Suporte de vida para células precursoras de neurônios: mero acaso, fortuita necessidade ou design inteligente?

segunda-feira, fevereiro 13, 2017

miRNAs cooperate in apoptosis regulation during C. elegans development

Ryan Sherrard 1,3, Sebastian Luehr 1,3, Heinke Holzkamp 1, Katherine McJunkin 2, Nadin Memar 1 and Barbara Conradt 1

- Author Affiliations

1Center for Integrated Protein Science Munich – CIPSM, Department Biology II, Ludwig-Maximilians-University Munich, Planegg-Martinsried 82152, Germany;

2Program in Molecular Medicine, RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01606, USA

Corresponding authors:,

↵3 These authors contributed equally to this work.

Source/Fonte: Google Images


Programmed cell death occurs in a highly reproducible manner during Caenorhabditis elegans development. We demonstrate that, during embryogenesis, miR-35 and miR-58 bantam family microRNAs (miRNAs) cooperate to prevent the precocious death of mothers of cells programmed to die by repressing the gene egl-1, which encodes a proapoptotic BH3-only protein. In addition, we present evidence that repression of egl-1 is dependent on binding sites for miR-35 and miR-58 family miRNAs within the egl-1 3′ untranslated region (UTR), which affect both mRNA copy number and translation. Furthermore, using single-molecule RNA fluorescent in situ hybridization (smRNA FISH), we show that egl-1 is transcribed in the mother of a cell programmed to die and that miR-35 and miR-58 family miRNAs prevent this mother from dying by keeping the copy number of egl-1 mRNA below a critical threshold. Finally, miR-35 and miR-58 family miRNAs can also dampen the transcriptional boost of egl-1 that occurs specifically in a daughter cell that is programmed to die. We propose that miRNAs compensate for lineage-specific differences in egl-1 transcriptional activation, thus ensuring that EGL-1 activity reaches the threshold necessary to trigger death only in daughter cells that are programmed to die.

Keywords miRNA programmed cell death BH3-only development embryo C. elegans


Supplemental material is available for this article.

Article published online ahead of print. Article and publication date are online at

Freely available online through the Genes & Development Open Access option.

Received August 4, 2016 Accepted January 11, 2017.

© 2017 Sherrard et al.; Published by Cold Spring Harbor Laboratory Press

This article, published in Genes & Development, is available under a Creative Commons License (Attribution 4.0 International), as described at



A morte programada das células, conhecida como apoptose, é um processo fundamental e altamente regulado que ocorre em todos os organismos chamados de superiores. É um processo essencial para o desenvolvimento embrionário normal, durante o qual células supérfluas devem ser descartadas, mas de forma ordenada.

Mero acaso, fortuita necessidade ou 100% design inteligente?