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Questions tagged [recombination]

The process of breaking and recombining strands of DNA.

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How did the Zinder-Lederberg experiment on Transduction work?

In the paper that introduced TRANSDUCTION (J Bacteriol. 1952 Nov;64(5):679-699), Lederberg and his student Zinder reported that S. typhimurium "LT-22 is lysogenic for a virus active on LT-2. ...
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What software can be used for simulating human meiosis, taking linkage and recombination into account?

I want to study the nature of genetic variation in offspring from the same set of human parents. To this end, I would like to take two (male and female) complete genomes, generate gametes from them, ...
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Why is the maximum propotion of MII 2/3 in the ordered tetrad analysis? How is it different from normal recombination?

My textbook says that the maximum propotion of MII gametes in the ordered tetrad analysis is 2/3, and if we put it into the formula RF(recombination frequency)=MII/2(MI+MII), we can find out that the ...
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How frequently does recombination occur, and how long are the recombinated fragments?

I understand the mechanics of recombination, but am struggling with the 'scale'. When two homologous chromosomes pair, roughly how many recombination events occur on average? I understand there will ...
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Why do many plasmids for Flp-mediated Flip-Excision only flanked by one FRT site on each side and not two non-homologous?

I'm trying to build some molecular gene switches into a model, and want to use both Cre and Flp. I understand how to invert gene segments with Cre, double floxing (e.g. with loxP and lox2272, like in ...
immunoLogical's user avatar
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How many generations does it take for the average descendant not to be genetically related to the ancestor?

Parent 1 and 2 have children. Assume infinite, randomly-mating population size. How many generations until the median descendant by lineage of parent 1 has 0 base pairs inherited from parent 1? I ...
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Trying to find information about intraspecific allelic expression divergence in recombinant individuals due to changes in the cis regulatory regions

I am trying to find any research articles or resources that focus on differences in expression levels at the allelic level due to changes in cis regulatory regions in recombinant individuals. For ...
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What makes protein binding to the DNA random?

We know that the genetic recombination process in known as a random process. On the other hand, it has also been discovered that certain proteins (such as PRDM9) determine what recombination hotspots ...
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How random is genetic recombination?

Two parents can have a very large number of different potential offsprings, and it's common knowledge that the daughter chromosomes in meiosis are produced randomly, i.e. in crossover, the exact spots ...
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Population structure and SNP's in Linkage Disequilibrium

I am reading about population structure and how you could as an example use plink to analyze a set of SNPs for individuals in a vcf file to identify a given population structure. I know that LD can be ...
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How can we use the number of crossovers per chromosome to calculate the recombination rate in cM / Mb?

I was reading a paper titled "Tetrad analysis in plants and fungi finds large differences in gene conversion rates but no GC bias" (2018). According to this paper: "The between-species ...
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Accessing the recombination map of Drosophila melanogaster

I'm looking for some information on the data of a recombination map of Drosophila melanogaster. In 2012, an extensive study by Comeron et al. appeared saying that they had reconstructed a ...
arara's user avatar
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Why does plasmid recombination require precise "copying and pasting" but microinjection doesn't?

Just learning about biotechnological techniques of gene transfer at the moment. With bacterial plasmid recombination, from a high-school level, we are taught that: The desired gene is cut using a ...
Scratch Cat's user avatar
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What does the term "centromere linkage" mean in genetics?

I am currently learning about tetrad/linkage analysis in yeast. I have read two statements similar to this: If two genes are unlinked, but linked to the centromere the distribution will be 50 ...
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What are the differences between different strains/types of Cre?

Reading from Hedgehog signaling reprograms hair follicle niche fibroblasts to a hyper-activated state: Lineage-specific genetic tools are necessary to precisely study HF fibroblasts; however, their ...
neurosciencecalc's user avatar
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What is an intuitive explanation of linkage disequilibrium?

Is it possible to give a simple and intuitive explanation of the concept of linkage disequilibrium? You know, so I can sort of sound like I know what I'm talking about. Everything I read about it has ...
Jason Scaff's user avatar
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How can I find/simulate mixed-ancestry DNA data?

Some collaborators and I are building an ancestral inference tool, and we're having trouble obtaining reliable ground-truth data for samples of mixed ancestry. All the ground-truth DNA datasets we're ...
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Gametes produced after single and double cross overs

A female genotype, shown as abc / +++ produces 100 meiotic tetrads. Among these, 68 showed no cross over (NCO) events; 20 showed single crossover (SCO1) between a and b; 10 showed single crossover ...
Neerav Singla's user avatar
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How to calculatie frequency of recombination between two genes based on their coordinates in ENSEMBL?

I have two genes: https://www.ncbi.nlm.nih.gov/gene/326619 and https://www.ncbi.nlm.nih.gov/gene/326620 both are mapped to chromosome 13. First is at position 23944778..23945232 second is at positions ...
Pavel Shliaha's user avatar
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Recombinations between Distant coronaviruses

With recombination I mean long ones, say > 1000 nucleotides, so that the two parents must be coronaviruses and the two pieces of genomes must have compatible genomic coordinates for the recombinant ...
reuns's user avatar
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Number of homozygous recessive offspring

A question from the KVPY-SX examination, organised by the Indian Institute of Science (IISc) in Bengaluru, India, held on 3rd November, 2019. A plant heterozygous for height and flower colour (TtRr) ...
Shishir Maharana's user avatar
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How can we know which alleles are together on a chromosome?

This illustration says that if the two homozygotes pr+ pr+ vg+ vg+ and pr pr vg vg are crossed to produce a heterozygous offspring (pr+ pr vg+ vg), then: this cross gives us exactly what we need to ...
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What is the map unit between the genes?

While doing some biology I came across this question: The following tables present results of plant crosses involving two linked genes: S is a seed-color gene, and L is a plant-height gene. Each gene ...
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What is the probability of having a son with blood type O? [closed]

So I was solving some biology questions, and this question left me confused. The response is supposed to be 22% according to the answers, but all the methods that I used did not lead me to it. I ...
Francesca's user avatar
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How can I change the payload of a bacteriophage used to transform E. coli?

I was looking at bacteriophages and how they're used to transform E.coli. While the whole process of how a bacteriophage works makes sense theoretically, I wanted to know how one goes about changing ...
rkrishnasanka's user avatar
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What is the correct nomenclature for expressing a genotype where a recombination event may occur?

Given an example punnett square: ...
lintunen's user avatar
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Confusion about how to compute probabilities for linked genes

I am confused about how to compute probabilities for linked genes. The problem that I am solving is this: P generation: AAbbddEEff X aaBBDDeeFF. If A and B are 40 centimorgan apart, what is the ...
user64444's user avatar
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Using punnett squares to express sex/gene linkage and recombination frequency

I have been using punnett squares to visualize mating experiments. I am looking at a pairing which is known to have a crossover event occur. I know from empirically collected data the recombination ...
lintunen's user avatar
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591 views

Why V(D)J recombination only happens in B and T cell development?

Does V(D)J recombination only happen in B and T cell development? Can it happen in other types of cells? If V(D)J recombination only happens in B and T cell development, why other types of cells ...
logstar's user avatar
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Clarifying distinction between genetic recombination , translocation. and transposition

Having thought about the distinciton between these terms I have come up with the following definitions, are these correct? Translocation describes the relocation of a chromosomal segment to a ...
Ganon's user avatar
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QA/monitoring in recombinant vaccine manufacturing

On a16z[0] podcast on vaccines[1], an interesting tidbit came up: vaccine manufacturing in cell cultures is expected to hit a major challenge in terms of quality control due to unpredictable behaviour ...
Grzegorz Kossakowski's user avatar
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How many of the four meiotic daughter chromosomes of a homologous pair can be recombinant via crossover?

In graphics I've seen, crossing over occurs between the "inner" two chromatids in a side-by-side arrangement of two duplicated chromosomes: This suggests that only two of the four meiotic daughter ...
fmg's user avatar
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How can prokaryotes repair double strand breaks by homologous recombination if they're haploids?

Title says it all, I must be going crazy.
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Why is Homologous Recombination (HR) more frequent at long sequence repeats?

I'm studying plasmids in bacteria (E. coli), and trying to understand the well-cited phenomenon that recombination frequency increases with longer repetitive sequences. I think this also applies to ...
ddm_ingram's user avatar
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Meiotic recombination hotspots

Im trying to find a proper and general file with chromosomal coordinates for meiotic recombination hotspots. I know that ucsc hgtables, has a table with recombination regions and their recombination ...
RAHenriksen's user avatar
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Are highly-polyploid organisms more resistant to ionising-radiation-induced DNA damage?

Homologous recombination, although most famous for its use to mix together maternal and paternal alleles during meiosis, is most commonly used as a DNA-repair mechanism, allowing cells to repair ...
Vikki's user avatar
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Help with gene linkage and mapping!

Here's an interesting question I've been trying to figure out: My annotations are in red. So far, I've figured out: We know 630 colonies survived when plated with ACD antibiotics...meaning they ...
Thomas's user avatar
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chromosome 19 and recombination

Im doing a project with structural variation created by recombination within the human genome during spermatogenesis, where im especially examining intrachromatid homolog recombination. I find that ...
RAHenriksen's user avatar
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1 answer
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Insertional inactivation using pBR322

I have questions regarding "selection using insertional inactivation". In a typical DNA recombination experiment using plasmid pBR322 where a new gene in inserted in the place of tet gene, it is ...
biology12323's user avatar
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Why do genetic testing companies (FTDNA,AncestryDNA,23andme) express DNA shared in centimorgans (cM) instead of in number of base pairs or in percent?

Expressing DNA shared in number of base pairs or in percent of total genome would be so much simpler and easier to understand for the customers. .
Aero's user avatar
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How did the molecular machinery for recombination originate?

I'm wondering about the origins of genetic recombination. During crossover new chromosomes are created. They have different allele combinations from the original two chromosomes. This process allows ...
Mohammad Al-Turkistany's user avatar
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How is the right amount of nucleotides synthesised during homologous recombination?

I'm reading about homologous recombination in the context of double-strand break repair. It seems like the trick is that around the break, homologous recombination uses a template duplex to generate ...
Abelaer's user avatar
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Cis and trans linkage

Question: Two dominant non-allelic genes are 50map units apart, the linkage is: (A) Cis type (B) Trans Type (C) Complete (D) Absent/Incomplete My take: After a lot of searching on the net I found ...
Hydroquinone's user avatar
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Difference between crossover rate and recombination rate?

I am not a biology student and therefore, need clarification if crossover rate and recombination rate are the same thing. So if the text says 'recombination rate per base pair per generation' or '...
Shafa Haider's user avatar
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How is a specific fragment isolated for PCR amplification?

For background I am interested in studying engineering applications of a specific protein, which is not commercially available. My end goal is to express the gene for the protein in bacterial cells, ...
Zachary Goddard's user avatar
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Join a linear plasmid just using a primer (without ligase enzyme)

Can I use just a primer and PCR to join the cutted plasmid like this ? without using any further enzyme like ligase. After the linear dsDNA plasmid annealed into 2 ssDNA, primer will bind to middle. ...
joe's user avatar
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Lambda red recombination without electroporation

All protocols that I found about Lambda red recombination are using Electroporation as a method to introduce (inject) the homologous DNA (usually a PCR products or a linear dsDNA) to the E.coli cell. ...
joe's user avatar
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Are there chromosomes that we inherit that are not recombinated? [closed]

We do have chromosomes that recombinated ,but aren't there pure chromosomes that are not recombinated that people would have?
Daniel Rigg's user avatar
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How would one go about isolating a specific mRNA out of a pool of others? [closed]

I'm writing an essay about DNA recombinant techniques where the question asks to outline all the steps to arrive at having a colony of bacteria expressing a gene of interest.The question makes you ...
Matt's user avatar
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DNA strand displacement and Branch migration- the same or different or interrelated?

So, recently I have begun studying DNA strand displacement and then I come across the term 'branch migration' (p.s. I am not a biology major student). What I understand is that branch migration is ...
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