MicroRNAs and essential components of the microRNA processing machinery are not encoded in the genome of the ctenophore Mnemiopsis leidyi

BMC Genomics

Research Article

William E Browne¹  Christine E Schnitzler²  Andreas D Baxevanis²  Evan K Maxwell³  Joseph F Ryan⁴ 

[1] Department of Biology, University of Miami, 33146, Coral Gables, FL, USA;Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, 20892, Bethesda, MD, USA;Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, 20892, Bethesda, MD, USA;Bioinformatics Program, Boston University, 02215, Boston, MA, USA;Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, 20892, Bethesda, MD, USA;Sars International Center for Marine Molecular Biology, University of Bergen, 5008, Bergen, Norway;

关键词: Mnemiopsis leidyi;    Ctenophore;    Metazoa;    microRNA;    miRNA;    Drosha;    Pasha;    Microprocessor complex;    Ribonuclease III;    RNase III;   

DOI  :  10.1186/1471-2164-13-714

 received in 2012-05-02, accepted in 2012-11-30,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundMicroRNAs play a vital role in the regulation of gene expression and have been identified in every animal with a sequenced genome examined thus far, except for the placozoan Trichoplax. The genomic repertoires of metazoan microRNAs have become increasingly endorsed as phylogenetic characters and drivers of biological complexity.ResultsIn this study, we report the first investigation of microRNAs in a species from the phylum Ctenophora. We use short RNA sequencing and the assembled genome of the lobate ctenophore Mnemiopsis leidyi to show that this species appears to lack any recognizable microRNAs, as well as the nuclear proteins Drosha and Pasha, which are critical to canonical microRNA biogenesis. This finding represents the first reported case of a metazoan lacking a Drosha protein.ConclusionsRecent phylogenomic analyses suggest that Mnemiopsis may be the earliest branching metazoan lineage. If this is true, then the origins of canonical microRNA biogenesis and microRNA-mediated gene regulation may postdate the last common metazoan ancestor. Alternatively, canonical microRNA functionality may have been lost independently in the lineages leading to both Mnemiopsis and the placozoan Trichoplax, suggesting that microRNA functionality was not critical until much later in metazoan evolution.

【 授权许可】

Unknown   
© Maxwell et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.