GO:0010705 meiotic DNA double-strand break processing involved in reciprocal meiotic recombination: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0010705 describes the 5' to 3' exonucleolytic resection of DNA at meiotic double-strand breaks to form 3' single-strand overhangs, a step required for repair through a double Holliday junction intermediate.
• This process is a sub-step of meiotic recombination and is essential for reciprocal crossover formation and genetic map specification.
• Key proteins include HORMAD1 and HORMAD2, which are depleted from synapsed axes with the help of TRIP13 AAA-ATPase.
• Histone H1 is dispensable for proper meiotic recombination in budding yeast, indicating that linker histones are not universally required for this processing step.
• The C2H2 zinc finger protein PbZfp is involved in histone modification and DNA damage response, linking chromatin modifiers to break processing.
• Meiotic recombination analyses in pigs with balanced chromosomal rearrangements provide insights into how structural variants affect recombination and processing.
Description
Meiotic recombination is a fundamental process that ensures proper chromosome segregation and generates genetic diversity. A critical early step is the processing of programmed DNA double-strand breaks (DSBs) into 3' single-strand DNA overhangs, which is required for strand invasion and repair through a double Holliday junction intermediate. This process is formally described by the Gene Ontology term GO:0010705, meiotic DNA double-strand break processing involved in reciprocal meiotic recombination. Understanding this term is essential for researchers studying meiosis, fertility, and genetic mapping. The specification of meiotic recombination sites defines the genetic map, and defects in DSB processing can lead to chromosome missegregation, aneuploidy, and infertility. Moreover, studies in diverse organisms, from plants to mammals, have revealed conserved and species-specific factors that regulate this step [1,6]. In this article, we provide a comprehensive overview of GO:0010705, covering its definition, mechanism, key genes, disease relevance, and research methods, with a focus on how CRISPR-based models can accelerate discovery.
meiotic DNA double-strand break processing involved in reciprocal meiotic recombination At A Glance
| GO ID | GO:0010705 |
|---|---|
| GO term | meiotic DNA double-strand break processing involved in reciprocal meiotic recombination |
| Ontology | biological_process |
| Synonym | none |
| Major function | 5' to 3' exonucleolytic resection of meiotic DSBs to form 3' single-strand overhangs for double Holliday junction repair |
| Parent term | meiotic DNA double-strand break processing |
| Related process | reciprocal meiotic recombination |
| Cellular context | nucleus, meiotic chromosomes |
| Key proteins | HORMAD1, HORMAD2, TRIP13, and other recombination factors |
What Is GO:0010705?
GO:0010705 is defined as the cell cycle process in which the 5' to 3' exonucleolytic resection of the DNA at the site of the break to form a 3' single-strand DNA overhang occurs, resulting in double strand break formation and repair through a double Holliday junction intermediate. In simpler terms, it is the step that chews back the broken DNA ends to create long single-stranded tails, which are then used as substrates for homologous recombination during meiosis.
Why Is meiotic DNA double-strand break processing involved in reciprocal meiotic recombination Important in Cell Biology?
GO:0010705 is important because it represents a committed step in meiotic recombination that determines whether a DSB is repaired as a crossover or non-crossover, directly influencing genetic diversity and chromosome segregation fidelity. Defects in this processing step can lead to unrepaired breaks, chromosome nondisjunction, and gametogenic failure, making it a focal point for studies on infertility and aneuploidy. Furthermore, understanding this process has implications for plant breeding, where manipulating recombination can alter genetic maps, and for livestock breeding, as shown by studies in pigs with chromosomal rearrangements.
• Ensures proper chromosome segregation during meiosis I by promoting crossover formation.
• Defects can cause infertility and aneuploidy in humans and model organisms.
• Influences genetic map length and distribution of crossovers.
• Conserved from yeast to plants and mammals, enabling comparative studies [1,6].
• Target for manipulating recombination in crop improvement.
• Relevant to livestock breeding, as structural chromosomal rearrangements affect recombination.
• Links chromatin modifications to DNA damage response via proteins like PbZfp.
• Histone H1 is dispensable, highlighting redundancy in chromatin regulation.
• Provides a model for studying DSB repair mechanisms in general.
• Potential therapeutic target for fertility disorders and cancer predisposition.
What Happens During meiotic DNA double-strand break processing involved in reciprocal meiotic recombination?
Initiation of meiotic DSBs
In simple terms: First, the cell deliberately cuts its own DNA to start recombination.
Meiotic recombination begins with the programmed formation of DNA double-strand breaks (DSBs) by the Spo11 complex. These breaks are made at specific hotspots, and their distribution defines the genetic map. In plants, manipulation of this step can alter recombination frequencies. The breaks are then subject to processing to generate single-stranded DNA overhangs.
5' to 3' exonucleolytic resection
In simple terms: The broken ends are chewed back to leave long single-stranded tails.
The core of GO:0010705 is the 5' to 3' exonucleolytic resection of the DNA at the break site. This resection creates 3' single-strand DNA overhangs, which are essential for strand invasion and repair through a double Holliday junction intermediate. This step is tightly regulated and involves multiple nucleases and accessory factors. In budding yeast, histone H1 is dispensable for proper meiotic recombination, indicating that linker histones are not universally required for this processing step.
Formation of 3' single-strand overhangs
In simple terms: The tails are used to search for matching DNA sequences.
The resulting 3' single-strand overhangs are bound by recombinases such as Rad51 and Dmc1, which facilitate invasion of the homologous chromosome. This invasion leads to the formation of double Holliday junctions, which are resolved to produce crossovers or non-crossovers. The length and stability of the overhangs influence the outcome of recombination.
Role of HORMAD proteins and TRIP13
In simple terms: Special proteins help remove others from synapsed chromosomes.
Mouse HORMAD1 and HORMAD2 are conserved meiotic chromosomal proteins that are depleted from synapsed chromosome axes with the help of TRIP13 AAA-ATPase. This depletion is important for proper recombination progression, and defects can lead to impaired DSB processing. HORMAD proteins are thought to monitor synapsis and coordinate recombination with chromosome structure.
Chromatin modifications and DNA damage response
In simple terms: Chemical tags on DNA-packaging proteins help recruit repair machinery.
Chromatin modifications, such as histone phosphorylation and ubiquitination, play a role in recruiting repair factors. The C2H2 zinc finger protein PbZfp is involved in histone modification and susceptibility to DNA damage response, linking chromatin state to DSB processing. In plants, understanding and manipulating meiotic recombination involves similar chromatin-based regulation.
Key Genes Involved in GO:0010705 meiotic DNA double-strand break processing involved in reciprocal meiotic recombination
The following genes and proteins are key players in meiotic DNA double-strand break processing involved in reciprocal meiotic recombination, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SPO11 | Catalytic subunit that generates meiotic DSBs | Initiation of recombination; target for manipulating crossover frequency |
| HORMAD1 | Meiotic chromosomal protein; depleted from synapsed axes | Regulates recombination progression; knockout causes meiotic arrest |
| HORMAD2 | Meiotic chromosomal protein; interacts with HORMAD1 | Similar to HORMAD1; involved in synapsis surveillance |
| TRIP13 | AAA-ATPase that helps deplete HORMAD proteins from synapsed axes | Essential for recombination and synapsis; mutations linked to infertility |
| RAD51 | Recombinase that binds single-strand DNA overhangs | Facilitates strand invasion; marker of recombination |
| DMC1 | Meiosis-specific recombinase | Essential for interhomolog recombination |
| MRE11 | Nuclease involved in DSB resection | Part of MRN complex; processes breaks |
| RAD50 | Part of MRN complex | Structural role in DSB processing |
| NBS1 | Part of MRN complex | Recruits MRN to DSBs |
| EXO1 | Exonuclease that resects DSB ends | Generates single-strand overhangs |
| SGS1 | Helicase involved in double Holliday junction resolution | Prevents crossovers; affects processing outcome |
| MLH1 | Mismatch repair protein; marks crossovers | Used to detect crossover sites |
| MLH3 | Part of MutL gamma complex | Promotes crossover formation |
| PbZfp | C2H2 zinc finger protein; involved in histone modification and DNA damage response | Links chromatin to DSB processing in malaria parasite |
| H1 | Linker histone | Dispensable for meiotic recombination in budding yeast |
| PCH2 | AAA-ATPase involved in meiotic checkpoint | Regulates HORMAD removal |
| RAD21 | Cohesin subunit | Maintains chromosome structure during recombination |
| REC8 | Meiosis-specific cohesin | Essential for sister chromatid cohesion and recombination |
How Is meiotic DNA double-strand break processing involved in reciprocal meiotic recombination Regulated?
The process of meiotic DSB processing is regulated at multiple levels. Chromatin modifications, such as histone phosphorylation and ubiquitination, recruit repair factors and modulate resection. The AAA-ATPase TRIP13 regulates the removal of HORMAD proteins from synapsed axes, which is critical for proper recombination progression. In budding yeast, histone H1 is dispensable, suggesting that linker histones are not essential regulators of this step. Additionally, the C2H2 zinc finger protein PbZfp is involved in histone modification and DNA damage response, indicating a role in regulating chromatin accessibility for processing. In plants, manipulation of recombination involves altering the expression of key genes, which can affect processing efficiency.
meiotic DNA double-strand break processing involved in reciprocal meiotic recombination and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| HORMAD1 | Infertility, meiotic arrest | Knockout mouse |
| TRIP13 | Infertility, meiotic defects | Point mutation mouse |
| MLH1 | Colorectal cancer, meiotic recombination defects | Knock-in mouse |
| RAD51 | Cancer predisposition, Fanconi anemia | Overexpression cell line |
| SPO11 | Infertility, meiotic recombination failure | Knockout mouse |
Infertility and Meiotic Arrest
Defects in meiotic DSB processing can lead to meiotic arrest and infertility. For example, mutations in HORMAD1 or TRIP13 cause impaired synapsis and recombination, resulting in germ cell loss. In humans, variants in genes involved in this process have been associated with premature ovarian failure and azoospermia.
Aneuploidy and Chromosomal Disorders
Failure to properly process DSBs can result in chromosome nondisjunction, leading to aneuploidy such as trisomy 21. Studies in pigs with balanced chromosomal rearrangements have shown altered recombination patterns, which can contribute to aneuploidy. Understanding this process is therefore relevant to reproductive genetics.
Cancer Predisposition
While meiotic recombination is germline-specific, many proteins involved in DSB processing, such as RAD51 and MRE11, also function in somatic DNA repair. Defects in these pathways can predispose to cancer. For instance, RAD51 is a target for cancer therapy, and its meiotic functions are studied for insights into its role in tumor cells.
From meiotic DNA double-strand break processing involved in reciprocal meiotic recombination-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate DSB resection? | Knockout cell line (e.g., HEK293T) |
| Does a point mutation in gene Y affect processing? | Point-mutation knock-in mouse |
| Can a tagged protein be used to track processing? | Tagged knock-in (e.g., GFP) |
| Does overexpression of gene Z alter recombination? | Overexpression cell model |
| What is the role of chromatin modifications? | Histone mutant yeast strains |
| How do chromosomal rearrangements affect recombination? | Pig model with balanced rearrangements |
How to Study the meiotic DNA double-strand break processing involved in reciprocal meiotic recombination Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Pulsed-field gel electrophoresis | DSB formation and processing | Yeast meiosis |
| RAD51 immunofluorescence | Processed DSB foci | Mouse spermatocytes |
| ChIP-seq for MLH1 | Crossover sites | Pig spermatocytes |
| CRISPR knockout library | Gene function in processing | Cell lines |
| Live-cell imaging | Dynamics of recombination proteins | Mouse germ cells |
| Southern blotting | Recombination intermediates | Yeast |
| RNA-seq | Gene expression changes | Plant meiosis |
| Proteomics | Protein interactions | Meiotic cells |
Detection of DSB Processing Intermediates
Researchers can use pulsed-field gel electrophoresis or Southern blotting to detect DSBs and their processed intermediates. In yeast, physical analysis of recombination intermediates is well established. In mammals, immunofluorescence of RAD51 foci serves as a marker of processed breaks.
Genomic Mapping of Recombination Sites
Techniques such as ChIP-seq for MLH1 or DMC1 can map recombination hotspots and crossovers. In pigs, MLH1 foci have been used to analyze recombination patterns in chromosomal rearrangements. In plants, similar approaches have been used to understand recombination.
Genetic Screens and CRISPR Libraries
CRISPR-based knockout libraries can be used to screen for genes involved in DSB processing. For example, a genome-wide screen in a meiotic cell model could identify novel regulators. This approach is powerful for uncovering factors that affect processing efficiency.
Live-Cell Imaging of Recombination
Fluorescently tagged proteins, such as GFP-RAD51, can be used to visualize recombination foci in live cells. This method provides spatiotemporal information about processing.
How CRISPR Can Be Used to Study GO:0010705 meiotic DNA double-strand break processing involved in reciprocal meiotic recombination
Knockout
CRISPR knockout of genes such as HORMAD1 or TRIP13 in cell lines or mouse models can reveal their essential roles in DSB processing. For example, Trip13 knockout mice exhibit meiotic arrest and impaired HORMAD removal. Knockout studies in budding yeast have shown that histone H1 is dispensable for recombination.
Point Mutation
Introducing point mutations in catalytic residues of nucleases like EXO1 or MRE11 can dissect their roles in resection. Such models help distinguish between functions in meiotic versus somatic cells.
Knock-in
Knock-in of tagged versions of proteins (e.g., GFP-HORMAD1) allows visualization of processing complexes. This approach has been used to study HORMAD dynamics in mouse meiosis.
Overexpression
Overexpression of recombination factors like RAD51 can lead to hyper-recombination or interfere with processing. Such models are useful for studying dosage effects.
How EDITGENE Supports meiotic DNA double-strand break processing involved in reciprocal meiotic recombination Research
Researchers studying meiotic DNA double-strand break processing involved in reciprocal meiotic recombination-related genes often need to determine whether a candidate gene is causally involved in the process or merely correlated with it. EDITGENE provides a comprehensive suite of CRISPR services to enable such functional studies.
Contact EDITGENE today to design your custom CRISPR model for meiotic DNA double-strand break processing involved in reciprocal meiotic recombination research.
Frequently Asked Questions About meiotic DNA double-strand break processing involved in reciprocal meiotic recombination
What is GO:0010705?
GO:0010705 is the Gene Ontology term for meiotic DNA double-strand break processing involved in reciprocal meiotic recombination, which describes the 5' to 3' exonucleolytic resection of DNA at meiotic DSBs to form 3' single-strand overhangs.
What genes are involved in meiotic DNA double-strand break processing?
Key genes include SPO11, HORMAD1, HORMAD2, TRIP13, RAD51, DMC1, MRE11, EXO1, and MLH1, among others [1,6].
Why is meiotic DSB processing important?
It is essential for crossover formation, proper chromosome segregation, and genetic diversity; defects can cause infertility and aneuploidy.
How is meiotic DSB processing studied?
Common methods include pulsed-field gel electrophoresis, immunofluorescence of RAD51 foci, ChIP-seq for MLH1, and CRISPR screens [2,4,6].
What is the role of HORMAD1 in this process?
HORMAD1 is a meiotic chromosomal protein that is depleted from synapsed axes with the help of TRIP13, and it regulates recombination progression.
Is histone H1 required for meiotic recombination?
In budding yeast, histone H1 is dispensable for proper meiotic recombination, indicating that linker histones are not universally required.
How do chromosomal rearrangements affect meiotic recombination?
Balanced chromosomal rearrangements can alter recombination patterns, as shown in pigs, potentially leading to aneuploidy.
What diseases are linked to defects in meiotic DSB processing?
Infertility, meiotic arrest, aneuploidy, and certain cancers have been linked to defects in this process [3,6].
Can CRISPR be used to study meiotic DSB processing?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are powerful tools to dissect gene function in this process [1,6].
What services does EDITGENE offer for studying this process?
EDITGENE provides knockout cell models, point mutation models, knock-in models, overexpression models, CRISPR library screening, and bioinformatics services [1,6].
Conclusion
GO:0010705, meiotic DNA double-strand break processing involved in reciprocal meiotic recombination, is a critical step in meiosis that ensures genetic diversity and proper chromosome segregation. Understanding its molecular players and regulation has broad implications for fertility, aneuploidy, and cancer research. With advanced CRISPR tools and services from EDITGENE, researchers can functionally dissect this process and accelerate discoveries.
References
- 1. Lambing C et al.. 2017. Understanding and Manipulating Meiotic Recombination in Plants.. Plant Physiol 173(3):1530-1542 PMID: 28108697
- 2. Mary N et al.. 2016. Meiotic Recombination Analyses in Pigs Carrying Different Balanced Structural Chromosomal Rearrangements.. PLoS One 11(4):e0154635 PMID: 27124413
- 3. Grey C et al.. 2011. [What defines the genetic map? The specification of meiotic recombination sites].. Med Sci (Paris) 27(1):63-9 PMID: 21299964
- 4. Brush GS. 2015. Evidence that histone H1 is dispensable for proper meiotic recombination in budding yeast.. BMC Res Notes 8:275 PMID: 26122007
- 5. Gopalakrishnan AM et al.. 2017. Multifunctional Involvement of a C2H2 Zinc Finger Protein (PbZfp) in Malaria Transmission, Histone Modification, and Susceptibility to DNA Damage Response.. mBio 8(4) PMID: 28851851
- 6. Wojtasz L et al.. 2009. Mouse HORMAD1 and HORMAD2, two conserved meiotic chromosomal proteins, are depleted from synapsed chromosome axes with the help of TRIP13 AAA-ATPase.. PLoS Genet 5(10):e1000702 PMID: 19851446
