scholarly journals The role of APETALA1 in petal number robustness

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Marie Monniaux ◽  
Bjorn Pieper ◽  
Sarah M McKim ◽  
Anne-Lise Routier-Kierzkowska ◽  
Daniel Kierzkowski ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Genetic Variation ◽  
Reproductive Success ◽  
Genetic Basis ◽  
Phenotypic Expression ◽  
Specific Difference ◽  
Closely Related Species ◽  
Epistatic Interactions ◽  
Species Specific

Invariant floral forms are important for reproductive success and robust to natural perturbations. Petal number, for example, is invariant in Arabidopsis thaliana flowers. However, petal number varies in the closely related species Cardamine hirsuta, and the genetic basis for this difference between species is unknown. Here we show that divergence in the pleiotropic floral regulator APETALA1 (AP1) can account for the species-specific difference in petal number robustness. This large effect of AP1 is explained by epistatic interactions: A. thaliana AP1 confers robustness by masking the phenotypic expression of quantitative trait loci controlling petal number in C. hirsuta. We show that C. hirsuta AP1 fails to complement this function of A. thaliana AP1, conferring variable petal number, and that upstream regulatory regions of AP1 contribute to this divergence. Moreover, variable petal number is maintained in C. hirsuta despite sufficient standing genetic variation in natural accessions to produce plants with four-petalled flowers.

scholarly journals Sex aggregation and species segregation cues in swarming mosquitoes: role of ground visual markers

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Serge B. Poda ◽  
Charles Nignan ◽  
Olivier Gnankiné ◽  
Roch K. Dabiré ◽  
Abdoulaye Diabaté ◽  
...  
Keyword(s):  
Experimental Conditions ◽  
Closely Related Species ◽  
Laboratory Setup ◽  
Visual Markers ◽  
Constant Distance ◽  
Species Specific ◽  
Marker Size ◽  
Swarm Size ◽  
Species Segregation

Abstract Background Mating swarm segregation in closely related insect species may contribute to reproductive isolation. Visual markers are used for swarm formation; however, it is unknown whether they play a key role in swarm location, species segregation and sex aggregation. Methods Using two sympatric closely related species of the Anopheles gambiae complex, An. coluzzii and An. gambiae (s.s.), we investigated in both laboratory and semi-field conditions (i) whether males of the two species use visual markers (black cloths) to locate their swarm; and (ii) whether the presence/absence and size of the marker may differentially affect swarm characteristics. We also investigated whether conspecific virgin females use these markers to join male swarm sites. Results We showed that males of the two species used visual markers but in different ways: An. coluzzii swarm right above the marker whereas An. gambiae (s.s.) locate their swarm at a constant distance of 76.4 ± 0.6 cm from a 20 × 20 cm marker in the laboratory setup and at 206 ± 6 cm from a 60 × 60 cm marker in the semi-field setup. Although increased marker size recruited more mosquitoes and consequently increased the swarm size in the two species, An. coluzzii swarms flew higher and were stretched both vertically and horizontally, while An. gambiae (s.s.) swarms were only stretched horizontally. Virgin females displayed a swarm-like behavior with similar characteristics to their conspecific males. Conclusions Our results provided experimental evidence that both An. coluzzii and An. gambiae (s.s.) males use ground visual markers to form and locate their swarm at species-specific locations. Moreover, the marker size differentially affected swarm characteristics in the two species. Our results also showed that virgin females displayed a swarm-like behavior. However, these “swarms” could be due to the absence of males in our experimental conditions. Nevertheless, the fact that females displayed these “swarms” with the same characteristics as their respective males provided evidence that visual markers are used by the two sexes to join mating spots. Altogether, this suggests that visual markers and the way species and sexes use them could be key cues in species segregation, swarm location and recognition.

Very Low Fruit : Flower Ratios in Grevillea (Proteaceae) are Independent of Breeding System

1998 ◽  
Vol 46 (4) ◽  
pp. 465 ◽  
Author(s):  
Luise Hermanutz ◽  
David Innes ◽  
Andrew Denham ◽  
Robert Whelan
Keyword(s):  
Fruit Set ◽  
Pollen Limitation ◽  
Breeding Systems ◽  
Mature Fruit ◽  
Closely Related Species ◽  
Woody Perennials ◽  
The Family ◽  
Self Compatibility ◽  
Species Specific

Members of the family Proteaceae have extremely low mature fruit : flower (FR : FL) ratios (range 0.001–0.163) compared with other temperate, hermaphroditic, woody perennials. Sutherland’s (1986) survey of FR : FL ratios indicated that compatibility was an important factor explaining levels of fruit set. The role of compatibility in regulating FR : FL ratios was tested in five closely related species of Grevillea (Proteaceae). Species-specific compatibility was compared using the self-compatibility index (SI = ratio of selfed fruit set to crossed fruit set) calculated at fruit initiation to minimise the confounding effect of other post-fertilisation fruit losses, such as inbreeding depression and pre-dispersal predation. Fruit : flower ratios at initiation ranged from 0.041–0.249, and at maturity 0.015–0.096. Grevillea species showed highly variable breeding systems: G. linearifolia was self-incompatible (SI = 0.003), G. sphacelata, G. mucronulata, and G. oleoides were partially self-compatible (SI = 0.07–0.28) and G. longifolia was self-compatible (SI = 0.61). Intrapopulation variability in the level of self-incompatibility was high in all species but G. linearifolia. The correlation between SI and FR: FL ratios was non-significant, indicating that compatibility has a minimal effect on fruit set in the Grevillea species studied, and that these data, together with other data on proteaceous species do not support trends observed in Sutherland’s survey. Low FR : FL ratios resulted from of a combination of pollen limitation, and high levels of flower and fruit predation.

scholarly journals Bovine tuberculosis: the genetic basis of host susceptibility

2010 ◽  
Vol 277 (1695) ◽  
pp. 2737-2745 ◽  
Author(s):  
A. R. Allen ◽  
G. Minozzi ◽  
E. J. Glass ◽  
R. A. Skuce ◽  
S. W. J. McDowell ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Bovine Tuberculosis ◽  
Genetic Basis ◽  
Host Susceptibility ◽  
Host Genotype ◽  
Future Studies ◽  
Badger Culling ◽  
Agricultural Industries ◽  
The Uk

The prevalence of bovine tuberculosis (BTB) in the UK remains a significant economic burden and problem for the agri-food industry. Much effort has been directed towards improving diagnostics, finding vaccine candidates and assessing the usefulness of badger culling. The contribution that host genotype makes to disease outcome has, until recently, been overlooked; yet, it is biologically untenable that genetic variation does not play a role. In this review, we highlight the evidence, past and present, for a role of host genetics in determining susceptibility to BTB in livestock. We then address some of the major issues surrounding the design of future studies tasked with finding the exact causative genetic variation underpinning the TB susceptibility phenotype. Finally, we discuss some of the potential future benefits, and problems, that a knowledge of the genetic component to BTB resistance/susceptibility may bring to the agricultural industries and the wider scientific community.

scholarly journals Floral pathway integrator gene expression mediates gradual transmission of environmental and endogenous cues to flowering time

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3197 ◽  
Author(s):  
Aalt D.J. van Dijk ◽  
Jaap Molenaar
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Genetic Variation ◽  
Reproductive Success ◽  
Environmental Factors ◽  
Flowering Time ◽  
Genetic Networks ◽  
Expression Levels ◽  
Quantitative Level ◽  
The Impact

The appropriate timing of flowering is crucial for the reproductive success of plants. Hence, intricate genetic networks integrate various environmental and endogenous cues such as temperature or hormonal statues. These signals integrate into a network of floral pathway integrator genes. At a quantitative level, it is currently unclear how the impact of genetic variation in signaling pathways on flowering time is mediated by floral pathway integrator genes. Here, using datasets available from literature, we connect Arabidopsis thaliana flowering time in genetic backgrounds varying in upstream signalling components with the expression levels of floral pathway integrator genes in these genetic backgrounds. Our modelling results indicate that flowering time depends in a quite linear way on expression levels of floral pathway integrator genes. This gradual, proportional response of flowering time to upstream changes enables a gradual adaptation to changing environmental factors such as temperature and light.

scholarly journals Floral pathway integrator gene expression mediates gradual transmission of environmental and endogenous cues to flowering time

2017 ◽  
Author(s):  
Aalt D.J. van Dijk ◽  
Jaap Molenaar
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Genetic Variation ◽  
Reproductive Success ◽  
Environmental Factors ◽  
Flowering Time ◽  
Genetic Networks ◽  
Expression Levels ◽  
Quantitative Level ◽  
The Impact

The appropriate timing of flowering is crucial for the reproductive success of plants. Hence, intricate genetic networks integrate various environmental and endogenous cues such as temperature or hormonal statues. These signals integrate into a network of floral pathway integrator genes. At a quantitative level, it is currently unclear how the impact of genetic variation in signaling pathways on flowering time is mediated by floral pathway integrator genes. Here, using datasets available from literature, we connect Arabidopsis thaliana flowering time in genetic backgrounds varying in upstream signalling components with the expression levels of floral pathway integrator genes in these genetic backgrounds. Our modelling results indicate that flowering time depends in a quite linear way on expression levels of floral pathway integrator genes. This gradual, proportional response of flowering time to upstream changes enables a gradual adaptation to changing environmental factors such as temperature and light.

Comparative seascape genetics of co-distributed intertidal snails Monodonta spp. in the Japanese and Ryukyu archipelagoes

2021 ◽  
Vol 657 ◽  
pp. 135-146
Author(s):  
D Yamazaki ◽  
O Miura ◽  
S Uchida ◽  
M Ikeda ◽  
S Chiba
Keyword(s):  
Genetic Variation ◽  
Ecological Factors ◽  
Ecological Studies ◽  
Ecological Traits ◽  
Habitat Specificity ◽  
Closely Related Species ◽  
Powerful Approach ◽  
Intertidal Snail ◽  
Seascape Genetics

Recent molecular ecological studies have focused on how the relationships between physical and ecological factors influence marine biogeography. Comparative phylogeography using closely related species is a powerful approach to evaluate the role of ecological traits in the genetic variation of marine organisms. In the present study, we compared ecological traits and genetic variation in 3 species of the intertidal snail genus Monodonta that co-occur in the Japanese and Ryukyu archipelagoes. We found that M. labio was dominant in sheltered habitats and M. perplexa was dominant in wave-exposed habitats, while M. confusa showed no habitat specificity. This indicates that M. labio and M. perplexa are habitat specialists regarding wave exposure, while M. confusa is a generalist. M. labio and M. perplexa showed lower genetic diversity and greater genetic differentiation among populations than M. confusa. Our findings support the specialist-generalist variation hypothesis in a well-connected marine environment.

scholarly journals Interactions between cytoplasmic and nuclear genomes confer sex-specific effects on lifespan in Drosophila melanogaster

2019 ◽  
Author(s):  
Rebecca C. Vaught ◽  
Susanne Voigt ◽  
Ralph Dobler ◽  
David J. Clancy ◽  
Klaus Reinhardt ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Large Body ◽  
Phenotypic Expression ◽  
Epistatic Interactions ◽  
Relative Contribution ◽  
Specific Effects ◽  
Nuclear Interactions ◽  
Sources Of Variation ◽  
Mitochondrial Sequences

ABSTRACTA large body of studies has demonstrated that genetic variation that resides outside of the cell nucleus can affect the organismal phenotype. The cytoplasm is home to the mitochondrial genome and, at least in arthropods, often hosts intracellular endosymbiotic bacteria such as Wolbachia. While numerous studies have implicated epistatic interactions between cytoplasmic and nuclear genetic variation as key to mediating patterns of phenotypic expression, two outstanding questions remain. Firstly, the relative contribution of mitochondrial genetic variation to other cytoplasmic sources of variation in shaping the phenotypic outcomes of cyto-nuclear interactions remains unknown. Secondly, it remains unclear whether the outcomes of cyto-nuclear interactions will manifest differently across the two sexes, as might be predicted given that cytoplasmic genomes are screened by natural selection only through females as a consequence of their maternal inheritance. Here, we address these questions, creating a fully-crossed set of replicated cyto-nuclear populations derived from three geographically distinct populations of Drosophila melanogaster, and measuring the lifespan of males and females from each population. We report cyto-nuclear interactions for lifespan, with the outcomes of these interactions differing across the sexes, and reconcile these findings with information on the full mitochondrial sequences and Wolbachia infection status of each of the populations.

scholarly journals Quantitative Trait Loci for Floral Morphology in Arabidopsis thaliana

Genetics ◽  
2000 ◽  
Vol 156 (3) ◽  
pp. 1379-1392 ◽  
Author(s):  
Thomas Juenger ◽  
Michael Purugganan ◽  
Trudy F C Mackay
Keyword(s):  
Arabidopsis Thaliana ◽  
Genetic Variation ◽  
Qtl Mapping ◽  
Candidate Genes ◽  
Inbred Line ◽  
Recombinant Inbred Line Population ◽  
Quantitative Trait ◽  
Recombinant Inbred ◽  
Genetic Basis ◽  
Genome Wide

Abstract A central question in biology is how genes control the expression of quantitative variation. We used statistical methods to estimate genetic variation in eight Arabidopsis thaliana floral characters (fresh flower mass, petal length, petal width, sepal length, sepal width, long stamen length, short stamen length, and pistil length) in a cosmopolitan sample of 15 ecotypes. In addition, we used genome-wide quantitative trait locus (QTL) mapping to evaluate the genetic basis of variation in these same traits in the Landsberg erecta × Columbia recombinant inbred line population. There was significant genetic variation for all traits in both the sample of naturally occurring ecotypes and in the Ler × Col recombinant inbred line population. In addition, broad-sense genetic correlations among the traits were positive and high. A composite interval mapping (CIM) analysis detected 18 significant QTL affecting at least one floral character. Eleven QTL were associated with several floral traits, supporting either pleiotropy or tight linkage as major determinants of flower morphological integration. We propose several candidate genes that may underlie these QTL on the basis of positional information and functional arguments. Genome-wide QTL mapping is a promising tool for the discovery of candidate genes controlling morphological development, the detection of novel phenotypic effects for known genes, and in generating a more complete understanding of the genetic basis of floral development.

scholarly journals FOXL2 activates P450 aromatase gene transcription: towards a better characterization of the early steps of mammalian ovarian development

2006 ◽  
Vol 36 (3) ◽  
pp. 399-413 ◽  
Author(s):  
Maëlle Pannetier ◽  
Stéphane Fabre ◽  
Frank Batista ◽  
Ayhan Kocer ◽  
Lauriane Renault ◽  
...  
Keyword(s):  
Ovarian Development ◽  
Expression Profiles ◽  
Differentiation Process ◽  
Vertebrate Species ◽  
Germinal Cell ◽  
Specific Difference ◽  
Strong Candidate ◽  
Species Specific

Previous studies have equated FOXL2 as a crucial actor in the ovarian differentiation process in different vertebrate species. Its transcriptional extinction in the polled intersex syndrome (PIS) leads primarily to a drastic decrease of aromatase (CYP19) expression in the first steps of goat ovarian development. In this study, we provide a better characterization of early ovarian development in goat, and we provide experimental evidence demonstrating that FOXL2 represents a direct transcriptional activator of the CYP19 gene through its ovarian-specific promoter 2. Moreover, the ovarian location of FOXL2 and CYP19 proteins, together with their expression profiles in the female gonads, stress the involvement of FOXL2 co-factor(s) for regulating CYP19 transcription. Expressional analyses show that activin-βA can be considered as a strong candidate for being one of these FOXL2 co-factors. Finally, we discuss evidence for a role of activin and estrogens in somatic and germinal cell proliferation occurring before germ cell meiosis. This period, of 20 days in goat, seems to have no equivalent in mouse. This species-specific difference could explain the phenotype discrepancy observed between XX goat PIS−/− and XX mouse Foxl2−/−.

scholarly journals Floral pathway integrator gene expression mediates gradual transmission of environmental and endogenous cues to flowering time

2017 ◽  
Author(s):  
Aalt D.J. van Dijk ◽  
Jaap Molenaar
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Genetic Variation ◽  
Reproductive Success ◽  
Environmental Factors ◽  
Flowering Time ◽  
Genetic Networks ◽  
Expression Levels ◽  
Quantitative Level ◽  
The Impact

The appropriate timing of flowering is crucial for the reproductive success of plants. Hence, intricate genetic networks integrate various environmental and endogenous cues such as temperature or hormonal statues. These signals integrate into a network of floral pathway integrator genes. At a quantitative level, it is currently unclear how the impact of genetic variation in signaling pathways on flowering time is mediated by floral pathway integrator genes. Here, using datasets available from literature, we connect Arabidopsis thaliana flowering time in genetic backgrounds varying in upstream signalling components with the expression levels of floral pathway integrator genes in these genetic backgrounds. Our modelling results indicate that flowering time depends in a quite linear way on expression levels of floral pathway integrator genes. This gradual, proportional response of flowering time to upstream changes enables a gradual adaptation to changing environmental factors such as temperature and light.

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