scholarly journals Selection for biparental inheritance of mitochondria under hybridization and mitonuclear fitness interactions

2021 ◽  
Vol 288 (1964) ◽  
Author(s):  
Tom M. Allison ◽  
Arunas L. Radzvilavicius ◽  
Damian K. Dowling
Keyword(s):  
Genetic Model ◽  
Empirical Studies ◽  
Outbreeding Depression ◽  
Recent Theory ◽  
Uniparental Inheritance ◽  
Biparental Inheritance ◽  
Transient Phenomenon ◽  
Adaptive Selection ◽  
Simulation Based ◽  
Selection For

Uniparental inheritance (UPI) of mitochondria predominates over biparental inheritance (BPI) in most eukaryotes. However, examples of BPI of mitochondria, or paternal leakage, are becoming increasingly prevalent. Most reported cases of BPI occur in hybrids of distantly related sub-populations. It is thought that BPI in these cases is maladaptive; caused by a failure of female or zygotic autophagy machinery to recognize divergent male-mitochondrial DNA ‘tags’. Yet recent theory has put forward examples in which BPI can evolve under adaptive selection, and empirical studies across numerous metazoan taxa have demonstrated outbreeding depression in hybrids attributable to disruption of population-specific mitochondrial and nuclear genotypes (mitonuclear mismatch). Based on these developments, we hypothesize that BPI may be favoured by selection in hybridizing populations when fitness is shaped by mitonuclear interactions. We test this idea using a deterministic, simulation-based population genetic model and demonstrate that BPI is favoured over strict UPI under moderate levels of gene flow typical of hybridizing populations. Our model suggests that BPI may be stable, rather than a transient phenomenon, in hybridizing populations.

SSAS: Spatiotemporal Scale Adaptive Selection for Improving Bias Correction on Precipitation

2021 ◽  
pp. 1-14
Author(s):  
Yiqun Liu ◽  
Junping Zhang ◽  
Lei Chen ◽  
Hai Chu ◽  
James Z. Wang ◽  
...  
Keyword(s):  
Bias Correction ◽  
Adaptive Selection ◽  
Spatiotemporal Scale ◽  
Selection For

scholarly journals Automated model selection for simulation based on relevance reasoning

1997 ◽  
Vol 96 (2) ◽  
pp. 351-394 ◽  
Author(s):  
Alon Y. Levy ◽  
Yumi Iwasaki ◽  
Richard Fikes
Keyword(s):  
Model Selection ◽  
Simulation Based ◽  
Selection For

Genetic variation in a line of mice selected to its limit for high body weight

1974 ◽  
Vol 19 (3) ◽  
pp. 273-289 ◽  
Author(s):  
W. K. Al-Murrani ◽  
R. C. Roberts
Keyword(s):  
Body Weight ◽  
Genetic Variance ◽  
Genetic Model ◽  
Random Mating ◽  
Inbred Lines ◽  
High Body Weight ◽  
High Body ◽  
Lower Body Weight ◽  
Recessive Genes ◽  
Selection For

SUMMARYA line of mice, at its limit to selection for high body weight did not decline in performance over 11 generations of random mating, neither did it respond when selection was renewed. The experiment tested a method of improving body weight by a scheme which had earlier increased litter size under similar circumstances. The scheme was to derive partially inbred lines from the plateaued line, to select during inbreeding and, finally, to cross the best inbreds. Body weight was not increased, but the study allowed further examination of the residual genetic variance in the line.During inbreeding, the inbred lines became clearly differentiated in body weight, proving that loci controlling body weight had not become fixed. There was also a significant response to selection for a lower body weight during inbreeding. The pattern of results suggested the segregation of recessive genes, detrimental to high body weight but which selection had become inefficient at removing. A genetic model compatible with the results accommodated several such recessives, perhaps as many as 10, each with an effect of about two-thirds of a standard deviation (or some equivalent combination of gene number and effect), and at frequencies of around 0·2. Nevertheless, the total improvement in body weight to be gained by their elimination was only half a gram, or less than 2 %. Thus, substantial genetic effects can occur at individual loci despite trivially low heritabilities and negligible potential gains.

scholarly journals Chloroplast competition is controlled by lipid biosynthesis in evening primroses

2019 ◽  
Vol 116 (12) ◽  
pp. 5665-5674 ◽  
Author(s):  
Johanna Sobanski ◽  
Patrick Giavalisco ◽  
Axel Fischer ◽  
Julia M. Kreiner ◽  
Dirk Walther ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Regulatory Region ◽  
Nuclear Genome ◽  
Lipid Biosynthesis ◽  
Metabolic Phenotype ◽  
Uniparental Inheritance ◽  
Biparental Inheritance ◽  
Turnover Rates ◽  
Evening Primrose ◽  
Evolutionary Forces

In most eukaryotes, organellar genomes are transmitted preferentially by the mother, but molecular mechanisms and evolutionary forces underlying this fundamental biological principle are far from understood. It is believed that biparental inheritance promotes competition between the cytoplasmic organelles and allows the spread of so-called selfish cytoplasmic elements. Those can be, for example, fast-replicating or aggressive chloroplasts (plastids) that are incompatible with the hybrid nuclear genome and therefore maladaptive. Here we show that the ability of plastids to compete against each other is a metabolic phenotype determined by extremely rapidly evolving genes in the plastid genome of the evening primroseOenothera. Repeats in the regulatory region ofaccD(the plastid-encoded subunit of the acetyl-CoA carboxylase, which catalyzes the first and rate-limiting step of lipid biosynthesis), as well as inycf2(a giant reading frame of still unknown function), are responsible for the differences in competitive behavior of plastid genotypes. Polymorphisms in these genes influence lipid synthesis and most likely profiles of the plastid envelope membrane. These in turn determine plastid division and/or turnover rates and hence competitiveness. This work uncovers cytoplasmic drive loci controlling the outcome of biparental chloroplast transmission. Here, they define the mode of chloroplast inheritance, as plastid competitiveness can result in uniparental inheritance (through elimination of the “weak” plastid) or biparental inheritance (when two similarly “strong” plastids are transmitted).

scholarly journals Divergence in social traits in Trinidadian guppies selectively bred for high and low leadership in a cooperative context

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
S. Dimitriadou ◽  
D. P. Croft ◽  
S. K. Darden
Keyword(s):  
Poecilia Reticulata ◽  
Animal Species ◽  
Selective Breeding ◽  
Empirical Studies ◽  
Phenotypic Selection ◽  
Evolution Of Cooperation ◽  
Moderate Degree ◽  
Social Traits ◽  
Trinidadian Guppy ◽  
Selection For

AbstractIn many animal species, individuals with certain morphological, physiological, or behavioural traits may have a disproportionately large role in determining group behaviour. While most empirical studies of leadership have focused on behaviour of individuals exploring new environments or foraging, little is known about leading behaviour in other ecological contexts. Here, we use a selective breeding design in the Trinidadian guppy (Poecilia reticulata) to quantify the heritability of leadership in a cooperative context, and determine the behavioural traits associated with it. Firstly we found that phenotypic selection for high and low leadership (HL and LL, respectively) over three filial generations resulted in pronounced differences in leadership tendency with a moderate degree of heritability. In our assay of other social traits, LL males were more aggressive and sampled their social environment less than HL males, but HL and LL females did not differ in either aggressiveness or sociability. Traits such as boldness and exploratory tendency did not diverge between the two lines. Leading behaviour was thus associated with social traits in males, but not females; suggesting that there may be sex-specific mechanisms driving the emergence of leadership in this context. We discuss our findings in the context of the evolution of cooperation.

On the Use of Conventional Dough Extension Tests in Characterising Flours for Dough Sheetability. II. Simulations

2016 ◽  
Vol 12 (3) ◽  
pp. 231-245 ◽  
Author(s):  
Milan J. Patel ◽  
Sumana Chakrabarti-Bell
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Fe Simulation ◽  
Force Extension ◽  
Product Use ◽  
Sample Shape ◽  
Simulation Based ◽  
Shape Effects ◽  
Selection For

Abstract Dough extension tests are used in industry to rate flours for dough processability. The results impact flour selection for product use. Previously, it was shown that dough extension data correlated poorly with dough sheetability irrespective of whether doughs were tested fresh or rested. It was noted that sample shapes varied between specimens of flours. To understand how sample shape affects extensigraph tests, a finite element (FE) simulation-based approach was taken. Real extensigraph samples were drawn on a computer equipped with the commercial FE package ABAQUS and using the anisotropic Bergstrom Boyce model with Mullins damage (ABBM) constitutive model to describe the dough’s rheology. Results show that the force–extension traces were affected by sample shape, and that thinning occurs more from the sides than the bulk for slumped samples. The FE predictions for sample shape effects on hook force were validated against real tests. Similar dependencies on sample shape are also predicted for the alveograph and Kieffer micro-extensigraph tests.

scholarly journals Marker assisted selection for genetic improvement of animal populations when a single QTL is marked

1995 ◽  
Vol 66 (1) ◽  
pp. 71-83 ◽  
Author(s):  
J. Ruane ◽  
J. J. Colleau
Keyword(s):  
Marker Assisted Selection ◽  
Genetic Variance ◽  
Genetic Model ◽  
Polymorphic Markers ◽  
Linkage Phase ◽  
Monte Carlo Simulation Study ◽  
Animal Populations ◽  
Single Character ◽  
Selection For ◽  
Trait Locus

SummaryA Monte Carlo simulation study to evaluate the benefits of marker assisted selection (MAS) in small populations with one marked bi-allelic quantitative trait locus (QTL) is described. In the base generation, linkage phase equilibrium between the markers, QTL and polygenes was assumed and frequencies of 0·5 for the two QTL alleles were used. Six discrete generations of selection for a single character measured on both sexes followed. An additive genetic model was used with the QTL positioned midway between two highly polymorphic markers. Schemes were simulated with a distance of 10 cM between the QTL and either of the two markers and with the QTL explaining 1/8 of the total genetic variance in the base generation. Values of 0·5, 0·25 or 0·1 were assumed for the heritability. Eight males and 16, 32 or 64 females were selected each generation with each dam producing four sons and four daughters as candidates for the next generation. Animals were evaluated with a conventional BLUP animal model or with a model using marker information. MAS resulted in substantially higher QTL responses (4–54%), especially with low heritabilities, than conventional BLUP but lower polygenic responses (up to 4%) so that the overall effect on the total genetic response, although in the majority of cases favourable, was relatively small. With QTLs of larger size (explaining 25% of the genetic variance) comparable results were found. When the distance between the QTL and the markers was reduced to 2 cM, genetic responses were increased very slightly with a heritability of 0·5 whereas with a heritability of 0·1 responses were increased by up to 10%, compared with conventional BLUP. Results emphasize that MAS should be most useful for lowly heritable traits and that once QTLs for such traits have been identified the search for closely linked polymorphic markers should be intensified.

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