Characterization Of miRNAs Research Articles

Identification and characterization of miRNAs and target genes response to hypoosmotic adaption in the cobia, Rachycentron canadum

Environmental salinity is a major factor influencing growth and development, reproduction, and physiology in fish. Recently, miRNAs have been confirmed to play an important role in regulating organismal adaptation in salinity challenge. Since the genomic studies on cobia (Rachycentron canadum) are limited, the miRNA transcriptome of R. canadum is important to investigate the salinity adaptation. In this study, the miRNA transcriptome analysis of the gills in R. canadum was performed under conditions of normal salinity (30‰) and low salinity (10‰). In total, 409 known miRNAs and 139 novel miRNAs were identified, with 56 DEMs (differentially expressed miRNAs). There were 64,983 target genes predicted based on the R. canadum transcriptome, in which 43,283 target genes were attributed to DEMs. The GO annotation and KEGG pathway analysis of target genes indicated that metabolic pathways and signal transduction were the most strongly affected pathways in R. canadum to tackle low-salinity stress, and R. canadum maintains osmotic homoeostasis and energy balance by regulating miRNAs in metabolism, ion channels, and transporters to adapt to low salinity. Overall, this study provides valuable genomic resources to further understanding the fundamental mechanisms of miRNA regulation in marine teleost response to hypoosmotic stress adaption.

Stress responses in expressions of microRNAs in mussel Mytilus galloprovincialis exposed to cadmium

MicroRNAs (miRNAs) are known to have complicated functions in aquatic species, but little is known about the role of miRNAs in mollusk species under environmental stress. In this study, we performed small RNA sequencing to characterize the differentially expressed miRNAs in different tissues (whole tissues, digestive glands, gills, and gonads) of blue mussels (Mytilus galloprovincialis) exposed to cadmium (Cd). In summary, 107 known miRNAs and 32 novel miRNAs were significantly (p < 0.01) differentially expressed after Cd exposure. The peak size of miRNAs was 22 nucleotides. Target genes of these differentially expressions of miRNAs related to immune defense, apoptosis, lipid and xenobiotic metabolism showed significant changes under Cd stress. These findings provide the first characterization of miRNAs in mussel M. galloprovincialis and expressions of many target genes in response to Cd stress.

Profiling of microRNA from skeletal muscle of Bandur sheep using RNA sequencing

MicroRNA profiling is a powerful approach for identifying key regulators of molecular functions which control skeletal muscle development, regeneration and function. Information on gene expression and the regulatory factors involved in myogenesis is very limited for Indian sheep. This study reports the identification and characterization of miRNAs from the skeletal muscles of Bandur sheep breed for the first time. Bandur is a consumer favoured, mutton type sheep of India, mainly distributed in Mandya district of Karnataka. Skeletal muscles from four animals of Bandur sheep of similar age, sex and reared under same management conditions were used for RNA sequencing. The total number of reads (15–36 bp) for each library of Bandur sheep ranged from 19,350,000 to 30,000,000. Highly expressed transcripts with an RPKM value of ≥1000 were observed to be 34%, whereas 38% transcripts exhibited RPKM between 100–1000 and 28% had RPKM &lt;100 in Bandur sheep. A total of 110 known mature miRNAs could be identified on comparison with known human and bovine sequences. All the identified miRNAs represented 32 miRNA families and 44 clusters. A total of 499 novel miRNAs were discovered in Bandur sheep. The miRNAs identified in our study were enriched for functions namely cell proliferation, cell differentiation, osteogenesis, lipid metabolism, muscle development, adipocyte differentiation and stress response. Potential gene targets for the identified miRNAs were predicted. Most relevant target genes predicted in our study included MYO5A, SIN3B and NR2F2 which are mainly involved in myogenesis. This study provides information of miRNAs in the skeletal muscle tissue of Bandur sheep.

Identification and characterization of miRNAs and target genes in developing flax seeds by multigroup analysis

Flax (Linum usitatissimum L.) is an important industrial crop, and its seeds are rich in a variety of functional nutrition and health components. Therefore, flaxseed is not only an important raw material in agricultural production but also an indispensable part to increase the added value of flax products. To investigate the role of miRNA in the development of flaxseed, the present study used flaxseed of Shuangya 4 at 10, 20 and 30 days post anthesis (DPA) as the study material. The study identified 130 known miRNAs and 93 new miRNAs; a total of 3,361 target genes were predicted, including 2401 target genes corresponding to known miRNAs and 960 target genes corresponding to new miRNAs. Combining the sequencing results of the degradation group, it was found that the known miRNAs including miR156, miR171, miR164, miR408 and miR398 as well as the new miRNA unconservative_scaffold3872_46150 showed significant differential expression in the development of flaxseed. These differentially expressed miRNAs and their target genes were analyzed by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The results showed that the target genes could be negatively regulated by their corresponding miRNAs and contribute to the development of flaxseed. Supplemental data for this article is available online at https://doi.org/10.1080/13102818.2021.1903337 .

Characterization of miRNAs in Extracellular Vesicles Released From Atlantic Salmon Monocyte-Like and Macrophage-Like Cells.

Cell-derived extracellular vesicles (EVs) participate in cell-cell communication via transfer of molecular cargo including genetic material like miRNAs. In mammals, it has previously been established that EV-mediated transfer of miRNAs can alter the development or function of immune cells, such as macrophages. Our previous research revealed that Atlantic salmon head kidney leukocytes (HKLs) change their morphology, phagocytic ability and miRNA profile from primarily “monocyte-like” at Day 1 to primarily “macrophage-like” at Day 5 of culture. Therefore, we aimed to characterize the miRNA cargo packaged in EVs released from these two cell populations. We successfully isolated EVs from Atlantic salmon HKL culture supernatants using the established Vn96 peptide-based pull-down. Isolation was validated using transmission electron microscopy, nanoparticle tracking analysis, and Western blotting. RNA-sequencing identified 19 differentially enriched (DE) miRNAs packaged in Day 1 versus Day 5 EVs. Several of the highly abundant miRNAs, including those that were DE (e.g. ssa-miR-146a, ssa-miR-155 and ssa-miR-731), were previously identified as DE in HKLs and are associated with macrophage differentiation and immune response in other species. Interestingly, the abundance relative of the miRNAs in EVs, including the most abundant miRNA (ssa-miR-125b), was different than the miRNA abundance in HKLs, indicating selective packaging of miRNAs in EVs. Further study of the miRNA cargo in EVs derived from fish immune cells will be an important next step in identifying EV biomarkers useful for evaluating immune cell function, fish health, or response to disease.

Mesenchymal stem cells negatively regulate CD4+ T cell activation in patients with primary Sj&ouml;gren syndrome through the miRNA‑125b and miRNA‑155 TCR pathway.

Treatment with mesenchymal stem cells (MSCs) has been revealed to suppress CD4+ T cells and autoimmunity in both mouse models and patients with primary Sjögren syndrome (pSS); however, the underlying mechanism remains unclear. MicroRNAs (miRNAs or miRs) mediate CD4+ T cell activation, but the mechanism is not understood, particularly for CD4+ T cells treated with MSCs. Characterization of miRNAs may reveal pSS pathogenesis, guide MSC treatment and provide more personalized management options. The present study aimed to perform an miRNome analysis of quiescent and T cell receptor (TCR)-activated CD4+ T cells treated with MSCs via miRNA profiles and bioinformatics. Following 72 h of co-culture, MSCs inhibited TCR-induced CD4+ T cell activation and decreased IFN-γ levels. The numbers of aberrant miRNAs in pSS naïve (vs. healthy naïve), pSS activation (vs. pSS naïve), MSC treatment and pre-IFN-γ MSC treatment (vs. pSS activation) groups were 42, 55, 27 and 32, respectively. Gene enrichment analysis revealed that 259 pathways were associated with CD4+ T cell stimulation, and 240 pathways were associated with MSC treatment. Increased miRNA-7150 and miRNA-5096 and decreased miRNA-125b-5p and miRNA-22-3p levels in activated CD4+ T cells from patients with pSS were reversed by MSC treatment. Notably, the proliferation of CD4+ T cells and CD4+ IFN-γ+ cells, expression levels of miRNA-125b-5p and miRNA-155 in CD4+ T cells and supernatant IFN-γ secretion were associated with disease activity. miRNA may play a vital role in MSC treatment for activated CD4+ T cells. The results indicated that the expression levels of miRNA-125b-5p and miRNA-155 in TCR-activated CD4+ T cells from patients with pSS may provide insight regarding autoimmune diseases and offer a novel target for prospective treatment. Therefore, these results may be crucial in providing MSC treatment for pSS.

Identification and expression profile of microRNA in seven tissues of the Golden snub-nosed monkey (Rhinopithecus roxellanae).

MicroRNAs (miRNAs) are key in the post-transcriptional regulation of gene expression and thus characterization of miRNAs and investigation of the relative abundance and specificity of tissue expression are essential for understanding gene expression in the golden snub-nosed monkey (GSM, Rhinopithecus roxellanae). Here, we report the first dataset of GSM miRNAs where we identified 460 miRNAs in seven tissues, with 246 conserved known mature miRNAs and 214 novel mature miRNAs. We determined miRNA abundance and expression in the seven tissues using a Tissue Specificity Index score and found that most novel GSM miRNAs showed a highly tissue-specific expression pattern. In particular, 67 novel miRNAs and the miR-34 family were expressed in abundance only in the lung. Five known miRNAs were highly abundant in digestive organs such as the pancreas and liver, and four novel miRNAs were highly expressed in the heart and muscle. Annotation of target genes of GSM miRNAs indicated that target genes were enriched in many important pathways, such as the HIF-1 signaling pathway and xenobiotic biodegradation-related pathways. Collectively, these results emphasize that miRNAs play important roles in GSM diet and high-elevation adaptation regulation. In summary, this study provides essential information on GSM miRNAs and will benefit further investigations of the function and mechanism of miRNAs in controlling gene expression in the GSM.

Identification and characterization of miRNAs during early pregnancy in domestic sheep.

SummaryMicroRNA resources in sheep are limited compared with those in other domesticated mammalian species. By sequencing small RNAs of sheep corpus luteum and endometrium, we have generated the largest amount of miRNA‐seq data and compiled the most comprehensive list thus far of miRNAs (n = 599) in sheep. Additionally, we observed a highly conserved maternally imprinted cluster of miRNAs on chromosome 18 homologous to that found on chromosome 14 in human and several other eutherian mammals.

Characterization of miRNAs in Cultured Atlantic Salmon Head Kidney Monocyte-Like and Macrophage-Like Cells.

Macrophages are among the first cells to respond to infection and disease. While microRNAs (miRNAs) are involved in the process of monocyte-to-macrophage differentiation in mammals, less is known in teleost fish. Here, Atlantic salmon head kidney leukocytes (HKLs) were used to study the expression of miRNAs in response to in vitro culture. The morphological analysis of cultures showed predominantly monocyte-like cells on Day 1 and macrophage-like cells on Day 5, suggesting that the HKLs had differentiated from monocytes to macrophages. Day 5 HKLs also contained a higher percentage of phagocytic cells. Small RNA sequencing and qPCR analysis were applied to examine the miRNA diversity and expression. There were 370 known mature Atlantic salmon miRNAs in HKLs. Twenty-two miRNAs (15 families) were downregulated while 44 miRNAs (25 families) were upregulated on Day 5 vs. Day 1. Mammalian orthologs of many of the differentially expressed (DE) miRNAs are known to regulate macrophage activation and differentiation, while the teleost-specific miR-2188, miR-462 and miR-731 were also DE and are associated with immune responses in fish. In silico predictions identified several putative target genes of qPCR-validated miRNAs associated with vertebrate macrophage differentiation. This study identified Atlantic salmon miRNAs likely to influence macrophage differentiation, providing important knowledge for future functional studies.

Sequencing and characterization of miRNAs and mRNAs from the longissimus dorsi of Xinjiang brown cattle and Kazakh cattle.

Breed improvement is an important genetic process affecting meat quality. Compared with Kazakh cattle, Xinjiang brown cattle have significantly improved carcass quality and meat quality. To elucidate the molecular mechanisms underlying the improvements in Xinjiang brown cattle and the differences in beef quality between the two breeds, we used RNA-Seq to study differentially expressed genes and miRNAs and regulatory pathways related to adipogenesis, myogenesis and fibrogenesis in the longissimus dorsi muscles of Xinjiang brown cattle and Kazakh cattle. The results showed that 1669 genes were differentially expressed in the longissimus dorsi muscle tissues of Xinjiang brown cattle and Kazakh cattle; 879 genes were upregulated and 790 genes were downregulated in Xinjiang brown cattle compared to Kazakh cattle. These genes were mainly involved in PPAR signaling, unsaturated fatty acid biosynthesis and vascular smooth muscle contraction. Additionally, 346 differentially expressed miRNAs were identified, of which 265 miRNAs were downregulated and 81 miRNAs were upregulated in Xinjiang brown cattle compared to Kazakh cattle. Association analysis of the differentially expressed genes and miRNAs revealed that 86 differentially expressed miRNAs related to adipogenesis were associated with 31 differentially expressed genes, 76 differentially expressed miRNAs associated with myogenesis were associated with 28 differentially expressed genes, and 54 differentially expressed miRNAs associated with fibrogenesis were associated with 19 differentially expressed genes. miRNA-target gene networks were also constructed. Finally, the expression levels of 19 genes and miRNAs were verified by qRT-PCR. Some differentially expressed genes, including FABP4, ACTA2 and ACTG2, were shown to play an important role in beef meat quality. This is the first study to perform transcriptomic analysis of muscle tissues from Xinjiang brown and Kazakh cattle.

Identification and Characteristics of Batrachuperus karlschmidti miRNA Using Illumina Deep Sequencing

MicroRNAs (miRNAs) play critical roles in regulating many biological processes of eukaryotes. Batrachuperus karlschmidti, as an endangered amphibian species of salamander endemic to China, has attracted much attention because of its high values for paleontology evolutionary history research and decreasing population size. Most miRNAs have been identified in animals, no study is available concerning the miRNAs in B. karlschmidti. Herein, deep sequencing technology was used to identify and analyze miRNAs in B. karlschmidti. Totally, 13 377 954 reads were yielded. Of them, 2 724 630 unique reads representing 866 known and three novel miRNAs were identified. All these identified miRNAs were also verified using stem-loop qRT-PCR test method. Additionally, 5452 candidate target genes were predicted. GO and KEGG pathway analysis showed that the majority of targets were involved in a broad range of biological processes and metabolic pathways. Results also revealed that certain miRNA target genes are transcription factors, which might be associated with environmental adaptation of B. karlschmidti. Overall, our results provided the first large-scale identification and characterization of miRNAs in B. karlschmidti. Discovery of miRNAs in B. karlschmidti contributes to a better understanding of the complex roles of miRNA-mediated regulatory networks in gene expression in regulating diverse biological processes and greatly facilitates further functional studies on miRNAs in this species.

Transcriptome-wide identification and profiling of miRNAs in a stress-tolerant conifer Sabina chinensis

miRNAs are important regulatory components involving in many biological processes, including plant development, vegetative and reproductive growth, and stress response. However, identification and characterization of miRNAs still remain limited for conifer species. In this study, with deep sequencing, we obtained 1,314,450 unique reads with 18-30 nt length from a stress-tolerant conifer, Sabina chinensis. We identified 37 conserved and 103 novel miRNAs, their unique characteristics were further analyzed, and 10 randomly selected were validated by qRT-PCR. Through miRNA target predictions and annotations, we found miRNA may have several targets as well a target could be regulated by several miRNAs, and a total of 2,397 mRNAs were predicted to be targets of the 140 miRNAs. These targets included not only important transcription factors such as auxin response factors, but also indispensable non-transcriptional factor proteins. Pathway-based analysis showed that S. chinensis miRNAs are involved in 172 metabolic pathways, of which 3 were discovered in adaptation-related pathways, indicating their possible relevance to the species' stress-tolerance characteristics. This study is expected to lay the foundation for exploring the regulative roles of miRNAs in development, growth, and response to environmental stresses of S. chinensis.

Computational prediction and characterisation of miRNAs and their pathway genes in human schistosomiasis caused by Schistosoma haematobium.

BACKGROUND Key genes control the infectivity of the Schistosoma haematobium causing schistosomiasis. A method for understanding the regulation of these genes might help in developing new disease strategies to control schistosomiasis, such as the silencing mediated by microRNAs (miRNAs). The miRNAs have been studied in schistosome species and they play important roles in the post-transcriptional regulation of genes, and in parasite-host interactions. However, genome-wide identification and characterisation of novel miRNAs and their pathway genes and their gene expression have not been explored deeply in the genome and transcriptome of S. haematobium.OBJECTIVES Identify and characterise mature and precursor miRNAs and their pathway genes in the S. haematobium genome.METHODS Computational prediction and characterisation of miRNAs and genes involved in miRNA pathway from S. haematobium genome on SchistoDB. Conserved domain analysis was performed using PFAM and CDD databases. A robust algorithm was applied to identify mature miRNAs and their precursors. The characterisation of the precursor miRNAs was performed using RNAfold, RNAalifold and Perl scripts.FINDINGS We identified and characterised 14 putative proteins involved in miRNA pathway including ARGONAUTE and DICER in S. haematobium. Besides that, 149 mature miRNAs and 131 precursor miRNAs were identified in the genome including novel miRNAs.MAIN CONCLUSIONS miRNA pathway occurs in the S. haematobium, including endogenous miRNAs and miRNA pathway components, suggesting a role of this type of non-coding RNAs in gene regulation in the parasite. The results found in this work will open up a new avenue for studying miRNAs in the S. haematobium biology in helping to understand the mechanism of gene silencing in the human parasite Schistosome.

Induction of miR 21 impairs the anti-Leishmania response through inhibition of IL-12 in canine splenic leukocytes.

Visceral Leishmaniasis is a chronic zoonosis and, if left untreated, can be fatal. Infected dogs have decreased cellular immunity (Th1) and develop a potent humoral response (Th2), which is not effective for elimination of the protozoan. Immune response can be modulated by microRNAs (miRNAs), however, characterization of miRNAs and their possible regulatory role in the spleen of infected dogs have not been done. We evaluated miRNA expression in splenic leukocytes (SL) from dogs naturally infected with Leishmania infantum and developing leishmaniasis (CanL; n = 8) compared to healthy dogs (n = 4). Microarray analysis showed increased expression of miR 21, miR 148a, miR 7 and miR 615, and downregulation of miR 150, miR 125a and miR 125b. Real-time PCR validated the differential expression of miR 21, miR 148a and miR 615. Further, decrease of miR 21 in SL, by means of transfection with a miR 21 inhibitor, increased the IL-12 cytokine and the T-bet/GATA-3 ratio, and decreased parasite load on SL of dogs with CanL. Taken together, these findings suggest that L. infantum infection alters splenic expression of miRNAs and that miR 21 interferes in the cellular immune response of L. infantum-infected dogs, placing this miRNA as a possible therapeutic target in CanL.

Identification and characterization of miRNAs in an endoparasitoid wasp, Pteromalus puparum.

MicroRNAs (miRNAs) are a form of endogenous small noncoding RNAs that regulate protein-coding gene expression at the posttranscriptional level. So far, knowledge of miRNAs in parasitoids remains rudimentary. We investigated miRNAs in Pteromalus puparum, a pupal endoparasitoid wasp with genome and transcriptome sequences completed. In this study, we constructed eight small RNA libraries from selected developmental stages and genders: male embryos, male larvae, male pupae, male adults, mixed-sex embryos, mixed-sex larvae, mixed-sex pupae, and female adults. We identified 254 mature miRNAs with 5p/3p arm features originated from 75 known and 119 novel miRNA genes in P. puparum, 88 of which reside in 26 clusters. The miRNAs in more than half of the clusters exhibit a consistent expression pattern, indicating they were co-transcribed from a long transcript. Comparing miRNA expression in the eight libraries, we found that 84 mature miRNAs were differentially expressed between embryos and larvae, 20 between larvae and pupae, and 26 between pupae and adults. We found some miRNAs were differentially expressed between sexes in embryos (10), larvae (29), pupae (8), and adults (14). Target predictions resulted in 211,571 miRNA-mRNA interactions for 254 different mature miRNAs. These miRNAs may be involved in sexual and developmental regulation of gene expression.

Identification and characterization of miRNAs and lncRNAs of coho salmon (Oncorhynchus kisutch) in normal immune organs

MicroRNAs (miRNAs) and long noncoding RNAs (lncRNAs) are two relevant non-coding RNAs (ncRNAs) class. Oncorhynchus kisutch (coho salmon) is an important aquaculture pacific salmon species without report of miRNAs and a very limited register of lncRNAs. To gain knowledge about the interaction and discovery of miRNAs and lncRNAs in coho salmon we used high-throughput sequencing technology to sequence small and transcriptome libraries from three immune organs. A total of 163 mature miRNAs and 4,975 lncRNAs were discovered. The profiles of expression of both ncRNAs indicated that liver and head-kidney share relatively similar expression patterns. We identified 814 and 181 putative target sequences for 1048 lncRNAs and 47 miRNAs, respectively. The results obtained provide new information and enlarge our understanding of the diversities of ncRNAs in coho salmon.

Identification and Characterization of MiRNAs in Coccomyxa subellipsoidea C-169.

Coccomyxa subellipsoidea C-169 (C-169) is an oleaginous microalga which is promising for renewable biofuel production. MicroRNAs (miRNAs), as the pivotal modulators of gene expression at post-transcriptional level, are prospective candidates for bioengineering practice. However, so far, no miRNA in C-169 has been reported and its potential impact upon CO2 supplementation remains unclear. High-throughput sequencing of small RNAs from C-169 cultured in air or 2% CO2 revealed 124 miRNAs in total, including 118 conserved miRNAs and six novel ones. In total, 384 genes were predicted as their potential target genes, 320 for conserved miRNAs and 64 for novel miRNAs. The annotated target genes were significantly enriched in six KEGG pathways, including pantothenate and CoA biosynthesis, C5-branched dibasic acid metabolism, 2-oxocarboxylic acid metabolism, butanoate metabolism, valine, leucine and isoleucine biosynthesis and alpha-linolenic acid metabolism. The miRNAs’ target genes were enriched in lipid metabolism as well as RNA-interacting proteins involved in translation, transcription and rRNA processing. The pioneering identification of C-169 miRNAs and analysis of their putative target genes lay the foundation for further miRNA research in eukaryotic algae and will contribute to the development of C-169 as an oleaginous microalga through bioengineering in the future.

Role of Liquid Biopsy in Clinical Decision-Making for Breast Cancer

Liquid biopsies are easily obtainable, non-invasive, longitudinal snapshots that can be used to measure micrometastatic disease burden, monitor disease progression, and provide genomic assessments of primary tumor/metastatic lesions. To date, most published studies have focused on circulating tumor cells (CTCs) and cell-free circulating tumor DNA (ctDNA); however, the liquid biopsy field is expanding exponentially and new blood components are currently under investigation. CTCs and ctDNA remain the most extensively studied liquid biopsy components to date. Several additional blood-based components are the basis of active, ongoing investigations. Some on the horizon include serum/plasma exosomes, platelet-mRNA, miRNA characterization, and global proteomic studies. In the era of individualized medicine, liquid biopsy has potential to improve upon current breast cancer management by offering dynamic monitoring possibilities as well as novel targets for therapy.

A microRNA profile of saliva and the role of miR-375 in Haemaphysalis longicornis (Ixodida: Ixodidae)

BackgroundTick saliva contains many bioactive molecules that are involved in attachment to the host, blood-feeding and transmission of pathogens. MicroRNAs (miRNAs) are a class of short non-coding RNAs with a length of 19–24 nucleotides. They act as regulators of gene expression by binding to their target mRNA at the post-transcriptional level and control a variety of cellular functions, including regulation of growth, metabolism and development. The detection and characterizations of miRNAs from tick saliva may help explain the molecular mechanisms involved in the interaction between ticks, pathogens and hosts. They may also contribute to the discovery of vaccines, which can control ticks and the pathogens they transmit.ResultsAn RNA library was generated from the saliva of fed adult Haemaphysalis longicornis ticks, containing 17.4 million clean reads of 18–30 nucleotides. Overall, 319 known miRNAs and 1 novel miRNA were found. The 10 most abundantly expressed miRNAs present in tick saliva were miR-100_2, miR-315, miR-184_1, miR-100-5p_2, miR-5307, miR-184-3p_3, Let-7-5p_6, miR-71_5, miR-1-3p_6 and miR-10-5p_2. miR-375, one of the abundantly expressed, was subjected to quantitative real-time PCR analysis (qRT-PCR) in various tick developmental stages, as well as in different tissues isolated from adult ticks. The expression of miR-375 in different tick development stages was highest in unfed nymphs and lowest in the egg stage. In the tissues of adult ticks, miR-375 was most highly expressed in the salivary gland. To investigate the possible role of miR-375, Ant-375 was used to inhibit the miR-375. The treated group (Ant-375) had a reduced number of eggs (t(10) = 2.652, P = 0.0242), eggs that were partially desiccated, and reduced egg hatchability (t(10) = 2.272, P = 0.044) compared to Ms-Ant and the non-injected control.ConclusionsThis is the first study to investigate the miRNA profile in tick saliva and the role of miR-375 in H. longicornis. The identification and characterization of miRNA in tick saliva may help to reveal the molecular mechanisms of interactions among ticks, pathogens and hosts, and suggest new vaccine strategies to control tick-borne diseases.

Identification and characterization of miRNAs during flag leaf senescence in rice by high-throughput sequencing

Flag leaf is the last leaf to senesce and its life span plays a critical role in determining grain quality and yield in rice. Little is known about the molecular changes that occur and their regulation in time-dependent manner during flag leaf senescence in rice. Several studies have explored different aspects of miRNA functions in plant development; however, a diminutive account is available about their role in flag leaf senescence. With an aim to unravel the role of miRNAs in ageing of flag leaf in rice, four small RNA libraries were prepared from three stages of senescence and sequenced by Illumina deep sequencing technology. Thirty-eight known and 494 novel miRNAs were identified in the senescing flag leaves. Digital expression analysis revealed that 21 known and 116 novel miRNAs were differentially expressed during senescence. Family member(s) of miR156, miR159, miR160, miR164, miR169, miR171, miR393, miR396, miR535, miR827, miR1428, miR1432 and miR1861 were differentially expressed in at least one stage of flag leaf senescence. The present study has generated a repository of senescence-related miRNAs that can be utilized to contemplate molecular approaches for manipulating the timing of flag leaf senescence in rice and other related crops.