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Carla Schommer

Bio: Carla Schommer is an academic researcher from National University of Rosario. The author has contributed to research in topics: Arabidopsis & Transcription factor. The author has an hindex of 15, co-authored 17 publications receiving 5241 citations. Previous affiliations of Carla Schommer include National Scientific and Technical Research Council & Max Planck Society.

Papers
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Journal ArticleDOI
18 Sep 2003-Nature
TL;DR: The JAW locus is identified, which produces a microRNA that can guide messenger RNA cleavage of several TCP genes controlling leaf development, indicating that microRNA-mediated control of leaf morphogenesis is conserved in plants with very different leaf forms.
Abstract: Plants with altered microRNA metabolism have pleiotropic developmental defects, but direct evidence for microRNAs regulating specific aspects of plant morphogenesis has been lacking In a genetic screen, we identified the JAW locus, which produces a microRNA that can guide messenger RNA cleavage of several TCP genes controlling leaf development MicroRNA-guided cleavage of TCP4 mRNA is necessary to prevent aberrant activity of the TCP4 gene expressed from its native promoter In addition, overexpression of wild-type and microRNA-resistant TCP variants demonstrates that mRNA cleavage is largely sufficient to restrict TCP function to its normal domain of activity TCP genes with microRNA target sequences are found in a wide range of species, indicating that microRNA-mediated control of leaf morphogenesis is conserved in plants with very different leaf forms

1,701 citations

Journal ArticleDOI
TL;DR: It is demonstrated that miR172, previously thought to act primarily by translational repression, can efficiently guide mRNA cleavage, although the effects on steady-state levels of target transcripts are obscured by strong feedback regulation.

1,385 citations

Journal ArticleDOI
TL;DR: It is proposed that miR319-controlled TCP transcription factors coordinate two sequential processes in leaf development: leaf growth and leaf senescence, which they positively regulate.
Abstract: Considerable progress has been made in identifying the targets of plant microRNAs, many of which regulate the stability or translation of mRNAs that encode transcription factors involved in development In most cases, it is unknown, however, which immediate transcriptional targets mediate downstream effects of the microRNA-regulated transcription factors We identified a new process controlled by the miR319-regulated clade of TCP (TEOSINTE BRANCHED/CYCLOIDEA/PCF) transcription factor genes In contrast to other miRNA targets, several of which modulate hormone responses, TCPs control biosynthesis of the hormone jasmonic acid Furthermore, we demonstrate a previously unrecognized effect of TCPs on leaf senescence, a process in which jasmonic acid has been proposed to be a critical regulator We propose that miR319-controlled TCP transcription factors coordinate two sequential processes in leaf development: leaf growth, which they negatively regulate, and leaf senescence, which they positively regulate

760 citations

Journal ArticleDOI
TL;DR: It is shown that miR396 attenuates cell proliferation in developing leaves, through the repression of GRF activity and a decrease in the expression of cell cycle genes, and can regulate cell proliferation and the size of the meristem.
Abstract: Cell proliferation is an important determinant of plant form, but little is known about how developmental programs control cell division. Here, we describe the role of microRNA miR396 in the coordination of cell proliferation in Arabidopsis leaves. In leaf primordia, miR396 is expressed at low levels that steadily increase during organ development. We found that miR396 antagonizes the expression pattern of its targets, the GROWTH-REGULATING FACTOR (GRF) transcription factors. miR396 accumulates preferentially in the distal part of young developing leaves, restricting the expression of GRF2 to the proximal part of the organ. This, in turn, coincides with the activity of the cell proliferation marker CYCLINB1;1. We show that miR396 attenuates cell proliferation in developing leaves, through the repression of GRF activity and a decrease in the expression of cell cycle genes. We observed that the balance between miR396 and the GRFs controls the final number of cells in leaves. Furthermore, overexpression of miR396 in a mutant lacking GRF-INTERACTING FACTOR 1 severely compromises the shoot meristem. We found that miR396 is expressed at low levels throughout the meristem, overlapping with the expression of its target, GRF2. In addition, we show that miR396 can regulate cell proliferation and the size of the meristem. Arabidopsis plants with an increased activity of the transcription factor TCP4, which reduces cell proliferation in leaves, have higher miR396 and lower GRF levels. These results implicate miR396 as a significant module in the regulation of cell proliferation in plants.

458 citations

Journal Article
TL;DR: In this article, the role of microRNA miR396 in the coordination of cell proliferation in Arabidopsis leaves was investigated and shown to be a significant module in the regulation of plant proliferation in plants.
Abstract: Cell proliferation is an important determinant of plant form, but little is known about how developmental programs control cell division. Here, we describe the role of microRNA miR396 in the coordination of cell proliferation in Arabidopsis leaves. In leaf primordia, miR396 is expressed at low levels that steadily increase during organ development. We found that miR396 antagonizes the expression pattern of its targets, the GROWTH-REGULATING FACTOR (GRF) transcription factors. miR396 accumulates preferentially in the distal part of young developing leaves, restricting the expression of GRF2 to the proximal part of the organ. This, in turn, coincides with the activity of the cell proliferation marker CYCLINB1;1. We show that miR396 attenuates cell proliferation in developing leaves, through the repression of GRF activity and a decrease in the expression of cell cycle genes. We observed that the balance between miR396 and the GRFs controls the final number of cells in leaves. Furthermore, overexpression of miR396 in a mutant lacking GRF-INTERACTING FACTOR 1 severely compromises the shoot meristem. We found that miR396 is expressed at low levels throughout the meristem, overlapping with the expression of its target, GRF2. In addition, we show that miR396 can regulate cell proliferation and the size of the meristem. Arabidopsis plants with an increased activity of the transcription factor TCP4, which reduces cell proliferation in leaves, have higher miR396 and lower GRF levels. These results implicate miR396 as a significant module in the regulation of cell proliferation in plants.

356 citations


Cited by
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Journal ArticleDOI
23 Jan 2004-Cell
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

Journal ArticleDOI
TL;DR: Two founding members of the microRNA family were originally identified in Caenorhabditis elegans as genes that were required for the timed regulation of developmental events and indicate the existence of multiple RISCs that carry out related but specific biological functions.
Abstract: MicroRNAs are a family of small, non-coding RNAs that regulate gene expression in a sequence-specific manner. The two founding members of the microRNA family were originally identified in Caenorhabditis elegans as genes that were required for the timed regulation of developmental events. Since then, hundreds of microRNAs have been identified in almost all metazoan genomes, including worms, flies, plants and mammals. MicroRNAs have diverse expression patterns and might regulate various developmental and physiological processes. Their discovery adds a new dimension to our understanding of complex gene regulatory networks.

6,282 citations

Journal Article
TL;DR: I MicroRNAs (miRNAs) are an abundant class of small non-protein-coding RNAs that function as negative gene regulators as discussed by the authors, and have been shown to repress the expression of important cancer-related genes and might prove useful in the diagnosis and treatment of cancer.
Abstract: I MicroRNAs (miRNAs) are an abundant class of small non-protein-coding RNAs that function as negative gene regulators. They regulate diverse biological processes, and bioinformatic data indicates that each miRNA can control hundreds of gene targets, underscoring the potential influence of miRNAs on almost every genetic pathway. Recent evidence has shown that miRNA mutations or mis-expression correlate with various human cancers and indicates that miRNAs can function as tumour suppressors and oncogenes. miRNAs have been shown to repress the expression of important cancer-related genes and might prove useful in the diagnosis and treatment of cancer.

6,064 citations

Journal ArticleDOI
TL;DR: Evidence has shown that miRNA mutations or mis-expression correlate with various human cancers and indicates that miRNAs can function as tumour suppressors and oncogenes.
Abstract: MicroRNAs (miRNAs) are an abundant class of small non-protein-coding RNAs that function as negative gene regulators They regulate diverse biological processes, and bioinformatic data indicates that each miRNA can control hundreds of gene targets, underscoring the potential influence of miRNAs on almost every genetic pathway Recent evidence has shown that miRNA mutations or mis-expression correlate with various human cancers and indicates that miRNAs can function as tumour suppressors and oncogenes miRNAs have been shown to repress the expression of important cancer-related genes and might prove useful in the diagnosis and treatment of cancer

5,693 citations

Journal ArticleDOI
26 Dec 2003-Cell
TL;DR: The predicted regulatory targets of mammalian miRNAs were enriched for genes involved in transcriptional regulation but also encompassed an unexpectedly broad range of other functions.

5,246 citations