Questions tagged [recombination]

The process of breaking and recombining strands of DNA.

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19
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1answer
3k views

Why does the insulin taken from pig when injected into humans causes allergy but not the insulin taken from bacteria?

At earlier times, insulin was injected to human patients that were taken from pigs and horses. But that caused allergy it seems. But why is the insulin produced by the recombinant bacteria not ...
17
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2answers
14k views

Genetic linkage greater than 50 centimorgans

Classically, the linkage between two loci can be measured in centimorgans (cM), which represents the percent chance that these two loci will recombine an odd number of times (generating a recombinant ...
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3answers
20k views

Why doesn't recombination occur in male Drosophila?

"Males do not show meiotic recombination, facilitating genetic studies." For a while I have known that this phenomenon occurs, this quote comes from the Wikipedia page on Drosophila melanogaster, and ...
11
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7answers
33k views

What's a non-allelic gene?

Non-allelic or non-alletic I stumbled across the term in my Human Genetics textbook. It didn't explain it there, and a quick google search only showed scientific papers that refer to 'recombinations ...
9
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4answers
3k views

Mitochondrial DNA and recombination

Firstly I could do with a brief description of mitochondrial DNA. How does the structure of DNA in mitochondria compare to animal DNA (for the sake of simplicity let's say human - some animals might ...
7
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1answer
274 views

Hill-Roberston effects and effective population size

From this article, first page, middle of the second column: Even if harmful alleles do not become fixed, they can still reduce the efficacy of selection on neighbouring loci through a process ...
7
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1answer
218 views

Why are recombination rates increasing in mammals?

I have recently become fascinated with an awesome topic in biology and evolution that I feel is rarely covered in biology courses. That is, rates of meiotic recombination, or the the amount that an ...
6
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1answer
2k views

Understanding recombination scoring in family pedigrees

I am having some problems understanding recombination, and I am not sure what element I am missing here. This figure is an example from my text book. The pedigree belongs to a family with an autosomal ...
5
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3answers
9k views

How many recombination events are there per generation in humans?

I'm looking for a reference that tells me how many recombenation events occur in humans from one generation to the next. Assuming that the human genome is a 3.3 GigaBases long DNA sequence, how many ...
5
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1answer
796 views

Mitotic crossover happens in G1?

I was reading this article in wikipedia and came across this : It has been suggested that recombination takes place during G1, when the DNA is in its 2-strand phase, and replicated during DNA ...
4
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3answers
3k views

Why asexual reproduction?

When I took a course on genetics and evolution, I learned that recombination and sexual reproduction is advantageous compared to asexual reproduction. Sexual reproduction allows more combinations of ...
4
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1answer
2k views

What is the difference between conditional and inducible activation?

In the modern genetically modified animal models, there are not only constitutive mutations which start producing proteins already in the embryo, but also mutations which can be turned on later. I've ...
4
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1answer
319 views

Effect of recombination on the rate of loss of genetic variation

Following up from this question: Does recombination increase the additive genetic variance for fitness? (I'm thinking about the evolution of additive genetic variance and differences between the sex ...
3
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1answer
5k views

recombination frequency problem

Three loci C, D and E are located on the same chromosome in this order. We found that the frequency of recombinants between C and D is 10% and that between D and E it is 20%. Assuming that ...
3
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1answer
111 views

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 ...
3
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1answer
87 views

What is the genetic distance where linkage can be ignored?

I heard several times that two SNPs, that have at least 1'000 nucleotides between them, can be seen as 'unlinked' due to frequent recombination events. I also once saw a paper showing a graph "degree ...
3
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1answer
105 views

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 '...
3
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1answer
46 views

What mechanisms exist for the excision of specific sequences from DNA?

I already know about recombinases (specifically excisionases), but was wondering if there were other mechanisms present.
3
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0answers
178 views

Question about genetic recombination

I am having some difficulty understanding a few things about genetic recombination, in part because of confusion from different diagrams in books. First of all, I wanted to verify whether I have ...
3
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0answers
377 views

A Genetic linkage problem [closed]

I have recently switched from electronics to computational biology. So having some hard time with my homeworks. Can someone guide me on this problem? Consider 6 genes A, B, C, D, E, F, G. Some ...
2
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1answer
139 views

meaning of “usually greater than 200 base pairs”

From "Risks from GMOs due to Horizontal Gene Transfer", by Paul Keese: Homologous recombination. All cellular organisms have molecular functions dedicated to recognizing and recombining DNA ...
2
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1answer
401 views

Does recombination increase the additive genetic variance for fitness?

On this article, first column, eighth line of the introduction: By bringing together favourable alleles from different chromosomes, sex and recombination increase the additive genetic variance for ...
2
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1answer
70 views

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) ...
2
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1answer
185 views

Why does the stability of YAC increase with size?

From Lehninger Principles of Biochemistry : The stability of YAC increases with size (up to a limit). Those with inserts of less than 100000 are gradually lost during mitosis. Why does this ...
2
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1answer
44 views

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 ...
2
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1answer
512 views

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 ...
2
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1answer
135 views

Size of DNA in phage

I have read that DNA(after recombination) is packaged in bacteriophages lambda only if it's between 40000 and 53000 bp long. This constraint can be used to ensure packaging of recombinant DNA. I don'...
2
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1answer
720 views

How does electroporation mediated recombination work?

For yeast and other organisms, DNA can be readily taken up into the cell naturally or through membrane disruption. What does applying a voltage to cells do exactly that allows more recombination to ...
2
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1answer
406 views

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 ...
2
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1answer
934 views

Which process is right to describe V(D)J recombination? RAG-1 and RSS recurring process

I'm studying V(D)J recombination. I think I have two incompatible books about explantaion of the process. Which is right? In Molecular Biology of the Cell 5th Ed., firstly RAG (-1?) combines to RSSs ...
2
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0answers
33 views

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 ...
2
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0answers
109 views

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 ...
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0answers
30 views

How is randomness of the branch migration process ensured?

Branch migration (part of genetic recombination) is a random process. It looks like Ruv-ABC proteins are mainly responsible for this process, but how is randomness ensured? After all, it can only be a ...
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1answer
161 views

Data on Recombination rate and Gene Positions in Humans

I am looking for estimates of per base pair recombination rate in humans and indication on gene positions. The goal is to be a able to plot recombination rate in the y-axis and position (in bp) along ...
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1answer
70 views

Breaking a gene during recombination

I just started reading about recombination frequencies of genes and related stuff, and can't find an answer to this (possibly naive) question. Can recombination possibly "kill off" a gene ? To be ...
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1answer
394 views

How long the homologous arms of the “repair” sequence must be to do homologous recombination? [duplicate]

I am trying to figure out the details of the homolougous recombination in order to be able to insert a certain piece of DNA in the host genome after double strand break.. Does anybody know how long ...
1
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1answer
137 views

How would homologous recombination and mutations affect speciation?

I'm wondering how homologous recombination and mutations can affect how speciation can occur from one species (so that 2 will be created). I'm doing research and I found that different mutations and ...
1
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1answer
422 views

Recombination fraction( frequency) in Homozygotes

I have a question about the recombination frequency I hope you have time to answer. Background: If we look at homozygous individual A/A B/B which has been formed from the gametes AB and AB, this ...
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1answer
151 views

How do I find the sequence of the phage BxB1 gene?

Specifically, I'm trying to find the sequence of BxB1 and its att sites. I have success finding the att site sequences, but I'm having a bit more of an issue with finding the sequence of the actual ...
1
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1answer
55 views

Study case of the inheritance system of Oenothera

I've been told some interesting facts about oenothera. Apparently in this species some lineages have been through some translocations and in results to these translocations and in consequence, some ...
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1answer
44 views

Could mating/recombination be responsible for evolution of entirely novel features?

The diploid chromosomal architecture is rather interesting. For example, because of diploidy we Humans have to mate. Of course in that sense, because diploid organisms often have mate, this has led to ...
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0answers
13 views

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 ...
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2answers
95 views

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 ...
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0answers
29 views

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 ...
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0answers
23 views

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 ...
1
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2answers
167 views

How do biologists determine the parents of a child

I am not well-versed in biology so this question might be wrong. As far as I understand meiosis, two germ line cells with 23 chromosomes each (one cell from the father and another from the mother) ...
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1answer
213 views

How exactly are genes swapped during the process of recombination?

I am studying recombination in Meiosis and the idea of crossing over doesn't make sense. My understanding is that 46 chromosomes in our germ-cell (23 from mom + 23 from dad) line up next to each other ...
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0answers
63 views

Need clarification on Coalescent with Recombination

I've been reading about recombination with coalescent. The link to that file is as follows: http://www.stats.ox.ac.uk/__data/assets/pdf_file/0008/4688/Reading_for_Recombination.pdf I get the part ...
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0answers
71 views

Is recombination suppressed in the males of all Drosophila species? Any other species?

Following up from this question, I am wondering if the phenomenon of genome-wide suppressed male recombination is limited to Drosophila melanogaster or is common to all Drosophila? The answer to the ...
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0answers
58 views

Recombination frequency as a function of genomic location in E coli?

Are there any databases or papers that give recombination frequency as a function of position in the E coli genome?