What do you mean by homologous recombination?
Homologous recombination is a type of genetic recombination that occurs during meiosis (the formation of egg and sperm cells). Paired chromosomes from the male and female parent align so that similar DNA sequences from the paired chromosomes cross over each other.
What are the 3 methods of genetic recombination?
This arrangement increases genetic diversity. However, bacteria have found ways to increase their genetic diversity through three recombination techniques: transduction, transformation and conjugation.
Who discovered homologous recombination?
Groundbreaking work on homologous recombination in mouse stem cells was carried out by scientists Mario Capecchi, Sir Martin J. Evans, and Oliver Smithies, who were awarded the 2007 Nobel Prize in Physiology or Medicine for their discoveries.
What are the steps of homologous recombination?
Homologous recombination can be divided into three key steps: strand exchange, branch migration and resolution. The identification of a protein complex that catalyses branch migration and Holliday junction resolution argues that the mechanism of homologous recombination is conserved from bacteria to man.
What is mechanism of genetic recombination?
Genetic recombination refers to the rearrangement of DNA sequences by the breakage and rejoining of chromosomes or chromosome segments. It also describes the consequences of such rearrangements, that is, the inheritance of novel combinations of alleles in the offspring that carry recombinant chromosomes.
Who discovered genetic recombination?
Between April and June 1946, Joshua Lederberg and Edward L. Tatum carried out a series of experiments that proved that bacteria can exchange their genes by sexual crossings. The experiments were reported in Nature just 40 years ago1.
What does Nonhomologous mean?
: being of unlike genetic constitution —used of chromosomes of one set containing nonallelic genes … is done by facilitating genetic recombination of the ends of the elements with other, nonhomologous sequences.— John Abelson.
What do you mean by nonhomologous chromosome?
Non-homologous chromosomes are chromosomes that do not belong to the same pair. Generally, the shape of the chromosome, that is, the length of the arms and the position of the centromere, is different in non-homologous chromosomes.
Why do Holliday junctions occur?
Holliday junction, cross-shaped structure that forms during the process of genetic recombination, when two double-stranded DNA molecules become separated into four strands in order to exchange segments of genetic information.
How is Holliday junction resolved?
Cleavage, or resolution, of the Holliday junction can occur in two ways. Cleavage of the original set of strands leads to two molecules that may show gene conversion but not chromosomal crossover, while cleavage of the other set of two strands causes the resulting recombinant molecules to show crossover.