Double-stranded RNA interference in the spider Cupiennius salei : the role of Distal-less is evolutionarily conserved in arthropod appendage formation

2001 ◽  
Vol 211 (2) ◽  
pp. 76-82 ◽  
Author(s):  
Michael Schoppmeier ◽  
Wim G.M. Damen
Keyword(s):  
Rna Interference ◽  
Cupiennius Salei ◽  
Double Stranded Rna ◽  
Evolutionarily Conserved ◽  
Appendage Formation ◽  
Spider Cupiennius Salei

scholarly journals Viroids as a Tool to Study RNA-Directed DNA Methylation in Plants

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1187
Author(s):  
Michael Wassenegger ◽  
Athanasios Dalakouras
Keyword(s):  
Dna Methylation ◽  
Rna Interference ◽  
Gene Silencing ◽  
Plant Cells ◽  
Transcriptional Gene Silencing ◽  
Rnai Machinery ◽  
Double Stranded Rna ◽  
Post Transcriptional Gene Silencing ◽  
Cumulative Amount

Viroids are plant pathogenic, circular, non-coding, single-stranded RNAs (ssRNAs). Members of the Pospiviroidae family replicate in the nucleus of plant cells through double-stranded RNA (dsRNA) intermediates, thus triggering the host’s RNA interference (RNAi) machinery. In plants, the two RNAi pillars are Post-Transcriptional Gene Silencing (PTGS) and RNA-directed DNA Methylation (RdDM), and the latter has the potential to trigger Transcriptional Gene Silencing (TGS). Over the last three decades, the employment of viroid-based systems has immensely contributed to our understanding of both of these RNAi facets. In this review, we highlight the role of Pospiviroidae in the discovery of RdDM, expound the gradual elucidation through the years of the diverse array of RdDM’s mechanistic details and propose a revised RdDM model based on the cumulative amount of evidence from viroid and non-viroid systems.

Neurogenesis in the spiderCupiennius salei

Development ◽  
2001 ◽  
Vol 128 (14) ◽  
pp. 2673-2688 ◽  
Author(s):  
Angelika Stollewerk ◽  
Mathias Weller ◽  
Diethard Tautz
Keyword(s):  
Stem Cells ◽  
General Pattern ◽  
Cupiennius Salei ◽  
Double Stranded Rna ◽  
Helix Loop Helix ◽  
Cell Groups ◽  
Cell Processes ◽  
Encoding Genes ◽  
Sequence Similarities ◽  
Spider Cupiennius Salei

To uncover similarities and differences in neurogenesis in arthropod groups, we have studied the ventral neuroectoderm of the spider Cupiennius salei (Chelicerata, Aranea, Ctenidae). We found that invaginating cell groups arose sequentially, at stereotyped positions in each hemisegment and in separate waves, comparable with the generation of neuroblasts in Drosophila. However, we found no evidence for proliferating stem cells that would be comparable with the neuroblasts. Instead, the whole group of invaginating cells was directly recruited to the nervous system. The invagination process is comparable with Drosophila, with the cells attaining a bottle-shaped form with the nuclei moving inwards, while actin-rich cell processes remain initially connected to the surface of the epithelium. This general pattern is also found in another spider, Pholcus phalangioides, and appears thus to be conserved at least among the Araneae. We have identified two basic helix-loop-helix encoding genes – CsASH1 and CsASH2 – that share sequence similarities with proneural genes from other species. Functional analysis of the genes by double-stranded RNA interference revealed that CsASH1 was required for the formation of the invagination sites and the process of invagination itself, whereas CsASH2 seemed to be required for the differentiation of the cells into neurones. Our results suggest that the basic processes of neurogenesis, as well as proneural gene function is conserved among arthropods, apart of the lack of neuroblast-like stem cells in spiders.

scholarly journals The Role of Micrornas in Genome Response to Plant–Lepidoptera Interaction

Plants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 529
Author(s):  
Katarína Ražná ◽  
Ľudovít Cagáň
Keyword(s):  
Rna Interference ◽  
Immune Responses ◽  
Host Resistance ◽  
Defense Mechanism ◽  
Plant Protection ◽  
Regulation Of Gene Expression ◽  
Basic Principles ◽  
Double Stranded Rna ◽  
Rna Molecules

RNA interference is a known phenomenon of plant immune responses, involving the regulation of gene expression. The key components triggering the silencing of targeted sequences are double-stranded RNA molecules. The regulation of host–pathogen interactions is controlled by miRNA molecules, which regulate the expression of host resistance genes or the genes of the pathogen. The review focused on basic principles of RNA interference as a gene-silencing-based defense mechanism and the role of miRNA molecules in insect genomes. RNA interference as a tool for plant protection management is discussed. The review summarizes current miRNA-based biotechnology approaches for plant protection management.

scholarly journals RNAi targeting Caenorhabditis elegans α-arrestins has little effect on lifespan

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1515
Author(s):  
Sangsoon Park ◽  
Yoonji Jung ◽  
Seon Woo A. An ◽  
Heehwa G. Son ◽  
Wooseon Hwang ◽  
...  
Keyword(s):  
Rna Interference ◽  
Caenorhabditis Elegans ◽  
Functional Role ◽  
Future Research ◽  
Biological Processes ◽  
Receptor Desensitization ◽  
Double Stranded Rna ◽  
C Elegans

Background: α-arrestins are a family of proteins that are implicated in multiple biological processes, including metabolism and receptor desensitization. Methods: Here, we sought to examine the roles of α-arrestins in the longevity of Caenorhabditis elegans through an RNA interference screen. Results: We found that feeding worms with bacteria expressing double-stranded RNA against each of 24 out of total 29 C. elegans α-arrestins had little effect on lifespan. Thus, individual C. elegans α-arrestins may have minor effects on longevity. Conclusions: This study will provide useful information for future research on the functional role of α-arrestins in aging and longevity.

scholarly journals The Centriole Cartwheel Protein SAS-6 in Trypanosoma brucei Is Required for Probasal Body Biogenesis and Flagellum Assembly

2015 ◽  
Vol 14 (9) ◽  
pp. 898-907 ◽  
Author(s):  
Huiqing Hu ◽  
Yi Liu ◽  
Qing Zhou ◽  
Sara Siegel ◽  
Ziyin Li
Keyword(s):  
Cell Cycle ◽  
Rna Interference ◽  
Trypanosoma Brucei ◽  
Basal Body ◽  
Essential Role ◽  
Microtubule Organizing Center ◽  
Content Type ◽  
Evolutionarily Conserved ◽  
Organizing Center

ABSTRACT The centriole in eukaryotes functions as the cell's microtubule-organizing center (MTOC) to nucleate spindle assembly, and its biogenesis requires an evolutionarily conserved protein, SAS-6, which assembles the centriole cartwheel. Trypanosoma brucei , an early branching protozoan, possesses the basal body as its MTOC to nucleate flagellum biogenesis. However, little is known about the components of the basal body and their roles in basal body biogenesis and flagellum assembly. Here, we report that the T. brucei SAS-6 homolog, TbSAS-6, is localized to the mature basal body and the probasal body throughout the cell cycle. RNA interference (RNAi) of TbSAS-6 inhibited probasal body biogenesis, compromised flagellum assembly, and caused cytokinesis arrest. Surprisingly, overexpression of TbSAS-6 in T. brucei also impaired probasal body duplication and flagellum assembly, contrary to SAS-6 overexpression in humans, which produces supernumerary centrioles. Furthermore, we showed that depletion of T. brucei Polo-like kinase, TbPLK, or inhibition of TbPLK activity did not abolish TbSAS-6 localization to the basal body, in contrast to the essential role of Polo-like kinase in recruiting SAS-6 to centrioles in animals. Altogether, these results identified the essential role of TbSAS-6 in probasal body biogenesis and flagellum assembly and suggest the presence of a TbPLK-independent pathway governing basal body duplication in T. brucei .

scholarly journals Silencing of the Baculovirus Op-iap3 Gene by RNA Interference Reveals that It Is Required for Prevention of Apoptosis during Orgyia pseudotsugata M Nucleopolyhedrovirus Infection of Ld652Y Cells

2003 ◽  
Vol 77 (8) ◽  
pp. 4481-4488 ◽  
Author(s):  
John C. Means ◽  
Israel Muro ◽  
Rollie J. Clem
Keyword(s):  
Rna Interference ◽  
Double Stranded Rna ◽  
Orgyia Pseudotsugata ◽  
Baculovirus Gene ◽  
Wide Range ◽  
Infected Cells ◽  
Rnai Technique ◽  
Almost All ◽  
First Time

ABSTRACT The Op-iap3 gene from the baculovirus Orgyia pseudotsugata M nucleopolyhedrovirus (OpMNPV) inhibits apoptosis induced by a mutant of Autographa californica MNPV (AcMNPV) that lacks the antiapoptotic gene p35, as well as apoptosis induced by a wide range of other stimuli in both mammalian and insect cells. However, the role of Op-iap3 during OpMNPV infection has not been previously examined. To determine the function of the Op-IAP3 protein during OpMNPV infection, we used RNA interference (RNAi) to silence Op-iap3 expression during OpMNPV infection of Ld652Y cells. Infected cells treated with Op-iap3 double-stranded RNA (dsRNA) did not accumulate detectable Op-iap3 mRNA, confirming that the Op-iap3 gene was effectively silenced. Op-IAP3 protein was found to be a component of the budded virion; however, in OpMNPV-infected cells treated with Op-iap3 dsRNA, the Op-IAP3 protein that was introduced by the inoculum virus decreased to almost undetectable levels by 12 h after dsRNA addition. Apoptosis was observed in infected cells treated with Op-iap3 dsRNA beginning at 12 h, and by 48 h, almost all of the cells had undergone apoptosis. These results show for the first time that Op-IAP3 is necessary to prevent apoptosis during OpMNPV infection. In addition, our results demonstrate that the RNAi technique can be an effective tool for studying baculovirus gene function.

Parasegmental organization of the spider embryo implies that the parasegment is an evolutionary conserved entity in arthropod embryogenesis

Development ◽  
2002 ◽  
Vol 129 (5) ◽  
pp. 1239-1250 ◽  
Author(s):  
Wim G. M. Damen
Keyword(s):  
Hox Genes ◽  
Ventral Region ◽  
Cubitus Interruptus ◽  
Cupiennius Salei ◽  
Compartment Boundary ◽  
Segment Polarity ◽  
Engrailed Genes ◽  
Arthropod Development ◽  
Spider Cupiennius Salei

Spiders belong to the chelicerates, which is a basal arthropod group. To shed more light on the evolution of the segmentation process, orthologs of the Drosophila segment polarity genes engrailed, wingless/Wnt and cubitus interruptus have been recovered from the spider Cupiennius salei. The spider has two engrailed genes. The expression of Cs-engrailed-1 is reminiscent of engrailed expression in insects and crustaceans, suggesting that this gene is regulated in a similar way. This is different for the second spider engrailed gene, Cs-engrailed-2, which is expressed at the posterior cap of the embryo from which stripes split off, suggesting a different mode of regulation. Nevertheless, the Cs-engrailed-2 stripes eventually define the same border as the Cs-engrailed-1 stripes. The spider wingless/Wnt genes are expressed in different patterns from their orthologs in insects and crustaceans. The Cs-wingless gene is expressed in iterated stripes just anterior to the engrailed stripes, but is not expressed in the most ventral region of the germ band. However, Cs-Wnt5-1 appears to act in this ventral region. Cs-wingless and Cs-Wnt5-1 together seem to perform the role of insect wingless. Although there are differences, the wingless/Wnt-expressing cells and en-expressing cells seem to define an important boundary that is conserved among arthropods. This boundary may match the parasegmental compartment boundary and is even visible morphologically in the spider embryo. An additional piece of evidence for a parasegmental organization comes from the expression domains of the Hox genes that are confined to the boundaries, as molecularly defined by the engrailed and wingless/Wnt genes. Parasegments, therefore, are presumably important functional units and conserved entities in arthropod development and form an ancestral character of arthropods. The lack of by engrailed and wingless/Wnt-defined boundaries in other segmented phyla does not support a common origin of segmentation.

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