Deletion

Definition

Deletion is a type of mutation that involves the loss of a segment of DNA from a chromosome, which can result in the removal of one or more nucleotide bases. This genetic alteration can lead to significant changes in the structure and function of proteins, potentially causing a variety of phenotypic effects. Deletions can occur spontaneously or be induced by external factors, and they play a crucial role in generating genetic variation within populations.

5 Must Know Facts For Your Next Test

1. Deletions can vary in size from a single nucleotide to large sections of chromosomes, impacting multiple genes at once.
2. Some deletions may be benign and have little to no effect on an organism, while others can lead to genetic disorders or increased susceptibility to diseases.
3. In some cases, deletions can result in gene dosage effects where the loss of genetic material alters the balance of gene expression.
4. Certain deletion mutations are associated with specific genetic disorders, such as cystic fibrosis and Duchenne muscular dystrophy.
5. Detection of deletions often involves techniques like PCR, comparative genomic hybridization, or next-generation sequencing.

Review Questions

• How do deletions impact protein synthesis and what are the potential outcomes?
  • Deletions can significantly impact protein synthesis by removing essential nucleotide sequences that code for amino acids. Depending on where the deletion occurs, it may lead to truncated proteins or entirely nonfunctional ones if critical regions are lost. This alteration can result in various outcomes, including developmental disorders or diseases if the affected proteins play crucial roles in cellular functions.
• Discuss how deletions contribute to genetic variation within populations and their role in evolution.
  • Deletions contribute to genetic variation by removing genetic material from the genome, which can create new phenotypes that may offer adaptive advantages or disadvantages. These variations can affect fitness and survival rates, thus influencing natural selection processes. Over time, such deletions may lead to significant evolutionary changes within populations as organisms with beneficial traits are more likely to reproduce and pass these traits on.
• Evaluate the techniques used to detect deletions and their implications for understanding genetic disorders.
  • Techniques such as PCR, comparative genomic hybridization, and next-generation sequencing are essential for detecting deletions in genetic studies. These methods allow researchers to identify specific mutations associated with various genetic disorders, facilitating diagnosis and potential treatment strategies. By understanding how deletions affect gene function, scientists can better grasp the underlying mechanisms of diseases and develop targeted therapies for affected individuals.

Related terms

Insertion: A mutation that involves the addition of one or more nucleotide bases into a DNA sequence, which can disrupt the reading frame and alter protein synthesis.

Frame Shift Mutation: A type of mutation that occurs when nucleotides are added or deleted from the DNA sequence in a number that is not a multiple of three, leading to a shift in the reading frame during translation.

Chromosomal Aberration: A structural alteration in chromosomes, which may include deletions, duplications, inversions, or translocations, affecting gene expression and function.