scholarly journals Gene Duplication and Spectral Diversification of Cone Visual Pigments of Zebrafish

Genetics ◽  
2003 ◽  
Vol 163 (2) ◽  
pp. 663-675 ◽  
Author(s):  
Akito Chinen ◽  
Takanori Hamaoka ◽  
Yukihiro Yamada ◽  
Shoji Kawamura
Keyword(s):  
Animal Model ◽  
Gene Duplication ◽  
Visual System ◽  
Genomic Organization ◽  
Developmental Regulation ◽  
Visual Pigments ◽  
Rt Pcr ◽  
Comprehensive Understanding ◽  
Peak Absorption ◽  
Opsin Genes

Abstract Zebrafish is becoming a powerful animal model for the study of vision but the genomic organization and variation of its visual opsins have not been fully characterized. We show here that zebrafish has two red (LWS-1 and LWS-2), four green (RH2-1, RH2-2, RH2-3, and RH2-4), and single blue (SWS2) and ultraviolet (SWS1) opsin genes in the genome, among which LWS-2, RH2-2, and RH2-3 are novel. SWS2, LWS-1, and LWS-2 are located in tandem and RH2-1, RH2-2, RH2-3, and RH2-4 form another tandem gene cluster. The peak absorption spectra (λmax) of the reconstituted photopigments from the opsin cDNAs differed markedly among them: 558 nm (LWS-1), 548 nm (LWS-2), 467 nm (RH2-1), 476 nm (RH2-2), 488 nm (RH2-3), 505 nm (RH2-4), 355 nm (SWS1), 416 nm (SWS2), and 501 nm (RH1, rod opsin). The quantitative RT-PCR revealed a considerable difference among the opsin genes in the expression level in the retina. The expression of the two red opsin genes and of three green opsin genes, RH2-1, RH2-3, and RH2-4, is significantly lower than that of RH2-2, SWS1, and SWS2. These findings must contribute to our comprehensive understanding of visual capabilities of zebrafish and the evolution of the fish visual system and should become a basis of further studies on expression and developmental regulation of the opsin genes.

Molecular diversity of visual pigments in Stomatopoda (Crustacea)

2009 ◽  
Vol 26 (3) ◽  
pp. 255-265 ◽  
Author(s):  
MEGAN L. PORTER ◽  
MICHAEL J. BOK ◽  
PHYLLIS R. ROBINSON ◽  
THOMAS W. CRONIN
Keyword(s):  
Gene Duplication ◽  
Molecular Diversity ◽  
Visual Complexity ◽  
Binding Pocket ◽  
Acid Sites ◽  
Visual Pigments ◽  
Long Wavelength ◽  
Anatomy And Physiology ◽  
Opsin Genes ◽  
Duplication Events

AbstractStomatopod crustaceans possess apposition compound eyes that contain more photoreceptor types than any other animal described. While the anatomy and physiology of this complexity have been studied for more than two decades, few studies have investigated the molecular aspects underlying the stomatopod visual complexity. Based on previous studies of the structure and function of the different types of photoreceptors, stomatopod retinas are hypothesized to contain up to 16 different visual pigments, with 6 of these having sensitivity to middle or long wavelengths of light. We investigated stomatopod middle- and long-wavelength-sensitive opsin genes from five species with the hypothesis that each species investigated would express up to six different opsin genes. In order to understand the evolution of this class of stomatopod opsins, we examined the complement of expressed transcripts in the retinas of species representing a broad taxonomic range (four families and three superfamilies). A total of 54 unique retinal opsins were isolated, resulting in 6–15 different expressed transcripts in each species. Phylogenetically, these transcripts form six distinct clades, grouping with other crustacean opsins and sister to insect long-wavelength visual pigments. Within these stomatopod opsin groups, intra- and interspecific clusters of highly similar transcripts suggest that there has been rampant recent gene duplication. Some of the observed molecular diversity is also due to ancient gene duplication events within the stem crustacean lineage. Using evolutionary trace analysis, 10 amino acid sites were identified as functionally divergent among the six stomatopod opsin clades. These sites form tight clusters in two regions of the opsin protein known to be functionally important: six in the chromophore-binding pocket and four at the cytoplasmic surface in loops II and III. These two clusters of sites indicate that stomatopod opsins have diverged with respect to both spectral tuning and signal transduction.

scholarly journals Evolution of regulatory networks associated with traits under selection in cichlids

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Tarang K. Mehta ◽  
Christopher Koch ◽  
Will Nash ◽  
Sara A. Knaack ◽  
Padhmanand Sudhakar ◽  
...  
Keyword(s):  
Visual System ◽  
Regulatory Sequence ◽  
Potential Candidate ◽  
East African ◽  
Regulatory Regions ◽  
A Genome ◽  
Opsin Genes ◽  
East African Cichlids ◽  
Gene Regulatory ◽  
African Cichlids

Abstract Background Seminal studies of vertebrate protein evolution speculated that gene regulatory changes can drive anatomical innovations. However, very little is known about gene regulatory network (GRN) evolution associated with phenotypic effect across ecologically diverse species. Here we use a novel approach for comparative GRN analysis in vertebrate species to study GRN evolution in representative species of the most striking examples of adaptive radiations, the East African cichlids. We previously demonstrated how the explosive phenotypic diversification of East African cichlids can be attributed to diverse molecular mechanisms, including accelerated regulatory sequence evolution and gene expression divergence. Results To investigate these mechanisms across species at a genome-wide scale, we develop a novel computational pipeline that predicts regulators for co-extant and ancestral co-expression modules along a phylogeny, and candidate regulatory regions associated with traits under selection in cichlids. As a case study, we apply our approach to a well-studied adaptive trait—the visual system—for which we report striking cases of network rewiring for visual opsin genes, identify discrete regulatory variants, and investigate their association with cichlid visual system evolution. In regulatory regions of visual opsin genes, in vitro assays confirm that transcription factor binding site mutations disrupt regulatory edges across species and segregate according to lake species phylogeny and ecology, suggesting GRN rewiring in radiating cichlids. Conclusions Our approach reveals numerous novel potential candidate regulators and regulatory regions across cichlid genomes, including some novel and some previously reported associations to known adaptive evolutionary traits.

scholarly journals Imunocompetent Mice Model for Dengue Virus Infection

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Denise Gonçalves ◽  
Rafael de Queiroz Prado ◽  
Eric Almeida Xavier ◽  
Natália Cristina de Oliveira ◽  
Paulo Marcos da Matta Guedes ◽  
...  
Keyword(s):  
Animal Model ◽  
Virus Infection ◽  
Dengue Virus ◽  
Viral Disease ◽  
Mice Model ◽  
Rt Pcr ◽  
Dengue Virus Infection ◽  
Dengue Disease ◽  
The Family ◽  
The World

Dengue fever is a noncontagious infectious disease caused by dengue virus (DENV). DENV belongs to the familyFlaviviridae, genusFlavivirus, and is classified into four antigenically distinct serotypes: DENV-1, DENV-2, DENV-3, and DENV-4. The number of nations and people affected has increased steadily and today is considered the most widely spread arbovirus (arthropod-borne viral disease) in the world. The absence of an appropriate animal model for studying the disease has hindered the understanding of dengue pathogenesis. In our study, we have found that immunocompetent C57BL/6 mice infected intraperitoneally with DENV-1 presented some signs of dengue disease such as thrombocytopenia, spleen hemorrhage, liver damage, and increase in production of IFNγand TNFαcytokines. Moreover, the animals became viremic and the virus was detected in several organs by real-time RT-PCR. Thus, this animal model could be used to study mechanism of dengue virus infection, to test antiviral drugs, as well as to evaluate candidate vaccines.

Total Alkaloids of Sophora alopecuroides Increases the Expression of CD4+ CD25+ Tregs and IL-10 in Rats with Experimental Colitis

2010 ◽  
Vol 38 (02) ◽  
pp. 265-277 ◽  
Author(s):  
Yi Zhou ◽  
He Wang ◽  
Lei Liang ◽  
Wen-Chan Zhao ◽  
Yan Chen ◽  
...  
Keyword(s):  
Animal Model ◽  
Activity Index ◽  
Disease Activity Index ◽  
Experimental Colitis ◽  
Histological Grading ◽  
Rt Pcr ◽  
Total Alkaloids ◽  
Sophora Alopecuroides ◽  
Study Results ◽  
Anti Inflammation

Previous studies have demonstrated that the total alkaloids of Sophora alopecuroides (TASA), which contains many different ingredients like sophocarpine, matrine, oxymatrine, sophoridine, sophoramine, aloperine and cytosine, were able to protect colon against ulcers caused by 2,4,6-trinitrobenze sulphonic acid (TNBS)/ethanol treated models. In order to elucidate the mechanisms by which TASA exerts its effect of anti-inflammation and immunoregulation on rats with colitis, DAI (disease activity index) and histological grading of colitis were evaluated in the animal model. Moreover, the expression of CD4+CD25+ regulatory T cells (Tregs) and IL-10 in rats with experimental colitis were observed by FCM, ELISA and RT-PCR in this study. Results showed that TASA (15, 30 or 60 mg/kg/day) significantly up-regulated CD4+CD25+Tregs (P = 0.02, P = 0.02, P = 0.03) and IL-10 levels (ELISA: P = 0.03, P = 0.02, P = 0.00; RT-PCR: P = 0.04, P = 0.02, P = 0.01) respectively and decreased the DAI and histological grading of colitis in the peripheral blood (PB) and colon of rat colitis models (3.44 ± 1.53, 4.25 ± 1.27, 4.42 ± 1.24 and 3.50 ± 1.42, 4.05 ± 1.32, 4.51 ± 1.55 vs. 7.18 ± 1.32 and 7.38 ± 1.52, P < 0.05, P < 0.01, respectively). Most interestingly, a negative correlation was demonstrated between the expression of CD4+CD25+ Tregs and DAI (Pearson rPB = -0.677, P < 0.01; Pearson rCOLON = -0.663, P < 0.01, n = 60), or histological grading of colitis (Pearson rPB = -0.725, P < 0.01; Pearson rCOLON = -0.623, P < 0.01, n = 60). Simultaneously, a positive correlation existed between CD4+CD25+ Tregs and IL-10 cytokine (IL-10 mRNA) in the colon and PB of rats (Pearson rPB = 0.789, P < 0.01, n = 60; Pearson rCOLON = 0.678, P < 0.01, n = 60). These results may explain to some extent the mechanisms of TASA on treating rats with experimental colitis.

Depth from shading and disparity in humans and monkeys

2007 ◽  
Vol 24 (2) ◽  
pp. 207-215 ◽  
Author(s):  
YING ZHANG ◽  
VERONICA S. WEINER ◽  
WARREN M. SLOCUM ◽  
PETER H. SCHILLER
Keyword(s):  
Animal Model ◽  
Visual System ◽  
Depth Perception ◽  
Discrimination Task ◽  
Stimulus Display ◽  
Neural Mechanisms ◽  
Depth Information ◽  
Depth Cues ◽  
Good Animal Model

A stimulus display was devised that enabled us to examine how effectively monkeys and humans can process shading and disparity cues for depth perception. The display allowed us to present these cues separately, in concert and in conflict with each other. An oddities discrimination task was used. Humans as well as monkeys were able to utilize both shading and disparity cues but shading cues were more effectively processed by humans. Humans and monkeys performed better and faster when the two cues were presented conjointly rather than singly. Performance was significantly degraded when the two cues were presented in conflict with each other suggesting that these cues are processed interactively at higher levels in the visual system. The fact that monkeys can effectively utilize depth information derived from shading and disparity indicates that they are a good animal model for the study of the neural mechanisms that underlie the processing of these two depth cues.

scholarly journals Neoteny in visual system development of the spotted unicornfish, Naso brevirostris (Acanthuridae)

2019 ◽  
Author(s):  
Valerio Tettamanti ◽  
Fanny de Busserolles ◽  
David Lecchini ◽  
Justin Marshall ◽  
Fabio Cortesi
Keyword(s):  
Visual System ◽  
System Development ◽  
Feeding Habits ◽  
Quantitative Difference ◽  
Photoreceptor Cells ◽  
Reef Fishes ◽  
Ontogenetic Changes ◽  
Cone Opsin ◽  
Opsin Genes ◽  
Visual System Development

AbstractOntogenetic changes of the visual system are often correlated to shifts in habitat and feeding behaviour of animals. Coral reef fishes begin their lives in the pelagic zone and then migrate to the reef. This transition of habitat frequently involves a change in diet and light environment as well as major morphological modifications. The spotted unicornfish, Naso brevirostris, is known to shift diet from zooplankton to algae and back to zooplankton when transitioning from larval to juvenile and then to adult stages. Concurrently, N. brevirostris also moves from an open pelagic to a coral-associated habitat before migrating up in the water column when reaching adulthood. Using retinal mapping techniques, we discovered that the distribution and density of ganglion and photoreceptor cells in N. brevirostris do not change with the habitat or the feeding habits of each developmental stage. Instead, fishes showed a neotenic development with a slight change from larval to juvenile stages and not many modifications thereafter. Visual gene expression based on RNA sequencing mirrored this pattern; independent of stage, fishes mainly expressed three cone opsin genes (SWS2B, RH2B, RH2A), with a quantitative difference in the expression of the green opsin genes (RH2A and RH2B) when transitioning from larvae to juveniles. Hence, contrary to the ontogenetic changes found in many animals, the visual system is fixed early on in N. brevirostris development calling for a thorough analysis of visual system development of the reef fish community.

scholarly journals RT-PCR Heteroduplex Analysis Permits Differentiation of Transgene and Host Gene Expression in a Transgenic Animal Model

BioTechniques ◽  
2002 ◽  
Vol 33 (1) ◽  
pp. 58-66 ◽  
Author(s):  
W. Duan ◽  
H. Ding ◽  
W.-G. Zhu ◽  
K. Srinivasan ◽  
G.A. Otterson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Animal Model ◽  
Transgenic Animal ◽  
Host Gene ◽  
Heteroduplex Analysis ◽  
Host Gene Expression ◽  
Rt Pcr ◽  
Transgenic Animal Model

scholarly journals Temporal expression of a PGIP-gene in strawberry cultivars induced by wounding or by Botrytis cinerea infection

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 504-506 ◽  
Author(s):  
L. Mehli
Keyword(s):  
Botrytis Cinerea ◽  
Developmental Regulation ◽  
Constitutive Expression ◽  
Comparative Experiment ◽  
Inhibitor Protein ◽  
Temporal Expression ◽  
Rt Pcr ◽  
Strawberry Cultivar ◽  
Strawberry Cultivars ◽  
Pgip Gene

The expression of a PGIP gene (polygalacturonase inhibitor protein) was monitored with semi-quantitative (SQ)-RT-PCR in green, white and red berries of the strawberry cultivar Korona upon infection with Botrytis cinerea and wounding. In addition, the PGIP expression in infected white berries was quantified in four additional cultivars. The constitutive expression of PGIP increased from green to red berries in Korona suggesting developmental regulation of the gene. Wounding and fungal infection caused a moderate or a high induction in the PGIP level, respectively. The maximum peak was observed 24 h after the treatments. In the comparative experiment with five cultivars, infection of white berries caused an induction in the PGIP level 24 h after inoculation in four out of five cultivars.

scholarly journals Evolution and spectral tuning of visual pigments in birds and mammals

2009 ◽  
Vol 364 (1531) ◽  
pp. 2941-2955 ◽  
Author(s):  
David M. Hunt ◽  
Livia S. Carvalho ◽  
Jill A. Cowing ◽  
Wayne L. Davies
Keyword(s):  
Visual System ◽  
Visual Pigment ◽  
Spectral Characteristics ◽  
Marine Species ◽  
Visual Pigments ◽  
Common Mechanism ◽  
Light Conditions ◽  
Uv Sensitivity ◽  
Pigment Genes ◽  
Number Of Classes

Variation in the types and spectral characteristics of visual pigments is a common mechanism for the adaptation of the vertebrate visual system to prevailing light conditions. The extent of this diversity in mammals and birds is discussed in detail in this review, alongside an in-depth consideration of the molecular changes involved. In mammals, a nocturnal stage in early evolution is thought to underlie the reduction in the number of classes of cone visual pigment genes from four to only two, with the secondary loss of one of these genes in many monochromatic nocturnal and marine species. The trichromacy seen in many primates arises from either a polymorphism or duplication of one of these genes. In contrast, birds have retained the four ancestral cone visual pigment genes, with a generally conserved expression in either single or double cone classes. The loss of sensitivity to ultraviolet (UV) irradiation is a feature of both mammalian and avian visual evolution, with UV sensitivity retained among mammals by only a subset of rodents and marsupials. Where it is found in birds, it is not ancestral but newly acquired.

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