The key difference between crossover frequency and recombination frequency is that crossover frequency determines the frequency of a homozygous and heterozygous crossover that takes place during meiosis. Meanwhile, recombination frequency is the frequency at which crossover takes place in heterozygous genes.
Genetic crossover is an important event in giving genetic variation to an offspring upon meiosis. Therefore, the genetic linkage is a result of genetic crossover. Crossover is either homozygous or heterozygous in nature. And, this is an important concept in gene mapping.
CONTENTS
1. Overview and Key Difference
2. What is Crossover Frequency
3. What is Recombination Frequency
4. Similarities Between Crossover Frequency and Recombination Frequency
5. Side by Side Comparison – Crossover Frequency vs Recombination Frequency in Tabular Form
6. Summary
What is Crossover Frequency?
Genetic crossing over takes place during meiosis. This results in the alteration of the genetic characters during gamete formation. Thus, it leads to genetic variation among organisms. The crossover takes place with the formation of the double-stranded breaks. This process is mediated by DNA topoisomerases. The formation of the double-stranded breaks leads to the crossover genetic material.
Figure 01: Crossover
The rate at which the crossover takes place is the frequency of crossover. The distance between the genes determines the frequency of crossover. The frequency of crossover determines the genetic map of a particular gene. Crossover frequency can be taken between homozygous crossover or heterozygous crossover.
What is Recombination Frequency?
Recombination is the phenomenon where crossing over occurs in a heterozygous manner. The frequency or the rate at which the recombination takes place during crossover is the recombination frequency. The increase of recombination frequency suggests the variation pattern of the offspring. The distance between the genes determines the rate at which recombination or heterozygous crossover takes place. Thus, when the distance between the genes is less, the frequency of recombination is more. This gives a higher genetic linkage between the genes.
What are the Similarities Between Crossover Frequency and Recombination Frequency?
- Both take place during meiosis.
- Crossing over takes place in generating crossover frequency and recombination frequency.
- The distance between the two genes determines the frequencies of both crossover and recombination.
- Both types of frequencies are used in determining the genetic linkage and the gene map.
What is the Difference Between Crossover Frequency and Recombination Frequency?
The key difference between crossover frequency and recombination frequency is the manner in which the crossover takes place during meiosis. Crossover frequency is the type of frequency that determines the rate at which crossover takes place between both homozygous and heterozygous crossovers. Recombination frequency is the type of frequency that determines the heterozygous recombination that takes place between the genes during the crossover. Furthermore, crossover frequency has a low variation rate, while recombination frequency has a high variation rate.
The below infographic summarizes the difference between crossover frequency and recombination frequency.
Summary – Crossover Frequency vs Recombination Frequency
Crossover frequency and recombination frequency suggest the rate at which crossover takes place in meiosis. In recombination frequency, the crossover is heterozygous in nature. Both crossover frequency and recombination frequency lead to the rate at which genetic linkage takes place. Therefore, both are important in constructing the genetic map. The distance between the genes determines crossover frequency and recombination frequency. So, this summarizes the difference between crossover frequency and recombination frequency.
Reference:
1. “CROSSING-OVER and RECOMBINATION FREQUENCY.” Genetics, Available here.
2. Saito, Takamune T, and Monica P Colaiácovo. “Regulation of Crossover Frequency and Distribution during Meiotic Recombination.” Cold Spring Harbor Symposia on Quantitative Biology, U.S. National Library of Medicine, 2017, Available here.
3. “Genetic Linkage & Mapping.” Khan Academy, Khan Academy, Available here.
Image Courtesy:
1. “Chromosomal Crossover” By Abbyprovenzano – Own work (CC BY-SA 3.0) via Commons Wikimedia