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At least 667 records · Page 37Linked to original sources
PubMed2026

Supergene control of chiral development in mirror-image flowers.

How genes determine the development of chiral structures is a fascinating question. The reciprocal placement of female and male organs on opposite sides of mirror-image flowers promotes efficient cross-pollination. Here, we identified that in butterfly lilies, female and male organs deflect by a combination of genetically controlled chirality and gravitropism, orienting left and right with respect to an external rather than internal reference axis. We found coordinated organ placement to be controlled by a hemizygous supergene containing two candidate causal loci, MIR156-R and YUCCA-R, that are responsible for opposite female and male organ orientation, respectively. The resulting differential placement of pollen carrying the two supergene alleles on pollinators' bodies leads to their transfer to the stigmas of flowers with opposite handedness and maintenance of the reproductive polymorphism.

Alleles↗
PubMed2006

A novel repeat-associated small interfering RNA-mediated silencing pathway downregulates complementary sense gypsy transcripts in somatic cells of the Drosophila ovary.

Replication of the gypsy endogenous retrovirus involves contamination of the female germ line by adjacent somatic tissues. This is prevented by flam, an as-yet-uncloned heterochromatic pericentromeric locus, at the level of transcript accumulation in these somatic ovarian tissues. We tested the effect of a presumptive RNA silencing mechanism on the accumulation of RNAs produced by constructs containing various gypsy sequences and report that the efficiency of silencing is indeed correlated with the amount of complementary RNAs, 25 to 30 nucleotides in length, in the ovary. For instance, while these RNAs were found to display a three- to fivefold excess of the antisense strands, only the transcripts that contain the complementary sense gypsy sequences could be repressed, indicating that they are targeted at the RNA, not DNA, level. Their size and asymmetry in strand polarity are typical of the novel repeat-associated small interfering RNA (rasiRNA)-mediated pathway, recently suspected to prevent the deleterious expression of selfish DNA specifically in the germ line. Unlike microRNAs (but like rasiRNAs and, surprisingly, siRNAs as well), gypsy rasiRNAs are modified at the 3' end. The rasiRNA-associated protein Piwi (but not Aub) is required for gypsy silencing, whereas Dicer-2 (which makes siRNAs) is not. In contrast, piwi, aub, and flam do not appear to affect somatic siRNA-mediated silencing. The amount of gypsy rasiRNAs is genetically determined by the flam locus in a provirus copy number-independent manner and is triggered in the somatic tissues by some pericentromeric provirus(es), which are thereby able to protect the germ line from retroviral invasion.

3' Flanking Region↗
PubMed2025

TPX2 promotes papillary renal cell carcinoma progression by forming a ceRNA with LINC00894.

PURPOSE: Papillary renal cell carcinoma (pRCC), particularly type 2, is associated with a poor prognosis. This study aimed to identify molecular mechanisms underlying pRCC progression and explore potential therapeutic targets to improve patient outcomes. METHODS: TPX2 expression was analyzed in tumor samples from patients with type 2 pRCC. In vitro experiments were conducted to assess the effects of TPX2 and LINC00894 knockdown and overexpression on the proliferation and migration of Caki-2 and ACHN cells. Immunohistochemical analysis of tissue microarrays was performed to evaluate the associations between TPX2 expression and clinicopathological characteristics in type 2 pRCC patients. RESULTS: Elevated TPX2 expression was significantly associated with a worse prognosis in type 2 pRCC patients and served as an independent risk factor for overall survival. Knockdown of TPX2 in Caki-2 and ACHN cells significantly reduced cell proliferation and migration. Additionally, LINC00894 was highly expressed in type 2 pRCC and correlated with poor prognosis. Mechanistically, miR-660-5p targeted the TPX2 3' UTR, promoting TPX2 degradation, while LINC00894 competitively bound to miR-660-5p, protecting TPX2 from miRNA-mediated degradation and exerting a pro-oncogenic effect. Immunohistochemical analysis revealed significant correlations between TPX2 expression and clinicopathological features, including tumor thrombus volume, tumor diameter, pathological TNM stage, and Fuhrman grade. CONCLUSION: This study underscores the critical role of TPX2 in type 2 pRCC progression and highlights its potential as a prognostic biomarker and therapeutic target. The TPX2/LINC00894/miR-660-5p regulatory axis provides novel insights into the molecular mechanisms driving pRCC and offers a promising avenue for improving patient prognosis.

Humans↗
PubMed2003

A small yeast RNA inhibits HCV IRES mediated translation and inhibits replication of poliovirus in vivo.

AIM: To investigate the anti-virus infection activity of internal ribosome entry site (IRES) specific inhibitor RNA (IRNA). METHODS: IRNA eukaryotic vector pcRz-IRNA or mIRNA eukaryotic vector pcRz-mIRNA was transfected into human hepatocarcinoma cells (HHCC), then selected with neomycin G418 for 4 to 8 weeks, and then infected with polio virus vaccines line. The cytopethogenesis effect was investigated and the cell extract was collected. At last the polio virus titer of different cells was determined by plaque assay. RESULTS: Constructive expression of IRNA was not detrimental to cell growth. HCV IRES-mediated cap-independent translation was markedly inhibited in cells constructively expressing IRNA compared to control hepatoma cells. However, cap-dependent translation was not significantly affected in these cell line. Additionally, HHCC cells constitutively expressing IRNA became refractory to infection of polio virus. CONCLUSION: IRES specific IRNA can inhibit HCV IRES mediated translation and poliovirus replication.

5' Untranslated Regions↗
PubMed2005

[Research advances on the mechanism of RNA silencing in plants].

RNA silencing is a supervising mechanism in eukaryote which can prevent virus duplication, repress transposition of transposon and regulate gene expression. Compared with that in animals, RNA silencing in plants shows some differences in the function of RdRP, in bi-directional transitive RNAi, and in systemic propagation, etc. Meanwhile,the endogenous small RNAs in plants are more diverse than those in animals. In this paper, it is reviewed of the mechanism of RNA silencing in plants and the possibility of its use in plant functional Genomics.

Gene Expression Regulation, Plant↗
PubMedDate not supplied

The tiny RNA world.

Explore the source record for details and available documents.

Animals↗
PubMed2006

Identification and characterization of two novel classes of small RNAs in the mouse germline: retrotransposon-derived siRNAs in oocytes and germline small RNAs in testes.

Small RNAs ranging in size between 18 and 30 nucleotides (nt) are found in many organisms including yeasts, plants, and animals. Small RNAs are involved in the regulation of gene expression through translational repression, mRNA degradation, and chromatin modification. In mammals, microRNAs (miRNAs) are the only small RNAs that have been well characterized. Here, we have identified two novel classes of small RNAs in the mouse germline. One class consists of approximately 20- to 24-nt small interfering RNAs (siRNAs) from mouse oocytes, which are derived from retroelements including LINE, SINE, and LTR retrotransposons. Addition of retrotransposon-derived sequences to the 3' untranslated region (UTR) of a reporter mRNA destabilizes the mRNA significantly when injected into full-grown oocytes. These results suggest that retrotransposons are suppressed through the RNAi pathway in mouse oocytes. The other novel class of small RNAs is 26- to 30-nt germline small RNAs (gsRNAs) from testes. gsRNAs are expressed during spermatogenesis in a developmentally regulated manner, are mapped to the genome in clusters, and have strong strand bias. These features are reminiscent of Tetrahymena approximately 23- to 24-nt small RNAs and Caenorhabditis elegans X-cluster small RNAs. A conserved novel small RNA pathway may be present in diverse animals.

3' Untranslated Regions↗
PubMed2006

Identification of new central nervous system specific mouse microRNAs.

MicroRNAs (miRNAs) are small regulatory molecules suppressing mRNA activity in metazoans. Here we describe two new miRNAs cloned from brain tissue of mouse embryos. These miRNAs are expressed mainly during embryogenesis and specifically in the central nervous system. We also established the expression patterns of three recently identified miRNAs that were found in our short RNA library. All of them were expressed in the brain and spinal chord but while miR-410 and miR-431 were central nervous system specific, miR-500 was also expressed in limb buds. In addition, the expression of miR-500 in limb buds showed very strong asymmetry in favour of the left hand side.

Animals↗
PubMed2006

The balance between the MIR164A and CUC2 genes controls leaf margin serration in Arabidopsis.

CUP-SHAPED COTYLEDON1 (CUC1), CUC2, and CUC3 define the boundary domain around organs in the Arabidopsis thaliana meristem. CUC1 and CUC2 transcripts are targeted by a microRNA (miRNA), miR164, encoded by MIR164A, B, and C. We show that each MIR164 is transcribed to generate a large population of primary miRNAs of variable size with a locally conserved secondary structure around the pre-miRNA. We identified mutations in the MIR164A gene that deepen serration of the leaf margin. By contrast, leaves of plants overexpressing miR164 have smooth margins. Enhanced leaf serration was observed following the expression of an miR164-resistant CUC2 but not of an miR164-resistant CUC1. Furthermore, CUC2 inactivation abolished serration in mir164a mutants and the wild type, whereas CUC1 inactivation did not. Thus, CUC2 specifically controls leaf margin development. CUC2 and MIR164A are transcribed in overlapping domains at the margins of young leaf primordia, with transcription gradually restricted to the sinus, where the leaf margins become serrated. We suggest that leaf margin development is controlled by a two-step process in Arabidopsis. The pattern of serration is determined first, independently of CUC2 and miR164. The balance between coexpressed CUC2 and MIR164A then determines the extent of serration.

Alleles↗
PubMed2006

The phylogenetic distribution of metazoan microRNAs: insights into evolutionary complexity and constraint.

How complex body plans evolved in animals such as fruit flies and vertebrates, as compared to the relatively simple jellyfish and sponges, is not known, given the similarity of developmental genetic repertoires shared by all these taxa. Here, we show that a core set of 18 microRNAs (miRNAs), non-coding RNA molecules that negatively regulate the expression of protein-coding genes, are found only in protostomes and deuterostomes and not in sponges or cnidarians. Because many of these miRNAs are expressed in specific tissues and/or organs, miRNA-mediated regulation could have played a fundamental evolutionary role in the origins of organs such as brain and heart--structures not found in cnidarians or sponges--and thus contributed greatly to the evolution of complex body plans. Furthermore, the continuous acquisition and fixation of miRNAs in various animal groups strongly correlates both with the hierarchy of metazoan relationships and with the non-random origination of metazoan morphological innovations through geologic time.

Animals↗
PubMed2026

Freely available genomic datasets for atrial fibrillation research: current resources and analytical pipeline.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, characterized by clinical and genetic heterogeneity. Increasing use of genomics and other omics approaches has driven reliance on publicly available AF datasets to advance biological discovery. Thus, this systematic review aimed to identify freely available genomic AF datasets through Mendeley Data and its interconnected repositories, and to characterize the most common analyses performed on these data. The search was conducted in adherence to the PRISMA 2020 guideline. Nineteen freely available genomic AF datasets were identified: Summary statistics for 'Biobank-driven genomic discovery yields new insight into atrial fibrillation biology', hum0014.v8.58qt.v1, AF GWAS in UK Biobank, UK Biobank (Publication 9659), GWAS summary statistics from a 2025 multi-ancestry AF meta-analysis, GSE115574, GSE128188, GSE14975, GSE2240, GSE238242, GSE254133, GSE261170, GSE271748, GSE271839, GSE293813, GSE294456, GSE31821, GSE41177, and GSE79768. The GEO datasets were further examined using differential gene expression, functional enrichment, protein-protein interaction networks, hub gene analysis, microRNA target prediction, and gene clustering, as well as, for the more recently deposited datasets, eQTL colocalization, single-cell/single-nucleus clustering, cell-cell communication analysis, and gene-dosage-dependent transcriptional and electrophysiological profiling. These analyses show some consistency but also considerable heterogeneity in initial conditions, data normalization, and analytical methodological settings. In conclusion, only a limited number of datasets are freely available, so additional, well-characterized and standardized datasets are needed to provide a complete picture of the AF pathology.

Mendeley Data↗