scholarly journals RNA Interference by Cyanobacterial Feeding Demonstrates the SCSG1 Gene Is Essential for Ciliogenesis during Oral Apparatus Regeneration in Stentor

2021 ◽  
Vol 9 (1) ◽  
pp. 176
Author(s):  
Wei Wei ◽  
Chuanqi Jiang ◽  
Xiaocui Chai ◽  
Juyuan Zhang ◽  
Cheng-Cai Zhang ◽  
...  

In the giant ciliate Stentor coeruleus, oral apparatus (OA) regeneration is an experimentally tractable regeneration paradigm that occurs via a series of morphological steps. OA regeneration is thought to be driven by a complex regulatory system that orchestrates the temporal expression of conserved and specific genes. We previously identified a S. coeruleus-specific gene (named SCSG1) that was significantly upregulated during the ciliogenesis stages of OA regeneration, with an expression peak at the stage of the first OA cilia appearance. We established a novel RNA interference (RNAi) method through cyanobacteria Synechocystis sp. PCC6803 feeding in S. coeruleus. The expression of SCSG1 gene was significantly knocked down by using this method and induced abnormal ciliogenesis of OA regeneration in S. coeruleus, suggesting that SCSG1 is essential for OA regeneration in S. coeruleus. This novel RNAi method by cyanobacterial feeding has potential utility for studying other ciliates.

2018 ◽  
Vol 24 (23) ◽  
pp. 2631-2631
Author(s):  
Fabiola Garcia Praça ◽  
Maria Vitória Lopes Badra Bentley


2002 ◽  
Vol 22 (15) ◽  
pp. 5467-5478 ◽  
Author(s):  
François Boudreau ◽  
Edmond H. H. M. Rings ◽  
Gary P. Swain ◽  
Angus M. Sinclair ◽  
Eun Ran Suh ◽  
...  

ABSTRACT Intestinal gene regulation involves mechanisms that direct temporal expression along the vertical and horizontal axes of the alimentary tract. Sucrase-isomaltase (SI), the product of an enterocyte-specific gene, exhibits a complex pattern of expression. Generation of transgenic mice with a mutated SI transgene showed involvement of an overlapping CDP (CCAAT displacement protein)-GATA element in colonic repression of SI throughout postnatal intestinal development. We define this element as CRESIP (colon-repressive element of the SI promoter). Cux/CDP interacts with SI and represses SI promoter activity in a CRESIP-dependent manner. Cux/CDP homozygous mutant mice displayed increased expression of SI mRNA during early postnatal development. Our results demonstrate that an intestinal gene can be repressed in the distal gut and identify Cux/CDP as a regulator of this repression during development.


2012 ◽  
Vol 56 (7) ◽  
pp. 3516-3523 ◽  
Author(s):  
Jeonghyun Ahn ◽  
Ara Ko ◽  
Eun Jung Jun ◽  
Minah Won ◽  
Yoo Kyum Kim ◽  
...  

ABSTRACTAntiviral therapeutics are currently unavailable for treatment of coxsackievirus B3, which can cause life-threatening myocarditis. A modified small interfering RNA (siRNA) containing 5′-triphosphate, 3p-siRNA, was shown to induce RNA interference and interferon activation. We aimed to develop a potent antiviral treatment using CVB3-specific 3p-siRNA and to understand its underlying mechanisms. Virus-specific 3p-siRNA was superior to both conventional virus-specific siRNA with an empty hydroxyl group at the 5′ end (OH-siRNA) and nonspecific 3p-siRNA in decreasing viral replication and subsequent cytotoxicity. A single administration of 3p-siRNA dramatically attenuated virus-associated pathological symptoms in mice with no signs of toxicity, and their body weights eventually reached the normal range. Myocardial inflammation and fibrosis were rare, and virus production was greatly reduced. A nonspecific 3p-siRNA showed relatively less protective effect under identical conditions, and a virus-specific OH-siRNA showed no protective effects. We confirmed that virus-specific 3p-siRNA simultaneously activated target-specific gene silencing and type I interferon signaling. We provide a clear proof of concept that coxsackievirus B3-specific 3p-siRNA has 2 distinct modes of action, which significantly enhance antiviral activities with minimal organ damage. This is the first direct demonstration of improved antiviral effects with an immunostimulatory virus-specific siRNA in coxsackievirus myocarditis, and this method could be applied to many virus-related diseases.


2005 ◽  
Vol 45 (8) ◽  
pp. 995 ◽  
Author(s):  
A. E. Lew ◽  
L. A. Jackson ◽  
M. I. Bellgard

Non-coding (nc) RNAs are important regulators of developmental genes, and essential for the modification of cellular DNA and chromatin through a process known as RNA interference (RNAi). The mediators of RNAi can be in the form of short double stranded (ds) RNAs, micro (mi) RNAs or small interfering (si) RNAs. miRNAs are involved in a translation repression pathway that inhibits protein translation in mRNA targets. Comparative genomic screens have revealed conserved regulatory non-coding sequences, which assist to predict the function of endogenous miRNAs. Only a few comparative studies include bovine genomic sequence, and RNAi has yet to be applied in bovine genome functional screens. siRNAs target homologous mRNAs for degradation, and thereby, silence specific genes. The use of synthetic siRNAs facilitates the elucidation of gene pathways by specific gene knockdown. A survey of the literature identifies a small number of reports using RNAi to examine immune pathways in bovine cell lines; however, they do not target genes involved in specific production traits. Applications of RNAi to elucidate bovine immune pathways for relevant bacterial and parasite diseases are yet to be reported. The inhibition of viral replication using RNAi has been demonstrated with bovine RNA viruses such as pestivirus and foot and mouth disease virus signifying the potential of RNAi as an antiviral therapeutic. RNAi approaches combined with genome data for protozoan parasites, insects and nematodes, will expedite the identification of novel targets for the treatment and prevention of economically important parasitic infections. This review will examine the approaches used in mammalian RNAi research, the current status of its applications to livestock systems and will discuss potential applications in beef cattle programs.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2673 ◽  
Author(s):  
Roberto A. Camargo ◽  
Guilherme O. Barbosa ◽  
Isabella Presotto Possignolo ◽  
Lazaro E. P. Peres ◽  
Eric Lam ◽  
...  

RNA interference (RNAi), a gene-silencing mechanism that involves providing double-stranded RNA molecules that match a specific target gene sequence, is now widely used in functional genetic studies. The potential application of RNAi-mediated control of agricultural insect pests has rapidly become evident. The production of transgenic plants expressing dsRNA molecules that target essential insect genes could provide a means of specific gene silencing in larvae that feed on these plants, resulting in larval phenotypes that range from loss of appetite to death. In this report, we show that the tomato leafminer (Tuta absoluta), a major threat to commercial tomato production, can be targeted by RNAi. We selected two target genes (Vacuolar ATPase-AandArginine kinase) based on the RNAi response reported for these genes in other pest species. In view of the lack of an artificial diet forT. absoluta, we used two approaches to deliver dsRNA into tomato leaflets. The first approach was based on the uptake of dsRNA by leaflets and the second was based on “in planta-induced transient gene silencing” (PITGS), a well-established method for silencing plant genes, used here for the first time to deliverin planta-transcribed dsRNA to target insect genes.Tuta absolutalarvae that fed on leaves containing dsRNA of the target genes showed an ∼60% reduction in target gene transcript accumulation, an increase in larval mortality and less leaf damage. We then generated transgenic ‘Micro-Tom’ tomato plants that expressed hairpin sequences for both genes and observed a reduction in foliar damage byT. absolutain these plants. Our results demonstrate the feasibility of RNAi as an alternative method for controlling this critical tomato pest.


2006 ◽  
Vol 2006 ◽  
pp. 1-13 ◽  
Author(s):  
Shi-Lung Lin ◽  
Joseph D. Miller ◽  
Shao-Yao Ying

Nearly 97% of the human genome is composed of noncoding DNA, which varies from one species to another. Changes in these sequences often manifest themselves in clinical and circumstantial malfunction. Numerous genes in these non-protein-coding regions encode microRNAs, which are responsible for RNA-mediated gene silencing through RNA interference (RNAi)-like pathways. MicroRNAs (miRNAs), small single-stranded regulatory RNAs capable of interfering with intracellular messenger RNAs (mRNAs) with complete or partial complementarity, are useful for the design of new therapies against cancer polymorphisms and viral mutations. Currently, many varieties of miRNA are widely reported in plants, animals, and even microbes. Intron-derived microRNA (Id-miRNA) is a new class of miRNA derived from the processing of gene introns. The intronic miRNA requires type-II RNA polymerases (Pol-II) and spliceosomal components for their biogenesis. Several kinds of Id-miRNA have been identified inC elegans, mouse, and human cells; however, neither function nor application has been reported. Here, we show for the first time that intron-derived miRNAs are able to induce RNA interference in not only human and mouse cells, but in also zebrafish, chicken embryos, and adult mice, demonstrating the evolutionary preservation of intron-mediated gene silencing via functional miRNA in cell and in vivo. These findings suggest an intracellular miRNA-mediated gene regulatory system, fine-tuning the degradation of protein-coding messenger RNAs.


2016 ◽  
Author(s):  
Roberto A Camargo ◽  
Guilherme O Barbosa ◽  
Isabella Presotto Possignolo ◽  
Lazaro E. P. Peres ◽  
Eric Lam ◽  
...  

RNA interference (RNAi), a gene-silencing mechanism that involves providing double-stranded RNA molecules that match a specific target gene sequence, is now widely used in functional genetic studies. The potential application of RNAi-mediated control of agricultural insect pests has rapidly become evident. The production of transgenic plants expressing dsRNA molecules that target essential insect genes could provide a means of specific gene silencing in larvae that feed on these plants, resulting in larval phenotypes that range from loss of appetite to death. In this report, we show that the tomato leafminer (Tuta absoluta), a major threat to commercial tomato production, can be targeted by RNAi. We selected two target genes [Vacuolar ATPase-A and Arginine kinase] based on the RNAi response reported for these genes in other pest species. In view of the lack of an artificial diet for T. absoluta, we used two approaches to deliver dsRNA into tomato leaflets. The first approach was based on the uptake of dsRNA by leaflets and the second was based on “in planta-induced transient gene silencing” (PITGS), a well-established method for silencing plant genes, used here for the first time to deliver in planta-transcribed dsRNA to target insect genes. Tuta absoluta larvae that fed on leaves containing dsRNA of the target genes showed an ~60% reduction in target gene transcript accumulation, an increase in larval mortality and less leaf damage. We then generated transgenic ‘Micro-Tom’ tomato plants that expressed hairpin sequences for both genes and observed a reduction in foliar damage by T. absoluta in these plants. Our results demonstrate the feasibility of RNAi as an alternative method for controlling this critical tomato pest.


Author(s):  
Changping Deng ◽  
Fabiao Hu ◽  
Zhangting Zhao ◽  
Yiwen Zhou ◽  
Yuping Liu ◽  
...  

Quantitative analysis and regulating gene expression in cancer cells is an innovative method to study key genes in tumors, which conduces to analyze the biological function of the specific gene. In this study, we found the expression levels of Survivin protein (BIRC5) and P-glycoprotein (MDR1) in MCF-7/doxorubicin (DOX) cells (drug-resistant cells) were significantly higher than MCF-7 cells (wild-type cells). In order to explore the specific functions of BIRC5 gene in multi-drug resistance (MDR), a CRISPR/Cas9-mediated knocking-in tetracycline (Tet)-off regulatory system cell line was established, which enabled us to regulate the expression levels of Survivin quantitatively (clone 8 named MCF-7/Survivin was selected for further studies). Subsequently, the determination results of doxycycline-induced DOX efflux in MCF-7/Survivin cells implied that Survivin expression level was opposite to DOX accumulation in the cells. For example, when Survivin expression was down-regulated, DOX accumulation inside the MCF-7/Survivin cells was up-regulated, inducing strong apoptosis of cells (reversal index 118.07) by weakening the release of intracellular drug from MCF-7/Survivin cells. Also, down-regulation of Survivin resulted in reduced phosphorylation of PI3K, Akt, and mTOR in MCF-7/Survivin cells and significantly decreased P-gp expression. Previous studies had shown that PI3K/Akt/mTOR could regulate P-gp expression. Therefore, we speculated that Survivin might affect the expression of P-gp through PI3K/Akt/mTOR pathway. In summary, this quantitative method is not only valuable for studying the gene itself, but also can better analyze the biological phenomena related to it.


Endocrinology ◽  
2016 ◽  
Vol 157 (4) ◽  
pp. 1385-1396 ◽  
Author(s):  
Shannon W. Davis ◽  
Jessica L. Keisler ◽  
María I. Pérez-Millán ◽  
Vanessa Schade ◽  
Sally A. Camper

Abstract Mutations in PROP1, the most common known cause of combined pituitary hormone deficiency in humans, can result in the progressive loss of all hormones of the pituitary anterior lobe. In mice, Prop1 mutations result in the failure to initiate transcription of Pou1f1 (also known as Pit1) and lack somatotropins, lactotropins, and thyrotropins. The basis for this species difference is unknown. We hypothesized that Prop1 is expressed in a progenitor cell that can develop into all anterior lobe cell types, and not just the somatotropes, thyrotropes, and lactotropes, which are collectively known as the PIT1 lineage. To test this idea, we produced a transgenic Prop1-cre mouse line and conducted lineage-tracing experiments of Prop1-expressing cells. The results reveal that all hormone-secreting cell types of both the anterior and intermediate lobes are descended from Prop1-expressing progenitors. The Prop1-cre mice also provide a valuable genetic reagent with a unique spatial and temporal expression for generating tissue-specific gene rearrangements early in pituitary gland development. We also determined that the minimal essential sequences for reliable Prop1 expression lie within 10 kilobases of the mouse gene and demonstrated that human PROP1 can substitute functionally for mouse Prop1. These studies enhance our understanding of the pathophysiology of disease in patients with PROP1 mutations.


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