User:George Kahwai W/Economic importance of Mutation

Compiled for u by George Kahwai Wanja BSc Microbiology & Biotechnology-

UNIVERSITY OF NAIROBI

ECONOMIC IMPORTANCE OF MUTATION

Introduction A mutation is a permanent change in the DNA sequence of a gene. Mutations in a gene's DNA sequence can alter the amino acid sequence of the protein encoded by the gene. The DNA sequence of each gene determines the amino acid sequence for the protein it encodes. Thus mutations are sudden inheritable changes that occur in the genetic material. Mutation can be advantageous, disadvantageous or neutral, it represent an original source of variation for natural selection to act upon. Thus the mutation are essential for adaptation to the environment and hence evolution.

Beneficial mutation is retained in the population and accumulates in the form of adaptations in the course of evolution; whereas, deleterious ones are not retained and are removed by means of natural selection. Neutral mutation, on the other hand, does not cause significant effects in the population. Generally, neutral mutations are accumulated through genetic drift. The effects of mutation vary depending upon the environment.

Economic importance of mutation include the following, The mutation may enable the mutant organism to withstand particular environmental stresses such us water shortage, extreme temperature and ph better than wild-type organisms, or reproduce more quickly. In these cases a mutation will tend to become more common in a population through natural selection.

Mutation can lead to drug resistances in bacteria, virus, and other pathogenic microorganism, drugs that target specific features of microorganism become very popular within microorganism. For example, Bacteria evolve very quickly so leading to the resistance to antibiotics. HIV viruses mutate against antiretroviral therapy drugs, as a general thing this involves changing the features that antibiotics or any drugs target. This has led to increase in the lack of effectiveness of many drugs used to treat viral and bacterial diseases.

Mutation has given some bacteria the ability to digest Nylon; Nylonase is an example of beneficial mutation in bacteria. The Nylonase bacteria can eat short molecules of nylon (nylon-6). The mutation in these bacteria involves insertion of a single nucleotide in the genetic material. It is estimated that this frame shift mutation might have occurred when nylon was invented. Nylonase can be used in wastewater treatment plants.

Mutations enable various living organism such us human to become immune to various microorganism caused diseases. For example, Immunity to HIV, HIV infects a number of cell types including T-lymphocytes, macrophages, dendritic cells and neurons. AIDS occurs when lymphocytes, particularly CD4+ T cells are killed off, leaving the patient unable to fight off opportunistic infections. The HIV virus has to attach to molecules that are expressed on the surface of the T-cells. One of these molecules is called CD4 (or CD4 receptor); another is C-C chemokine receptor 5, known variously as CCR5, CCCKR5 and CKR5. Some people carry a mutant allele of the CCR5 gene that results in lack of expression of this protein on the surface of T-cells. Homozygous individuals are resistant to HIV infection and AIDS.

Mutation can lead to genetic disorders such us sickle cell anemia, though it is an undesirable mutation because the sickle cells are less efficient than normal cells it enables Sickle cell resistance to malaria. The sickle cell allele causes the normally round blood cell to have a sickle shape. The effect of this allele depends on whether a person has one or two copies of the allele. It is generally fatal if a person has two copies. If they have one they have sickle shaped blood cells. In areas where malaria is prevalent it turns out to be favorable because people with sickle shaped blood cells are less likely to get malaria from mosquitoes. In case Blue Skin disorder (Diaphorase deficiency): People with a blue skin trait have, obviously, blue, plum- colored, indigo, or almost purple skin. The blood of the person accumulates a blue molecule that shows more than the normal pink pigments, so a blue color results. This is caused by a deficiency of the enzyme diaphorase.

Mutation is believed to have enabled Lactose tolerance in mammals; the onset of lactose intolerance makes it easy to wean the young. Human beings, however, have taken up the habit of eating milk products. This is not universal; it is something that originated in cultures that kept cattle and goats. In these cultures lactose tolerance had a strong selective value. In the modern world there is a strong correlation between lactose tolerance and having ancestors who lived in cultures that exploited milk as a food. it was a matter of chance that the lactose tolerance mutation appeared in a group where it was advantageous. It might have been established first by genetic drift within a group which then discovered that they could use milk.

Resistance to atherosclerosis, Atherosclerosis is a disease or a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol. One produced by modern diets and modern life-styles. There are some communities in Italy near Milan whose residents don't get atherosclerosis because of a fortunate mutation in one of their fore bearers. This is a mutation that is favorable in modern times because people live longer and have diets and life-styles that are not like those of their ancestors.

Beneficial genetic mutations in agriculture made some of our best crops and animals and then we humans cultivated the differences. Mutation can lead to crops and animals that are resistant to diseases, high yielding, fast growing and resistant to harsh environmental conditions. Thus it is possible to make profit from beneficial genetic mutations in agriculture by recognizing their value and breeding it up and sell the offspring.

Mutations is applied economically in genetic engineering, for example, Mutation breeding where this is the process of exposing seeds to chemicals or radiation in order to generate mutants with desirable traits to be bred with other cultivars. Plants created using mutagenesis are sometimes called mutagenic plants or mutagenic seeds. The mutagenic crops tend to be high yielding, pest and disease resistant, drought resistant and fast growing.

Another application of induced mutations comes from efforts to improve the yield of penicillin by the mold penicillium. When penicillin was first discovered, the yield was low and production was seriously limited. Then millions of spores were irradiated and selected for higher yields. Such mutants who produce penicillin more than the average have proven invaluable in the commercial production of this important antibiotic.

Lethal Mutants - In lethal mutation, the organism dies due to mutation. The mutation abolishes the gene function totally. Many lethal mutations affect some vital functions of the organism thus causing it’s death. For xample, in case of sicklecell anemia. The sickle cell allele causes the normally round blood cell to have a sickle shape. The effect of this allele depends on whether a person has one or two copies of the allele. It is generally fatal if a person has two copies

Mutations have also formed the basis of treatment of some diseases especially cancer. Cancerous cells have been exposed to mutagens so as to interfere with their normal multiplication and replication. This has led to reduction of diseases related to cancer, tumors and other malignant cells have been mutagenized and this has minimized the spread of some disease.

Mutations have also led to variations that are detrimental. Some weaker strains that are less adapted to the environment and which ma be highly susceptible to diseases have been produced in some instances. This has adversely reduced agriculture yields and led to the full of many economies which particularly depend on agriculture as the main stem of their economy

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