Early origins and evolution of microRNAs and Piwi-interacting RNAs in animals

Grimson, Andrew; Srivastava, Mansi; Fahey, Bryony; Woodcroft, Ben J.; Chiang, Hou‐Yu; King, Nicole; Degnan, Bernard M.; Rokhsar, Daniel S.; Bartel, David P.

doi:10.1038/nature07415

Cited by 656 publications

(707 citation statements)

References 36 publications

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“…While piRNAs are involved in many inherited immunity effects, they are obviously not central to all such mechanisms. piRNAs are absent in several organisms that display heritable genome immunity, such as plants, fungi, and even in some worms, for example in the parasitic nematode, Ascaris suum, a relative of C.elegans [45,46].…”

Section: Inherited Protection Against Transposonsmentioning

confidence: 99%

Guest list or black list: heritable small RNAs as immunogenic memories

Rechavi

2014

Trends in Cell Biology

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Small RNA-mediated gene silencing plays a pivotal role in genome immunity by recognizing and eliminating viruses and transposons which otherwise may colonize the genome. However, this can be challenging since individual genomic parasites are highly diverse, and employ multiple immune evasion techniques. In this review, I discuss a new theory proposing that the integrity of the germline is maintained by transgenerationally-transmitted RNA "memories" that record ancestral gene expression patterns, and delineate "Self" from "Foreign" sequences. To maintain such recollection two tactics are employed in parallel: "black listing" of invading nucleic acids, and "guest listing" of endogenous genes. Studies in a number of organisms have shown that this memorization is used by the next generation small RNAs to act as "Inherited Vaccines" that ambush invading elements, or as "Inherited Licenses" that grant the transcription of autogenous sequences. KeywordsSmall RNA; Transgenerational Inheritance; Inherited Immunity; Self Vs. Non-Self; "Inherited Vaccines" Overview of transgenerational inheritanceEvolution progresses through an interplay between two major forces, selection and variation. Since the formulation of the Modern Synthesis the theory holds that the environment is limited in its contribution to the evolutionary course of action -it affects selection, but not the degree of variation [1,2]. However, recent discoveries in epigenetics suggest that the environment may influence variability as well [1]. If the parental environment is predictive of the conditions that the progeny will face (often for sessile or short-lived organisms), epigenetic responses can change the output of the encoded genetic information in an adaptive manner [3]. For example, the water flea Daphnia changes its normal developmental course and develops a "helmet" that protects it from predators, if it is born to a mother that survived a similar attack [4].Correspondence to: odedrechavi@gmail.com. Over the years, controversy surrounded the study of environmentally affected transgenerational inheritance. Today, an improved understanding of epigenetic mechanisms at the molecular level has provided a logical background to explain how, heretically, an adaptive acquired trait could become heritable [5]. Several epigenetic mechanisms could regulate the expression of relevant genes during transgenerational inheritance including DNA methylation, histone modification, and transmission of regulatory RNAs. Moreover, in many organisms, these pathways appear to be interconnected [5][6][7][8]. Europe PMC Funders GroupThis review will concentrate on recent discoveries that establish a role for small RNAs in transgenerational transmission of acquired defense. Furthermore, exciting examples of RNA-mediated non-Mendelian genetic effects will be discussed, along with their possible implications for the study of evolution and immunology. RNA-mediated gene silencing and inheritanceSince the original discovery that small RNAs derived from exogenously-provided dou...

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Section: Inherited Protection Against Transposonsmentioning

confidence: 99%

Guest list or black list: heritable small RNAs as immunogenic memories

Rechavi

2014

Trends in Cell Biology

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“…It has been reported that the mir-100 is the only microRNA which is shared by all bilateria (Grimson et al, 2008;. Therefore, we also analyzed the relationship between the mir-100 and mir-155 using NeighborJoining (NJ) method.…”

Section: The Construction Of Phylogenetic Treesmentioning

confidence: 99%

Evolution of the Mir-155 Family and Possible Targets in Cancers and the Immune System

Xie

Liu²,

Pan³

et al. 2014

Asian Pacific Journal of Cancer Prevention

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The mir-155 family is not only involved in a diversity of cancers, but also as a regulator of the immune system. However, the evolutionary history of this family is still unclear. The present study indicates that mir-155 evolved independently with lineage-specific gain of miRNAs. In addition, arm switching has occurred in the mir-155 family, and alternative splicing could produce two different lengths of ancestral sequences, implying the alternative splicing can also drive evolution for intragenic miRNAs. Here we screened validated target genes and immunityrelated proteins, followed by analyzation of the mir-155 family function by high-throughput methods like the gene ontology (GO) and Kyoto Eneyclopedin of Genes and Genemes (KEGG) pathway enrichment analysis. The high-throughput analysis showed that the CCND1 and EGFR genes were outstanding in being significantly enriched, and the target genes cebpb and VCAM1 and the protein SMAD2 were also vital in mir-155-related immune reponse activities. Therefore, we conclude that the mir-155 family is highly conserved in evolution, and CCND1 and EGFR genes might be potential targets of mir-155 with regard to progress of cancers, while the cebpb and VCAM1 genes and the protein SMAD2 might be key factors in the mir-155 regulated immune activities.

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“…Les piARN ont été détectés dans les cellules des lignées germinales de tous les animaux étudiés à ce jour et semblent apparaître très tôt au cours de l'évolution, chez l'ancêtre commun de tous les animaux [8]. Dans tous ces organismes, ils sont pressentis pour être les acteurs majeurs de la lutte contre les éléments transposables au cours de la gamétogenèse.…”

Section: Caractéristiques Des Piarnunclassified