scholarly journals Persistent parental RNAi in the beetle Tribolium castaneum involves maternal transmission of long double-stranded RNA

2021 ◽  
Author(s):  
Thorsten Horn ◽  
Kalin D. Narov ◽  
Kristen A. Panfilio
Keyword(s):  
Tribolium Castaneum ◽  
Double Stranded Rna ◽  
Highly Sensitive ◽  
Systemic Rnai ◽  
Clustering Data ◽  
Copy Number Changes ◽  
Hierarchical Assessment ◽  
Visualization Strategy ◽  
Rnai Response

Parental RNA interference (pRNAi) is a powerful and widely used method for gene-specific knockdown. Yet in insects its efficacy varies between species, and how the systemic RNAi response is transmitted from mother to offspring remains elusive. Using the flour beetle Tribolium castaneum, we report an RT-qPCR strategy to unmask the presence of double-stranded RNA (dsRNA) distinct from endogenous mRNA. We find that the injected dsRNA is directly transmitted into the egg and persists throughout embryogenesis. Despite this depletion of dsRNA from the mother, we show that strong pRNAi can persist for months before waning at strain-specific rates. In seeking the receptor proteins for cellular uptake of long dsRNA into the egg, we lastly present a phylogenomics profiling approach to ascertain macroevolutionary distributions of candidate proteins. We demonstrate a visualization strategy based on taxonomically hierarchical assessment of orthology clustering data to rapidly assess gene age and copy number changes, refined by several lines of sequence-based evidence. We use this approach to document repeated losses of SID-1-like channel proteins in the arthropods, including wholesale loss in the Heteroptera (true bugs), which are nonetheless highly sensitive to pRNAi. Overall, we elucidate practical considerations for insect pRNAi against a backdrop of outstanding questions on the molecular mechanism of dsRNA transmission to achieve long-term, systemic knockdown.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

scholarly journals Analysis of maxillopedia Expression Pattern and Larval Cuticular Phenotype in Wild-Type and Mutant Tribolium

Genetics ◽  
2000 ◽  
Vol 155 (2) ◽  
pp. 721-731 ◽  
Author(s):  
Teresa D Shippy ◽  
Jianhua Guo ◽  
Susan J Brown ◽  
Richard W Beeman ◽  
Robin E Denell
Keyword(s):  
Rna Interference ◽  
Expression Pattern ◽  
Tribolium Castaneum ◽  
Expression Patterns ◽  
Ectopic Expression ◽  
Homeotic Gene ◽  
Wild Type ◽  
Double Stranded Rna ◽  
Similar Expression ◽  
Mutant Phenotypes

Abstract The Tribolium castaneum homeotic gene maxillopedia (mxp) is the ortholog of Drosophila proboscipedia (pb). Here we describe and classify available mxp alleles. Larvae lacking all mxp function die soon after hatching, exhibiting strong transformations of maxillary and labial palps to legs. Hypomorphic mxp alleles produce less severe transformations to leg. RNA interference with maxillopedia double-stranded RNA results in phenocopies of mxp mutant phenotypes ranging from partial to complete transformations. A number of gain-of-function (GOF) mxp alleles have been isolated based on transformations of adult antennae and/or legs toward palps. Finally, we have characterized the mxp expression pattern in wild-type and mutant embryos. In normal embryos, mxp is expressed in the maxillary and labial segments, whereas ectopic expression is observed in some GOF variants. Although mxp and Pb display very similar expression patterns, pb null embryos develop normally. The mxp mutant larval phenotype in Tribolium is consistent with the hypothesis that an ancestral pb-like gene had an embryonic function that was lost in the lineage leading to Drosophila.

scholarly journals Discounting Disentangled

2018 ◽  
Vol 10 (4) ◽  
pp. 109-134 ◽  
Author(s):  
Moritz A. Drupp ◽  
Mark C. Freeman ◽  
Ben Groom ◽  
Frikk Nesje
Keyword(s):  
Discount Rate ◽  
Time Preference ◽  
Wealth Effect ◽  
Social Discount Rate ◽  
Economic Values ◽  
Public Projects ◽  
Highly Sensitive ◽  
The Social ◽  
Ramsey Rule

The economic values of investing in long-term public projects are highly sensitive to the social discount rate (SDR). We surveyed over 200 experts to disentangle disagreement on the risk-free SDR into its component parts, including pure time preference, the wealth effect, and return to capital. We show that the majority of experts do not follow the simple Ramsey Rule, a widely used theoretical discounting framework, when recommending SDRs. Despite disagreement on discounting procedures and point values, we obtain a surprising degree of consensus among experts, with more than three-quarters finding the median risk-free SDR of 2 percent acceptable. (JEL C83, D61, D82, H43, Q58)

Effects of long-term protection from grazing on phenotypic expression in geographically separated mountain rough fescue populations

2014 ◽  
Vol 94 (1) ◽  
pp. 33-39 ◽  
Author(s):  
D. J. Thompson ◽  
W. D. Willms
Keyword(s):  
Plant Communities ◽  
Phenotypic Expression ◽  
Highly Sensitive ◽  
History Of ◽  
Genetic Makeup ◽  
Rough Fescue ◽  
Geographic Sources ◽  
Lake Site ◽  
Summer Grazing

Thompson, D. J. and Willms, W. D. 2014. Effects of long-term protection from grazing on phenotypic expression in geographically separated mountain rough fescue populations. Can. J. Plant Sci. 94: 33–39. Whether or not long-term grazing or protection from grazing alters the genetic makeup of grass populations has been debated. Mountain rough fescue [(Festuca campestris (Rydb.)], which is highly sensitive to summer grazing, and becomes dominant in plant communities with long-term protection, was chosen to address this question. Plants from three geographic sites (Stavely in AB, Milroy in the Kootenay trench, BC and Goose Lake on the BC interior plateau) with divergent grazing histories were vegetatively propagated from tillers. Daughter plants were planted into two field nurseries (at Kamloops, BC, and Stavely, AB) and morphological measurements were taken in two field seasons post-establishment. Plants from all three populations were taller, flowered earlier, and were more productive at the Kamloops nursery site. Of the three geographic sources, plants from the Goose Lake site were most distinct with narrower leaves, later flowering, and greater yield. Plants with a long history of grazing had slightly shorter fertile tillers and leaves than plants with a history of long-term protection.

scholarly journals dsCheck: highly sensitive off-target search software for double-stranded RNA-mediated RNA interference

2005 ◽  
Vol 33 (Web Server) ◽  
pp. W589-W591 ◽  
Author(s):  
Y. Naito ◽  
T. Yamada ◽  
T. Matsumiya ◽  
K. Ui-Tei ◽  
K. Saigo ◽  
...  
Keyword(s):  
Rna Interference ◽  
Target Search ◽  
Double Stranded Rna ◽  
Highly Sensitive

scholarly journals The external environment of birds as a factor of immunobiochemical conditions

2020 ◽  
Vol 9 (3) ◽  
pp. 152-157
Author(s):  
Rinat R. Fatkullin ◽  
Aikumis K. Saken
Keyword(s):  
Metabolic Disorders ◽  
Clinical Manifestations ◽  
The Body ◽  
Household Waste ◽  
Trophic Chain ◽  
Behavioral Strategies ◽  
The Public ◽  
Initial Stage ◽  
Highly Sensitive

Abnormal environmental factors contribute to advanced behavioral strategies in higher regulatory centers as well as to the assessment of possible morphofunctional and energy transformations in the body. Animals, especially birds, which are characterized by curiosity, are highly sensitive to the presence of environmental pollution, since they interact with elements of the environment and surroundings. Contamination of broiler products can also be caused by contaminated soil and dust, unknown sources of persistent heavy metals and organic pollutants that are unknown to the public, such as car wreckage, household waste, and so on. In general, adverse factors that regularly affect small details do not require significant changes in the body at the initial stage, mainly affect non-specific mechanisms that lead to long-term activation. The paper contains significant work based on the analysis of microbiogenic links in the trophic chain, but the formation of processes associated with metabolic disorders from the development of trace elements to clinical manifestations is still insufficiently studied, so it is difficult to diagnose and treat previously unknown animal diseases in veterinary practice.

scholarly journals E. coli OxyS non-coding RNA does not trigger RNAi in C. elegans

2014 ◽  
Author(s):  
Alper Akay ◽  
Peter Sarkies ◽  
Eric Alexander Miska
Keyword(s):  
Small Rnas ◽  
Biological Function ◽  
Rapid Development ◽  
Rnai Pathway ◽  
Regulate Gene Expression ◽  
Double Stranded Rna ◽  
E Coli ◽  
C Elegans ◽  
Non Coding Rna ◽  
Rnai Response

The discovery of RNA interference (RNAi) in C. elegans has had a major impact on scientific research, led to the rapid development of RNAi tools and has inspired RNA-based therapeutics. Astonishingly, nematodes, planaria and many insects take up double-stranded RNA (dsRNA) from their environment to elicit RNAi; the biological function of this mechanism is unclear. Recently, the E. coli OxyS non-coding RNA was shown to regulate gene expression in C. elegans when E. coli is offered as food. This was surprising given that C. elegans is unlikely to encounter E. coli in nature. To directly test the hypothesis that the E. coli OxyS non-coding RNA triggers the C. elegans RNAi pathway, we sequenced small RNAs from C. elegans after feeding with bacteria. We clearly demonstrate that the OxyS non-coding RNA does not trigger an RNAi response in C. elegans. We conclude that the biology of environmental RNAi remains to be discovered.

scholarly journals DNA Amplifications and Aneuploidy, High Proliferative Activity and Impaired Cell Cycle Control Characterize Breast Carcinomas with Poor Prognosis

2003 ◽  
Vol 25 (3) ◽  
pp. 103-114 ◽  
Author(s):  
Harald Blegen ◽  
John S. Will ◽  
B. Michael Ghadimi ◽  
Hesed‐Padilla Nash ◽  
Anders Zetterberg ◽  
...  
Keyword(s):  
Copy Number ◽  
Proliferative Activity ◽  
Distant Metastases ◽  
Comparative Genomic ◽  
Short Term ◽  
Ki 67 ◽  
Chromosomal Copy ◽  
Copy Number Changes ◽  
Long Term Survivors

In order to explore whether specific cytogenetic abnormalities can be used to stratify tumors with a distinctly different clinical course, we performed comparative genomic hybridization (CGH) of tumors from patients who were diagnosed with metastatic disease after an interval of less than 2 years or who remained free from distant metastases for more than 10 years. All patients presented with distant metastases after mastectomy indicating that none of the patients in this study was cured and free of remaining tumor cells. Tumors in the group of short‐term survivors showed a higher average number of chromosomal copy alterations compared to the long‐term survivors. Of note, the number of sub‐chromosomal high‐level copy number increases (amplifications) was significantly increased in the group of short‐term survivors. In both short‐ and long‐term survivors recurrent chromosomal gains were mapped to chromosomes 1q, 4q, 8q, and 5p. Copy number changes that were more frequent in the group of short‐term survivors included gains of chromosome 3q, 9p, 11p and 11q and loss of 17p. Our results indicate that low‐ and high grade malignant breast adenocarcinomas are characterized by a specific pattern of chromosomal copy number changes. Furthermore, immunohistochemical evaluation of the expression levels of Ki‐67, p27KIP1, p21WAF1, p53, cyclin A and cyclin E revealed a correlation between increased proliferative activity and poor outcome.

scholarly journals Red flour beetle (Tribolium castaneum): From population genetics to functional genomics

2018 ◽  
pp. 1043-1046 ◽  
Author(s):  
Harshit Kumar ◽  
Manjit Panigrahi ◽  
Supriya Chhotaray ◽  
V. Bhanuprakash ◽  
Rahul Shandilya ◽  
...  
Keyword(s):  
Functional Genomics ◽  
Tribolium Castaneum ◽  
Insertional Mutagenesis ◽  
Molecular Genetic ◽  
Genetic Studies ◽  
Immune Priming ◽  
Systemic Rnai ◽  
Basic Facts

Tribolium castaneum is a small and low maintenance beetle that has emerged as a most suitable insect model for studying developmental biology and functional genetic analysis. Diverse population genetic studies have been conducted using Tribolium as the principal model to establish basic facts and principles of inbreeding experiments and response to the selection and other quantitative genetics fundamentals. The advanced molecular genetic studies presently focused on the use of Tribolium as a typical invertebrate model for higher diploid eukaryotes. After a whole genome sequencing of Tribolium, many areas of functional genomics were unraveled, which enabled the use of it in many technical approaches of genomics. The present text reviews the use of Tribolium in techniques such as RNAi, transgenic studies, immune priming, immunohistochemistry, in situ hybridization, gene sequencing for characterization of microRNAs, and gene editing using engineered endonuclease. In contrast to Drosophila, the T. castaneum holds a robust systemic RNAi response, which makes it an excellent model for comparative functional genetic studies. Keywords: functional genomics, hox gene, insertional mutagenesis, RNAi, Tribolium.

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