scholarly journals Differential Adaptation to a Harsh Granite Outcrop Habitat between Sympatric Mimulus Species

2016 ◽  
Author(s):  
Kathleen G. Ferris ◽  
John H. Willis
Keyword(s):  
Flowering Time ◽  
Evolutionary Biology ◽  
Leaf Shape ◽  
Plant Size ◽  
Seasonally Dry ◽  
Granite Outcrops ◽  
Differential Adaptation ◽  
Selective Forces ◽  
Survival Differences ◽  
Lobed Leaf

ABSTRACTA primary goal in evolutionary biology is to understand which environmental variables and traits drive adaptation to harsh environments. This is difficult since many traits evolve simultaneously as populations or species diverge. Here we investigate the ecological variables and traits that underlie Mimulus laciniatus’ adaptation to granite outcrops compared to its sympatric, mesic-adapted progenitor M. guttatus. We use fine scale measurements of soil moisture and herbivory to examine differences in selective forces between the species’ habitats, and measure selection on flowering time, flower size, plant height, and leaf shape in a reciprocal transplant using M. laciniatus x M. guttatus F4 hybrids. We find that differences in drought & herbivory drive survival differences between habitats, that M. laciniatus and M. guttatus are each better adapted to their native habitat, and differential habitat selection on flowering time, plant stature, and leaf shape. We conclude that while early flowering time, small stature, and lobed leaf shape underlie plant fitness in M. laciniatus’ seasonally dry environment, increased plant size is advantageous in a competitive mesic environment replete with herbivores like M. guttatus’.

scholarly journals Impact of transition to a subterranean lifestyle on morphological disparity and integration in talpid moles (Mammalia, Talpidae)

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Gabriele Sansalone ◽  
Paolo Colangelo ◽  
Anna Loy ◽  
Pasquale Raia ◽  
Stephen Wroe ◽  
...  
Keyword(s):  
Evolutionary Biology ◽  
Morphological Variability ◽  
Phenotypic Integration ◽  
Phenotypic Traits ◽  
Phenotypic Evolution ◽  
Morphological Disparity ◽  
Morphological Diversification ◽  
Phylogenetic Conservatism ◽  
Selective Forces ◽  
Subterranean Species

Abstract Background Understanding the mechanisms promoting or constraining morphological diversification within clades is a central topic in evolutionary biology. Ecological transitions are of particular interest because of their influence upon the selective forces and factors involved in phenotypic evolution. Here we focused on the humerus and mandibles of talpid moles to test whether the transition to the subterranean lifestyle impacted morphological disparity and phenotypic traits covariation between these two structures. Results Our results indicate non-subterranean species occupy a significantly larger portion of the talpid moles morphospace. However, there is no difference between subterranean and non-subterranean moles in terms of the strength and direction of phenotypic integration. Conclusions Our study shows that the transition to a subterranean lifestyle significantly reduced morphological variability in talpid moles. However, this reduced disparity was not accompanied by changes in the pattern of traits covariation between the humerus and the mandible, suggesting the presence of strong phylogenetic conservatism within this pattern.

scholarly journals Modifications to a LATE MERISTEM IDENTITY1 gene are responsible for the major leaf shapes of Upland cotton (Gossypium hirsutum L.)

2016 ◽  
Vol 114 (1) ◽  
pp. E57-E66 ◽  
Author(s):  
Ryan J. Andres ◽  
Viktoriya Coneva ◽  
Margaret H. Frank ◽  
John R. Tuttle ◽  
Luis Fernando Samayoa ◽  
...  
Keyword(s):  
Genetic Basis ◽  
Leaf Shape ◽  
Primary Source ◽  
Tetraploid Cotton ◽  
Virus Induced Gene Silencing ◽  
Unique Role ◽  
Leaf Formation ◽  
Elevated Expression ◽  
Transcriptomic Signature ◽  
Lobed Leaf

Leaf shape varies spectacularly among plants. Leaves are the primary source of photoassimilate in crop plants, and understanding the genetic basis of variation in leaf morphology is critical to improving agricultural productivity. Leaf shape played a unique role in cotton improvement, as breeders have selected for entire and lobed leaf morphs resulting from a single locus, okra (l-D1), which is responsible for the major leaf shapes in cotton. The l-D1 locus is not only of agricultural importance in cotton, but through pioneering chimeric and morphometric studies, it has contributed to fundamental knowledge about leaf development. Here we show that an HD-Zip transcription factor homologous to the LATE MERISTEM IDENTITY1 (LMI1) gene of Arabidopsis is the causal gene underlying the l-D1 locus. The classical okra leaf shape allele has a 133-bp tandem duplication in the promoter, correlated with elevated expression, whereas an 8-bp deletion in the third exon of the presumed wild-type normal allele causes a frame-shifted and truncated coding sequence. Our results indicate that subokra is the ancestral leaf shape of tetraploid cotton that gave rise to the okra allele and that normal is a derived mutant allele that came to predominate and define the leaf shape of cultivated cotton. Virus-induced gene silencing (VIGS) of the LMI1-like gene in an okra variety was sufficient to induce normal leaf formation. The developmental changes in leaves conferred by this gene are associated with a photosynthetic transcriptomic signature, substantiating its use by breeders to produce a superior cotton ideotype.

Alteration in flowering time causes accelerated or decelerated progression through Arabidopsis vegetative phases

2001 ◽  
Vol 79 (6) ◽  
pp. 657-665 ◽  
Author(s):  
Quintin J Steynen ◽  
Dee A Bolokoski ◽  
Elizabeth A Schultz
Keyword(s):  
Arabidopsis Thaliana ◽  
Flowering Time ◽  
Leaf Shape ◽  
Central Mechanism ◽  
Second Phase ◽  
Wild Type ◽  
Low Light ◽  
Terminal Flower ◽  
Vegetative Phases ◽  
Short Days

We have identified three phases within the wild-type Arabidopsis thaliana (L.) Heynh. rosette, based on significant differences in leaf shape, size, vascular pattern, and presence of abaxial trichomes. To test the hypothesis that a single, central mechanism controls the progression through all plant phases and that conditions that alter the time to flowering will also alter the progression through vegetative phases, we analysed the rosette phases under such conditions. In support of our hypothesis, we determined that those conditions (loss of LEAFY activity, short days) that decelerate time to flowering show decelerated progression through the rosette phases, while those conditions (loss of TERMINAL FLOWER, overexpression of LEAFY, low light) that accelerate time to flowering show accelerated progression through the rosette phases. In all conditions except short days, the length of the first phase was unaffected, indicating that this phase is less susceptible to influences of the central mechanism. Progression through the subsequent two rosette phases was accelerated differentially, such that the second phase was affected more strongly than the first. This supports the idea that, in the rosette, as in the inflorescence, the inhibition of phase transition by the central mechanism is gradually decreasing.Key words: phase change, flowering time, Arabidopsis thaliana, LEAFY, TERMINAL FLOWER, heteroblasty.

scholarly journals Identification of an ant queen pheromone regulating worker sterility

2010 ◽  
Vol 277 (1701) ◽  
pp. 3793-3800 ◽  
Author(s):  
Luke Holman ◽  
Charlotte G. Jørgensen ◽  
John Nielsen ◽  
Patrizia d'Ettorre
Keyword(s):  
Evolutionary Biology ◽  
Cuticular Hydrocarbon ◽  
Division Of Labour ◽  
Queen Pheromone ◽  
Lasius Niger ◽  
Strong Response ◽  
Selective Forces ◽  
The Right ◽  
Worker Sterility ◽  
Reproductive Division

The selective forces that shape and maintain eusocial societies are an enduring puzzle in evolutionary biology. Ordinarily sterile workers can usually reproduce given the right conditions, so the factors regulating reproductive division of labour may provide insight into why eusociality has persisted over evolutionary time. Queen-produced pheromones that affect worker reproduction have been implicated in diverse taxa, including ants, termites, wasps and possibly mole rats, but to date have only been definitively identified in the honeybee. Using the black garden ant Lasius niger , we isolate the first sterility-regulating ant queen pheromone. The pheromone is a cuticular hydrocarbon that comprises the majority of the chemical profile of queens and their eggs, and also affects worker behaviour, by reducing aggression towards objects bearing the pheromone. We further show that the pheromone elicits a strong response in worker antennae and that its production by queens is selectively reduced following an immune challenge. These results suggest that the pheromone has a central role in colony organization and support the hypothesis that worker sterility represents altruistic self-restraint in response to an honest quality signal.

scholarly journals Genomic analysis reveals major determinants of cis-regulatory variation in Capsella grandiflora

2015 ◽  
Author(s):  
Kim A. Steige ◽  
Benjamin Laenen ◽  
Johan Reimegård ◽  
Douglas Scofield ◽  
Tanja Slotte
Keyword(s):  
Evolutionary Biology ◽  
Genomic Analysis ◽  
Purifying Selection ◽  
Gene Body ◽  
Gene Body Methylation ◽  
Specific Expression ◽  
Regulatory Variation ◽  
Wide Range ◽  
Allele Specific ◽  
Selective Forces

Understanding the causes of cis-regulatory variation is a long-standing aim in evolutionary biology. Although cis-regulatory variation has long been considered important for adaptation, we still have a limited understanding of the selective importance and genomic determinants of standing cis-regulatory variation. To address these questions, we studied the prevalence, genomic determinants and selective forces shaping cis-regulatory variation in the outcrossing plant Capsella grandiflora. We first identified a set of 1,010 genes with common cis-regulatory variation using analyses of allele-specific expression (ASE). Population genomic analyses of whole-genome sequences from 32 individuals showed that genes with common cis-regulatory variation are 1) under weaker purifying selection and 2) undergo less frequent positive selection than other genes. We further identified genomic determinants of cis-regulatory variation. Gene-body methylation (gbM) was a major factor constraining cis-regulatory variation, whereas presence of nearby TEs and tissue specificity of expression increased the odds of ASE. Our results suggest that most common cis-regulatory variation in C. grandiflora is under weak purifying selection, and that gene-specific functional constraints are more important for the maintenance of cis-regulatory variation than genome-scale variation in the intensity of selection. Our results agree with previous findings that suggest TE silencing affects nearby gene expression, and provide novel evidence for a link between gbM and cis-regulatory constraint, possibly reflecting greater dosage-sensitivity of body-methylated genes. Given the extensive conservation of gene-body methylation in flowering plants, this suggests that gene-body methylation could be an important predictor of cis-regulatory variation in a wide range of plant species.

scholarly journals In the presence of population structure: From genomics to candidate genes underlying local adaptation

2019 ◽  
Author(s):  
Nicholas Price ◽  
Lua Lopez ◽  
Adrian E. Platts ◽  
Jesse R. Lasky ◽  
John K. McKay
Keyword(s):  
Population Structure ◽  
Flowering Time ◽  
Local Adaptation ◽  
Evolutionary Biology ◽  
Indirect Evidence ◽  
Mixed Linear Model ◽  
Functional Constraint ◽  
Heterogeneous Environments ◽  
Functional Sites ◽  
And Function

AbstractUnderstanding the genomic signatures, genes, and traits underlying local adaptation of organisms to heterogeneous environments is of central importance to the field evolutionary biology. Mixed linear mrsodels that identify allele associations to environment, while controlling for genome-wide variation at other loci, have emerged as the method of choice when studying local adaptation. Despite their importance, it is unclear whether this approach performs better than identifying environmentally-associated SNPs without accounting for population structure. To examine this, we first use the mixed linear model GEMMA, and simple Spearman correlations, to identify SNPs showing significant associations to climate with and without accounting for population structure. Subsequently, using Italy and Sweden populations, we compare evidence of allele frequency differentiation (FST), linkage disequilibrium (LD), fitness variation, and functional constraint, underlying these SNPs. Using a lenient cut-off for significance, we find that SNPs identified by both approaches, and SNPs uniquely identified by Spearman correlations, were enriched at sites showing genomic evidence of local adaptation and function but were limited across Quantitative Trait Loci (QTL) explaining fitness variation. SNPs uniquely identified by GEMMA, showed no direct or indirect evidence of local adaptation, and no enrichment along putative functional sites. Finally, SNPs that showed significantly high FST and LD, were enriched along fitness QTL peaks and cis-regulatory/nonsynonymous sites showing significant functional constraint. Using these SNPs, we identify genes underlying fitness QTL, and genes linking flowering time to local adaptation. These include a regulator of abscisic-acid (FLDH) and flowering time genes PIF3, FIO1, and COL5.

scholarly journals Map-based cloning and promoter variation analysis of the lobed leaf gene BoLMI1a in ornamental kale (Brassica oleracea L. var. acephala)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Bin Zhang ◽  
Wendi Chen ◽  
Xing Li ◽  
Wenjing Ren ◽  
Li Chen ◽  
...  
Keyword(s):  
Brassica Oleracea ◽  
Promoter Region ◽  
Leaf Shape ◽  
Dominant Gene ◽  
Orthologous Gene ◽  
Snp Markers ◽  
Leaf Trait ◽  
Shape Formation ◽  
Ornamental Kale ◽  
Lobed Leaf

Abstract Background Leaf shape is an important agronomic trait in ornamental kale (Brassica oleracea L. var. acephala). Although some leaf shape-related genes have been reported in ornamental kale, the detailed mechanism underlying leaf shape formation is still unclear. Here, we report a lobed-leaf trait in ornamental kale, aiming to analyze its inheritance and identify the strong candidate gene. Results Genetic analysis of F2 and BC1 populations demonstrate that the lobed-leaf trait in ornamental kale is controlled by a single dominant gene, termed BoLl-1 (Brassica oleracea lobed-leaf). By performing whole-genome resequencing and linkage analyses, the BoLl-1 gene was finely mapped to a 127-kb interval on chromosome C09 flanked by SNP markers SL4 and SL6, with genetic distances of 0.6 cM and 0.6 cM, respectively. Based on annotations of the genes within this interval, Bo9g181710, an orthologous gene of LATE MERISTEM IDENTITY 1 (LMI1) in Arabidopsis, was predicted as the candidate for BoLl-1, and was renamed BoLMI1a. The expression level of BoLMI1a in lobed-leaf parent 18Q2513 was significantly higher compared with unlobed-leaf parent 18Q2515. Sequence analysis of the parental alleles revealed no sequence variations in the coding sequence of BoLMI1a, whereas a 1737-bp deletion, a 92-bp insertion and an SNP were identified within the BoLMI1a promoter region of parent 18Q2513. Verification analyses with BoLMI1a-specific markers corresponding to the promoter variations revealed that the variations were present only in the lobed-leaf ornamental kale inbred lines. Conclusions This study identified a lobed-leaf gene BoLMI1a, which was fine-mapped to a 127-kb fragment. Three variations were identified in the promoter region of BoLMI1a. The transcription level of BoLMI1a between the two parents exhibited great difference, providing new insight into the molecular mechanism underlying leaf shape formation in ornamental kale.

Modern synthesis, the

2018 ◽  
Author(s):  
Anya Plutynski
Keyword(s):  
Population Genetics ◽  
Cell Biology ◽  
Evolutionary Biology ◽  
Modern Synthesis ◽  
Science Theory ◽  
Genotype Frequencies ◽  
Hereditary Variation ◽  
Long Time ◽  
Selective Forces ◽  
Synthetic View

Huxley coined the phrase, the ‘modern synthesis’ to refer to the acceptance by a vast majority of biologists in the mid-twentieth century of a ‘synthetic’ view of evolution. According to its main chroniclers, Mayr and Provine, the ‘synthesis’ consisted in the acceptance of natural selection acting on minor hereditary variation as the primary cause of both adaptive change within populations and major changes, such as speciation, and the evolution of higher taxa (e.g. families and genera). However, the dating and substance of the synthesis is controversial. The evolutionary synthesis may be broken down into two periods, the ‘early’ synthesis from 1918 to 1932, and the later, ‘modern synthesis’ from 1936 to 1947. The authors most commonly associated with the early synthesis are J. B. S. Haldane, R. A. Fisher, and S. Wright. These three authored a number of important advances; first, they demonstrated the compatibility of a Mendelian theory of inheritance with the results of Biometry, a study of the correlations of measures of traits between relatives. Second, they developed the theoretical framework for evolutionary biology, classical population genetics. This is a family of mathematical models representing evolution as change in genotype frequencies, from one generation to the next, as a product of selection, mutation, migration, and drift, or chance. Third, there was a broader synthesis of population genetics with cytology (cell biology), genetics, and biochemistry, as well as both empirical and mathematical demonstrations to the effect that very small selective forces acting over a relatively long time were able to generate substantial evolutionary change. The later ‘modern’ synthesis is most often identified with the work of Mayr, Dobzhansky and Simpson. There was a major institutional change in biology at this stage, insofar as different subdisciplines formerly housed in different departments, and using different methods, were united under the institutional umbrella of ‘evolutionary biology’. Mayr played an important role as a community architect, in founding the Society for the Study of Evolution, and the journal Evolution, which drew together work in systematics, biogeography, paleontology, and theoretical population genetics. The synthesis presents an occasion for addressing a number of important philosophical questions about the nature of theories, explanation, progress in science, theory unification, and reduction.

The early-flowering mutant efs is involved in the autonomous promotion pathway of Arabidopsis thaliana

Development ◽  
1999 ◽  
Vol 126 (21) ◽  
pp. 4763-4770 ◽  
Author(s):  
W.J. Soppe ◽  
L. Bentsink ◽  
M. Koornneef
Keyword(s):  
Arabidopsis Thaliana ◽  
Flowering Time ◽  
Double Mutant ◽  
Plant Size ◽  
Early Flowering ◽  
Wild Type ◽  
Late Flowering ◽  
Long Day ◽  
Short Days ◽  
Transition To Flowering

The transition to flowering is a crucial moment in a plant's life cycle of which the mechanism has only been partly revealed. In a screen for early flowering, after mutagenesis of the late-flowering fwa mutant of Arabidopsis thaliana, the early flowering in short days (efs) mutant was identified. Under long-day light conditions, the recessive monogenic efs mutant flowers at the same time as wild type but, under short-day conditions, the mutant flowers much earlier. In addition to its early-flowering phenotype, efs has several pleiotropic effects such as a reduction in plant size, fertility and apical dominance. Double mutant analysis with several late-flowering mutants from the autonomous promotion (fca and fve) and the photoperiod promotion (co, fwa and gi) pathways of flowering showed that efs reduces the flowering time of all these mutants. However, efs is completely epistatic to fca and fve but additive to co, fwa and gi, indicating that EFS is an inhibitor of flowering specifically involved in the autonomous promotion pathway. A vernalisation treatment does not further reduce the flowering time of the efs mutant, suggesting that vernalisation promotes flowering through EFS. By comparing the length of the juvenile and adult phases of vegetative growth for wild-type, efs and the double mutant plants, it is apparent that efs mainly reduces the length of the adult phase.

scholarly journals The evolution of non-reproductive workers in insect colonies with haplodiploid genetics

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Jason W Olejarz ◽  
Benjamin Allen ◽  
Carl Veller ◽  
Martin A Nowak
Keyword(s):  
Natural Selection ◽  
Evolutionary Biology ◽  
Functional Relationship ◽  
Genetic Relatedness ◽  
Reproductive Potential ◽  
Reproductive Rate ◽  
Distinct Form ◽  
Biological Organization ◽  
Selective Forces ◽  
Widespread Belief

Eusociality is a distinct form of biological organization. A key characteristic of advanced eusociality is the presence of non-reproductive workers. Why evolution should produce organisms that sacrifice their own reproductive potential in order to aid others is an important question in evolutionary biology. Here, we provide a detailed analysis of the selective forces that determine the emergence and stability of non-reproductive workers. We study the effects, in situations where the queen of the colony has mated once or several times, of recessive and dominant sterility alleles acting in her offspring. Contrary to widespread belief based on heuristic arguments of genetic relatedness, non-reproductive workers can easily evolve in polyandrous species. The crucial quantity is the functional relationship between a colony’s reproductive rate and the fraction of non-reproductive workers present in that colony. We derive precise conditions for natural selection to favor the evolution of non-reproductive workers.

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