tissues). Other than that, she looks the same as other sheep her "age".
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