Tissue-specific transcriptome assemblies of the marine medaka Oryzias melastigma and comparative analysis with the freshwater medaka Oryzias latipes

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MicroRNA-sequence profiling reveals novel osmoregulatory microRNA expression patterns in catadromous eel anguilla marmorata

MicroRNAs (miRNAs) are a class of endogenous small non-coding RNAs that regulate gene expression by post-transcriptional repression of mRNAs. Recently, several miRNAs have been confirmed to execute directly or indirectly osmoregulatory functions in fish via translational control. In order to clarify whether miRNAs play relevant roles in the osmoregulation of Anguilla marmorata, three sRNA libraries of A. marmorata during adjusting to three various salinities were sequenced by Illumina sRNA deep sequencing methods. Totally 11,339,168, 11,958,406 and 12,568,964 clear reads were obtained from 3 different libraries, respectively. Meanwhile, 34 conserved miRNAs and 613 novel miRNAs were identified using the sequence data. MiR-10b-5p, miR-181a, miR-26a-5p, miR-30d and miR-99a-5p were dominantly expressed in eels at three salinities. Totally 29 mature miRNAs were significantly up-regulated, while 72 mature miRNAs were significantly down-regulated in brackish water (10‰ salinity) compared with fresh water (0‰ salinity); 24 mature miRNAs were significantly up-regulated, while 54 mature miRNAs were significantly down-regulated in sea water (25‰ salinity) compared with fresh water. Similarly, 24 mature miRNAs were significantly up-regulated, while 45 mature miRNAs were significantly down-regulated in sea water compared with brackish water. The expression patterns of 12 dominantly expressed miRNAs were analyzed at different time points when the eels transferred from fresh water to brackish water or to sea water. These miRNAs showed differential expression patterns in eels at distinct salinities. Interestingly, miR-122, miR-140-3p and miR-10b-5p demonstrated osmoregulatory effects in certain salinities. In addition, the identification and characterization of differentially expressed miRNAs at different salinities can clarify the osmoregulatory roles of miRNAs, which will shed lights for future studies on osmoregulation in fish

[[alternative]]Zebrafish transforming growth factor-β-stimulated clone 22 domain 3 (TSC22D3) plays critical roles in Bmp-dependent dorsoventral patterning via 2 deubiquitinating enzymes Usp15 and Otud4

[[abstract]]AbstractBackground Osmotic stress transcription factor 1/transforming growth factor-β-stimulated clone 22 domain 3 (Ostf1/Tsc22d3) is a transcription factor that plays an osmoregulatory role in euryhaline fishes. Its mRNA and protein levels are up-regulated under hyperosmotic stress. However, its osmoregulatory and developmental functions have not been studied in any stenohaline freshwater fishes. Zebrafish is an excellent model to perform such study to unfold the functional role of Tsc22d3. Methods We identified the zebrafish Tsc22d3 and performed knockdown studies using morpholino antisense oligonucleotide (MO). Results Zebrafish Tsc22d3 did not response to hypertonic stress and ts22d3 knockdown or overexpression by injecting MO or capped RNA did not change the transcriptional levels of any of the known ionocyte markers. To reveal the unknown function of zebrafish Tsc22d3, we performed several in situ molecular marker studies on tsc22d3 morphants and found that Tsc22d3 plays multi-functional roles in dorsoventral (DV) patterning, segmentation, and brain development. We then aimed to identify the mechanism of Tsc22d3 in the earliest stages of DV patterning. Our results demonstrated that tsc22d3 is a ventralized gene that can stimulate the transcription of bone morphogenetic protein 4 (bmp4) and, thus, has a positive effect on the Bmp signaling pathway. Furthermore, we showed that Tsc22d3 interacts with deubiquitinating enzymes, ubiquitin-specific protease 15 (Usp15) and ovarian tumor domain containing protein 4 (Otud4). In addition, the interruption of Bmp4 signaling by double knockdown of usp15 and otud4 reduced the ventralized effects in tsc22d3-overexpressing embryos. Conclusions This is the first study to identify new developmental functions of Tsc22d3 in zebrafish. General significance Zebrafish tsc22d3 is a ventralized gene and a plays role in early embryogenesis

Early Zebrafish Development, a Screening Model to Identify Effects of Endocrine Disrupting Chemicals

Poster SessionThe exposure of mammalian foetus to endocrine disrupting chemicals (EDCs) has been hypothesized to increase the propensity of offspring to develop organ dysfunction or diseases in adult life. Since fetal development is recognized as the most susceptible stage to be affected by different kinds of stress, there is a pressing need to understand the effects of EDCs on this critical developmental window. However, the understanding of the mechanistic basis of this cause-effect relationship is in fact stunningly complex, largely hampered by the complexity of the mammalian developmental processes. Zebrafish, an excellent model widely used in the field of developmental biology, provides an invaluable tool to the field of developmental toxicology. Furthermore, zebrafish was used in classical toxicological studies in sublethal or lethal toxicity test by exposure to different types of chemical contaminants. However, these studies did not provide information on the mechanistic action of the contaminants at realistic exposure dosages. In this study, the approach of using standard whole-mount in situ hybridization screening method was adopted to determine early developmental defects in zebrafish embryos exposed to the ubiquitous contaminant, bisphenol A (BPA) at three critical early developmental stages (60–75% epiboly, 8–10 somite, and prim-5). This screening strategy provided an important evidence to illustrate the effects of BPA on dorsal-ventral (DV) patterning, segmentation, and brain development in zebrafish embryos within 24 hours of the exposure

Data for transcriptomic and iTRAQ proteomic analysis of Anguilla japonica gills in response to osmotic stress

This article contains data related to the two research articles titled Transcriptomic and iTRAQ proteomic approaches reveal novel short-term hyperosmotic stress responsive proteins in the gill of the Japanese eel (Anguilla japonica) and iTRAQ-based quantitative proteomic analysis reveals acute hypo-osmotic responsive proteins in the gills of the Japanese eel (Anguilla japonica). The two research articles show the usefulness of combining transcriptomic and proteomic approaches to provide molecular insights of osmoregulation mechanism in a non-model organism, the Japanese eel. The information presented here combines the raw data from the two studies and provides an overview on the physiological functions of fish gills