New species of Gyrodactylus von Nordmann, 1832 (Monogenoidea: Gyrodactylidae) from Gymnodiptychus dybowskii (Kessler, 1874) (Schizothoracinae) in the Kunes River (Yili River basin), China.

Yili River system hosts a diverse fauna of fishes and parasites. Gymnodiptychus dybowskii is a rare and endangered aboriginal cold-water fish inhabit in the Yili river system. Our research identified a new species Gyrodactylus gymnodiptychi n. sp. isolated from G. dybowskii in the Kunes River (Yili River, China). Morphological comparison revealed identifiable differences between the new species and other parasites, including Gyrodactylus aksuensis, and Gyrodactylus tokobaevi, which are two known parasites living in G. dybowskii inhabit in the Aksu River west of Frunze (Kyrgyzstan), as well as Gyrodactylus montanus living in Shizothorax intermedius inhabited in the Tadzhikistan or Uzbekistan. Especially, the dorsal bar of G. gymnodiptychi n. sp. was raised at both ends with a hollow, and its hamulus roots were curved inward. The BLASTN search of GenBank did not detect any other ITS1-5.8S-ITS2 rDNA sequences same as G. gymnodiptychi's. Using the Bayesian Information and Maximum Likelihood methods to analyze the ITS1-5.8S-ITS2 rDNA gene sequences, we constructed phylogenetic trees for G. gymnodiptychi n. sp. Accordingly, our morphological and molecular research indicated that G. gymnodiptychi n. sp. was not only a new species of parasites but also the first Gyrodactylus member identified in the Yili River in China.

A New Species of Paradiplozoon (Monogenea: Diplozoidae), A Gill Parasite of the Schizothorax Fish (Cyprinidae: Schizothoracinae) from the Yarkand River, Xinjiang, China.

INTRODUCTION: Monogeneans of the genus Paradiplozoon were found on the gills of specimens of five species of schizothoracid caught using fyke nets in the upper stream of the Yarkand River, Xinjiang, China in May-August 2019. METHODS: The preserved parasite were stained with boric acid magenta and hematoxylin, respectively. Morphological observations, line drawings, photomicrographs and measurements were made in Nikon ECLIPSE E200 imaging optical microscope and digitally edited. The molecular analysis included the study of the sequence of the second internal transcribed spacer (ITS 2) of the ribosomal DNA region, calculation and analysis of genetic distance, with phylogenetic reconstructions based on the Bayesian inference and Maximum Likelihood analysis. RESULTS: The natural infection rate of host fish was 10-88%. Morphological analysis indicated that the average length of the new species was 2.125 mm while the width was 0.69 mm. The anterior part was 1.387 mm in length and the average length of the posterior part was 0.545 mm. The vitellaria was well-developed and located in the front of the body. A single ovary (oval shaped) was located at the back end of the reproductive binding area. A testis (irregular mass) was located behind or parallelled to the ovary. The new species can be distinguished from all the recorded Paradiplozoon species in terms of morphological characteristics such as haptor, clamp and central hook morphology, intestine shape and body size. In addition, the second internal transcribed spacer (ITS 2) of the ribosomal DNA region of the diplozoid was compared with that of known diplozoids previously published. It indicated that there were significant differences between the new species and the published diplozoids. CONCLUSION: Both morphological and molecular analysis support that the diplozoid is a new species. Based on the sampling location, the new species was named Paradiplozoon yarkandense n. sp.

Sulcisporasupratumida sp. nov. (Phaeosphaeriaceae, Pleosporales) on Anthoxanthumodoratum from Italy.

Sulcispora is typified by S.pleurospora. We collected a sulcispora-like taxon on leaves of Anthoxanthumodoratum L. in Italy and obtained single ascospore isolates. Combined ITS, LSU, SSU and tef1 sequence analyses suggested that Sulcispora is placed in the family Phaeosphaeriaceae and a newly collected Sulcispora species is introduced here as S.supratumida sp. nov. Detailed descriptions and illustrations are provided for Sulcisporasupratumida and it is compared with the type species, S.pleurospora.

Nano-sized TiO2 (nTiO2) induces metabolic perturbations in Physarum polycephalum macroplasmodium to counter oxidative stress under dark conditions.

Nano-sized TiO2 (nTiO2) exerts an oxidative effect on cells upon exposure to solar or UV irradiation and ecotoxicity of the nTiO2 is an urgent concern. Little information is available regarding the effect of TiO2 on cells under dark conditions. Metabolomics is a unique approach to the discovery of biomarkers of nTiO2 cytotoxicity, and leads to the identification of perturbed metabolic pathways and the mechanism underlying nTiO2 toxicity. In the present study, gas chromatography mass spectrometry (GC/MS)-based metabolomics was performed to investigate the effect of nTiO2 on sensitive cells (P. polycephalum macroplasmodium) under dark conditions. According to the multivariate pattern recognition analysis, at least 60 potential metabolic biomarkers related to sugar metabolism, amino acid metabolism, nucleotide metabolism, polyamine biosynthesis, and secondary metabolites pathways were significantly perturbed by nTiO2. Notably, many metabolic biomarkers and pathways were related to anti-oxidant mechanisms in the living organism, suggesting that nTiO2 may induce oxidative stress, even under dark conditions. This speculation was further validated by the biochemical levels of reactive oxygen species (ROS), 8-hydroxy-2-deoxyguanosine (8-OHdG), and total soluble phenols (TSP). We inferred that the oxidative stress might be related to nTiO2-induced imbalance of cellular ROS. To the best of our knowledge, the present study is the first to investigate the nTiO2-induced metabolic perturbations in slime mold, provide a new perspective of the mechanism underlying nTiO2 toxicity under dark conditions, and show that metabolomics can be employed as a rapid, reliable and powerful tool to investigate the interaction among organisms, the environment, and nanomaterials.

Construction of a directional T vector for cloning PCR products and expression in Escherichia coli.

In order to clone PCR products and express them effectively in Escherichia coli, a directional cloning system was constructed by generating a T vector based on pQE-30Xa. The vector was prepared by inserting an XcmI cassette containing an endonuclease XcmI site, a kanamycin selective marker, a multiple-cloning-site (MCS) region and an opposite endonuclease XcmI site into the vector pQE-30Xa. The T vector pQE-T with single overhanging dT residues at both 3' ends was obtained by digesting with the restriction enzyme XcmI. For directional cloning, a BamHI site was introduced to the ends of the PCR products. A BamHI site was also located on the multiple cloning site of pQE-T. The PCR products were ligated with pQE-T. The directionally inserted recombinants were distinguished by using BamHI to digest the recombinants because there are two BamHI sites located on the both sides of PCR fragment. In order to identify the T-vector functions, the 14-3-3-ZsGreen and hRBP genes were amplified and a BamHI site was added to the ends of the genes to confirm this vector by ligation with pQE-T. Results showed that the 14-3-3-ZsGreen and hRBP were cloned to the vector pQE-T directly and corresponding proteins were successfully produced. It was here demonstrated that this directional vector is capable of gene cloning and is used to manipulate gene expression very easily. The methodology proposed here involves easy incorporation of the construct into other vectors in various hosts.

Improving cellulase production in Trichoderma koningii through RNA interference on ace1 gene expression.

Ribonucleic acid interference (RNAi) inhibits the expression of target genes in a sequence-specific manner, and shows potential for gene knockdown in filamentous fungi, in which the locus-specific gene knockout occurs in low frequency. In this study, the function of the repressor of cellulase expression I (ACEI) was verified in Trichoderma koningii (T. koningii) YC01 through RNAi, and ace1- silenced strains with improved cellulase productivity were obtained. An expression cassette that transcribed the interfering double-stranded RNA (dsRNA) of ace1 was constructed and transformed into T. koningii, and the transformants, in which the expression of ace1 was successfully silenced, were selected. As a result of the ace1 gene silencing, the expression levels of the main cellulase and xylanase genes were elevated, and the enhanced production of total proteins, cellulase, and xylanase was observed in the cultivation. In addition, the downregulation of ace1 resulted in an increasing expression of xyr1, but no clear variation in the expression of cre1, which suggested that ACEI acted as a repressor of the xyr1 transcription, but was not involved in the regulation of the cre1 expression. The results of this work indicate that ace1 is a valid target gene for enhancing enzyme production in T. koningii, and RNAi is an appropriate tool for improving the properties of industrial fungi.

Identification of a novel PSR as the substrate of an SR protein kinase in the true slime mold.

Here, a novel cDNA encoding a serine/arginine (SR)-rich protein, designated PSR, was isolated from the true slime mold Physarum polycephalum and expressed in Escherichia coli. The deduced amino acid (aa) sequence reveals that PSR contains RS repeats at its C-terminus, similar to the conventional PSRPK substrate ASF/SF2. To study the novel protein, we generated a variety of mutant constructs by PCR and site-directed mutagenesis. Our analysis indicated that the purified recombinant PSR was phosphorylated by PSRPK in vitro and the SR-rich domain (amino acids 460-469) in the PSR protein was required for phosphorylation. In addition, removal of the docking motif (amino acids 424-450) from PSR significantly reduced the overall catalytic efficiency of the phosphorylation reaction. We also found that the conserved ATP-binding region (62)LGWGHFSTVWLAIDEKNGGREVALK(86) and the serine/threonine protein kinases active-site signature (184)IIHTDLKPENVLL(196) of PSRPK played a crucial role in substrate phosphorylation and Lys(86) and Asp(188) were crucial for PSRPK phosphorylation of PSR. These results suggest that PSR is a novel SR-related protein that is phosphorylated by PSRPK.

Expression inhibition of multidrug resistance-associated protein (MRP1) by multi-ribozyme expression system in HEK293 cells.

To study application of multi-ribozyme expression system on expression inhibition of multidrug resistance-associated protein (MRP1) in HEK293 cells, the multi-ribozyme expression system containing 20 cis-acting ribozymes for self-cleavage and 10 trans-acting ribozymes for targeting to MRP1 gene specific site were constructed. HEK293 cells cotransfected multi-ribozyme expression system with MRP1 target gene or full length of MRP1 gene respectively were analyzed by RT-PCR, Western blot analysis and MTT assay. The results showed that multi-ribozyme systems were able to dramatically decrease fluorescent fusion protein expression in HEK293 cells. RT-PCR analysis indicated that the extent of MRP1 target mRNA decrease was correlated with the number of trans-acting ribozyme contained in multi-ribozyme expression system. Similar changes have been observed from Western blot. MTT assay showed that multi-ribozyme systems were able to reverse MDR generated by MRP1 gene in HEK cells. These results suggested that inhibitory effects of multiple copies of ribozymes contained in the system were better than that of single ribozyme contained. Therefore, this strategy could be used in treatment of tumor or other diseases via gene therapy.

[Expression silence of Physarum polycephalum serine/arginine protein kinase by small interfering RNA].

Serine/arginine protein kinases are specific kinase family for phosphorylating SR protein regulating alternative splicing of SR protein and its distribution, localization in the nucleus. However, it is unclear how Physarum Polycephalum Serine/Arginine Protein Kinase(PSRPK) functions in the cells. In order to study its function, Oligonucleotides for transcribing siRNAs were designed and inserted into pSIREN-RetroQ vector to construct pSIREN-PSRPK-1, pSIREN-PSRPK-2, pSIREN-PSRPK-3, pSIREN-PSRPK-4, pSIREN-PSRPK-5 for expressing siRNAs targeting at PSRPK, as well as the negative control pSIREN-PSRPK-Neg. The PSRPK cDNA amplified by PCR was inserted into the pDsRed-N1 vector to construct a pPSRPK-DsRed plasmid. After the pPSRPK-DsRed was co-transfected into HEK293 cell with recombinant siRNA expression plasmids respectively, the PSRPK-DsRed fusion fluorescent protein was observed under fluorescent microscope after 72 hours co-transfection. The results indicated that pSIREN-PSRPK-2 and pSIREN-PSRPK-5 were able to inhibit the expression of PSRPK-DsRed fusion fluorescent protein efficiently. RT-PCR and Northern dot blot analysis further demonstrated that pSIREN-PSRPK-2 and pSIREN-PSRPK-5 can effectively inhibit PSRPK expression, which accorded with the results under the fluorescent microscope.

[Effects of Yisui Jiedu Recipe on JAK2-STAT5 signal transduction pathway in bone marrow hematopoietic cells from patients with myelodysplastic syndrome-refractory anemia].

OBJECTIVE: To investigate the effect of Yisui Jiedu Recipe (YSJDR), a compound traditional Chinese herbal medicine, on cytokines and their corresponding just another kinase 2-signal transducers and activators of transcription 5 (JAK2-STAT5) signal transduction pathway in bone marrow hematopoietic cells from patients with myelodysplastic syndrome-refractory anemia (MDS-RA). METHODS: Fluorogenic quantitative polymerase chain reaction (FQ-PCR) method was established to detect the levels of JAK2, STAT5 and Bcl-xL mRNA expressions, and JAK2-STAT5 signal transduction pathway was activated by granulocyte-macrophage-colony stimulating factor (GM-CSF) in cultured bone marrow hematopoietic cells from 10 patients with MDS-RA. The levels of interleukin-2 (IL-2), interleukin-3 (IL-3), gamma-interferon (gamma-INF) and tumor necrosis factor-alpha (TNF-alpha) in the cultural supernatant of untreated control, AG490-treated and YSJDF-treated cells were measured by enzyme-linked immunosorbent assay. RESULTS: The levels of IL-2 and TNF-alpha in YSJDR-treated group were significantly lower than those in untreated control group and AG490-treated group (P<0.01, P<0.05), and IL-3 level in YSJDP-treated group was remarkably higher than that in the other two groups (P<0.01). There were no significant differences in the levels of IL-2 and IL-3 between AG490-treated group and untreated control group (P>0.05), while the TNF-alpha level in AG490-treated group was decreased obviously as compared with the untreated control group (P<0.01). There was no significant difference in gamma-INF level between YSJDR-treated group and AG490-treated group (P>0.05), while TNF-alpha level in the two groups were significantly lower than that in the untreated control group (P<0.01). The expressions of JAK2, STAT5 and Bcl-xL mRNAs were significantly down-regulated in the YSJDR-treated and the AG490-treated groups as compared with those in the untreated control group (P<0.05, P<0.01), while there were no differences in the expressions of JAK2, STAT5 and Bcl-xL mRNAs between YSJDR-treated group and AG490-treated group. CONCLUSION: YSJDR can modulate cytokine level in bone marrow hematopoietic cells of MDS-RA, suppress JAK2-STAT5 signal transduction, and inhibit the Bcl-xL mRNA expression.