MicrORNAs (miRNAs) are a class of short, evolutionary conserved non-coding RNA molecules, which are shown as the key regulators of many biological functions. External stress can alter miRNA expression levels, thereby changing the expression of mRNA target genes. Here, we show that miR-21 is involved in the regulation of alkalinity tolerance in Nile tilapia. Alkalinity stress results in a marked reduction in miR-21 levels. miR-21 loss of function could affect ion balance regulation, ROS production, and antioxidant enzyme activity in vivo. Moreover, miR-21 knockdown protects cell against alkalinity stress-induced injury in vitro. miR-21 directly regulates VEGFB and VEGFC expression by targeting the 3'-untranslated regions (UTRs) of their mRNAs, and inhibition of miR-21 significantly increases the levels of VEGFB and VEGFC expression in vivo. Taken together, our study reveals that miR-21 knockdown plays a protective role in alkalinity tolerance in tilapia. (C) 2016 Elsevier Inc. All rights reserved.
Zhao, Jin-Liang
Wu, Yu-Peng
Su, Tian-Juan
Jiang, Guo-Fang
Wu, Chun-Sheng
The yellow tortrix, Acleris fimbriana belongs to Tortricidae in Lepidoptera. We described the complete mitogenome of A. fimbriana, which is typical circular duplex molecules and 15,933 bp in length containing the standard metazoan set of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and an A + T-rich region with macro-repeat sequences. All the inferred tRNA secondary structures show the common cloverleaf pattern, with the exception of trnS1(AGN) which lacks the DHU arm. The A. fimbriana mitochondrial genome has the same gene order with other lepidopterans.
MicroRNAs (miRNAs) are endogenous small non-coding RNAs that play crucial roles in numerous biological processes. However, the role of miRNAs in skin color determination in fish has not been completely determined. Here, we identified that 13 miRNAs are differentially expressed between red and white skin. The analysis of miRNA spatial and temporal expression patterns suggests that miR-429 is a potential regulator of skin pigmentation. miR-429 silencing results in an obvious change in skin pigmentation. Bioinformatics analysis and a luciferase reporter assay show that miR-429 directly regulates expression of Foxd3 by targeting its 3'-untranslated (3'-UTR) region. miR-429 silencing leads to a substantial increase in the expression of Foxd3 in vivo, thereby repressing the transcription of MITF and its downstream genes, such as TYR, TYRP1 or TYRP2. These findings would provide a novel insight into the determination of skin color in fish.
miRNAs comprise a class of similar to 22 nt noncoding RNAs that modulate the stability and/or translational potential of their mRNA targets. Emerging data suggest that stress conditions can alter the biogenesis of miRNAs, thereby changing the expression of mRNA targets. Here, we reveal that miR-30c, a kidney-enriched miRNA, emerges as a crucial osmoregulator in Nile tilapia. miR-30c loss of function leads to an inability to respond to osmotic stress. We identify HSP70 as one of the direct regulatory targets of miR-30c. miR-30c directly regulates HSP70 by targeting its 3'-UTR, and inhibition of miR-30c substantially increases HSP70 mRNA level in vivo. Taken together, our experiments suggest that miRNAs participate in a regulatory circuit that allows rapid gene program transitions in response to osmotic stress. miR-30c may be developed as a molecular marker to assist to breed or genetically engineer salt tolerant species. (c) 2012 Elsevier Inc. All rights reserved.
Magnetic properties and magnetocaloric effects (MCEs) of the Dy(3)Co compound are studied. Two successive magnetic transitions: the antiferromagnetic (AFM)-to-AFM transition at T (AF) =29 K and the AFM-to-paramagnetic (PM) transition with increasing temperature at the N,el temperature T (N) =44 K are observed. Dy(3)Co undergoes a field-induced metamagnetic transition from the AFM to the ferromagnetic (FM) state below T (N) , giving rise to a large MCE. The maximal value of magnetic entropy change Delta S (m) is -13.9 J/kg K with a refrigerant capacity (RC) of 498 J/kg around T (N) for a field change of 0-5 T. A sign change of MCE in Dy(3)Co with magnetic field and temperature is observed near the critical field where the metamagnetic transition occurs.
Interferon regulatory factor 3 (IRF3) plays a key role in interferon (IFN) response and binding to the MN stimulatory response elements (ISREs) within the promoter of IFN and IFN-stimulated genes followed by virus infection. In the current study, we discovered one IRF3 homologue in tilapia genome and analyzed the characterizations and functions of tilapia IRF3. Tilapia IRF3 contains 1368 bp with an ORE of 455 aa. Structurally, tilapia IRF3 protein typically shares the conserved characterizations with other species' IRF3 homologues, displaying conserved DNA-binding domain, IRF association domain, serine-rich C terminal domain, and tryptophan residue cluster. Phylogenetic analysis illustrated that tilapia IRF3 belongs to the IRF3 subfamily. Real-time PCR revealed a broad expression pattern of tilapia IRF3 in various tissues. Subcellular localization analysis showed that tilapia IRF3 mainly resides in the cytoplasm, Western blot demonstrated that IRF3 was distributed in the cytoplasmic fraction. Functionally, IRF3 was found to be transcriptionally up-regulated by the poly I:C stimulation. Moreover, reporter assay elucidated that tilapia IRF3 serves as a regulator in mediating IFN response by increasing the activity of IFN-beta and ISRE-containing promoter. These data supported the view that tilapia IRF3 is a potential molecule in IFN immune defense system against viral infection. (C) 2015 Elsevier Ltd. All rights reserved.
The Nile tilapia (Oreochromis niloticus; Cichlidae) is an economically important species in aquaculture and occupies a prominent position in the aquaculture industry. MicroRNAs (miRNAs) are a class of noncoding RNAs that post-transcriptionally regulate gene expression involved in diverse biological and metabolic processes. To increase the repertoire of miRNAs characterized in tilapia, we used the Illumina/Solexa sequencing technology to sequence a small RNA library using pooled RNA sample isolated from the different developmental stages of tilapia. Bioinformatic analyses suggest that 197 conserved and 27 novel miRNAs are expressed in tilapia. Sequence alignments indicate that all tested miRNAs and miRNAs* are highly conserved across many species. In addition, we characterized the tissue expression patterns of five miRNAs using real-time quantitative PCR. We found that miR-1/206, miR-7/9, and miR-122 is abundantly expressed in muscle, brain, and liver, respectively, implying a potential role in the regulation of tissue differentiation or the maintenance of tissue identity. Overall, our results expand the number of tilapia miRNAs, and the discovery of miRNAs in tilapia genome contributes to a better understanding the role of miRNAs in regulating diverse biological processes. =20
Magnetic properties and magnetocaloric effects (MCEs) of the antiferromagnetic (AFM) ErTiSi compound with a Neel temperature T(N)=46 K are studied by magnetization measurements. Two successive magnetic transitions in the thermomagnetic M-T curves, an AFM-AFM transition followed by an AFM-paramagnetic transition with increasing temperature, are observed. ErTiSi undergoes a field-induced metamagnetic transition from AFM to FM state below T(N). A sign change in MCE with increasing temperature or magnetic field in ErTiSi is observed near the critical field. The maximal value of magnetic entropy change Delta S(m) is -8.9 J/kg K around T(N) for a field change of 0-5 T. The modest Delta S(m) as well as no hysteresis loss around T(N) in ErTiSi may be useful for its application in magnetic refrigeration. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3365531]
Wu, Yu-Peng
Zhao, Jin-Liang
Su, Tian-Juan
Li, Jie
Yu, Fang
Chesters, Douglas
Fan, Ren-Jun
Chen, Ming-Chang
Wu, Chun-Sheng
Zhu, Chao-Dong
The mitochondrial genome (mitogenome) of Leucoptera malifoliella (=L. scitella) (Lepidoptera: Lyonetiidae) was sequenced. The size was 15,646bp with gene content and order the same as those of other lepidopterans. The nucleotide composition of L. malifoliella mitogenome is highly A+T biased (82.57%), ranked just below Coreana raphaelis (82.66%) (Lepidoptera: Lycaenidae). All protein-coding genes (PCGs) start with the typical ATN codon except for the cox1 gene, which uses CGA as the initiation codon. Nine PCGs have the common stop codon TAA, four PCGs have the common stop codon T as incomplete stop codons, and nad4l and nad6 have TAG as the stop codon. Cloverleaf secondary structures were inferred for 22 tRNA genes, but trnS1(AGN) was found to lack the DHU stem. The secondary structure of rrnL and rrnS is generally similar to other lepidopterans but with some minor differences. The A+T-rich region includes the motif ATAGA, but the poly (T) stretch is replaced by a stem-loop structure, which may have a similar function to the poly (T) stretch. Finally, there are three long repeat (154bp) sequences followed by one short repeat (56bp) with four (TA)(n) intervals, and a 10-bp poly-A is present upstream of trnM. Phylogenetic analysis shows that the position of Yponomeutoidea, as represented by L. malifoliella, is the same as traditional classifications. Yponomeutoidea is the sister to the other lepidopteran superfamilies covered in the present study.
Zhao, Jin-Liang
Zhang, Yan-Yan
Luo, A-Rong
Cameron, Stephen L.
We determined the nucleotide sequence of the mitochondrial genome (mtgenome) of Spilonota lechriaspis Meyrick (Lepidoptera: Tortricidae). The entire closed circular molecule is 15,368 bp and contains 37 genes with the typical gene complement and order for lepidopteran mtgenomes. All tRNAs except tRNA(Ser(AGN)) can be folded into the typical cloverleaf secondary structures. The protein-coding genes (PCGs) have typical mitochondrial start codons, with the exception of COI, which uses the unusual CGA one as is found in all other Lepidoptera sequenced to date. In addition, six of 13 PCGs harbor the incomplete termination codons, a single T. The A + T-rich region contains some conserved structures that are similar to those found in other lepidopteran mtgenomes, including a structure combining the motif 'ATAGA', a 19-bp poly(T) stretch and three microsatellite (AT)(n) elements which are part of larger 122+ bp macrorepeats. This is the first report of macrorepeats in a lepidopteran mtgenome.
The Nile tilapia represents an excellent model for osmoregulation study. Osmotic stress transcription factor 1 (OSTF1) identified in tilapia gill epithelium is a critical element of osmosensory signal transduction by means of transcriptional regulation. Thus, tight regulation of OSTF1 level is necessary for tilapia osmotic adaptation. microRNAs (miRNAs), have emerged as a crucial regulator of gene expression at post-transcriptional level. We reasoned that OSTF1 expression could be regulated by miRNAs. By bioinformatics analysis, we identified a putative miR-429 binding site in the OSTF1 mRNA. Interestingly, miR-429 is down-regulated in tilapia upon osmotic stress, consistent with OSTF1 protein up-regulation. miR-429 directly regulates OSTF1 expression by targeting its 3'-UTR, and inhibition of miR-429 substantially increases OSTF1 level in vivo. Moreover, miR-429 loss of function could influence the regulation of plasma osmolality and ion concentration responding to osmotic stress. Taken together, miR-429 is an endogenous regulator of OSTF1 expression, which participates in a regulatory circuit that allows rapid gene program transitions in response to osmotic stress. Crown Copyright (c) 2012 Published by Elsevier Inc. All rights reserved.
In the present study, we obtained the full-length cDNA sequences of TLR21 and TLR22 from Nile tilapia (Oreochromis niloticus) (OnTLR21 and OnTLR22, respectively). The gene structure and expression patterns of OnTLR21 and OnTLR22 were also studied in order to understand the function of these genes in tilapia immunity. The OnTLR21 gene was 3196bp in length, with an open reading frame (ORF) of 2940bp encoding 979 amino acid residues and with no introns. The OnTLR22 gene contained three exons and two introns, with an ORF of 2886bp, encoding 961 amino acid residues. The TLR family motifs, that is leucine-rich repeat (LRR) domains and Toll/interleukin (IL)-1 receptor (TIR) domains, are conserved in the putative OnTLR21 and OnTLR22 proteins. Quantitative real-time PCR (qRT-PCR) analysis revealed the presence of the OnTLR21 transcript in 10 tissues of healthy fish, with the highest expression level in the gill and the lowest expression level in the liver. In contrast, the highest expression level of OnTLR22 was detected in the spleen, while the lowest expression level was in the liver. The expression pattern of TLR during embryonic development showed that the expression levels of OnTLR21 significantly increased from 2.5 to 6.5days post fertilization (dpf), decreased at 7.5 dpf and increased at 8.5 dpf. While the expression levels of OnTLR22 significantly decreased from 3.5 dpf, and there were no significant differences from 3.5 to 8.5 dpf. Upon stimulation with an intraperitoneal injection of Streptococcus agalactiae, the expression levels of OnTLR21 and OnTLR22 were downregulated in the spleen, kidney and gill. These results may indicate that OnTLR21 and OnTLR22 play important roles in mediating the response protection against S.agalactiae in Nile tilapia.
The effect of the B-addition on magnetic entropy change Delta S(M) and hysteresis loss in La(Fe, Si)(13) is studied. The maximal values of Delta S(M) for LaFe(11.9)Si(1.1), LaFe(11.5)B(0.4)Si(1.1), LaFe(11.5)Si(1.5), and LaFe(11.0)B(0.5)Si(1.5) are found to be 27.0, 26.1, 23.7, and 21.2 J/kg K at Curie temperature T(C) for a field change in 0-5 T, respectively. The maximal hysteresis losses around T(C) are 43 and 21 J/kg for LaFe(11.9)Si(1.1) and LaFe(11.5)Si(1.5), respectively, while almost no magnetic hysteresis is observed for the B-doped compounds. Our result reveals that a large Delta S(M) and a small hysteresis loss can be simultaneously achieved in NaZn(13)-type La(Fe, Si)(13) compounds by the addition of B. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3349325]
Huang, Ai-Xia
Wang, Yong-Shun
She, Xiao-Ping
Mu, Juan
Zhao, Jin-Liang
Hydrogen peroxide is an important intermediate in darkness-induced stomatal closure. In the present work, we provide evidence that copper amine oxidase (CuAO) was involved in H2O2 production in darkness-induced stomatal closure in Vicia faba L. Darkness activated CuAO in intercellular washing fluid from leaves. Aminoguanidine (AG) and 2-bromoethylamine (BEA), which were both irreversible inhibitors of CuAO, significantly suppressed darkness-induced stomatal closure and H2O2 generation. The effects of AG and BEA were reversed only by H2O2 but not by other products of CuAO. These results indicate that CuAO participates in darkness-induced stomatal closure through its reaction product, H2O2. Furthermore, darkness-induced nitric oxide (NO) production and cytosolic alkalinisation were obviously inhibited by AG and BEA, and only H2O2, among the products of CuAO, could reverse the effects, implying that the CuAO-catalysed product H2O2 is required for NO production and cytosolic alkalinisation to a large extent in darkness-induced stomatal closure. In addition, butyric acid blocked but methylamine enhanced the ability of H2O2 to reverse the effect of BEA on NO production, suggesting that cytosolic alkalinisation is involved in CuAO-mediated NO generation in darkness-induced stomatal closure.
Magnetic properties and magnetocaloric effects (MCEs) have been investigated in hydrogenated La(0.5)Pr(0.5)Fe(11.4)Si(1.6)H(x) (x=0, 0.9, and 1.6) compounds. It is found that the Curie temperature T(C) can be tuned from 189 to 317 K by adjusting hydrogen content from 0 to 1.6. It is attractive that both thermal and magnetic hysteresis are remarkably reduced because of the weakness of the itinerant-electron metamagnetic transition after hydrogenation, while the large magnetic entropy change is retained. The maximal hysteresis loss at T(C) decreases from 17.8 to 2.3 J/kg as x increases from 0 to 1.6. For the samples with x=0, 0.9, and 1.6, the maximal values of -Delta S are 26.3, 24.1, and 22.1 J/kg K at T(C), with efficient refrigeration capacities of 463, 366, and 351 J/kg for a field change of 0-5 T, respectively. Large reversible MCE and small hysteresis with considerable value of refrigeration capacity indicate the potentiality of La(0.5)Pr(0.5)Fe(11.4)Si(1.6)H(x) hydrides as a candidate magnetic refrigerant around room temperature. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3374635]