What is Spo11?
Spo11 is a protein that in humans is encoded by the SPO11 gene. Spo11, in a complex with mTopVIB, creates double strand breaks to initiate meiotic recombination. Its active site contains a tyrosine which ligates and dissociates with DNA to promote break formation.
What does dmc1 stand for?
disrupted meiotic cDNA
The name “Dmc” stands for “disrupted meiotic cDNA” and refers to the method used for its discovery which involved using clones from a meiosis-specific cDNA library to direct knock-out mutations of abundantly expressed meiotic genes.
What is the major protein in yeast involved in the initiation of meiotic recombination?
3.1 DSB Proteins in S. cerevisiae. Spo11 is the catalytic center of the meiotic recombination initiation mechanism, but it is not sufficient to generate DSBs: numerous additional proteins are also required.
What does the Synaptonemal complex do?
The synaptonemal complex (SC) is a meiosis-specific structure formed between homologous chromosomes during prophase that promotes DSB formation and biases repair of DSBs to homologs over sister chromatids.
Is SPO11 and endonuclease?
SPO11 encodes a meiosis-specific endonuclease that catalyzes the formation of double-strand breaks (DSBs) that are required to initiate meiotic recombination (10).
What do you predict is the phenotype of a SPO11 mutant that will make it so hard to maintain and why?
What do you predict is the phenotype of a spo11 mutant that will make it so hard to maintain, and why? SPO11 mutants would therefore be unable to produce offspring. It would be difficult to maintain a strain of SPO11 mutants since they will be unable to produce offspring.
How does homologous recombination work?
Homologous Recombination Paired chromosomes from the male and female parent align so that similar DNA sequences from the paired chromosomes cross over each other. Crossing over results in a shuffling of genetic material and is an important cause of the genetic variation seen among offspring.
What is the recombination frequency?
A number that describes the proportion of recombinant offspring produced in a genetic cross between two organisms.
In which synaptonemal complex is formed?
prophase I of meiosis I
The synaptonemal complex is a zipper-like proteinaceous structure that is formed during prophase I of meiosis I. It is evident particularly during the zygotene stage.
What is the difference between an endonuclease and exonuclease enzyme?
The main difference between these enzymes is that endonucleases cleave the phosphodiester bond in the polynucleotide present internal in the polynucleotide chain, whereas exonucleases cleave the phosphodiester bond from the ends.
What is the difference between spo11α and SPO 11β?
In wild-type mice, SPO11 protein is expressed as two separate isoforms as a result of alternate splicing of exon 2, producing an exon 2-skipped isoform, SPO11α, and an exon 2-containing isoform, SPO11β.
What is the catalytic activity of Spo11?
The catalytic activity of Spo11 comprises a nucleolytic attack of the DNA, resulting in a 5′ phosphotyrosyl bond and a 3′ hydroxyl, and Spo11 protein remains bound to the DNA ends until it is actively removed.
Does Spo11 act alone in yeast?
Spo11 does not act alone; in yeast, it is known to require at least nine accessory proteins, both to localize Spo11 appropriately and to facilitate DSB formation ( Figure 1.10 (B); reviewed in Ref. 203 ).
Where is SPO11 found in the body?
Spo11 is expressed predominantly in the testes and ovaries of mice, although real-time polymerase chain reaction studies have found expression in certain somatic tissues in humans. 2 Early Conjugal Phenotypes: Meiotic Defects. spo11.