Evidence map›Paper›PMID 29995583›Full record

ArticleRNA biology2019

CRISPR-Cas systems in multicellular cyanobacteria.

Shengwei Hou, Manuel Brenes-Álvarez, Viktoria Reimann, Omer S Alkhnbashi, Rolf Backofen, Alicia M Muro-Pastor, Wolfgang R Hess

Open access · bronzeAbstract read
In one paragraph

Article in RNA biology, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 22 papers.

0numbers the graph read from it
0cells of the map it votes in
22citing papers in PubMed
1.9field-weighted citation impact, top 13% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

22 citing papers in PubMed, 51 citations in OpenAlex.

  1. Biosynthetic origin of anticancer dolastatin 15 reveals a noncanonical NRPS architecture enabling 2-keto acid activation.Proceedings of the National Academy of Sciences of the United States of America · 2026
    Article
  2. From pond to platform: howJournal of bacteriology · 2026
    Review
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  14. Review
  15. CRISPR Arrays Away fromThe CRISPR journal · 2020
    Article
  16. Review
  17. Article
  18. Review
  19. Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors at 2 institutions in 2 countries.

Shengwei Houa Faculty of Biology, Genetics and Experimental Bioinformatics , University of Freiburg , Freiburg , Germany.ORCID 0000-0002-4474-7443
Manuel Brenes-Álvarezb Instituto de Bioquímica Vegetal y Fotosíntesis , Consejo Superior de Investigaciones Científicas and Universidad de Sevilla , Seville , Spain.
Viktoria Reimanna Faculty of Biology, Genetics and Experimental Bioinformatics , University of Freiburg , Freiburg , Germany.
Omer S Alkhnbashic Bioinformatics group, Department of Computer Science , University of Freiburg , Freiburg , Germany.
Rolf Backofenc Bioinformatics group, Department of Computer Science , University of Freiburg , Freiburg , Germany.ORCID 0000-0001-8231-3323
Alicia M Muro-Pastorc Bioinformatics group, Department of Computer Science , University of Freiburg , Freiburg , Germany.ORCID 0000-0003-2503-6336
Wolfgang R Hessa Faculty of Biology, Genetics and Experimental Bioinformatics , University of Freiburg , Freiburg , Germany.ORCID 0000-0002-5340-3423
University of Freiburg · DEConsejo Superior de Investigaciones Científicas · ES

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Novel CRISPR-Cas systems possess substantial potential for genome editing and manipulation of gene expression. The types and numbers of CRISPR-Cas systems vary substantially between different organisms. Some filamentous cyanobacteria harbor > 40 different putative CRISPR repeat-spacer cassettes, while the number of cas gene instances is much lower. Here we addressed the types and diversity of CRISPR-Cas systems and of CRISPR-like repeat-spacer arrays in 171 publicly available genomes of multicellular cyanobacteria. The number of 1328 repeat-spacer arrays exceeded the total of 391 encoded Cas1 proteins suggesting a tendency for fragmentation or the involvement of alternative adaptation factors. The model cyanobacterium Anabaena sp. PCC 7120 contains only three cas1 genes but hosts three Class 1, possibly one Class 2 and five orphan repeat-spacer arrays, all of which exhibit crRNA-typical expression patterns suggesting active transcription, maturation and incorporation into CRISPR complexes. The CRISPR-Cas system within the element interrupting the Anabaena sp. PCC 7120 fdxN gene, as well as analogous arrangements in other strains, occupy the genetic elements that become excised during the differentiation-related programmed site-specific recombination. This fact indicates the propensity of these elements for the integration of CRISPR-cas systems and points to a previously not recognized connection. The gene all3613 resembling a possible Class 2 effector protein is linked to a short repeat-spacer array and a single tRNA gene, similar to its homologs in other cyanobacteria. The diversity and presence of numerous CRISPR-Cas systems in DNA elements that are programmed for homologous recombination make filamentous cyanobacteria a prolific resource for their study. Abbreviations: Cas: CRISPR associated sequences; CRISPR: Clustered Regularly Interspaced Short Palindromic Repeats; C2c: Class 2 candidate; SDR: small dispersed repeat; TSS: transcriptional start site; UTR: untranslated region.

Indexed as

Base SequenceCell DifferentiationCRISPR-Cas SystemsCyanobacteriaGene Expression Regulation, BacterialHomologous RecombinationPhylogenySyntenyCRISPRcyanobacteriaheterocystnitrogen fixationprogrammed DNA recombination

Identifiers

PMID29995583
PMCPMC6546389
OpenAlexW2842415563

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.