scholarly journals Evolution of flower color pattern through selection on regulatory small RNAs

Science ◽  
2017 ◽  
Vol 358 (6365) ◽  
pp. 925-928 ◽  
Author(s):  
Desmond Bradley ◽  
Ping Xu ◽  
Irina-Ioana Mohorianu ◽  
Annabel Whibley ◽  
David Field ◽  
...  
Keyword(s):  
Small Rnas ◽  
Phenotypic Diversity ◽  
Flower Color ◽  
Color Pattern ◽  
Natural Hybrid ◽  
Color Patterns ◽  
Regulatory Interactions ◽  
Inverted Duplication ◽  
Biosynthesis Gene ◽  
Pigment Biosynthesis

Small RNAs (sRNAs) regulate genes in plants and animals. Here, we show that population-wide differences in color patterns in snapdragon flowers are caused by an inverted duplication that generates sRNAs. The complexity and size of the transcripts indicate that the duplication represents an intermediate on the pathway to microRNA evolution. The sRNAs repress a pigment biosynthesis gene, creating a yellow highlight at the site of pollinator entry. The inverted duplication exhibits steep clines in allele frequency in a natural hybrid zone, showing that the allele is under selection. Thus, regulatory interactions of evolutionarily recent sRNAs can be acted upon by selection and contribute to the evolution of phenotypic diversity.

Functional significance of preserved color patterns of mollusks from the Gosport Sand (Eocene) of Alabama

1988 ◽  
Vol 62 (01) ◽  
pp. 83-87 ◽  
Author(s):  
Patricia H. Kelley ◽  
Charles T. Swann
Keyword(s):  
Functional Morphology ◽  
Functional Significance ◽  
Intraspecific Variability ◽  
Color Pattern ◽  
Color Patterns ◽  
Historical Factors ◽  
Life Mode ◽  
Molluscan Fauna ◽  
Excellent Preservation ◽  
Architectural Constraints

The excellent preservation of the molluscan fauna from the Gosport Sand (Eocene) at Little Stave Creek, Alabama, has made it possible to describe the preserved color patterns of 15 species. In this study the functional significance of these color patterns is tested in the context of the current adaptationist controversy. The pigment of the color pattern is thought to be a result of metabolic waste disposal. Therefore, the presence of the pigment is functional, although the patterns formed by the pigment may or may not have been adaptive. In this investigation the criteria proposed by Seilacher (1972) for testing the functionality of color patterns were applied to the Gosport fauna and the results compared with life mode as interpreted from knowledge of extant relatives and functional morphology. Using Seilacher's criteria of little ontogenetic and intraspecific variability, the color patterns appear to have been functional. However, the functional morphology studies indicate an infaunal life mode which would preclude functional color patterns. Particular color patterns are instead interpreted to be the result of historical factors, such as multiple adaptive peaks or random fixation of alleles, or of architectural constraints including possibly pleiotropy or allometry. The low variability of color patterns, which was noted within species and genera, suggests that color patterns may also serve a useful taxonomic purpose.

scholarly journals Butterfly Mimicry Polymorphisms Highlight Phylogenetic Limits of Gene Reuse in the Evolution of Diverse Adaptations

2019 ◽  
Vol 36 (12) ◽  
pp. 2842-2853 ◽  
Author(s):  
Nicholas W VanKuren ◽  
Darli Massardo ◽  
Sumitha Nallu ◽  
Marcus R Kronforst
Keyword(s):  
Phylogenetic Relationship ◽  
Gene Networks ◽  
Genetic Basis ◽  
Color Pattern ◽  
Butterfly Wing ◽  
Color Patterns ◽  
Developmental Gene ◽  
Genome Region ◽  
Correlated Factors ◽  
Unique Genes

Abstract Some genes have repeatedly been found to control diverse adaptations in a wide variety of organisms. Such gene reuse reveals not only the diversity of phenotypes these unique genes control but also the composition of developmental gene networks and the genetic routes available to and taken by organisms during adaptation. However, the causes of gene reuse remain unclear. A small number of large-effect Mendelian loci control a huge diversity of mimetic butterfly wing color patterns, but reasons for their reuse are difficult to identify because the genetic basis of mimicry has primarily been studied in two systems with correlated factors: female-limited Batesian mimicry in Papilio swallowtails (Papilionidae) and non-sex-limited Müllerian mimicry in Heliconius longwings (Nymphalidae). Here, we break the correlation between phylogenetic relationship and sex-limited mimicry by identifying loci controlling female-limited mimicry polymorphism Hypolimnas misippus (Nymphalidae) and non-sex-limited mimicry polymorphism in Papilio clytia (Papilionidae). The Papilio clytia polymorphism is controlled by the genome region containing the gene cortex, the classic P supergene in Heliconius numata, and loci controlling color pattern variation across Lepidoptera. In contrast, female-limited mimicry polymorphism in Hypolimnas misippus is associated with a locus not previously implicated in color patterning. Thus, although many species repeatedly converged on cortex and its neighboring genes over 120 My of evolution of diverse color patterns, female-limited mimicry polymorphisms each evolved using a different gene. Our results support conclusions that gene reuse occurs mainly within ∼10 My and highlight the puzzling diversity of genes controlling seemingly complex female-limited mimicry polymorphisms.

scholarly journals Plugging Small RNAs into the Network

mSystems ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Lars Barquist
Keyword(s):  
Small Rnas ◽  
Posttranscriptional Regulation ◽  
Network Inference ◽  
Functional Characterization ◽  
The State ◽  
Diverse Range ◽  
Regulatory Interactions ◽  
Link Type ◽  
Wide Range

ABSTRACT Small RNAs (sRNAs) have been discovered in every bacterium examined and have been shown to play important roles in the regulation of a diverse range of behaviors, from metabolism to infection. However, despite a wide range of available techniques for discovering and validating sRNA regulatory interactions, only a minority of these molecules have been well characterized. In part, this is due to the nature of posttranscriptional regulation: the activity of an sRNA depends on the state of the transcriptome as a whole, so characterization is best carried out under the conditions in which it is naturally active. In this issue of mSystems, Arrieta-Ortiz and colleagues (M. L. Arrieta-Ortiz, C. Hafemeister, B. Shuster, N. S. Baliga, et al., mSystems 5:e00057-20, 2020, https://doi.org/10.1128/mSystems.00057-20) present a network inference approach based on estimating sRNA activity across transcriptomic compendia. This shows promise not only for identifying new sRNA regulatory interactions but also for pinpointing the conditions in which these interactions occur, providing a new avenue toward functional characterization of sRNAs.

Measuring Perceptual Distance of Organismal Color Pattern using the Features of Deep Neural Networks

2019 ◽  
Author(s):  
Drew C. Wham ◽  
Briana Ezray ◽  
Heather M. Hines
Keyword(s):  
Deep Neural Networks ◽  
Color Pattern ◽  
Color Contrast ◽  
Biological Processes ◽  
Color Patterns ◽  
Biologically Relevant ◽  
Perceptual Distance ◽  
Data Formats ◽  
Wide Range ◽  
Study Designs

ABSTRACTA wide range of research relies upon the accurate and repeatable measurement of the degree to which organisms resemble one another. Here, we present an unsupervised workflow for analyzing the relationships between organismal color patterns. This workflow utilizes several recent advancements in deep learning based computer vision techniques to calculate perceptual distance. We validate this approach using previously published datasets surrounding diverse applications of color pattern analysis including mimicry, population differentiation, heritability, and development. We demonstrate that our approach is able to reproduce the biologically relevant color pattern relationships originally reported in these studies. Importantly, these results are achieved without any task-specific training. In many cases, we were able to reproduce findings directly from original photographs or plates with minimum standardization, avoiding the need for intermediate representations such as a cartoonized images or trait matrices. We then present two artificial datasets designed to highlight how this approach handles aspects of color patterns, such as changes in pattern location and the perception of color contrast. These results suggest that this approach will generalize well to support the study of a wide range of biological processes in a diverse set of taxa while also accommodating a variety of data formats, preprocessing techniques, and study designs.

scholarly journals Long-Range Effects of Wing Physical Damage and Distortion on Eyespot Color Patterns in the Hindwing of the Blue Pansy Butterfly Junonia orithya

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 195 ◽  
Author(s):  
Joji Otaki
Keyword(s):  
Long Range ◽  
Color Pattern ◽  
Color Patterns ◽  
Physical Damage ◽  
Damage Site ◽  
Disk Size ◽  
Close Proximity ◽  
Butterfly Wings ◽  
Pattern Determination ◽  
Background Area

Butterfly eyespot color patterns have been studied using several different approaches, including applications of physical damage to the forewing. Here, damage and distortion experiments were performed, focusing on the hindwing eyespots of the blue pansy butterfly Junonia orithya. Physical puncture damage with a needle at the center of the eyespot reduced the eyespot size. Damage at the eyespot outer rings not only deformed the entire eyespot, but also diminished the eyespot core disk size, despite the distance from the damage site to the core disk. When damage was inflicted near the eyespot, the eyespot was drawn toward the damage site. The induction of an ectopic eyespot-like structure and its fusion with the innate eyespots were observed when damage was inflicted in the background area. When a small stainless ball was placed in close proximity to the eyespot using the forewing-lift method, the eyespot deformed toward the ball. Taken together, physical damage and distortion elicited long-range inhibitory, drawing (attracting), and inducing effects, suggesting that the innate and induced morphogenic signals travel long distances and interact with each other. These results are consistent with the distortion hypothesis, positing that physical distortions of wing tissue contribute to color pattern determination in butterfly wings.

scholarly journals A conserved paint box underlies color pattern diversity in Estrildid finches

2021 ◽  
Author(s):  
Magdalena Hidalgo ◽  
Camille Curantz ◽  
Nicole Quenech’Du ◽  
Thanh-Lan Gluckman ◽  
Julia Neguer ◽  
...  
Keyword(s):  
Color Pattern ◽  
Color Patterns ◽  
Color Distribution ◽  
Comparative Analyses ◽  
Developmental Mechanisms ◽  
Pattern Diversity ◽  
Molecular Map ◽  
Small Set ◽  
Molecular Landscape

AbstractMany animals exhibit typical color patterns that have been linked to key adaptive functions, yet the developmental mechanisms establishing these crucial designs remain unclear. Here, we surveyed color distribution in the plumage across a large number of passerine finches. Despite extreme apparent pattern diversity, we identified a small set of conserved color regions whose combinatory association can explain all observed patterns. We found these domains are instructed by early embryonic landmarks, and through profiling and comparative analyses produced a molecular map marking putative color domains in the developing skin. This revealed cryptic pre-patterning common to differently colored species, uncovering a simple molecular landscape underlying extensive color pattern variation.

scholarly journals Patternize: An R Package For Quantifying Color Pattern Variation

2017 ◽  
Author(s):  
Steven M. Van Belleghem ◽  
Riccardo Papa ◽  
Humberto Ortiz-Zuazaga ◽  
Frederik Hendrickx ◽  
Chris Jiggins ◽  
...  
Keyword(s):  
Association Studies ◽  
Genetic Association Studies ◽  
Image Data ◽  
Principal Component ◽  
R Package ◽  
Color Pattern ◽  
Color Patterns ◽  
Wide Range ◽  
Potential Applications ◽  
Population Comparisons

The use of image data to quantify, study and compare variation in the colors and patterns of organisms requires the alignment of images to establish homology, followed by color-based segmentation of images. Here we describe an R package for image alignment and segmentation that has applications to quantify color patterns in a wide range of organisms. patternize is an R package that quantifies variation in color patterns obtained from image data. patternize first defines homology between pattern positions across specimens either through manually placed homologous landmarks or automated image registration. Pattern identification is performed by categorizing the distribution of colors using an RGB threshold, k-means clustering or watershed transformation. We demonstrate that patternize can be used for quantification of the color patterns in a variety of organisms by analyzing image data for butterflies, guppies, spiders and salamanders. Image data can be compared between sets of specimens, visualized as heatmaps and analyzed using principal component analysis (PCA). patternize has potential applications for fine scale quantification of color pattern phenotypes in population comparisons, genetic association studies and investigating the basis of color pattern variation across a wide range of organisms.

Sign in / Sign up

Export Citation Format

Share Document