scholarly journals Avian color expression and perception: is there a carotenoid link?

2021 ◽  
Vol 224 (12) ◽  
Author(s):  
Matthew B. Toomey ◽  
Kelly L. Ronald
Keyword(s):  
Color Vision ◽  
Discrimination Performance ◽  
Color Discrimination ◽  
Visual Signals ◽  
Carotenoid Content ◽  
Comparative Genomic ◽  
Carotenoid Concentration ◽  
Signal Perception ◽  
Functional Connections ◽  
Genomic Studies

ABSTRACT Carotenoids color many of the red, orange and yellow ornaments of birds and also shape avian vision. The carotenoid-pigmented oil droplets in cone photoreceptors filter incoming light and are predicted to aid in color discrimination. Carotenoid use in both avian coloration and color vision raises an intriguing question: is the evolution of visual signals and signal perception linked through these pigments? Here, we explore the genetic, physiological and functional connections between these traits. Carotenoid color and droplet pigmentation share common mechanisms of metabolic conversion and are both affected by diet and immune system challenges. Yet, the time scale and magnitude of these effects differ greatly between plumage and the visual system. Recent observations suggest a link between retinal carotenoid levels and color discrimination performance, but the mechanisms underlying these associations remain unclear. Therefore, we performed a modeling exercise to ask whether and how changes in droplet carotenoid content could alter the perception of carotenoid-based plumage. This exercise revealed that changing oil droplet carotenoid concentration does not substantially affect the discrimination of carotenoid-based colors, but might change how reliably a receiver can predict the carotenoid content of an ornament. These findings suggest that, if present, a carotenoid link between signal and perception is subtle. Deconstructing this relationship will require a deeper understanding of avian visual perception and the mechanisms of color production. We highlight several areas where we see opportunities to gain new insights, including comparative genomic studies of shared mechanisms of carotenoid processing and alternative approaches to investigating color vision.

Effect of digitally generated colored filters on Farnsworth-Munsell 100 hue test by red-green color vision-deficient observers

2021 ◽  
Vol 2021 (29) ◽  
pp. 148-153
Author(s):  
Shunnma Saito ◽  
Keiko Sato
Keyword(s):  
Color Vision ◽  
Discrimination Performance ◽  
Color Discrimination ◽  
Spectral Transmittance ◽  
Green Color ◽  
Colored Filter

In this study, the effects of four different digitally generated colored filters on the Farnsworth-Munsell 100 hue test (100-hue test) are analyzed by red-green color-vision deficient (CVD) observers. We digitally simulate the colored filters based on the spectral transmittance of four colored filters, which have been used previously. Five red-green CVD observers are subjected to the 100-hue test on a monitor under nine filter conditions, which comprise one condition without filter and eight conditions with filters. The results suggest that a colored filter that transmits long wavelengths and absorbs medium wavelengths may improve the color discrimination performance of protans and deutans.

scholarly journals High-Density Genetic Map Construction and Identification of QTLs Controlling Leaf Abscission Trait in Poncirus trifoliata

2021 ◽  
Vol 22 (11) ◽  
pp. 5723
Author(s):  
Yuan-Yuan Xu ◽  
Sheng-Rui Liu ◽  
Zhi-Meng Gan ◽  
Ren-Fang Zeng ◽  
Jin-Zhi Zhang ◽  
...  
Keyword(s):  
Qtl Mapping ◽  
Linkage Map ◽  
Genetic Map ◽  
Expression Patterns ◽  
High Density ◽  
Poncirus Trifoliata ◽  
Leaf Abscission ◽  
Comparative Genomic ◽  
Map Comparison ◽  
Genomic Studies

A high-density genetic linkage map is essential for genetic and genomic studies including QTL mapping, genome assembly, and comparative genomic analysis. Here, we constructed a citrus high-density linkage map using SSR and SNP markers, which are evenly distributed across the citrus genome. The integrated linkage map contains 4163 markers with an average distance of 1.12 cM. The female and male linkage maps contain 1478 and 2976 markers with genetic lengths of 1093.90 cM and 1227.03 cM, respectively. Meanwhile, a genetic map comparison demonstrates that the linear order of common markers is highly conserved between the clementine mandarin and Poncirus trifoliata. Based on this high-density integrated citrus genetic map and two years of deciduous phenotypic data, two loci conferring leaf abscission phenotypic variation were detected on scaffold 1 (including 36 genes) and scaffold 8 (including 107 genes) using association analysis. Moreover, the expression patterns of 30 candidate genes were investigated under cold stress conditions because cold temperature is closely linked with the deciduous trait. The developed high-density genetic map will facilitate QTL mapping and genomic studies, and the localization of the leaf abscission deciduous trait will be valuable for understanding the mechanism of this deciduous trait and citrus breeding.

scholarly journals The Diversity and Evolution of Sex Chromosomes in Frogs

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 483
Author(s):  
Wen-Juan Ma ◽  
Paris Veltsos
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
Comparative Genomic ◽  
Ancestral State ◽  
Heteromorphic Sex Chromosomes ◽  
Genomic Studies ◽  
Evolutionary Trajectories ◽  
Heterogametic Sex

Frogs are ideal organisms for studying sex chromosome evolution because of their diversity in sex chromosome differentiation and sex-determination systems. We review 222 anuran frogs, spanning ~220 Myr of divergence, with characterized sex chromosomes, and discuss their evolution, phylogenetic distribution and transitions between homomorphic and heteromorphic states, as well as between sex-determination systems. Most (~75%) anurans have homomorphic sex chromosomes, with XY systems being three times more common than ZW systems. Most remaining anurans (~25%) have heteromorphic sex chromosomes, with XY and ZW systems almost equally represented. There are Y-autosome fusions in 11 species, and no W-/Z-/X-autosome fusions are known. The phylogeny represents at least 19 transitions between sex-determination systems and at least 16 cases of independent evolution of heteromorphic sex chromosomes from homomorphy, the likely ancestral state. Five lineages mostly have heteromorphic sex chromosomes, which might have evolved due to demographic and sexual selection attributes of those lineages. Males do not recombine over most of their genome, regardless of which is the heterogametic sex. Nevertheless, telomere-restricted recombination between ZW chromosomes has evolved at least once. More comparative genomic studies are needed to understand the evolutionary trajectories of sex chromosomes among frog lineages, especially in the ZW systems.

Color-Discrimination Performance of Pigeons: Effects of Reward

Science ◽  
1965 ◽  
Vol 149 (3688) ◽  
pp. 1113-1114 ◽  
Author(s):  
C. A. Boneau ◽  
M. K. Holland ◽  
W. M. Baker
Keyword(s):  
Discrimination Performance ◽  
Color Discrimination

Bipolar cell pathways for color vision in non-primate dichromats

2010 ◽  
Vol 28 (1) ◽  
pp. 51-60 ◽  
Author(s):  
CHRISTIAN PULLER ◽  
SILKE HAVERKAMP
Keyword(s):  
Color Vision ◽  
Bipolar Cell ◽  
Ganglion Cells ◽  
Color Discrimination ◽  
Model Systems ◽  
Retinal Ganglion ◽  
Retinal Pathways ◽  
Retinal Information Processing ◽  
Cone Opsins ◽  
Retinal Information

AbstractColor vision in mammals is based on the expression of at least two cone opsins that are sensitive to different wavelengths of light. Furthermore, retinal pathways conveying color-opponent signals are required for color discrimination. Most of the primates are trichromats, and “color-coded channels” of their retinas are unveiled to a large extent. In contrast, knowledge of cone-selective pathways in nonprimate dichromats is only slowly emerging, although retinas of dichromats like mice or rats are extensively studied as model systems for retinal information processing. Here, we review recent progress of research on color-coded pathways in nonprimate dichromats to identify differences or similarities between di- and trichromatic mammals. In addition, we applied immunohistochemical methods and confocal microscopy to retinas of different species and present data on their neuronal properties, which are expected to contribute to color vision. Basic neuronal features such as the “blue cone bipolar cell” exist in every species investigated so far. Moreover, there is increasing evidence for chromatic OFF channels in dichromats and retinal ganglion cells that relay color-opponent signals to the brain. In conclusion, di- and trichromats share similar retinal pathways for color transmission and processing.

scholarly journals Identification of RD5-EncodedMycobacterium tuberculosisProteins As B-Cell Antigens Used for Serodiagnosis of Tuberculosis

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Miao-Miao Zhang ◽  
Jun-Wei Zhao ◽  
Zhan-Qiang Sun ◽  
Jun Liu ◽  
Xiao-Kui Guo ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Detection Sensitivity ◽  
Comparative Genomic ◽  
Healthy Controls ◽  
Specific Diagnosis ◽  
Pulmonary Tb ◽  
Genomic Studies ◽  
Immunodominant Antigens ◽  
Genomic Regions ◽  
Hiv Negative

Comparative genomic studies have identified severalMycobacterium tuberculosis-specific genomic regions of difference (RDs) which are absent in the vaccine strains ofMycobacterium bovisBCG and which may be useful in the specific diagnosis of tuberculosis (TB). In this study, all encoded proteins from DNA segment RD5 ofMycobacterium tuberculosis, that is, Rv3117–Rv3121, were recombined and evaluated by enzyme-linked immunosorbent assays for antibody reactivity with sera from HIV-negative pulmonary TB patients (n=60) and healthy controls (n=32). The results identified two immunodominant antigens, that is, Rv3117 and Rv3120, both of which revealed a statistically significant antigenic distinction between healthy controls and TB patients (P<0.05). In comparison with the well-known early-secreted antigen target 6 kDa (ESAT-6) (sensitivity 21.7%, specificity 90.6%), the higher detection sensitivity and higher specificity were achieved (Rv3117: sensitivity 25%, specificity 96.9%; Rv3120: sensitivity 31.7%, specificity 96.9%). Thus, the results highlight the immunosensitive and immunospecific nature of Rv3117 and Rv3120 and indicate promise for their use in the serodiagnosis of TB.

scholarly journals Unexpected cryptic species among streptophyte algae most distant to land plants

2021 ◽  
Vol 288 (1963) ◽  
Author(s):  
Iker Irisarri ◽  
Tatyana Darienko ◽  
Thomas Pröschold ◽  
Janine M. R. Fürst-Jansen ◽  
Mahwash Jamy ◽  
...  
Keyword(s):  
Land Plants ◽  
Comparative Genomic ◽  
Future Studies ◽  
Form And Function ◽  
Genomic Studies ◽  
Plant Form ◽  
Phylogenomic Analyses ◽  
And Function ◽  
Shed Light ◽  
Green Lineage

Streptophytes are one of the major groups of the green lineage (Chloroplastida or Viridiplantae). During one billion years of evolution, streptophytes have radiated into an astounding diversity of uni- and multicellular green algae as well as land plants. Most divergent from land plants is a clade formed by Mesostigmatophyceae, Spirotaenia spp. and Chlorokybophyceae. All three lineages are species-poor and the Chlorokybophyceae consist of a single described species, Chlorokybus atmophyticus. In this study, we used phylogenomic analyses to shed light into the diversity within Chlorokybus using a sampling of isolates across its known distribution. We uncovered a consistent deep genetic structure within the Chlorokybus isolates, which prompted us to formally extend the Chlorokybophyceae by describing four new species. Gene expression differences among Chlorokybus species suggest certain constitutive variability that might influence their response to environmental factors. Failure to account for this diversity can hamper comparative genomic studies aiming to understand the evolution of stress response across streptophytes. Our data highlight that future studies on the evolution of plant form and function can tap into an unknown diversity at key deep branches of the streptophytes.

scholarly journals Evolution of multicellularity in Dictyostelia

2019 ◽  
Vol 63 (8-9-10) ◽  
pp. 359-369 ◽  
Author(s):  
Yoshinori Kawabe ◽  
Qingyou Du ◽  
Christina Schilde ◽  
Pauline Schaap
Keyword(s):  
Life Cycle ◽  
Experimental Studies ◽  
Evolutionary Conservation ◽  
Comparative Genomic ◽  
Camp Signalling ◽  
Life Styles ◽  
Phenotypic Complexity ◽  
Genomic Studies ◽  
Developmental Programme ◽  
Differentiation Pathways

The well-orchestrated multicellular life cycle of Dictyostelium discoideum has fascinated biologists for over a century. Self-organisation of its amoebas into aggregates, migrating slugs and fruiting structures by pulsatile cAMP signalling and their ability to follow separate differentiation pathways in well-regulated proportions continue to be topics under investigation. A striking aspect of D. discoideum development is the recurrent use of cAMP as chemoattractant, differentiation inducing signal and second messenger for other signals that control the developmental programme. D. discoideum is one of >150 species of Dictyostelia and aggregative life styles similar to those of Dictyostelia evolved many times in eukaryotes. Here we review experimental studies investigating how phenotypic complexity and cAMP signalling co-evolved in Dictyostelia. In addition, we summarize comparative genomic studies of multicellular Dictyostelia and unicellular Amoebozoa aimed to identify evolutionary conservation and change in all genes known to be essential for D. discoideum development.

scholarly journals High-Quality Genome Assembly of Peronospora destructor, the Causal Agent of Onion Downy Mildew

2020 ◽  
Vol 33 (5) ◽  
pp. 718-720
Author(s):  
Karthi Natesan ◽  
Ji Yeon Park ◽  
Cheol-Woo Kim ◽  
Dong Suk Park ◽  
Young-Seok Kwon ◽  
...  
Keyword(s):  
Downy Mildew ◽  
De Novo ◽  
Gc Content ◽  
Comparative Genomic ◽  
High Quality ◽  
Sequencing Platform ◽  
Peronospora Destructor ◽  
Genomic Studies ◽  
Genome Assemblies ◽  
High Quality Genome

Peronospora destructor is an obligate biotrophic oomycete that causes downy mildew on onion (Allium cepa). Onion is an important crop worldwide, but its production is affected by this pathogen. We sequenced the genome of P. destructor using the PacBio sequencing platform, and de novo assembly resulted in 74 contigs with a total contig size of 29.3 Mb and 48.48% GC content. Here, we report the first high-quality genome sequence of P. destructor and its comparison with the genome assemblies of other oomycetes. The genome is a very useful resource to serve as a reference for analysis of P. destructor isolates and for comparative genomic studies of the biotrophic oomycetes.

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