On the multiple expression of negation in Romance

2001 ◽  
pp. 87 ◽  
Author(s):  
Francis Corblin ◽  
Lucia M. Tovena
Keyword(s):  
Multiple Expression

DNA rearrangements and antigenic variation in Trypanosoma equiperdum: multiple expression-linked sites in independent isolates of trypanosomes expressing the same antigen

1983 ◽  
Vol 3 (3) ◽  
pp. 399-409
Author(s):  
S Longacre ◽  
U Hibner ◽  
A Raibaud ◽  
H Eisen ◽  
T Baltz ◽  
...  
Keyword(s):  
Immune Response ◽  
Molecular Mechanism ◽  
Antigenic Variation ◽  
Cdna Probe ◽  
Surface Glycoprotein ◽  
Dna Rearrangements ◽  
African Trypanosomes ◽  
Trypanosoma Equiperdum ◽  
Variant Surface Glycoproteins ◽  
Multiple Expression

African trypanosomes resist the immune response of their mammalian hosts by varying the surface glycoprotein which constitutes their antigenic identity. The molecular mechanism of this antigenic variation involves the successive activation of a series of genes which code for different variant surface glycoproteins (VSGs). We have studied the expression of two VSG genes (those of VSG-1 and VSG-28) in Trypanosoma equiperdum, and we report the following findings. (i) The expression of both VSG genes is associated with the duplication and transposition of corresponding basic copy genes. (ii) The duplicated transposed copy appears to be the expressed copy. (iii) Although there are multiple genes which cross-hybridize with the VSG-1 cDNA probe, only one of these appears to be used as a template for the expression-linked copy in four independent BoTat-1 clones. (iv) Analysis of the genomic environments of the expressed VSG-1 genes from each of four independently derived BoTat-1 trypanosome clones revealed that there are at least three different sites into which the expression-linked copy can be inserted.

scholarly journals Enhancer Trapping and Annotation in Zebrafish Mediated with Sleeping Beauty, piggyBac and Tol2 Transposons

Genes ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 630 ◽  
Author(s):  
Dan Shen ◽  
Songlei Xue ◽  
Shuheng Chan ◽  
Yatong Sang ◽  
Saisai Wang ◽  
...  
Keyword(s):  
Expression Profiles ◽  
Expression Patterns ◽  
Genomic Analysis ◽  
Sleeping Beauty ◽  
Comparative Genomic Analysis ◽  
Regulatory Function ◽  
Comparative Genomic ◽  
Gfp Expression ◽  
Enhancer Trapping ◽  
Multiple Expression

Although transposon-mediated enhancer trapping (ET) is successfully applied in diverse models, the efficiency of various transposon systems varies significantly, and little information is available regarding efficiency of enhancer trapping by various transposons in zebrafish. Most potential enhancers (Ens) still lack evidence of actual En activity. Here, we compared the differences in ET efficiency between sleeping beauty (SB), piggyBac (PB) and Tol2 transposons. Tol2 represented the highest germline transfer efficiencies at 55.56% (NF0 = 165), followed by SB (38.36%, NF0 = 151) and PB (32.65%, NF0 = 149). ET lines generated by the Tol2 transposon tended to produce offspring with a single expression pattern per line, while PB and SB tended to generate embryos with multiple expression patterns. In our tests, 10 putative Ens (En1–10) were identified by splinkerette PCR and comparative genomic analysis. Combining the GFP expression profiles and mRNA expression patterns revealed that En1 and En2 may be involved in regulation of the expression of dlx1a and dlx2a, while En6 may be involved in regulation of the expression of line TK4 transgene and rps26, and En7 may be involved in the regulation of the expression of wnt1 and wnt10b. Most identified Ens were found to be transcribed in zebrafish embryos, and their regulatory function may involve eRNAs.

scholarly journals A modular cloning toolkit for genome editing in plants

2019 ◽  
Author(s):  
Florian Hahn ◽  
Andrey Korolev ◽  
Laura Sanjurjo Loures ◽  
Vladimir Nekrasov
Keyword(s):  
Genome Editing ◽  
Higher Order ◽  
Plant Science ◽  
Golden Gate ◽  
Coding Sequences ◽  
Guide Rna ◽  
Guide Rnas ◽  
Science Community ◽  
Modular Cloning ◽  
Multiple Expression

AbstractBackgroundCRISPR/Cas has recently become a widely used genome editing tool in various organisms, including plants. Applying CRISPR/Cas often requires delivering multiple expression units into plant and hence there is a need for a quick and easy cloning procedure. The modular cloning (MoClo), based on the Golden Gate (GG) method, has enabled development of cloning systems with standardised genetic parts, e.g. promoters, coding sequences or terminators, that can be easily interchanged and assembled into expression units, which in their own turn can be further assembled into higher order multigene constructs.ResultsHere we present an expanded cloning toolkit that contains ninety-nine modules encoding a variety of CRISPR/Cas-based nucleases and their corresponding guide RNA backbones. Among other components, the toolkit includes a number of promoters that allow expression of CRISPR/Cas nucleases (or any other coding sequences) and their guide RNAs in monocots and dicots. As part of the toolkit, we present a set of modules that enable quick and facile assembly of tRNA-sgRNA polycistronic units without a PCR step involved. We also demonstrate that our tRNA-sgRNA system is functional in wheat protoplasts.ConclusionsWe believe the presented CRISPR/Cas toolkit is a great resource that will contribute towards wider adoption of the CRISPR/Cas genome editing technology and modular cloning by researchers across the plant science community.

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