scholarly journals Evolutionary Implications of Mechanistic Models of TE-Mediated Hybrid Incompatibility

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Dean M. Castillo ◽  
Leonie C. Moyle
Keyword(s):  
Mechanistic Models ◽  
Hybrid Inviability ◽  
Hybrid Incompatibility ◽  
Mode Of Reproduction ◽  
Geographical Structure ◽  
New Models

New models of TE repression in plants (specifically Arabidopsis) have suggested specific mechanisms by which TE misregulation in hybrids might result in the expression of hybrid inviability. If true, these models suggest as yet undescribed consequences for (1) mechanistic connections between hybrid problems expressed at different postzygotic stages (e.g., inviability versus sterility), (2) the predicted strength, stage, and direction of isolation between diverging lineages that differ in TE activity, and (3) the association between species attributes that influence TE dynamics (e.g., mode of reproduction, geographical structure) and the rate at which they could accumulate incompatibilities. In this paper, we explore these implications and outline future empirical directions for generating data necessary to evaluate them.

scholarly journals Cytoplasmic-nuclear incompatibility between wild-isolates of Caenorhabditis nouraguensis

2016 ◽  
Author(s):  
Piero Lamelza ◽  
Michael Ailion
Keyword(s):  
Genetic Basis ◽  
Hybrid Sterility ◽  
Reproductive Barrier ◽  
Reproductive Barriers ◽  
Cytoplasmic Factor ◽  
Hybrid Inviability ◽  
Hybrid Incompatibility ◽  
Endosymbiotic Bacteria ◽  
Nuclear Locus ◽  
Shed Light

ABSTRACTHow species arise is a fundamental question in biology. Species can be defined as populations of interbreeding individuals that are reproductively isolated from other such populations. Therefore, understanding how reproductive barriers evolve between populations is essential for understanding the process of speciation. Hybrid incompatibility (e.g. hybrid sterility and lethality) is a common and strong reproductive barrier in nature, but few studies have molecularly identified its genetic basis. Here we report a lethal incompatibility between two wild-isolates of the nematode Caenorhabditis nouraguensis. Hybrid inviability results from the incompatibility between a maternally inherited cytoplasmic factor from each strain and a recessive nuclear locus from the other. We have excluded the possibility that maternally inherited endosymbiotic bacteria cause the incompatibility by treating both strains with tetracycline and show that hybrid death is unaffected. Furthermore, cytoplasmic-nuclear incompatibility commonly occurs between other wild-isolates, indicating that this is a significant reproductive barrier within C. nouraguensis. We hypothesize that the maternally inherited cytoplasmic factor is the mitochondrial genome and that mitochondrial dysfunction underlies hybrid death. This system has the potential to shed light on the dynamics of divergent mitochondrial-nuclear coevolution and its role in promoting speciation.

scholarly journals Mapping of Hybrid Incompatibility Loci in Nasonia

Genetics ◽  
1999 ◽  
Vol 153 (4) ◽  
pp. 1731-1741 ◽  
Author(s):  
Jürgen Gadau ◽  
Robert E Page ◽  
John H Werren
Keyword(s):  
Rapd Markers ◽  
Hybrid Breakdown ◽  
Hybrid Lethality ◽  
Hybrid Inviability ◽  
F1 Hybrid ◽  
Hybrid Incompatibility ◽  
Short Generation Time ◽  
Productive System ◽  
Zygotic Gene ◽  
Gene Complexes

Abstract According to theory, F2 hybrid breakdown (lethality or sterility) is due to incompatibilities between interacting genes of the different species (i.e., the breaking up of coadapted gene complexes). Detection of such incompatibilities is particularly straightforward in haplodiploid species, because virgin F1 hybrid females will produce haploid recombinant F2 males. This feature allows for screening of the complete genome for recessive genetic incompatibilities. Crosses were performed between Nasonia vitripennis (v) and its sibling species N. giraulti (g). First, a linkage map was produced using RAPD markers. RAPD markers showed an overall bias toward vitripennis alleles, a pattern not predicted by the basic two-interactor Dobzhansky-Muller model. Recovery patterns of visible markers were consistent with those of linked RAPD markers. If particular genetic interactions between two loci are causing hybrid lethality, then those genotypes should be underrepresented or absent among adult F2 males. Four sets of significant incompatibilities were detected by performing pairwise comparisons of markers on different chromosomes. Likely explanations for the observed patterns are maternal effect-zygotic gene incompatibilities or clustering of incompatibility loci. Due to the short generation time, advantages of haplodiploidy, and availability of markers, Nasonia promises to be a productive system for investigating the genetics of hybrid inviability.

Review of New models for mass communication research.

1975 ◽  
Vol 20 (5) ◽  
pp. 431-432
Author(s):  
ANTHONY G. GREENWALD
Keyword(s):  
Mass Communication ◽  
Communication Research ◽  
New Models

Educational Psychology Texts: Two New Models

1969 ◽  
Vol 14 (8) ◽  
pp. 421-423 ◽  
Author(s):  
W. ROBERT DIXON
Keyword(s):  
Educational Psychology ◽  
New Models

Anti-crisis measures or structural reforms: Russia’s economic policy in 2015

2016 ◽  
pp. 5-33 ◽  
Author(s):  
V. Mau
Keyword(s):  
Economic Growth ◽  
Economic Policy ◽  
Structural Transformation ◽  
Growth Model ◽  
Emerging Economies ◽  
Social Issues ◽  
Import Substitution ◽  
Structural Reforms ◽  
Energy Prices ◽  
New Models

The paper deals with 2015 trends and challenges for social and economic policy in the nearest future. The analysis of global crisis includes: uneven developments in the leading advanced and emerging economies; new models of economic growth which look differently in different countries; prospects of globalization and challenges of ‘regional globalization’; currency configurations of the future; energy prices dynamics and its influence on political and economic prospects of particular states. Current challenges are discussed in the context of previous 30 years. Among the main topics on Russia, there are approaches to a new growth model, structural transformation (including import substitution issues), economic dynamics, budget and monetary outlines, social issues. The priorities of economic policy are also considered.

Emerging patterns of artistic organizations in Portugal: A three case studies analysis

2020 ◽  
pp. 84-107
Author(s):  
Vera Borges ◽  
Luísa Veloso
Keyword(s):  
Labour Market ◽  
Economic Crisis ◽  
Performing Arts ◽  
Work Organization ◽  
The Arts ◽  
Emerging Patterns ◽  
New Models ◽  
Organizational Patterns ◽  
New Forms Of Work ◽  
Anal Yses

In the wake of the 2008 global financial and economic crisis, new forms of work organization emerged in Europe. Following this trend, Portugal has undergone a reconfiguration of its artistic organizations. In the performing arts, some organiza-tions seem to have crystalized and others are reinventing their artistic mission. They follow a plurality of organizational patterns and resilient profiles framed by cyclical, structural and occupational changes. Artistic organizations have had to adopt new models of work and seek new opportunities to try out alternatives in order to deal, namely, with the constraints of the labour market. The article anal-yses some of the restructuring processes taking place in three Portuguese artistic organizations, focusing on their contexts, individual trajectories and collective missions for adapting to contemporary challenges of work in the arts. We conclude that organizations are a key domain for understanding the changes taking place.

New models of breast and lung cancer bone metastases for preclinical efficacy testing

2016 ◽  
Author(s):  
Mari I. Suominen ◽  
Urs B. Hagemann ◽  
Yvonne Konkol ◽  
Jenni Bernoulli ◽  
Katja M. Fagerlund ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Bone Metastases ◽  
New Models ◽  
Preclinical Efficacy

New Algorithm for Modeling of Bronchial Trees

2012 ◽  
Vol 17 (4) ◽  
pp. 179-190
Author(s):  
Kacper Pluta ◽  
Marcin Janaszewski ◽  
Michał Postolski
Keyword(s):  
Quantitative Analysis ◽  
3D Model ◽  
Ct Images ◽  
Basic Algorithm ◽  
New Model ◽  
Comparison Of Results ◽  
Basic Model ◽  
New Models ◽  
Bronchial Tubes

Abstract The article presents new conception of 3D model of human bronchial tubes, which represents bronchial tubes extracted from CT images of the chest. The new algorithm which generates new model is an extension of the algorithm (basic algorithm) proposed by Hiroko Kitaoka, Ryuji Takaki and Bela Suki. The basic model has been extended by geometric deformations of branches and noise which occur in bronchial trees extracted from CT images. The article presents comparison of results obtained with the use of the new algorithm and the basic one. Moreover, the discussion of usefulness of generated new models for testing of algorithms for quantitative analysis of bronchial tubes based on CT images is also included.

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