Deletion

Definition

Deletion is a type of genetic mutation where one or more nucleotides are removed from a DNA sequence. This loss can lead to significant changes in the structure and function of proteins, often resulting in altered phenotypes. Understanding deletion is crucial as it can impact evolutionary processes by influencing genetic diversity and adaptability within populations.

5 Must Know Facts For Your Next Test

1. Deletions can be as small as a single nucleotide or involve large segments of DNA, potentially affecting entire genes.
2. The effects of deletions on an organism can range from benign to severe, depending on the role of the deleted genes and their importance in biological processes.
3. Some deletions can lead to genetic disorders when critical genes are lost; for example, a deletion in chromosome 22 is associated with DiGeorge syndrome.
4. In evolutionary terms, deletions can provide a mechanism for adaptation, as they may remove detrimental traits and allow for the emergence of advantageous traits over generations.
5. Research into deletions contributes to our understanding of cancer biology since many tumors have deletions in tumor suppressor genes that promote uncontrolled cell growth.

Review Questions

• How does deletion as a type of mutation contribute to evolutionary change within populations?
  • Deletion can significantly influence evolutionary change by removing genetic material that may be harmful or redundant. By eliminating such sequences, populations may adapt more readily to their environments. In some cases, this can lead to beneficial traits becoming more common through natural selection, particularly if the deletion confers an advantage for survival or reproduction.
• Discuss how deletions differ from insertions and their potential impacts on protein function.
  • Deletions differ from insertions in that they remove genetic material rather than adding it. Both types of mutations can cause frameshift mutations if they involve nucleotides not divisible by three, leading to dramatic changes in protein function. However, deletions often result in the loss of essential parts of proteins, potentially causing nonfunctional or malfunctioning proteins, while insertions might introduce new functionalities if they enhance the protein's properties.
• Evaluate the role of deletions in genetic disorders and how understanding these mutations can inform treatment strategies.
  • Deletions play a critical role in various genetic disorders by disrupting gene function or expression. Identifying specific deletions linked to conditions like cystic fibrosis or muscular dystrophy helps researchers develop targeted therapies that address these underlying genetic issues. Advances in gene therapy aim to correct or compensate for the effects of these deletions, highlighting the importance of understanding their mechanisms in developing effective treatments for genetic disorders.

Related terms

Mutation: A mutation is a change in the DNA sequence that can result from various factors, including environmental influences or errors during DNA replication.

Insertion: Insertion is a genetic mutation involving the addition of one or more nucleotide bases into a DNA sequence, which can also alter protein production and function.

Frameshift Mutation: A frameshift mutation 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 of the codons.