Gene Duplication

Definition

Gene duplication is a genetic event where a DNA sequence is duplicated, resulting in the presence of two or more identical or highly similar genes within the same genome. This process is a key mechanism by which asexual prokaryotes can achieve genetic diversity, as it allows for the creation of new genetic material that can then undergo further mutations and adaptations.

5 Must Know Facts For Your Next Test

1. Gene duplication can create redundant copies of genes, allowing one copy to accumulate mutations without affecting the essential function of the original gene.
2. The duplicated genes can then diverge and evolve new functions, leading to the emergence of novel traits and increased adaptability.
3. Gene duplication is a major driver of genomic complexity and is particularly important in the evolution of new genes and functions in asexual prokaryotes, which lack the genetic shuffling of sexual reproduction.
4. Duplicated genes can undergo further mutations, such as insertions, deletions, or substitutions, which can lead to the creation of new gene variants with potentially beneficial or novel functions.
5. The rate of gene duplication can be influenced by various factors, such as the organism's replication fidelity, the presence of repetitive DNA sequences, and the selective pressures acting on the population.

Review Questions

• Explain how gene duplication contributes to the genetic diversity of asexual prokaryotes.
  • Gene duplication is a crucial mechanism that allows asexual prokaryotes to increase their genetic diversity without the genetic shuffling of sexual reproduction. By creating redundant copies of genes, prokaryotes can accumulate mutations in one copy while maintaining the essential function of the original gene. These duplicated genes can then diverge and evolve new functions, leading to the emergence of novel traits and adaptations that can enhance the organism's fitness and survival in different environments.
• Describe the role of further mutations in the evolution of new gene functions following gene duplication.
  • After gene duplication, the duplicated genes can undergo various types of mutations, such as insertions, deletions, or substitutions. These mutations can lead to the creation of new gene variants with potentially beneficial or novel functions. The accumulation of these mutations in the duplicated genes allows for the exploration of new evolutionary pathways, as the organism can experiment with different gene functions without compromising the essential functions of the original gene. This process can ultimately result in the emergence of new genes and the expansion of the organism's genetic repertoire, which is crucial for adapting to changing environmental conditions.
• Analyze how the rate of gene duplication can be influenced by factors such as replication fidelity, the presence of repetitive DNA sequences, and selective pressures in asexual prokaryotic populations.
  • The rate of gene duplication in asexual prokaryotes can be influenced by a variety of factors. Replication fidelity, or the accuracy of DNA replication, can impact the likelihood of errors that lead to gene duplication events. Prokaryotes with higher replication fidelity may experience lower rates of gene duplication, as there are fewer opportunities for errors to occur. The presence of repetitive DNA sequences, such as transposable elements or tandem repeats, can also increase the probability of gene duplication, as these sequences can facilitate unequal crossing-over or other recombination events. Additionally, the selective pressures acting on the prokaryotic population can influence the retention and fixation of duplicated genes. Beneficial gene duplications that confer a fitness advantage are more likely to be maintained and spread within the population, while neutral or deleterious duplications may be lost over time. Understanding these factors can provide insights into the mechanisms underlying the genetic diversity of asexual prokaryotes.

Related terms

Mutation:

A permanent change in the DNA sequence of a gene, which can lead to the creation of new genetic variations.

Genetic Drift:

The random changes in the frequency of gene variants within a population over successive generations, which can lead to the loss or fixation of certain genetic traits.

Horizontal Gene Transfer:

The transfer of genetic material between organisms other than via vertical transmission from parent to offspring, which can introduce new genes and increase genetic diversity in asexual prokaryotes.