Difference between Recombination and Crossover

Main difference

The main difference between recombination and crossover is that recombination is the formation of a diverse mix of alleles in the next generation, while crossover is the exchange of genetic material between non-sister chromatids and then the formation of recombination …

Recombination versus crossover

Recombination generally refers to the formation of offspring consisting of many diverse or different combinations of traits; on the other hand, crossover generally refers to the exchange of genetic material such as DNA segments between non-sister chromatids. In recombination, crossing over is the reason that leads to genetic recombination of chromosomes; conversely, when crossing, the synapse results in a crossing. Recombination always occurs in individuals and is transferred to the next generation; on the other hand, the crossing may or may not always occur on homologous chromosomes or, if it does not occur, only the parental chromosomes will be observed.

Genetic recombination plays a vital role in genetic diversity at the species or population level; on the contrary, the crossing using genetic recombination allows variations in the alleles of the chromosomes in an offspring. In recombination, the two different alleles always combine during meiosis and are transferred to subsequent generations; on the other hand, when crossing, the DNA segments on non-sibling or homologous chromosomes are exchanged during this procedure. Recombination functions as a renewal mechanism for double-stranded breaks during the meiosis process and forms genetic variations in the offspring; on the other hand, the crossing overlaps a role in the exercise of genetic recombination between homologous chromosomes.

Comparative chart

Recombination Crossing
Recombination is the assortment of different alleles in combinations that is the result of an independent assortment. Crossover is the process of exchange of genetic material between non-sister chromatids that results in the formation of new traits in the next generation.
Refers to
It refers to the formation of offspring consisting of many diverse or different combinations of traits. It refers to the exchange of genetic material as DNA segments between non-sister chromatids.
Correspondence
The crossover is the reason that leads to the genetic recombination of chromosomes. Synapsis results in crossover
Idea
It always occurs in individuals and is transferred to the next generation. It may or may not always occur on homologous chromosomes, or if it does not, only the parental chromosomes will be observed
Genetic diversity
It plays an important role in the genetic diversity of species or population level. Through genetic recombination it allows variations in the alleles of the chromosomes in an offspring.
Mechanism
The two different alleles always combine during meiosis and are passed on to subsequent generations. DNA segments on homologous or non-sibling chromosomes are swapped during this procedure.
Features
It works as a renewal mechanism for double chain breaks during the meiosis process and forms genetic variations in the offspring. Plays a role in the exercise of genetic recombination between non-homologous chromosomes
What is recombination?

The term recombination is defined as the formation of an offspring that has different trait arrangements as an associate of the father by combining different alleles on the chromosomes. Genetic recombination is considered a natural process and always occurs during meiosis. Genetic recombination in eukaryotes occurs in prophase 1 of meiosis 1. Meiosis is considered the method of formation of different gametes for the process of sexual production. The formation of offspring that vary genetically is the result of the variation that occurs in the genes of the gametes of the parents during meiosis by the process of genetic recombination.

Homologous chromosome pairing, followed by the exchange of genetic knowledge between non-sister chromatids, occurs in eukaryotic genetic recombination. The combination of non-sister chromatids is considered synapse. The exchange of DNA segments could occur by non-physical transfer or physical transfer. Non-physical transfer types are Synthesis Dependent Strand Annealing (SDSA) or Double Holliday Junction (DHJ) which start with a double strand break or a space that follows strand attack to initiate copying of genetic material . Therefore, both the SDSA and DHJ pathways are discussed as renewal mechanisms.

In the process of mitosis, the exchange of genetic information occurs between sister chromatids just after DNA replication ends at the point of interface. However, in this process no new groups of alleles are formed because the exchange of material occurs between the identical DNA molecules that are formed by the replication method.

Catalysts for genetic recombination are made by the class of enzymes known as recombinases. RecA recombinase is commonly found in E. coli bacteria . In this type of bacteria, recombination occurs through the process of mitosis, and the transmission of genetic material by sister chromatids occurs between your body. In the type of bacteria, archaea, the enzyme RadA recombinase is found which is considered an ortholog of RecA. Another id for RAD51 recombinase found in yeast. One particular meiotic recombinase found is DMC1.

Types of recombinase enzyme
  • RecA: found in E. coli
  • RadA: Found in archaea as an ortholog of RecA
  • RAD51: found in yeast
  • DMC1: found as a particular meiotic recombinase

Forms of genetic information transfer

  • Physical transfer : The transfer of genetic information that occurs by the exchange of chromosomal segments between non-sister chromatids is generally physical transfer .
  • Non-physical transfer: The method in which sections of a genetic material that are present on one chromosome can be copied onto another segment of the chromosome without physically exchanging chromosomal parts is known as non-physical transfer .

Non-physical transfer types

  • Synthesis Dependent Strand Annealing (SDSA): In this type of non-physical transfer, the copying of genetic material occurs in which it allows the exchange of materials but not through the physical exchange of DNA segments.
  • Double Holliday Junction (DHJ) – This is another copy of genetic information that results in the non-physical transmission of genetic material.

Information copy types

  • Non-Crossover (NCO): In this type, when a renewal of a broken strand occurs, only the chromosome that embraces the double-strand break is transmitted with the new information.
  • Crossover (CO): In this type, the two chromosomes that support the double beak strand or others that do not are transmitted with new genetic material.

What is Crossing Over?

The term crossover is defined as the exchange of DNA parts between non-sister chromatids during the synapse process. The crossover process occurs in prophase 2 of meiosis 1. Crossover generally facilitates genetic recombination by exchanging genetic material between two homologous chromosomes and forming a new mix of alleles.

The crossover process begins with the dissociation of the same DNA segments that occur on homologous chromosome pairs. The DNA molecule is introduced through double strand breaks, either by DNA damaging agents or by the Spo 11 protein. After this, the 5 ‘end of the DNA corners is broken down by exonucleases. Digestion of the 5 ‘end introduces the 3’ end that extends towards the DNA edges of the double-stranded DNA.

The extended single-stranded 3 ‘is coated by recombinases that form nucleoprotein strands, Rad51 and Dmc 1. Acceleration of the occupied 3′ extension in non-sister chromatids is by recombinases. The introduced 3 ‘extension primes DNA synthesis by using the DNA strand of non-sister chromatids as a template. The main structure of this 3 ‘invaded is termed as interchain exchange or Holliday crossing. The recombinase dragged the Holliday junction along the chiasm.

Key differences

  1. Recombination commonly refers to the formation of a progeny consisting of many unique or different mixtures of traits, while crossover generally refers to the exchange of genetic material as pieces of DNA between homologous chromosomes.
  2. When two different alleles combine during meiosis, the recombination process occurs and they are transferred to the next generation; On the other hand, when DNA segments on non-sibling or non-homologous chromosomes are swapped, a crossover will occur during this procedure.
  3. Crossover is the main cause of genetic recombination of chromosomes during the recombination process, while crossover occurs due to synapse, which commonly results in crossover.
  4. Recombination occurs continuously in individuals and is then assigned to the next offspring; on the other hand, in the crossover, the parental chromosomes will only be observed if no crossover occurs on the non-sister chromatids because the crossover may or may not occur on the homologous chromosomes.
  5. Genetic recombination plays the main role in genetic diversity in species or population level; on the contrary, the crossing allows variations in different alleles of chromosomes in a specific population of species through genetic recombination.
  6. Recombination functions as a restoration mechanism during the meiosis process and forms the double-stranded interruptions that result in the formation of genetic variations in the offspring; on the other hand, crossing is of great importance in the physical effort of genetic recombination between homologous chromosomes.

Final Thought

The above discussion concludes that recombination and crossover are the two main terms that are used interchangeably and occur primarily during synapse. Recombination is the combination of different alleles that results in the formation of new traits in the offspring. Crossover is another mechanism in which parts of DNA are exchanged during meiosis between non-sister chromatids.

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button