MiRNA-mediated post-transcriptional regulation of gene expression in ABR17 transgenic Arabidopsis thaliana under salt stress
ABSTRACT: Micro RNAs (miRNAs) are a class of small endogenous RNAs conserved in eukaryotic organisms including plants. They suppress gene expression post-transcriptionally in many different biological processes. Previously, we reported salinity-induced changes in gene expression in transgenic Arabidopsis thaliana plants that constitutively expressed a pea abscisic acid-responsive (ABR17) gene. In the current study, we used a microarray to investigate the role of miRNA-mediated post-transcriptional gene regulation in these same transgenic plants in the presence and absence of salinity stress. We identified nine miRNAs that were significantly modulated due to ABR17 gene expression, and seven miRNAs that were modulated in response to salt stress. The target genes regulated by these miRNAs were identified using starBase (sRNA target Base) Degradome analysis and through 5' RNA Ligase Mediated-Rapid Amplification of cDNA Ends (RLM-RACE). Our findings revealed miRNA:mRNA interactions comprising regulatory networks of Auxin Response Factor (ARF), ARGONAUTE 1, (AGO1), Dicer-like proteins 1 (DCL1), Squamosa Promoter Binding (SPB), NAC, APETALA 2 (AP2), Nuclear Factor-Y (NFY), RNA binding proteins, Arabidopsis thaliana vacuolar phyrophosphate 1 (AVP1) and Pentatricopetide repeat (PPR) in ABR17 transgenic A. thaliana, which control physiological, biochemical and stress signalling cascades due to the imposition of salt stress. Our results are discussed within the context of the effect of the transgene, ABR17, and the roles miRNA expression may play in mediating plant responses to salinity. In this miRNA-microarray experiment, a total of 4 samples were analyzed with their 3 biological replicates. Two samples, WT and ABR17 control (without salt treatment), were used as reference controls.
Project description:UB cells FACS sorted from E15.5 mouse kidneys were analyzed for miRNAs expression. E15.5 UB cells FACS sorted from Rosa26YFP; Hoxb7Cre mice, total RNAs including miRNAs were purified and used for miRNA microarray
Project description:MicroRNAs (miRNAs) are small non-coding RNAs with strong biological functions. However, the roles of miRNAs in alcohol addiction are still unclear. In this study, we analyzed miRNA profile of in the nucleus accumbens (NAc) of rats treated with alcohol. The results demonstrated, among the 300 detected miRNAs in NAc, multiple miRNAs were aberrantly expressed after treatment with alcohol. To perform the experiment, 18 male rats (weighing 150-180 g) were divided into two treatment groups: vehicle (500 ul saline, ip bid) or alcohol (1 g/kg, ip bid). Seven days later, the animals were sacrificed and their NAc were isolated for miRNA microarray analysis. The miRNA expressions were determined using miRNA microarrays for rat (LC Sciences). Data were normalized using cyclic method and statistically analyzed using Ttest.
Project description:Background: There is a limited capacity to repair damage in the mammalian heart after birth, which is primarily due to the inability of cardiomyocytes to proliferate after birth. This is in contrast to zebrafish and salamander, in which cardiomyocytes retain the ability to proliferate throughout life and can regenerate their heart after significant damage. Recent studies in zebrafish and rodents implicate microRNAs (miRNAs) in the regulation of genes responsible for cardiac cell cycle progression and regeneration, in particular, miR-133a, the miR-15 family, miR-199a and miR-590. However, the significance of these miRNAs and miRNA in general in the regulation of cardiomyocyte proliferation in large mammals, including humans, where the timing of heart development relative to birth is very different than in rodents, is unclear. To determine the involvement of miRNAs in the down-regulation of cardiomyocyte proliferation occurring before birth in large mammals, we investigated miRNA and target gene expression in sheep hearts before and after birth. The experimental approach included targeted transcriptional profiling of miRNA and target mRNA previously identified in rodent studies as well as genome-wide miRNA profiling using microarrays. Results: The cardiac expression of miR-133a increased and its target gene IGF1R decreased with increasing age, reaching their respective maximum and minimum abundance when the majority of ovine cardiomyocytes were quiescent. The expression of the miR-15 family members was variable with age, however, four of their target genes decreased with age. These latter profiles are inconsistent with the direct involvement of this family of miRNA in cardiomyocyte quiescence in late gestation sheep. The expression patterns of ‘pro-proliferative’ miR-199a and miR-590 were also inconsistent with their involvement in cardiomyocyte quiescence. Consequently, miRNA microarray analysis was undertaken, which identified six discrete clusters of miRNA with characteristic developmental profiles. The functions of predicted target genes for the miRNA in four of the six clusters were enriched for aspects of cell division and regulation of cell proliferation suggesting a potential role of these miRNA in regulating cardiomyocyte proliferation. Conclusion: The results of this study show that the expression of miR-133a and one of its target genes is consistent with it being involved in the suppression of cardiomyocyte proliferation, which occurs across the last third of gestation in sheep. The expression patterns of the miR-15 family, miR-199a and miR-590 were inconsistent with direct involvement in the regulation cardiomyocyte proliferation in sheep, despite studies in rodents demonstrating that their manipulation can influence the degree of cardiomyocyte proliferation. miRNA microarray analysis suggests a coordinated and potentially more complex role of multiple miRNA in the regulation of cardiomyocyte quiescence and highlights significant differences between species that may reflect their substantial differences in the timing of this developmental process. RNA, (2 µg) from three heart samples from each of the 91 d (fetus), 141 d (fetus), 5 d (postnatal) and 173 d (postnatal) groups, was used for analysis according to standard procedures. The experimental design included three biological replicates from each of the four normal developmental ages in sheep and thus a total of 12 samples was analyzed.
Project description:MicroRNAs (miRNAs) are small noncoding RNAs that play critical roles in regulating post transcriptional gene expression. Gall midges encompass a large group of insects that are of economic importance and also possess fascinating biological traits. The gall midge Mayetiola destructor, commonly known as the Hessian fly, is a model organism for studying gall midge biology and insect – host plant interactions. In this study, we systematically analyzed miRNAs from the Hessian fly. Deep-sequencing a Hessian fly larval transcriptome led to the identification of 89 miRNA species that are either identical or very similar to known miRNAs from other insects, and 184 novel miRNAs that have not been reported from other species. Microarray analyses revealed the expression of miRNA genes was strictly regulated during Hessian fly larval development and abundance of many miRNA genes were affected by host genotypes. The identification of a large number of miRNAs for the first time from a gall midge provides a foundation for further studies of miRNA functions in gall midge biology and behavior. Two wheat lines “Molly” and “Newton” were used in the experiment. Newton is a susceptible winter wheat that contains no Hessian fly R gene, and Molly is a nearly isogenic line of Newton, but contains the R gene H13. Larvae were collected one and three days after egg hatch from susceptible Newton and resistant Molly plants. Total RNA extracted from the collected larvae was used for microarray analysis. Three biological replications were used for each treatment and at each time point.
Project description:We wished to determine the effects of activating the transcription factor, ATF6, on global miRNA expression. We utilized transgenic mice with a conditionally tamoxien-responsive form of ATF6 and assessed cardiac lysates from NTG and TG mice, both treated with tamoxifen and untreated, in order to identify differentially expressed miRNAs. We then focused on miRNAs of interest as well as the genes they are predicted to regulate. Four sample groups were assessed for miRNA expression: non-transgenic (NTG) mice treated with vehicle, NTG mice treated with tamoxifen, ATF6 transgenic (TG) mice treated with vehicle, and TG mice treated with tamoxifen
Project description:This study examined the expression of pig-specific microRNAs (miRNAs) at gestation day 20 (gd20) of pregnancy in Yorkshire sows. Tissue differences in miRNA expression, and miRNA differences between healthy and arresting embryo attachment sites (i.e., healthy endometrium vs. arresting endometrium; healthy trophoblast vs. arresting trophoblast), were of prime interest. For more information, please refer to the primary research paper. Paired endometrium and trophoblast samples were collected at gestation day 20 from two conceptus attachement sites (1 healthy, 1 arresting) per sow (n=3). Endometrial samples were collected from four non-pregnant sows at mid-estrus.
Project description:Spontaneous paroxysmal atrial fibrillation (PAF) is one of the very common heart rhythm disorders. The molecular mechanisms underlying PAF susceptibility and persistence are multiple and incompletely understood. To study the contribution of microRNAs (miRNAs) to the development and perpetuation of PAF, we used microarray/qPCR analyses to search for changes in miRNA expression in atrial myocardium upon pacing-induced PAF. The miRNA microarray analysis was performed at LC Sciences (Houston, TX, USA). Following screening-microarray, several miRNAs were selected for detailed real-time qPCR assay. Our results suggest that immediate-early miR remodeling of LAA underlies the development and persistence of PAF. A closed-chest model of PAF was established in postnatal pigs via a rapid atrial electrical stimulation with a controlled ventricular response rate. A pacing catheter (delivered into the right atrium via femoral vein access under fluoroscopic guidance) was connected with an external pulse generator for programmed pacing rates. The burst-pacing stimuli were repeated several times, and the induced PAF occurrence rates and durations were recorded. Burst pacing was not performed in sham-operated group. Animals were euthanized 24 hours after cessation of pacing. Given that the right atrium might have been damaged by catheter insertion, we studied miRNA expression changes associated with PAF in the left atrial appendage (LAA) from paced vs control pigs. Six piglet were randomized in two groups, the PAF group (3 replicates) and the sham-control group (3 replicates)
Project description:Maternal obesity programs the offspring to cardiovascular disease, insulin resistance, and obesity. We sequenced and profiled the cardiac miRNAs that were dysregulated in the hearts of baboon fetuses born to a high fat / high fructose diet fed mothers compared to a regular diet fed mothers. Fetal hearts were collected from baboon fetuses born to obese and lean mothers, total RNA was isolated, and fetal cardiac miRNA were sequenced and profiled
Project description:Canola (oilseed rape, Brassica napus L.), is susceptible to infection by the biotrophic protist Plasmodiophora brassicae, the causal agent of clubroot. To understand the roles of microRNAs (miRNAs) during the post-transcriptional regulation of disease initiation and progression, we have characterized the changes in miRNA expression profiles in canola roots during clubroot disease development and have compared these to uninfected roots. Two different stages of clubroot development were targeted in this miRNA profiling study: an early time of 10-dpi for disease initiation and a later 20-dpi, by which time the pathogen had colonized the roots (as evident by visible gall formation and histological observations). P. brassicae responsive miRNAs were identified and validated by qRT-PCR of miRNAs and the subsequent validation of the target mRNAs through starBase degradome analysis, and through 5’ RLM-RACE. This study identifies putative miRNA-regulated genes with roles during clubroot disease initiation and development. Putative target genes identified in this study included: transcription factors (TFs), hormone-related genes, as well as genes associated with plant stress response regulation such as cytokinin, auxin/ethylene response elements. The results of our study may assist in elucidating the role of miRNAs in post-transcriptional regulation of target genes during disease development and may contribute to the development of strategies to engineer durable resistance to this important phytopathogen. In this miRNA-microarray experiment a total of 4 samples were analyzed with their 3 biological replicates. In which 2 samples C 10 DAY and C 20 DAY was used as referrence contols.
Project description:To assess changes in the miRNA-ome during the early stages of endothelial differentiation, the expression of mature human miRNAs at days 2, 4 and 10 of endothelial differentiation (vs pluripotent time-matched samples) in SA461 hESC cell line was analysed in a two-channel microarray. Expression of the pluripotency-associated miRNAs miR-302a – d and miR-372 and miR-373 was significantly suppressed with progression of differentiation. The expression of miR-99b, miR-181a and miR-181b was, in contrast, increased in a time- and differentiation-dependent manner compared to time-matched pluripotent samples. The expression profiles were validated and good concordance was observed between microarray, Q-PCR and Northern blot analysis. This experiment includes a total of 28 samples which are divided in to 3 groups, each with 4 biological repeats: group 1, Parental pluripotent hESC control sample. group 2, time-matched pluripotent hESC control samples. Group 3, hESC cells directed toward endothelial differentiation at time points 2 days, 4 days and 10 days.