Author
Earl G. Weinstein
Bio: Earl G. Weinstein is an academic researcher from Massachusetts Institute of Technology. The author has contributed to research in topics: Lin-4 microRNA precursor & Mirtron. The author has an hindex of 3, co-authored 3 publications receiving 6869 citations.
Papers
More filters
TL;DR: Two small temporal RNAs, lin-4 andlet-7, control developmental timing in Caenorhabditis elegans and are found to be members of a large class of 21- to 24-nucleotide noncodingRNAs, called microRNAs (miRNAs), which imply that, as a class, miRNAs have broad regulatory functions in animals.
Abstract: Two small temporal RNAs (stRNAs), lin-4 and let-7, control developmental timing in Caenorhabditis elegans. We find that these two regulatory RNAs are members of a large class of 21- to 24-nucleotide noncoding RNAs, called microRNAs (miRNAs). We report on 55 previously unknown miRNAs in C. elegans. The miRNAs have diverse expression patterns during development: a let-7 paralog is temporally coexpressed with let-7; miRNAs encoded in a single genomic cluster are coexpressed during embryogenesis; and still other miRNAs are expressed constitutively throughout development. Potential orthologs of several of these miRNA genes were identified in Drosophila and human genomes. The abundance of these tiny RNAs, their expression patterns, and their evolutionary conservation imply that, as a class, miRNAs have broad regulatory functions in animals.
3,539 citations
[...]
TL;DR: Mutation of an Arabidopsis Dicer homolog, CARPEL FACTORY, prevents the accumulation of miRNAs, showing that similar mechanisms direct miRNA processing in plants and animals.
Abstract: The present invention generally relates to the production and expression of microRNA (miRNA) in plants. In some cases, production and expression of miRNA can be used to at least partially inhibit or alter gene expression in plants. For instance, in some embodiments, a nucleotide sequence, which may encode a sequence substantially complementary to a gene to be inhibited or otherwise altered, may be prepared and inserted into a plant cell. Expression of the nucleotide sequence may cause the formation of precursor miRNA, which may, in turn, be cleaved (for example, with Dicer or other nucleases, including, for example, nucleases associated with RNA interference), to produce an miRNA sequence substantially complementary to the gene. The miRNA sequence may then interact with the gene (e.g., complementary binding) to inhibit the gene. In some cases, the nucleotide sequence may be an isolated nucleotide sequence. Other embodiments of the invention are directed to the precursor miRNA and/or the final miRNA sequence, as well as methods of making, promoting, and use thereof.
2,179 citations
TL;DR: The census of the worm miRNAs and their expression patterns helps define this class of noncoding RNAs, lays the groundwork for functional studies, and provides the tools for more comprehensive analyses of miRNA genes in other species.
Abstract: MicroRNAs (miRNAs) are an abundant class of tiny RNAs thought to regulate the expression of protein-coding genes in plants and animals. In the present study, we describe a computational procedure to identify miRNA genes conserved in more than one genome. Applying this program, known as MiRscan, together with molecular identification and validation methods, we have identified most of the miRNA genes in the nematode Caenorhabditis elegans. The total number of validated miRNA genes stands at 88, with no more than 35 genes remaining to be detected or validated. These 88 miRNA genes represent 48 gene families; 46 of these families (comprising 86 of the 88 genes) are conserved in Caenorhabditis briggsae, and 22 families are conserved in humans. More than a third of the worm miRNAs, including newly identified members of the lin-4 and let-7 gene families, are differentially expressed during larval development, suggesting a role for these miRNAs in mediating larval developmental transitions. Most are present at very high steady-state levels-more than 1000 molecules per cell, with some exceeding 50,000 molecules per cell. Our census of the worm miRNAs and their expression patterns helps define this class of noncoding RNAs, lays the groundwork for functional studies, and provides the tools for more comprehensive analyses of miRNA genes in other species.
1,377 citations
Cited by
More filters
TL;DR: Although they escaped notice until relatively recently, miRNAs comprise one of the more abundant classes of gene regulatory molecules in multicellular organisms and likely influence the output of many protein-coding genes.
32,946 citations
TL;DR: The current understanding of miRNA target recognition in animals is outlined and the widespread impact of miRNAs on both the expression and evolution of protein-coding genes is discussed.
18,036 citations
TL;DR: In a four-genome analysis of 3' UTRs, approximately 13,000 regulatory relationships were detected above the estimate of false-positive predictions, thereby implicating as miRNA targets more than 5300 human genes, which represented 30% of the gene set.
11,624 citations
TL;DR: Evidence is mounting that animal miRNAs are more numerous, and their regulatory impact more pervasive, than was previously suspected.
Abstract: MicroRNAs (miRNAs) are small RNAs that regulate the expression of complementary messenger RNAs. Hundreds of miRNA genes have been found in diverse animals, and many of these are phylogenetically conserved. With miRNA roles identified in developmental timing, cell death, cell proliferation, haematopoiesis and patterning of the nervous system, evidence is mounting that animal miRNAs are more numerous, and their regulatory impact more pervasive, than was previously suspected.
9,986 citations
TL;DR: A new, bead-based flow cytometric miRNA expression profiling method is used to present a systematic expression analysis of 217 mammalian miRNAs from 334 samples, including multiple human cancers, and finds the miRNA profiles are surprisingly informative, reflecting the developmental lineage and differentiation state of the tumours.
Abstract: Recent work has revealed the existence of a class of small non-coding RNA species, known as microRNAs (miRNAs), which have critical functions across various biological processes. Here we use a new, bead-based flow cytometric miRNA expression profiling method to present a systematic expression analysis of 217 mammalian miRNAs from 334 samples, including multiple human cancers. The miRNA profiles are surprisingly informative, reflecting the developmental lineage and differentiation state of the tumours. We observe a general downregulation of miRNAs in tumours compared with normal tissues. Furthermore, we were able to successfully classify poorly differentiated tumours using miRNA expression profiles, whereas messenger RNA profiles were highly inaccurate when applied to the same samples. These findings highlight the potential of miRNA profiling in cancer diagnosis.
9,470 citations