Mutation

The human body might be visualized as a simple organism. But it is the combination of different complex processes. From the outside, a human body might resemble a very simple one. A body that has two arms, two legs & one head for monitoring purposes. But from the inside of the body, there are many surprises still present for scientists. One of the major surprises was the Genetic Sequence of humans. This is still a field where scientists are working to find out some important details. Genes or DNA are the micro-controlling areas in the human body. They are most important than the brain. As the brain is also functioning with the help of DNA & its sequences. Any changes in this structure might be fatal for the body. Mutation is one type of change in DNA.

Definition of Mutation

DNA or genes are made of some specific amino acid sequences. These sequences are altogether known as DNA. They are tiny little structures present in every cell of the body. But they have a major role in the structuring & functioning of the human body. If there is any change occurs due to some agents or factors, then the sequence of the amino acids will get changed. As a result, the DNA or the gene will start malfunctioning. This means, whatever their task was will be replaced by a new task. So, there will be a massive change in the body. This process is known as Mutation.

The mutation is lethal for the human body, as DNA is going to generate proteins for the body’s different tasks. If there is a change in the DNA structure, then the protein formation will also get affected. This can be demonstrated with a simple example. If anyone's DNA is faced with the mutation process, then there will be a change in the mRNA process. So, the damaged DNA will produce nearly 100 damaged mRNA. And from that damaged mRNA, nearly 50000 improper proteins will get produced. So, this is a large number of proteins as considered.

This is the reason; the mutation in DNA level is termed as very fatal. Mutation in protein level might be tolerated & handled. But at the DNA level, it is hard to reduce its effect. That is why; the cells inside the body know the consequences of mutation at the DNA level. That is why; they try to remove the mutation from the affected DNA at the earliest. They repair the DNA & make fresh DNA without mutation.

Causes of Mutation

The mutation is the process that is being controlled by some causes. It is prompted out in the body's DNA due to some causes. These causes can be divided not two categories. Depending upon the cause from where it is arising, the mutation can be two types.

1. Internal Mutation: This is the mutation type that can be observed most of the time. DNAs need to split into two parts. As they also need to increase their number. During the process of cell division, the DNA of one single cell divides into two parts. One DNA set belongs to one cell. On the other hand, another DNA set will belong to a newly formed cell. During this splitting or the replication process, the genomic sequences get changed. As a result, there will be a mutation in that DNA. Normally, these mutations are required for the evolution process.
2. External Mutation: This is a very rare type of mutation process. In this process, there is no role in the DNA replication process. Rather than, some chemicals or agents inserted into the human body from the outside. And they started reacting on the DNA sequences. Like the UV Rays. The UV Rays are inserted into the body. And then they start acting upon some DNA bases. This causes the breaking of the DNA from the unexpected region. The UV Rays act upon the Thymine base in the DNA. As a result, the DNA sequences are changed. And mutation can be seen there.

General Characteristics of Mutation

1. There are certain characteristics set in mutation. This helps to draw the general properties of the mutation process. The mutation is a large process that is going on in small steps day by day. So, there will be some characteristics of this process.
2. Mutations that are happening to the body are generally recessive in order. But dominant mutation can also be possible. But the rate is very low. This means, the recessive character often comes to nature due to the mutation process.
3. The mutation process generally leads to fatal traits for an organism. This means the mutation process often creates harmful changes. But sometimes a change can be used for the organism’s benefit.
4. The mutation process generally occurs randomly. This means the mutation process can be witnessed at any position in the gene. That position will be chosen randomly.
5. The mutation process generally occurs in a repeated format. This means, if a mutation happens to any gene, then there will be a chance of happening mutation again. So, the mutation process is recurrent.
6. The mutation process generally leads to the creation of other genes from any mutated genes. So, it is observed that the mutation process shows the pleiotropy process in the genes.

Role of Mutation

Scientists often believe that the mutation process occurs in the body for the creation of any harmful process. And eventually, that process will lead to death for any individual. This statement is moreover true. Mutation plays a role in the creation of any harmful process. Many times, mutation of any certain gene is the reason for any special disease. But that doesn’t mean any individual is going to be dead. The mutation sometimes appears as a boon to survive in nature.

Mutation is a process that has its role in the evolution process. The creatures that can be seen nowadays are the result of the mutation process. But they all used their mutation for their beneficiary purpose. Mutation in the red blood cells creates Sickle Cell Anemia disease. But this disease often comes as a boon for individuals. In Africa continent, Sickle Cell Anemia was the protector of individuals from severe Malaria disease. So, the mutation doesn’t always play a role for any destruction purpose. But they also help to survive in nature & keep the evolution process moving.

Classification and types of Mutation

1. Spontaneous Mutation: It is a special type of mutation. In this case, the mutation is happening in the body, without any external factor. This means the mutation is started in the body due to some internal factor. In this case, the mutation process is known as Spontaneous Mutation. This mutation process is linked to the internal factors that cause mutation. Like here, the DNA replication process will cause Spontaneous Mutation. Spontaneous means anything that can happen without any agent. So, form that way, the name of this mutation process is appropriate.
2. Induced Mutation: This is the opposite of the Spontaneous Mutation process. In this case, the mutation is not happening in the body automatically. Rather, there is a need to induce any special agent in the body that might cause the mutation process. In this case, the agents are known as the Mutagens. This mutation process is completely linked to External causes. Here, the UV Rays will be a mutagen. In presence of these agents, the DNA will break down or make some changes. That will cause the mutation process. As the agents need to be induced or inserted into the body, so from that purpose the name is appropriate.

Errors in DNA Replication

DNA is those structures where the genes are situated. Now, to affect any genes in the DNA, the DNA should get affected. Any problem with the DNA will be a problem for the genes. Like every cell in the body, DNA should also need to produce more DNA. And this process is known as the replication process. This means from one DNA another similar DNA will be produced. During this replication process, there are some errors occur that lead to the mutation of the processing gene or DNA.

DNAs are placed as a coiled structure. This means they are closely, tightly coiled. Before doing the replication process, DNA removes the coils there & becomes a straight version. Now, during the replication process, there might be some errors happen. All these errors are linked to the bases in the DNA. There are some processes like Insertion, Substitution, Deletion, Inversion, etc. In all of these errors, the base sequences will be changed. So, there will be some types of mutation witnessed that are created due to the base location changes in the DNA. These mutation processes will be covered more deeply in the coming section.

1. Substitution Mutation: In this process, a DNA sequence will be changed with its substitute. Suppose, there is thymine in the DNA sequence, in this process, the Thymine will be changed with its substitute. In this way, the DNA sequence might get changed. And the task of the DNA sequence will also be changed. This leads to the mutation process.
2. Deletion Mutation: This is another case. In this process, an amino acid in the DNA sequences gets deleted. This means, in the earlier stage there was an amino acid present. But after this process, there will be no amino acid present. This will cause a change in the DNA sequences. As a result, the protein synthesis & overall process of DNA will get changed. This will cause the mutation process.
3. Insertion Mutation: This is another process by which mutation might cause in the human body. This also occurs in the DNA sequences. In this case, amino acids get inserted into the DNA sequences at any random position. In this way, the overall structure of the DNA gets changed. And protein synthesis also hampers there.
4. Inversion Mutation: In this process, there will be a change in the genetic sequence in DNA. In this case, in any random place in the DNA, the sequences will be reversed. This means, in an earlier time if it was a “TGA” base sequence, now it will become “AGT”. In this way, the structure of the chromosome will be changed.

Types of Mutation Based on Location

The mutation process might be different in the case of the location. This means, the mutation might happen in the DNA sequence or might happen in the Chromosomal structure. Also, there might be a chance of occurring mutation in some completely other parts of the body. Now, after the type of mutation based on process, there are also some types of mutation based on location. These can be categorized into three groups.

Point Mutation

This is the mutation process where the mutation is happening in the DNA sequences. This means the DNA sequence will be changed in this type of mutation process. The changing process is different in different cases. There are mainly three types of the process by which there might be a mutation can be occurred.

1. Substitution Process: In this process, a DNA sequence will be changed with its substitute. Suppose, there is thymine in the DNA sequence, in this process, the Thymine will be changed with its substitute. In this way, the DNA sequence might get changed. And the task of the DNA sequence will also be changed. This leads to the mutation process.
2. Insertion Process: This is another process by which mutation might cause in the human body. This also occurs in the DNA sequences. In this case, amino acids get inserted into the DNA sequences at any random position. In this way, the overall structure of the DNA gets changed. And protein synthesis also hampers there.
3. Deletion Process: This is another case. In this process, an amino acid in the DNA sequences gets deleted. This means, in the earlier stage there was an amino acid present. But after this process, there will be no amino acid present. This will cause a change in the DNA sequences. As a result, the protein synthesis & overall process of DNA will get changed. This will cause the mutation process.

Chromosomal Mutation

The chromosomal mutation process can be divided into two parts. In one case, the mutation happens directly to the base of the chromosomes. In the other case, the number of chromosomes gets affected due to the mutation process. Also, these processes can be further divided into sub-types.

Structural Mutation

This is the mutation process, where the mutation is not happening in the DNA sequences. Rather, the mutation is happening on a more large scale. This means this mutation process is happening in the Chromosomal body. Mutations can be seen in the arms of the chromosomes. Some processes help to do this mutation process.

1. Inversion Process: In this process, there will be a change in the genetic sequence in the chromosomal arm. In this case, in any random position in the chromosomal arm, the DNA sequences will be reversed. This means, in an earlier time if it was an “ATG” base sequence, now it will become “GTA”. In this way, the structure of the chromosome will be changed & cause mutations.
2. Deletion Process: This is the same process that was visualized in the DNA sequence case. But this process occurs on a very large scale. This means this process can be recognized in the chromosomal arm. In this case, a DNA sequence will be removed from the chromosomal arm. As a result, the overall structure of the chromosomal arm will be changed. And mutation will happen there.
3. Duplication Process: This is the process where some extra amino acid base is attached to the chromosomal arm. In any random position in the chromosomal arm, a subsequence of that DNA sequence will be extra added. This will increase the length of the DNA sequence. As a result, there will be a mutation process.
4. Translocation Process: This is the process where there will be an interaction between two chromosomes. This means some DNA sequences from one chromosomal arm will be changed to another chromosomal arm. In this way, there will be some decrease in DNA sequence in one chromosomal arm. And in another case, there will be an increase in DNA sequence in another chromosomal arm.

Numerical Mutation

Other than the Structural Mutation of the Chromosomal Mutation, there is also another type of mutation present. In this type of mutation, the change will not happen to the structure. This means the base of the amino acids will not be changed here. Here, the number of chromosomes will be changed. There are two types of Numerical Mutation is present:

1. Polyploidy: This is a type of numerical mutation. In this case, in one simple cell, the number of chromosomes will be increased. In a normal case, there are 23 pairs of chromosomes are present in the body. But in this mutation case, one or more chromosomes might present in the body. This means the body chromosome number will increase from 23 pairs to more. This is known as Polyploidy.
2. Aneuploidy: This is another subtype of the numerical mutation under chromosomal mutation. This is completely different from the Polyploidy concept. In this case, the number of chromosomes will be decreased. This means the number of chromosomes in the body will be less than the 23 pairs. In any of the cells, there might be a mutation & for that reason, the chromosomes might get changed.

Copy Number Variation Mutation

This is the mutation process that is the combination of the above two mutation process. This means, after those two mutation processes, there will be a change in the number of DNA sequences. This causes this mutation process.

1. Gene Amplification: When the Copy Number Variation Mutation happens, the gene number gets increased sometime. This also happens due to the Gene Amplification process. In this case, some new genes are added that change the sequences.
2. Tri-Nucleotide Repeat: This is another process of addition of the bases to the sequences. In this case, the Tri-Nucleotides will repeat more & more times & hence there will be an increase in the DNA sequence base. This will lead to the mutation process. But this process is very rare. Scientists are still researching it.

Other Types of Mutation

Mutation At the Protein Level

There might be some mutation possible at the protein level. After the chromosomal level mutation, this is one of the major mutation areas. This mutation will directly hamper the synthesis of the proteins. This mutation will affect protein synthesis which is the reason; this mutation is known as Protein Level Mutation. There are certain types present in the mutation process

1. Silent Mutation: This is one kind of mutation process. This mutation happens in the gene. But this mutation happens in the protein-coding region. But in this case, there is not any effect of this mutation process. This means, a mutation happens at the gene protein level, but it can’t able to change the amino acid sequence. So, the protein synthesis process will not be hampered.
2. Missense Mutation: This is different from the Silent Mutation process. Here, the substitution process can be witnessed. When there is a mutation happens at the gene protein level & one base is changed with its substitution. This leads to another protein synthesis instead of the original one. This mutation process is known as the Missense Mutation process. As the protein that will produce here will not be the same as required.
3. Nonsense Mutation: Nonsense Mutation might be similar to Missense Mutation, but there are conceptual changes present. The nonsense mutation is also developed by the change in the base of the gene protein area. But here a protein is going to be developed that is nonfunctional. This means the protein will not work in the body. This is the reason; it is termed the Nonsense Mutation. While in the Missense mutation, the protein that is occurring there will work on the body.
4. Frameshift Deletion Mutation: This is also a type of mutation under the protein level of a gene. In this case, some of the continuous bases in the gene get deleted. As a result, the length of the gene gets small. So, the frame for a particular protein will be shifted in any direction. This will create issues while developing the proteins.
5. Frameshift Insertion Mutation: This is another type or subtype under the frameshift mutation process. Here, a continuous base will be added to the gene. This will lead to an increase in the length of the gene. So, the protein area in the gene will be shifted in either direction. This will also cause errors while producing the protein. As the frame is shifted, so the combination of the amino acids will be different.

Mutation at Molecular Level

Now, there is also some mutation that happens in the body in different areas. These mutations affected regions don’t fall under any protein or gene level. That is the reason, they are termed at a molecular level as a vast area. Any part of the body can be affected by the mutation. But the genes & proteins will not hamper. This mutation process has two types.

1. Neutral Mutation: This is the mutation process that can be viewed in every human body. This mutation always goes on in the body. But this mutation doesn’t react to any places in the body. This mutation will not help to survive in nature. Nor this mutation is liable for the disappearance of any creature from nature. This follows a Neutral Concept.
2. Non-Neutral Mutation: This mutation process is different from the Neutral mutation process. This is not the mutation process that occurs in the body every time. This mutation is the key factor for the evolution process. If this mutation happens in the body, it might have two effects. In one case, the mutation gives new traits to the species that might survive in nature. In another case, it might remove some traits from the species so, the species will get disappear from nature eventually.

Importance of Mutation

Mutation is a very important step in the human body. Oftentimes, the mutation is considered a fatal change in the body. And this is quite true in maximum times. But still, there is some importance is present in the mutation process. Like the mutation is important for the evolution process. The mutations that are going in the body, means those are spontaneous mutation, which helps a lot in the evolution process. These mutations help to gain some important new features for the body. And this mutation helps to survive in nature. As a result, the features or traits that are occurring in the body will be transferred to the next generation. As mutation always happens to the genetic structure. So, a mutation that might be fatal helps to shape the generations to survive in nature.

Molecular Basis of Gene Mutation

The mutation is a process that can’t be seen from the outside of the body. This process is happening in the cellular structure of the body. More preciously, this process is going on inside the genetic structure of the cell. Genes are very small elements in the human body. Mutation occurs there inside any gene. Often genes are termed as a molecule of the body. As they are so tiny like any molecule. That is the reason; the mutation often has a relation with the molecular base.

Gene is nothing but some combination of different molecules. There are several amino acids are present those lead to the creation of any gene. Now, the mutation is happening in those amino acids. This means, in a very small molecular base the mutation process is going on. DNA has the gene & as there is a change in the gene, DNAs will also get change. As DNA get changes, the proteins that are produced from the DNA will also get affected. And a defective protein will influence the body differently. So, a small change in the molecule leads to a large change in the body. Mutation always arises in the molecule base. This means they will always be witnesses in a small amount. But their influence is much greater. That is the reason; mutation is being studied from a molecular basis.

Effects of Mutation Process

The effects of the mutation process are unbelievable. There are a lot of effects are present in the mutation process. The mutation process might sometimes cause a benefit for the organization. Or sometimes it causes problems for the organisms. So, depending upon their effect on the human body, the mutation process can be divided into two categories. One will be the beneficiary effect and another will be the fatal effect.

1. Beneficiary Effect Of Mutation: The most beneficiary effect of a mutation can be visualized in the evolution process. Evolution is the result of the mutation process. The spontaneous mutation that is happening to the body every day has a prominent role in the evolution process. This is the beneficiary effect of the mutation as it helps to survive with nature. And without the evolution process, one can’t develop & acquire more traits.
2. Fatal Effect Of Mutation: Fatal effect of the mutation is unstoppable. Some severe diseases occur due to the mutation in abnormal processes. Cancer is a disease that is occurred due to abnormal mutation processes & changes in the genetic structure. Some changes occur to the reproductive cells only. So, they are hereditary changes. This means those changes can be inherited by the next generation. If those changes rise to any disease, then the next generations will face the disease. So, all of these are the fatal effects of the mutation on the human body.