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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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Are there any phenotypically visible examples of gene linkage in humans?

Sex-linkage would be the canonical example. In other words, people with phenotypically male or female sex characteristics have non-random genetic predilections towards specific X-linked traits such as ...
Maximilian Press's user avatar
4 votes
Accepted

What exactly is a centimorgan?

I personally like to talk in Morgan (M), instead of centiMorgan (cM), because the Morgan has a more intuitive meaning than one-hundredth of its value. Morgan If two loci are at distance 1M, it means ...
Remi.b's user avatar
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3 votes
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How is a haploblock defined with only one SNP location?

Reading the methods In the methods, it is stated that haplotype blocks were inferred with the software Haploview: Genotype information for ESR1 and ESR2 and regions approximately 10 000 base pairs up-...
Maximilian Press's user avatar
3 votes
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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
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3 votes

Non-coding DNA correlation with rate of evolution

Whether or not species with less non-coding DNA evolve faster, the assumption that this could be explained by their genomes being more susceptible to mutation would seem to me to be based on a false ...
David's user avatar
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3 votes
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Linked genes outcomes in offspring

There is nothing wrong with the question and it can be explained with not much more than mendelian genetics + linkage. What do you think are the genotypes of parents? First hint: If there is more ...
BagiM's user avatar
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2 votes

Sex linked genes?

It is not easy for an individual to figure out if it is haploid or diploid at a given sequence. To my knowledge, this is feasible only by searching for specific case of heterozygosity. The most ...
Remi.b's user avatar
  • 68.1k
2 votes

How to identify whether something is in linkage disequilibrium?

As per the definition you gave, you check whether there is a statistical association between the two. If knowing when allele is present at a locus does not affect the probability of finding a given ...
Remi.b's user avatar
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2 votes
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Crossover Value and Genetic Mapping

As a silly example: Let's say that you are traveling along a road where you know there are bandits and thieves. You want to finish your journey quickly, and spend very little time on the road, ...
Maximilian Press's user avatar
2 votes

Why is linkage disequilibrium high on either side of a beneficial mutation, but not between sites across the mutation, during a selective sweep?

In addition to the other great answer, I would like to revisit my question because I came across a stellar explanation in another paper I am now reading that also answers the question very succinctly ...
arara's user avatar
  • 706
2 votes

Why is linkage disequilibrium high on either side of a beneficial mutation, but not between sites across the mutation, during a selective sweep?

High-level answer Obviously, if the positively selected site occurs on a single haplotype, then all the polymorphisms on that haplotype "win" due to hitchhiking and will have some degree of ...
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
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1 vote
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What software can be used for simulating human meiosis, taking linkage and recombination into account?

I believe that this is an application of the ms program, which is widely used in population genetics. More recent programs also exist (here is another; here is another, here is another) that may be ...
Maximilian Press's user avatar
1 vote
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Gametes produced after single and double cross overs

You are not taking into account that crossovers happen at the four-chromatid stage and between cromatids. Take a look at the following picture1:                 I suggest you draw down all the ...
Domen's user avatar
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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

Recombination Data Set

b+/c+ b/c b+/c b/c+ Ada ~0.39 ~0.42 ~0.08 ~0.1 Donald ~0.09 ~0.09 ~0.4 ~0.41 The other chromosome beeing b/c (I assume each one got an heterozygote fly and than they did a testcross) There are a ...
Hachiloni's user avatar
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1 vote

Crossover Value and Genetic Mapping

There are two main question: (a) dependence of the frequency of recombination with the distance that separates genes and (b) do all crossover events take place with a single break on one chromosome? ...
Luis Sierra'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
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1 vote
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Are SNPs always in linkage disequilibrium with other SNPs

Linkage disequilibrim is a result of two SNPs both appearing after a cross (e.g. in offspring). As such even at great distances two SNPs could both appear in offspring 50% of the time. Linkage ...
shigeta's user avatar
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1 vote

Are SNPs always in linkage disequilibrium with other SNPs

There can be a number of reasons for Linkage Disequilibriunm (LD). Here is a non-exhaustive (non-referenced also) list. Random LD happens Epistasis A recent selective sweep Hybridization Population ...
Remi.b's user avatar
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1 vote

Linkage between chromosomal loci and the Hardy-Weinberg principle

Linkage is a physical reality Linkage refers to the physical presence of several loci on the same chromosome. Two loci that are said to be in close linkage mean that they are locataed relatively ...
Remi.b's user avatar
  • 68.1k
1 vote

Linkage Disequilibrium - What does it mean when D < 0?

Consider two bi-allelic loci, A and B with alleles A1, A2 for A and B1, ...
Remi.b's user avatar
  • 68.1k
1 vote
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What is the exact concept of "Repulsion" and "Coupling" (Genetics)?

I guess the confusion is stemming from trying to fit the phenotypic terms coupling and repulsion to their genotypic basis. Coupling and Repulsion are both used considering the phenotypic profile of ...
stochastic13's user avatar
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