scholarly journals Mechanisms of the phototropic pathway

2018 ◽  
Author(s):  
◽  
Johanna Lynn Morrow
Keyword(s):  
Blue Light ◽  
Leaf Movement ◽  
Allelic Series ◽  
Differential Growth ◽  
Ubiquitin Ligase Complex ◽  
Developmental Responses ◽  
Sessile Organisms ◽  
High Intensity Light ◽  
Bending Response

Plants are sessile organisms and therefore are limited in their ability to gather resources. Therefore, they have evolved several mechanisms that aid them in their quest to gather light, water and nutrients. One such mechanism is phototropism, a plants ability to bend towards or away from a light source. This mechanism is mediated by the blue light photoreceptor phototropin (phot). Arabidopsis thaliana contains two phototropins, phot1 which is the primary photoreceptor under low intensity light and phot2, which acts redundantly with phot1 under high intensity light. The perception of blue light by the phototropins (phot1 and phot2) initiates signaling events that lead to a lateral redistribution of the plant hormone auxin; which ultimately results in differential growth and the bending response. In addition to phototropism, these proteins mediate several other growth and developmental responses such as leaf movement, chloroplast movement, and stomatal opening. A second protein which is critical to the phototropic response and interacts with phot1 is NONPHOTOTROPIC HYPOCOTYL3 (NPH3). In addition to phototropism, NPH3 has a role in phot1-mediated leaf movement. NPH3 has been shown to act as a substrate adapter in an E3 ubiquitin ligase complex with the protein CULLIN3 (CUL3). This CRL3NPH3 complex is responsible for ubiquitinating the phot1 photoreceptor in a blue light fashion. This ubiquitination has been shown to be necessary for the bending response, but it's role in receptor ubiquitination is still not fully understood. To better understand this component of phot1-mediated phototropism, we characterized an allelic series of NPH3 mutants to further understand the role of this substrate adapter in this mechanism. Additionally, we characterized several mutant plant lines containing a mutant phot1 protein in which critical ubiquitination sites were mutated in an effort to render the protein unable to be ubiquitinated to further understand phot1 ubiquitination.

scholarly journals Biomonitoring of Heavy Metals: The Unexplored Role of Marine Sessile Taxa

2021 ◽  
Vol 11 (2) ◽  
pp. 580
Author(s):  
Camilla Roveta ◽  
Anna Annibaldi ◽  
Afghan Afghan ◽  
Barbara Calcinai ◽  
Cristina Gioia Di Camillo ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Current Knowledge ◽  
Marine Species ◽  
Shallow Waters ◽  
Anthropogenic Inputs ◽  
Current Review ◽  
European Water ◽  
To Receive ◽  
Sessile Organisms

Coastal areas are known to receive significant anthropogenic inputs, mainly deriving from metropolitan areas, industries, and activities related to tourism. Among these inputs, some trace elements are listed as priority pollutants in the European Water Framework Directive, due to their ability to bioaccumulate in organisms. Many studies have been conducted on heavy metals (HMs) accumulation and on their possible effects on different edible marine species. While the most studied sessile organisms are bivalves, in the current review, we focus our attention on other sessile taxa (sponges, cnidarians, bryozoans, polychaetes, cirripeds, and tunicates), proposed as bioindicators in coastal shallow waters. Although their potential as bioindicator tools has been repeatedly highlighted in the literature, these organisms are still poorly investigated and considered for monitoring. In this context, we analyze the available literature about this topic, in order to summarize the current knowledge and identify possible applications of these organisms in a bioremediation scenario.

The critical role of the coordination sphere in the high-efficiency blue-light emission from aminopyrazine metal-organic polymers

2021 ◽  
Vol 186 ◽  
pp. 109025
Author(s):  
João Humberto Dias Campos ◽  
Meiry Edivirges Alvarenga ◽  
Maykon Alves Lemes ◽  
José Antônio do Nascimento Neto ◽  
Freddy Fernandes Guimarães ◽  
...  
Keyword(s):  
Blue Light ◽  
Coordination Sphere ◽  
High Efficiency ◽  
Light Emission ◽  
Critical Role ◽  
Organic Polymers ◽  
Blue Light Emission ◽  
Metal Organic

Understanding the Role of Fuels and impure phases on Photo‐ and Thermoluminescence Properties of Combustion Derived nano Sr 2 CeO 4 Blue Light Emitting Phosphor †

Luminescence ◽  
2021 ◽  
Author(s):  
D. L. Monika ◽  
R. Hari Krishna ◽  
M. N. Chandraprabha ◽  
R. Preetham ◽  
R. Sivaramakrishna
Keyword(s):  
Blue Light ◽  
Light Emitting

Evaluation of Photobiogoverning Role of Blue Light Irradiation on Viral Replication

2021 ◽  
Author(s):  
Phil‐Sun Oh ◽  
Kyung Won Kang ◽  
Seung Rok Ryu ◽  
SeokTae Lim ◽  
Myung‐Hee Sohn ◽  
...  
Keyword(s):  
Viral Replication ◽  
Blue Light ◽  
Light Irradiation

scholarly journals The role of thickness inhomogeneities in hierarchical cortical folding

2020 ◽  
Author(s):  
Lucas da Costa Campos ◽  
Raphael Hornung ◽  
Gerhard Gompper ◽  
Jens Elgeti ◽  
Svenja Caspers
Keyword(s):  
Fetal Brain ◽  
Epileptic Seizures ◽  
Quantitative Model ◽  
Higher Order ◽  
Mammalian Brain ◽  
Cortical Folding ◽  
Differential Growth ◽  
The Brain ◽  
Short Life Expectancy

AbstractThe morphology of the mammalian brain cortex is highly folded. For long it has been known that specific patterns of folding are necessary for an optimally functioning brain. On the extremes, lissencephaly, a lack of folds in humans, and polymicrogyria, an overly folded brain, can lead to severe mental retardation, short life expectancy, epileptic seizures, and tetraplegia. The construction of a quantitative model on how and why these folds appear during the development of the brain is the first step in understanding the cause of these conditions. In recent years, there have been various attempts to understand and model the mechanisms of brain folding. Previous works have shown that mechanical instabilities play a crucial role in the formation of brain folds, and that the geometry of the fetal brain is one of the main factors in dictating the folding characteristics. However, modeling higher-order folding, one of the main characteristics of the highly gyrencephalic brain, has not been fully tackled. The effects of thickness inhomogeneity in the gyrogenesis of the mammalian brain are studied in silico. Finite-element simulations of rectangular slabs are performed. The slabs are divided into two distinct regions, where the outer layer mimics the gray matter, and the inner layer the underlying white matter. Differential growth is introduced by growing the top layer tangentially, while keeping the underlying layer untouched. The brain tissue is modeled as a neo-Hookean hyperelastic material. Simulations are performed with both, homogeneous and inhomogeneous cortical thickness. The homogeneous cortex is shown to fold into a single wavelength, as is common for bilayered materials, while the inhomogeneous cortex folds into more complex conformations. In the early stages of development of the inhomogeneous cortex, structures reminiscent of the deep sulci in the brain are obtained. As the cortex continues to develop, secondary undulations, which are shallower and more variable than the structures obtained in earlier gyrification stage emerge, reproducing well-known characteristics of higher-order folding in the mammalian, and particularly the human, brain.

scholarly journals Role of Short-wavelength Blue Light in the Formation of Cataract and Expression of Caspase-1, -11 and Gasdermin D in rat Lens Epithelium Cells: Insight into the Novel Pathogenesis of Cataract.

2019 ◽  
Author(s):  
Yamin Wang ◽  
Min Zhang ◽  
Ying Sun ◽  
Xiaohui Wang ◽  
Zhaowei Song ◽  
...  
Keyword(s):  
Blue Light ◽  
Short Wavelength ◽  
Light Exposure ◽  
The Novel ◽  
Blue Led ◽  
Caspase 1 ◽  
Epithelium Cells ◽  
Experimental Group ◽  
Insight Into

Abstract Background Cataracts have been verified to be associated with a number of risk factors. The sun and artificial light sources, including light-emitting diode (LED) and fluorescent light tubes, are the primary sources of short-wavelength blue light. With the increasing popularity of blue-rich LED-backlit display devices, our eyes are now exposed to more short-wavelength blue light than they were in the past. The goal of this study was to evaluate the role of short-wavelength blue light in the formation of cataract. Additionally, the pathogenesis of cataracts after short-wavelength light exposure was investigated.Methods SD rats were randomly divided into 2 main groups: a control group (10 rats each for the 4-, 8-, and 12-week groups) and an experimental group (10 rats each for the 4-, 8-, and 12-week groups). The rats in the experimental group were exposed to a short-wavelength blue LED lamp for 12 hours per day. After exposure to the blue LED lamp, the rats were maintained in total darkness for 12 hours, after which a 12-hour light/dark cycle was resumed. The intensity of the lamp was 3000 lux. At the end of the short-wavelength blue LED lamp exposure (for 4, 8, and 12 weeks), the expression levels of caspase-1, caspase-11 and gasdermin D (GSDMD) in rat epithelium cells (LECs) were examined in rat epithelial cells (LECs) using qRT-PCR and Western blotting analyses. Results After 6 weeks, cataracts had developed in the experimental rats (4/20 eyes). The clarity of the lens then gradually worsened with the duration of exposure. Twelve weeks later, all of the rat eyes had developed cataracts. Then the expression levels of caspase-1, caspase-11 and GSDMD at 4, 8, and 12 weeks were significantly higher in samples from rats exposed to a short-wavelength blue LED lamp than samples from control rat (p˂0.05). Conclusion The data indicate that pyroptosis play a key role of in cataracts induced by short-wavelength blue light exposure, highlighting caspase-1, caspase-11 and GSDMD as possible therapeutic targets for cataract treatment. This study might provide new insight into the novel pathogenesis of cataracts.

Cryptochrome 2 is involved in betacyanin decomposition induced by blue light in Suaeda salsa

2006 ◽  
Vol 33 (7) ◽  
pp. 697 ◽  
Author(s):  
Wang Chang-Quan ◽  
Liu Tao
Keyword(s):  
Western Blot ◽  
Blue Light ◽  
Hypocotyl Elongation ◽  
Suaeda Salsa ◽  
Biosynthesis Pathway ◽  
Tyrosine Hydroxylation ◽  
Key Enzyme ◽  
Cryptochrome 2 ◽  
Hydroxylation Activity

Seeds of the halophyte Suaeda salsa (L.) Pall. were cultured in 24 h dark and 14 h blue light / 10 h dark to examine the role of blue light and the blue-light-absorbing photoreceptor cryptochrome 2 (CRY2) in betacyanin accumulation, hypocotyl elongation and cotyledon opening in S. salsa seedlings. Darkness significantly promoted betacyanin accumulation and hypocotyl elongation but inhibited cotyledon opening. Blue light suppressed betacyanin accumulation and hypocotyl elongation but stimulated cotyledon opening. Betacyanin in S. salsa seedlings decomposed with time in blue light. Western blot analysis showed that CRY2 protein accumulated both in hypocotyls and cotyledons of S. salsa seedlings grown in dark, but degraded with time in blue light, which was paralleled by a decrease of tyrosine hydroxylation activity of tyrosinase, a key enzyme involved in the betalain biosynthesis pathway. These results suggest that CRY2 protein mediates betacyanin decomposition via inactivation of tyrosinase in S. salsa seedlings, and the blue-light-dependent degradation of CRY2 protein is crucial to its function.

Drosophila brachyenteron regulates gene activity and morphogenesis in the gut

Development ◽  
1996 ◽  
Vol 122 (12) ◽  
pp. 3707-3718 ◽  
Author(s):  
J.B. Singer ◽  
R. Harbecke ◽  
T. Kusch ◽  
R. Reuter ◽  
J.A. Lengyel
Keyword(s):  
Genetic Locus ◽  
Malpighian Tubules ◽  
Gene Activity ◽  
Phenotypic Characterization ◽  
Gut Development ◽  
Allelic Series ◽  
Genes Encoding

Chromosomal region 68D/E is required for various aspects of Drosophila gut development; within this region maps the Brachyury homolog T-related gene (Trg), DNA of which rescues the hindgut defects of deficiency 68D/E. From a screen of 13,000 mutagenized chromosomes we identified six non-complementing alleles that are lethal over deficiencies of 68D/E and show a hindgut phenotype. These mutations constitute an allelic series and are all rescued to viability by a Trg transgene. We have named the mutant alleles and the genetic locus they define brachyenteron (byn); phenotypic characterization of the strongest alleles allows determination of the role of byn in embryogenesis. byn expression is activated by tailless, but byn does not regulate itself. byn expression in the hindgut and anal pad primordia is required for the regulation of genes encoding transcription factors (even-skipped, engrailed, caudal, AbdominalB and orthopedia) and cell signaling molecules (wingless and decapentaplegic). In byn mutant embryos, the defective program of gene activity in these primordia is followed by apoptosis (initiated by reaper expression and completed by macrophage engulfment), resulting in severely reduced hindgut and anal pads. Although byn is not expressed in the midgut or the Malpighian tubules, it is required for the formation of midgut constrictions and for the elongation of the Malpighian tubules.

Experiments in vitro on the Role of Movement in the Development of Joints

Development ◽  
1958 ◽  
Vol 6 (2) ◽  
pp. 183-186
Author(s):  
G. Lelkes
Keyword(s):  
Nerve Supply ◽  
Essential Factor ◽  
Differential Growth ◽  
Joint Formation ◽  
Articular Surfaces ◽  
Early Formation ◽  
Further Development

It has been pointed out by Fell & Canti (1934) as a result of their experiments in vitro concerning the early formation of the avian limb skeleton and kneejoint, that the appearance of the articular rudiment is independent of the bloodand nerve-supply as well as of mechanical influences. These authors believe that the formation of articular surfaces occurs in consequence of the differential growth of the scleroblastema (the ‘Anlage’ of the limb skeleton, skeletal rudiment) the essential factor in joint formation being the association of undifferentiated tissue with the rapidly growing chondrification centres. They emphasize, however, that only the earlier stages of joint formation can be obtained in vitro, the conditions of cultivation are not adequate for the further development of the joints. The articular rudiment disappears by secondary fusion of the cartilages of the limb skeleton.

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