32 votes

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

Proteins and peptides vary across species, even if we give them the same name. Some are very homologous among even distantly related organisms, others differ even within a genus. Of course there are ...
Bryan Krause's user avatar
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16 votes

Genetic linkage greater than 50 centimorgans

Understanding the statistics we use when talking about recombination rate is an important question that is unfortunately too often dismissed in an intro course to evolutionary biology or population ...
Remi.b's user avatar
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6 votes
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How can I change the payload of a bacteriophage used to transform E. coli?

I am currently using a 'phage integrase' system to insert my gene of interest into P. putida and it is definitely a seamless process with high efficiency so I highly recommend it! As for your question,...
Ian_Schlander's user avatar
6 votes
Accepted

How can I find/simulate mixed-ancestry DNA data?

Price et al 2009 describe how to simulate admixed genomes in this paper. We constructed 40 haploid admixed genomes (nā€Š=ā€Š1 to 40) from the 40 haploid Yoruba and 40 haploid French genomes by using ...
user438383's user avatar
  • 2,351
4 votes

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

A recombination map of the E. coli genome was recently published (several years after question was asked).
Maximilian Press's user avatar
4 votes

How many recombination events are there per generation in humans?

"On average, between two and three crossover events occur on each pair of human chromosomes during meiotic division I" according to Molecular Biology of the Cell. 4th edition by Alberts B, Johnson A, ...
pas28's user avatar
  • 41
3 votes
Accepted

Number of homozygous recessive offspring

Taking your assumption of a cis arrangement of alleles to be true, here is how I would solve the problem. A diploid plant heterozygous for height and flower color is selfed. $TR / tr \times TR / tr$ A ...
acvill's user avatar
  • 8,286
3 votes
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Data on Recombination rate and Gene Positions in Humans

A good baseline for this type of research in human genetics is Standards and guidelines for the interpretation of sequence variants from ACMG. It is a guideline for clinicians, and it gives a good ...
Maxim Kuleshov's user avatar
3 votes
Accepted

Difference between crossover rate and recombination rate?

Let's start with the second question. Is 'per base pair' and 'per locus' the same thing? No, not necessarily. A locus (plur. loci) is a location in the genome. It can be of any size. A locus can be ...
Remi.b's user avatar
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3 votes
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What are the differences between different strains/types of Cre?

CreER is Cre coupled with a binding site for the estrogen receptor ("ER") to make an inducible version of the Cre system triggered by tamoxifen. CreERT2 is just a particular variety of this ...
Bryan Krause's user avatar
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3 votes
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Accessing the recombination map of Drosophila melanogaster

Yes, the original links stopped working, apologies. I have now added a file/link in my current website with per-chromosome recombination maps in R5 and R6 coordinates. https://comeron.lab.uiowa.edu/...
Josep Comeron's user avatar
2 votes
Accepted

How is a specific fragment isolated for PCR amplification?

There are a number of primer testing tools that will compare primer sequences against the genome to ensure specificity, or help you design specific primers to amplify a specific region. One place to ...
divibisan's user avatar
  • 355
2 votes

Are there chromosomes that we inherit that are not recombinated?

As you say people, I will assume you are talking about humans only. Except for the small pseudo-autosomal regions (PAR1, PAR2), the Y-chromosome and the X-...
Remi.b's user avatar
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2 votes
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How would one go about isolating a specific mRNA out of a pool of others?

First of all you need to figure out what your goal is: an expression vector (i.e. plasmid) which will drive expression of a gene in bacteria (let's say E.coli), and your gene's coding sequence needs ...
Armatus's user avatar
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2 votes
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Clarifying distinction between genetic recombination , translocation. and transposition

Translocation is a mutation . Others are not necessarily . By the way do not confuse those 3 terms with transversion and transition mutations. Translocation refers to 2 concepts : In protein ...
Amirreza Mousavi's user avatar
2 votes
Accepted

How many of the four meiotic daughter chromosomes of a homologous pair can be recombinant via crossover?

There can be and often is more than one crossover per chromosome in meiosis, but how many crossovers occur can depend on the species, sex, age, environment, and which particular chromosome is ...
tyersome's user avatar
  • 5,588
2 votes

How can prokaryotes repair double strand breaks by homologous recombination if they're haploids?

Several answers to this question: Much of the time what bacteria are doing to repair DSBs is actually non-homologous end-joining, which does not require strict homology. This is the more likely ...
Maximilian Press's user avatar
2 votes

What is an intuitive explanation of linkage disequilibrium?

During sexual reproduction, the process of crossing-over means that parts of the maternal and paternal chromosomes become shuffled up with one another into chromosome 'chunks', as shown by the red and ...
user438383's user avatar
  • 2,351
2 votes

How many generations does it take for the average descendant not to be genetically related to the ancestor?

Graham Coop performed simulations related to this question, based on actual transmission data for each chromosome in humans. He found that after 10 or 11 generations there was >50% chance that any ...
Darlingtonia's user avatar
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2 votes

How frequently does recombination occur, and how long are the recombinated fragments?

When crossover happens, it's a whole swap from that point on, not just a little chunk. So if there's only one crossover event, then the lengths are "p" and "100% - p", where p is ...
Bryan Krause's user avatar
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1 vote

How to calculatie frequency of recombination between two genes based on their coordinates in ENSEMBL?

I would strongly recommend consulting a mouse recombination map. Hopefully no need to compute anything, as you should be able to just look up recombination rates between named SNPs. Here is one mouse ...
Maximilian Press's user avatar
1 vote
Accepted

What is the map unit between the genes?

Here's a hint: you're right about 0.01 being the recombinant (crossed-over) double homozygous recessive offspring. I think you're forgetting that each offspring contains 2 gamete haplotypes, and so ...
Armand's user avatar
  • 1,711
1 vote

Why asexual reproduction?

Sexual reproduction probably evolved because an asexually reproducing species of bacteria evolved an evolutionary stable strategy and then there was a rapid change in the environment and only the ...
Timothy's user avatar
  • 886
1 vote

What is the correct nomenclature for expressing a genotype where a recombination event may occur?

I would suggest "genotype". A Punnett square is a visualization technique to help us think, it doesn't change the terminology. If what you mean is the 1N genotypes represented in the rows/...
Maximilian Press's user avatar
1 vote

Confusion about how to compute probabilities for linked genes

0.000625 looks right to me. On one chromosome, you have a 50% chance of a. Then you have a 40% chance of b (if and only if a crossover occurs). These multiply out to 20%. You multiply that by 50% ...
Mike Serfas's user avatar
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1 vote
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Using punnett squares to express sex/gene linkage and recombination frequency

Punnett squares show the possible gametes from each parent. I suppose you could write out all the possible recombined gametes with their frequency in the same format, explicitly stating the ...
Mike Serfas's user avatar
  • 2,455
1 vote

Using punnett squares to express sex/gene linkage and recombination frequency

The Punnett squares are a general way to visualize the product of any two polynomials; for example, you know that the result of (a + b)(c + d) is the sum of the four terms ab, ac, bc, bd. You may put ...
Silvano's user avatar
  • 136
1 vote
Accepted

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

The genes that do recombination likely aren't expressed in any other tissues. A quick look at expression of RAG1 shows expression in immune cells, and not really anywhere else.
swbarnes2's user avatar
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1 vote
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Why is Homologous Recombination (HR) more frequent at long sequence repeats?

HR rarely occurs at all in normal somatic cells, because multiple different mechanisms try to prevent this from happening between sister chromosomes during mitosis; the implications of this ...
mpprogram6771's user avatar
1 vote

Help with gene linkage and mapping!

I think your reasoning is sound and your ordering very likely, but I wouldn't feel comfortable with deciding the side B is on. Actually, it's more than that: I think that by using basically the same ...
allepasse's user avatar
  • 341

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