Identification and Characterization of MicroRNAs in Zebrafish Spermatozoa by Illumina Sequencing
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ABSTRACT: MicroRNAs (miRNAs) are involved in nearly every biological process examined to date. Mounting evidence show that some spermatozoa specific miRNAs play important roles in the regulation of spermatogenesis and germ cells development, but little is known of the exact identity and function of miRNA in sperm cells or their potential involvement in spermatogenesis and germ cells development. Here, we investigated the spermatozoa miRNA profiles using illumina deep sequencing combined with bioinformatic analysis using zebrafish as a model system. Deep sequencing of small RNAs yielded 12 million raw reads from zebrafish spermatozoa. Analysis showed that the noncoding RNA of the spermatozoa included tRNA, rRNA, snRNA, snoRNA and miRNA. By mapping to the zebrafish genome, we identified 400 novel and 204 conserved miRNAs which could be grouped into 104 families, including zebrafish specific families, such as mir-731, mir-724, mir-725, mir-729 and mir-2185. We report the first characterization of the miRNAs profiling in zebrafish spermatozoa. The obtained spermatozoa miRNAs profiling will serve as valuable resources to systematically study spermatogenesis in fish and vertebrate. Examination of small RNA populations in zebrafish spermatozoa
Project description:MicroRNAs (miRNAs) are involved in nearly every biological process examined to date. Mounting evidence show that some spermatozoa specific miRNAs play important roles in the regulation of spermatogenesis and germ cells development, but little is known of the exact identity and function of miRNA in sperm cells or their potential involvement in spermatogenesis and germ cells development. Here, we investigated the spermatozoa miRNA profiles using illumina deep sequencing combined with bioinformatic analysis using zebrafish as a model system. Deep sequencing of small RNAs yielded 12 million raw reads from zebrafish spermatozoa. Analysis showed that the noncoding RNA of the spermatozoa included tRNA, rRNA, snRNA, snoRNA and miRNA. By mapping to the zebrafish genome, we identified 400 novel and 204 conserved miRNAs which could be grouped into 104 families, including zebrafish specific families, such as mir-731, mir-724, mir-725, mir-729 and mir-2185. We report the first characterization of the miRNAs profiling in zebrafish spermatozoa. The obtained spermatozoa miRNAs profiling will serve as valuable resources to systematically study spermatogenesis in fish and vertebrate.
Project description:MicroRNAs (miRNAs) are small non-coding regulatory RNAs that play key roles in many diverse biological processes such as spermatogenesis. However, no study has been performed on the miRNA transcriptome of developing porcine testes. Here, we employed Solexa deep sequencing technology to extend the repertoire of porcine testis miRNAs and extensively compare the expression patterns of the sexually immature and mature porcine testes. Solexa sequencing of two small RNA libraries derived from immature (30 days) and mature (180 days) pig testis samples yielded over 25 million high-quality reads. Overall, the two developmental stages had significantly different small RNA compositions. A custom data analysis pipeline identified 398 known and/or homologous conserved porcine miRNAs, 15 novel pig-specific miRNAs, and 56 novel candidate miRNAs. We further observed multiple mature miRNA variants (isomiRs) and identified a new bidirectional transcribed miRNA locus, ssc-mir-181a. One hundred twenty-two miRNAs were differentially expressed in the immature and mature testes, and 10 were validated using quantitative RT-PCR. Furthermore, GO and KEGG pathway analyses of the predicted miRNA targets further illustrate the likely roles for these differentially expressed miRNAs in spermatogenesis. This study is the first comparative profile of the miRNA transcriptome in immature and mature porcine testes using a deep sequencing approach, and it provides a useful resource for future studies on the role of miRNAs in spermatogenesis and male infertility treatment. microRNA profiling and discovery in two small RNA cDNA libraries derived from sexually immature (30-day) and mature (180-day) pig testes.
Project description:The role of microRNAs in gene regulation has been well established. The extent of miRNA regulation also increases with increasing genome complexity. Though the number of genes appear to be equal between human and zebrafish, substantially less microRNAs have been discovered in zebrafish compared to human (Release 19). It appears that most of the miRNAs in zebrafish are yet to be discovered. We sequenced small RNAs from brain, gut, liver, ovary, testis, eye, heart and embryo of zebrafish. In brain, gut and liver sequencing was done in male and female separately. Majority of the sequenced reads (16-62%) mapped to known miRNAs, with the exception of ovary (5.7%) and testis (7.8%). Using the miRNA discovery tool (miRDeep2), we discovered novel miRNAs from the un-annotated reads that ranged from 7.6 to 23.0%, with exceptions of ovary (51.4%) and testis (55.2%). The prediction tool identified a total of 459 novel pre-miRNAs. We compared expression of miRNAs between different tissues and between males and females to identify tissue associated and sex associated miRNAs respectively. These miRNAs could serve as putative biomarkers for these tissues. The brain and liver had highest number of tissue associated (22) and sex associated (34) miRNAs, respectively. This study comprehensively identifies tissue and sex associated miRNAs in zebrafish. Further, we have discovered 459 novel pre-miRNAs (~30% seed homology to human miRNA) as a genomic resource which can facilitate further investigations to understand miRNA-mRNA gene regulatory networks in zebrafish which will have implications in understanding the function of human homologs. Known miRNA profiling, novel miRNA discovery and identification of tissue associated and sex associated miRNAs from sRNA deep sequencing data of different tissues and embryo of zebrafish (in triplicate) was carried out using the Illumina HiSeq 2000 platform.
Project description:We present an efficient method to genome-wide discover new and drought stress responsive miRNAs in P. euphratica. High throughput sequencing of P. euphratica leaves found 197 conserved miRNAs between P. euphratica and Populus trichocarpa. Meanwhile, 189 new miRNAs which belonged to 120 families were identified, a large increasing to the number of P. euphratica miRNAs. Target prediction and degradome sequencing verification of 22 new and 21 conserved miRNA targets showed these targets were involved in multiple biological processes, including transcription regulation and response to stimulus. Furthermore, comparison of high-throughput sequencing with miRNA microarray profiling data indicated that 104 miRNA sequences were up-regulated, while 27 were down-regulated under drought stress. This preliminary characterization based on our findings provided a framework for future analysis of miRNA genes and their roles in key traits of poplar as stress resistance plant breeding and environment protection usage. Examination of sRNA expression in 2 poplar leaf samples in drought and normal growth conditions.
Project description:MicroRNAs (miRNAs) regulate different aspects of plant development by post-transcriptional regulation of target genes. In Arabidopsis, DICER-LIKE 1 (DCL1) processes miRNA precursors (pri-miRNAs) to miRNA duplexes, which associate with ARGONAUTE 1 (AGO1). AGO1 together with the miRNA guide strand binds complementary RNA sequences within target mRNAs. Additional proteins act in concert with DCL1 (e.g. HYL1 and SERRATE) and AGO1, respectively, to facilitate efficient and precise pri-miRNA processing and loading into the effector protein. Here, we show that RECEPTOR OF ACTIVATED C KINASE 1 (RACK1) is a novel component of the Arabidopsis miRNA pathway. RACK1 is a seven-bladed WD-repeat protein that has previously been shown to act as a scaffold protein mediating multiple simultaneous protein-protein interactions. Our molecular analyses demonstrate that RACK1 function is required for controlling miRNA-mediated gene expression. rack1 mutants contain only low levels of mature miRNAs without affecting the first step of pri-miRNA processing. Physical and genetic interaction studies revealed that RACK1 acts in concert with AGO1 and also interacts with a SERRATE, a component of the miRNA processing machinery. These results suggest that RACK1 also functions as a scaffold protein in the miRNA pathway to orchestrates miRNA maturation steps after the initial events of pri-miRNA processing. sequencing of small RNAs from WT and rack1abc mutants (two biological replicates each)
Project description:High-throughput small RNA sequencing were performed to identify a large number of miRNAs and their targets in mature female and male G. biloba leaves for the first time. We ascertained that the regulatory networks of the miRNAs are involved in many different primary biological processes based on potential target designations. Our study is the first to provide useful information for uncovering the regulatory networks of miRNAs in basal gymnosperm G. biloba leaves. small RNA sequencing in female and male leaves of G. biloba
Project description:Background: MicroRNAs (miRNAs), a class of small non-coding endogenous RNAs that regulate gene expression posttranscriptionally, play multiple key roles in plant growth and development and the stress response. Knowledge of and the roles of miRNAs in pomegranate fruit development have not been explored. Results: Pomegranate, which accumulates a large amount of anthocyanins in skin and arils, is valuable to human health, mainly because of antioxidant properties. In this study, we developed a small RNA library from pooled RNA samples from young seedling to matured fruits and identified both conserved and pomegranate-specific miRNA from 29,948,480 high-quality reads. For the pool of 15- to 30-nt small RNAs, ~50% were 24 nt. The miR157 family was the most abundant, followed by miR156, miR160, and miR159, with many variants within each family. The base bias at the first position from the 5â end has a strong preference for U for most 18- to 26-nt miRNAs but a preference for A for 18-nt miRNAs. In addition, for all 24-nt miRNAs, the nucleotide U is preferred (97%) in the first position. RT-qPCR was used to validate the expression of the predominant miRNA families in leaves, male and female flowers, and multiple fruit developmental stages; miR156, miR156-v1, miR159, miR159-v1, and miR319 were upregulated during the later stages of fruit development. Gene ontology and KEGG pathway analyses revealed predominant metabolic processes and catalytic activities, important for fruit development. In addition, KEGG pathway analyses revealed the involvement of miRNAs in ascorbate and linolenic acid, starch and sucrose metabolism; RNA transport; plant hormone signaling pathways; and circadian clock. Conclusion: Pomegranate largely contains anthocyanin, flavonoids, and antioxidants, which play critical roles in treating cancer, Alzheimer disease, and preventing heart attacks. Our first and preliminary report of novel miRNAs provides information on the biochemical compounds of pomegranate for future research. The functions of the targets of these novel miRNAs need further investigation. Profiling of miRNAs in pomegranate using Illumina HiSeq 2000 platform
Project description:Here we identify a Dicer-independent miRNA biogenesis pathway that employs the slicer catalytic activity of Argonaute2 (Ago2). To uncover Dicer-independent miRNAs, we sequenced small RNAs in wild type, maternal-zygotic dicer (MZdicer) and MZago2 mutants, using zebrafish as a model system. We find that, in contrast to other miRNAs, miR-451 levels were increased in MZdicer but drastically reduced in the MZago2 mutants. We show that pre-miR-451 processing requires Ago2 catalytic activity in vivo. MZago2 mutant embryos display delayed erythrocyte maturation that can be rescued by wild type Ago2 or miR-451 duplex but not catalytically dead Ago2. We propose that Ago2-mediated cleavage of a subset of pre-miRNAs, followed by uridylation and trimming, generates functional miRNAs in a Dicer-independent manner. Examination of small RNAs (18 to 35 nucleotides) in 3 different zebrafish genotypes (wild type, MZago2, MZdicer) at 48 hours post-fertilization.
Project description:In nature, animals often face feast or famine conditions. We aimed to identify the miRNAs of Caenorhabditis elegans that changed their expression under starvation conditions in stage L4 larvae. Our results highlight 14 miRNAs that show differential expression in starved versus well-fed larvae. In particular, miRNAs of the miR-35-3p/miR-41-3p family were upregulated 6-20 fold upon starvation. We verified the upregulation of miR-35-3p with qPCR. Additionally, we showed that the expression of gld-1, important in ovogenesis, and a validated target of miR-35-3p, was downregulated when the expression of miR-35-3p was higher. This study represents a starting point for a more comprehensive understanding of the role of miRNAs during starvation in C. elegans. Illumina small RNA sequencing of starved and well-fed L4 worms.
Project description:High-throughput small RNA sequencing were performed to identify a large number of miRNAs and their targets in mature G. biloba ovules. Our study is the first to provide useful information for uncovering the regulatory networks of miRNAs in basal gymnosperm G. biloba ovules. small RNAÂ sequencing in ovules of G. biloba