scholarly journals Early development of apoplastic barriers and molecular mechanisms in juvenile maize roots in response to La2O3 nanoparticles

2019 ◽  
Vol 653 ◽  
pp. 675-683 ◽  
Author(s):  
Le Yue ◽  
Feiran Chen ◽  
Kaiqiang Yu ◽  
Zhenggao Xiao ◽  
Xiaoyu Yu ◽  
...  
2013 ◽  
Vol 200 (5) ◽  
pp. 667-679 ◽  
Author(s):  
Kathryn Ellis ◽  
Jennifer Bagwell ◽  
Michel Bagnat

The notochord plays critical structural and signaling roles during vertebrate development. At the center of the vertebrate notochord is a large fluid-filled organelle, the notochord vacuole. Although these highly conserved intracellular structures have been described for decades, little is known about the molecular mechanisms involved in their biogenesis and maintenance. Here we show that zebrafish notochord vacuoles are specialized lysosome-related organelles whose formation and maintenance requires late endosomal trafficking regulated by the vacuole-specific Rab32a and H+-ATPase–dependent acidification. We establish that notochord vacuoles are required for body axis elongation during embryonic development and identify a novel role in spine morphogenesis. Thus, the vertebrate notochord plays important structural roles beyond early development.


2019 ◽  
Author(s):  
Allison Edgar ◽  
Maria Byrne ◽  
David R. McClay ◽  
Gregory A. Wray

AbstractDevelopmental gene regulatory networks (GRNs) describe the interactions among gene products that drive the differential transcriptional and cell regulatory states that pattern the embryo and specify distinct cell fates. GRNs are often deeply conserved, but whether this is the product of constraint inherent to the network structure or stabilizing selection remains unclear. We have constructed the first formal GRN for early development in Heliocidaris erythrogramma, a species with dramatically accelerated, direct development. This life history switch has important ecological consequences, arose rapidly, and has evolved independently many times in echinoderms, suggesting it is a product of selection. We find that H. erythrogramma exhibits dramatic differences in GRN topology compared with ancestral, indirect-developing sea urchins. In particular, the GRN sub-circuit that directs the early and autonomous commitment of skeletogenic cell precursors in indirect developers appears to be absent in H. erythrogramma, a particularly striking change in relation to both the prior conservation of this sub-circuit and the key role that these cells play ancestrally in early development as the embryonic signaling center. These results show that even highly conserved molecular mechanisms of early development can be substantially reconfigured in a relatively short evolutionary time span, suggesting that selection rather than constraint is responsible for the striking conservation of the GRN among other sea urchins.


2021 ◽  
Vol 55 (4) ◽  
pp. 234-237
Author(s):  
Annamaria Srancikova ◽  
Alexandra Reichova ◽  
Zuzana Bacova ◽  
Jan Bakos

Abstract Objectives. The balance between DNA methylation and demethylation is crucial for the brain development. Therefore, alterations in the expression of enzymes controlling DNA methylation patterns may contribute to the etiology of neurodevelopmental disorders, including autism. SH3 and multiple ankyrin repeat domains 3 (Shank3)-deficient mice are commonly used as a well-characterized transgenic model to investigate the molecular mechanisms of autistic symptoms. DNA methyltransferases (DNMTs), which modulate several cellular processes in neurodevelopment, are implicated in the pathophysiology of autism. In this study, we aimed to describe the gene expression changes of major Dnmts in the brain of Shank3-deficient mice during early development. Methods and Results. The Dnmts gene expression was analyzed by qPCR in 5-day-old homo-zygous Shank3-deficient mice. We found significantly lower Dnmt1 and Dnmt3b gene expression levels in the frontal cortex. However, no such changes were observed in the hippocampus. However, significant increase was observed in the expression of Dnmt3a and Dnmt3b genes in the hypothalamus of Shank3-deficient mice. Conclusions. The present data indicate that abnormalities in the Shank3 gene are accompanied by an altered expression of DNA methylation enzymes in the early brain development stages, therefore, specific epigenetic control mechanisms in autism-relevant models should be more extensively investigated.


2020 ◽  
Author(s):  
Liyan Yang ◽  
Jingyun Tian ◽  
Manxi Zhu ◽  
Bo Yu ◽  
YI Sun

Abstract Background: Hydrogen gas (H2) is a newly-discovered signaling molecular that plays an important role in plants. This study investigated physiological and molecular mechanisms of hydrogen-rich water (HRW)-mediated beneficial effects on maize roots exposed to saline stress. Results: The results showed that growth of maize seedlings treated with 150 mM NaCl was greatly reduced. Under saline stress, 50% HRW diminished lipid damage in root which was confirmed by malondialdehyde (MDA) content assay and root histochemical staining, and the decreased activities of dismutase (SOD) and peroxidase (POD) further verified the reduced oxidant damage in roots cells under saline stress. HRW up-regulated the expression of ZmSOS1, ZmSKOR, and especially CDPK21 under saline stress, and it also stimulated the activities of PM H+-ATPase and tonoplast H+-ATPase and H+-PPase in maize roots. Thereby, Na+ content was decreased and K+ uptake was increased with the application of HRW. Conclusion: In summary, under saline stress, exogenous HRW application on maize roots up-regulated the key genes expression, improved H+-transport activity and thereby maintained the Na+/K+ balance, diminished oxidant damage and therefore promoted the root growth and biomass accumulation. Our results suggested exogenous HRW treatment on maize could improve root development under saline conditions and might be applied to alleviate salinity stress.


Development ◽  
1994 ◽  
Vol 1994 (Supplement) ◽  
pp. 193-199
Author(s):  
Diethard Tautz ◽  
Markus Friedrich ◽  
Reinhard Schröder

The systematic genetic analysis of Drosophila development has provided us with a deep insight into the molecular pathways of early embryogenesis. The question arises now whether these insights can serve as a more general paradigm of early development, or whether they apply only to advanced insect orders. Though it is too early to give a definitive answer to this question, we suggest that there is currently no firm reason to believe that the molecular mechanisms that were elucidated in Drosophila may not also apply to other forms of insect embryogenesis. Thus, many of the Drosophila genes involved in early pattern formation may have comparable functions in other insects and possibly throughout the arthropods.


2006 ◽  
Vol 26 (3) ◽  
pp. 1142-1155 ◽  
Author(s):  
Shingo Kajimura ◽  
Katsumi Aida ◽  
Cunming Duan

ABSTRACT Insulin-like growth factor binding protein 1 (IGFBP-1) is a hypoxia-inducible gene that plays an important role in regulating embryonic growth and development under hypoxic stress. The molecular mechanisms underlying hypoxia-induced IGFBP-1 gene expression in the embryonic tissues are not well understood. Here we report that the hypoxia-inducible factor 1 (HIF-1) pathway is established in early embryogenesis and mediates hypoxia-induced IGFBP-1 expression. Hypoxia increased the HIF-1 activity, and HIF-1α overexpression or CoCl2 treatment resulted in elevated IGFBP-1 expression in zebra fish embryos. Although the zebra fish IGFBP-1 promoter contains 13 consensus hypoxia response elements (HREs), deletion and mutational analysis revealed that only the HRE positioned at −1090/−1086 is required for the hypoxia and HIF-1 induction. Further experiments revealed that there is an HIF-1 ancillary sequence (HAS) adjacent only to the functional HRE. Mutation of this HAS greatly reduced the responsiveness of the IGFBP-1 promoter to hypoxia and HIF-1. The HAS does not directly bind to HIF-1 or affect the binding of the HRE to HIF-1. The HAS is bound to a nuclear protein(s), and this HAS binding activity is reduced by hypoxia. These results suggest that HIF-1 mediates hypoxia-induced IGFBP-1 gene expression in early development by selectively interacting with the −1090/−1086 HRE and its adjacent HAS.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4345 ◽  
Author(s):  
Jóhannes Guðbrandsson ◽  
Sigríður Rut Franzdóttir ◽  
Bjarni Kristófer Kristjánsson ◽  
Ehsan Pashay Ahi ◽  
Valerie Helene Maier ◽  
...  

Phenotypic differences between closely related taxa or populations can arise through genetic variation or be environmentally induced, leading to altered transcription of genes during development. Comparative developmental studies of closely related species or variable populations within species can help to elucidate the molecular mechanisms related to evolutionary divergence and speciation. Studies of Arctic charr (Salvelinus alpinus) and related salmonids have revealed considerable phenotypic variation among populations and in Arctic charr many cases of extensive variation within lakes (resource polymorphism) have been recorded. One example is the four Arctic charr morphs in the ∼10,000 year old Lake Thingvallavatn, which differ in numerous morphological and life history traits. We set out to investigate the molecular and developmental roots of this polymorphism by studying gene expression in embryos of three of the morphs reared in a common garden set-up. We performed RNA-sequencing, de-novo transcriptome assembly and compared gene expression among morphs during an important timeframe in early development, i.e., preceding the formation of key trophic structures. Expectedly, developmental time was the predominant explanatory variable. As the data were affected by some form of RNA-degradation even though all samples passed quality control testing, an estimate of 3′-bias was the second most common explanatory variable. Importantly, morph, both as an independent variable and as interaction with developmental time, affected the expression of numerous transcripts. Transcripts with morph effect, separated the three morphs at the expression level, with the two benthic morphs being more similar. However, Gene Ontology analyses did not reveal clear functional enrichment of transcripts between groups. Verification via qPCR confirmed differential expression of several genes between the morphs, including regulatory genes such as AT-Rich Interaction Domain 4A (arid4a) and translin (tsn). The data are consistent with a scenario where genetic divergence has contributed to differential expression of multiple genes and systems during early development of these sympatric Arctic charr morphs.


Development ◽  
1995 ◽  
Vol 121 (3) ◽  
pp. 693-705 ◽  
Author(s):  
G. Oliver ◽  
R. Wehr ◽  
N.A. Jenkins ◽  
N.G. Copeland ◽  
B.N. Cheyette ◽  
...  

In vertebrates, limb tendons are derived from cells that migrate from the lateral plate mesoderm during early development. While some of the developmental steps leading to the formation of these tissues are known, little is known about the molecular mechanisms controlling them. We have identified two murine homeobox-containing genes, Six 1 and Six 2, which are expressed in a complementary fashion during the development of limb tendons. Transcripts for both genes are found in different sets of phalangeal tendons. Six 1 and Six 2 also are expressed in skeletal and smooth muscle, respectively. These genes may participate in the patterning of the distal tendons of the limb phalanges by setting positional values along the limb axes.


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