Conceiving a Subject of Mutation: Event, Plasticity, and Mutation

2015 ◽  
Vol 48 (2) ◽  
pp. 197-209
Author(s):  
Nancy Nisbet
Keyword(s):  
Mutation Event

scholarly journals Multitype Bienaymé–Galton–Watson processes escaping extinction

2009 ◽  
Vol 41 (01) ◽  
pp. 225-246
Author(s):  
Serik Sagitov ◽  
Maria Conceição Serra
Keyword(s):  
Markov Chain ◽  
Asymptotic Analysis ◽  
Random Number ◽  
Asymptotic Structure ◽  
Limit Process ◽  
Stem Lineage ◽  
Mutation Event

In the framework of a multitype Bienaymé–Galton–Watson (BGW) process, the event that the daughter's type differs from the mother's type can be viewed as a mutation event. Assuming that mutations are rare, we study a situation where all types except one produce on average less than one offspring. We establish a neat asymptotic structure for the BGW process escaping extinction due to a sequence of mutations toward the supercritical type. Our asymptotic analysis is performed by letting mutation probabilities tend to 0. The limit process, conditional on escaping extinction, is another BGW process with an enriched set of types, allowing us to delineate a stem lineage of particles that leads toward the escape event. The stem lineage can be described by a simple Markov chain on the set of particle types. The total time to escape becomes a sum of a random number of independent, geometrically distributed times spent at intermediate types.

A NOVEL COMPLEX MUTATION EVENT IN THE PERIPHERIN/RDS GENE IN A FAMILY WITH RETINAL PATTERN DYSTROPHY

Retina ◽  
2006 ◽  
Vol 26 (8) ◽  
pp. 947-953 ◽  
Author(s):  
BOJAN PAJIC ◽  
MAIKE WEIGELL-WEBER ◽  
ISAAK SCHIPPER ◽  
CHRISTOPH KRYENBüHL ◽  
ERNST R. BüCHI ◽  
...  
Keyword(s):  
Pattern Dystrophy ◽  
Complex Mutation ◽  
Novel Complex ◽  
Mutation Event

An infinite-alleles version of the simple branching process

1988 ◽  
Vol 20 (03) ◽  
pp. 489-524 ◽  
Author(s):  
R. C. Griffiths ◽  
Anthony G. Pakes
Keyword(s):  
Frequency Spectrum ◽  
Limit Theorems ◽  
Branching Process ◽  
Expected Number ◽  
Generation Number ◽  
Tail Behaviour ◽  
Mutation Event

Individuals in a population which grows according to the rules defining the simple branching process can mutate to novel allelic forms. We obtain limit theorems for the number of alleles present in any generation, the total number of alleles ever seen and the number of the generation containing the last mutation event.In addition we define a notion of frequency spectrum for each generation as the expected number of alleles having a given number of representatives. As the generation number increases we prove the existence of a limiting notion of the frequency spectrum and discuss its upper tail behaviour. Our results here are incomplete and we make some conjectures which are supported by informal argument and specific examples.

scholarly journals Multitype Bienaymé–Galton–Watson processes escaping extinction

2009 ◽  
Vol 41 (1) ◽  
pp. 225-246 ◽  
Author(s):  
Serik Sagitov ◽  
Maria Conceição Serra
Keyword(s):  
Markov Chain ◽  
Asymptotic Analysis ◽  
Random Number ◽  
Asymptotic Structure ◽  
Limit Process ◽  
Stem Lineage ◽  
Mutation Event

In the framework of a multitype Bienaymé–Galton–Watson (BGW) process, the event that the daughter's type differs from the mother's type can be viewed as a mutation event. Assuming that mutations are rare, we study a situation where all types except one produce on average less than one offspring. We establish a neat asymptotic structure for the BGW process escaping extinction due to a sequence of mutations toward the supercritical type. Our asymptotic analysis is performed by letting mutation probabilities tend to 0. The limit process, conditional on escaping extinction, is another BGW process with an enriched set of types, allowing us to delineate a stem lineage of particles that leads toward the escape event. The stem lineage can be described by a simple Markov chain on the set of particle types. The total time to escape becomes a sum of a random number of independent, geometrically distributed times spent at intermediate types.

scholarly journals Fitness Estimation for Genetic Evolution of Bacterial Populations

2020 ◽  
Author(s):  
Sergey S. Sarkisov ◽  
Ilya Timofeyev ◽  
Robert Azencott
Keyword(s):  
Genetic Evolution ◽  
Bacterial Populations ◽  
Mutant Strains ◽  
Bacterial Genetic ◽  
The Mean ◽  
Mutation Event ◽  
Algorithmic Techniques ◽  
Available Information ◽  
Least Squares Approach

AbstractIn this paper we develop and test algorithmic techniques to estimate genotypes fitnesses by analysis of observed daily frequency data monitoring the long-term evolution of bacterial populations. In particular, we develop a non-linear least squares approach to estimate selective advantages of emerging new mutant strains in locked-box stochastic models describing bacterial genetic evolution similar to the celebrated Lenski experiment on Escherichia Coli. Our algorithm first analyses emergence of new mutant strains for each individual trajectory. For each trajectory our analysis is progressive in time, and successively focuses on the first mutation event before analyzing the second mutation event. The basic principle applied here is to minimize (for each trajectory) the mean squared errors of prediction w(t) − W(t) where the observed white cell frequencies w(t) are predicted by W(t), which is computed as the conditional expectation of w(t) given the available information at time (t − 1). The pooling of all selective advantages estimates across all trajectories provides histograms on which we perform a precise peak analysis to compute final estimates of selective advantages. We validate our approach using ensembles of simulated trajectories.

scholarly journals SUBSTRATE-PREFERENCE POLYMORPHISM AT AN ESTERASE LOCUS OF DROSOPHILA MOJAVENSIS

Genetics ◽  
1982 ◽  
Vol 100 (2) ◽  
pp. 307-314
Author(s):  
E Zouros ◽  
W van Delden
Keyword(s):  
Balancing Selection ◽  
Allozyme Variation ◽  
Substrate Preference ◽  
Single Mutation ◽  
Drosophila Mojavensis ◽  
Enzyme Loci ◽  
Multiple Substrate ◽  
Mutation Event

ABSTRACT In a larval esterase of Drosophila mojavensis there are alleles whose products preferentially hydrolyze α-naphthyl esters, whereas the majority of the alleles hydrolyze preferentially β-naphthyl esters. In a collection of laboratory stocks α alleles have a frequency of 15%. Three different mobilities of α alleles were discovered, suggesting a polymorphism rather than a single mutation event. If substrate-preference polymorphisms are common among "multiple-substrate" enzymes (category II of Gillespie and Langley 1974), allozyme variation at these enzyme loci may well be maintained by balancing selection.

An infinite-alleles version of the simple branching process

1988 ◽  
Vol 20 (3) ◽  
pp. 489-524 ◽  
Author(s):  
R. C. Griffiths ◽  
Anthony G. Pakes
Keyword(s):  
Frequency Spectrum ◽  
Limit Theorems ◽  
Branching Process ◽  
Expected Number ◽  
Generation Number ◽  
Tail Behaviour ◽  
Mutation Event

Individuals in a population which grows according to the rules defining the simple branching process can mutate to novel allelic forms. We obtain limit theorems for the number of alleles present in any generation, the total number of alleles ever seen and the number of the generation containing the last mutation event.In addition we define a notion of frequency spectrum for each generation as the expected number of alleles having a given number of representatives. As the generation number increases we prove the existence of a limiting notion of the frequency spectrum and discuss its upper tail behaviour. Our results here are incomplete and we make some conjectures which are supported by informal argument and specific examples.

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