Project description:Here we used functional proteomics approaches to identify an upstream transcription complex (USTC) that is required for piRNA biogenesis. The complex contains PRDE-1, SNPC-4, TOFU-4, and TOFU-5, all of which are enriched on the two piRNA clusters on chromosome IV and form distinct piRNA foci in the nucleus.
2019-04-04 | GSE112682 | GEO
Project description:Metagenomics of Kebrit brine pools
Project description:Silver nanoparticles (NPs) are extensively used due to their antimicrobial activity and, therefore, their input into the ecosystem will increase. Silver can be bioaccumulated by low trophic level organisms and, then, incorporated into the food chain, reaching high level predators. The objectives of this study were to test the acute toxicity of N-vynil-2-pirrolidone/polyethylenimine (PVP-PEI) coated Ag NPs of 5 nm to brine shrimp (Artemia sp) larvae and to assess bioaccumulation and effects of silver transferred by the diet. For the later, brine shrimps were exposed to two different concentrations of Ag NPs, 100 ng/L as an environmentally relevant concentration and 100 µg/L as a likely effective concentration, in parallel with an unexposed control group and, then, used to feed zebrafish during 21 days in order to simulate two trophic levels of a simplified food web. For brine shrimp larvae, EC50 values ranged from 7.39 mg Ag/L (48 h post hatch larvae (hph) exposed for 48 h) to 19.63 mg Ag/L (24 hph larvae exposed for 24 h. Silver accumulation was measured in brine shrimps exposed to 0.1 and 1 mg/L of Ag NPs for 24 h. In zebrafish fed with brine shrimps exposed to Ag NPs, intestine showed higher metal accumulation than liver, although both organs presented the same pattern of dose and time-dependent metal accumulation as revealed by autometallography. Feeding of zebrafish for 3 days with brine shrimps exposed to 100 ng/L of Ag NPs was enough to impair fish health as reflected by the significant reduction of the lysosomal membrane stability and the presence of several histopathological conditions in the liver. Overall, results showed that Ag NPs were able to exert toxic effects on zebrafish through dietary exposure, even at an environmentally relevant concentration, which should act as concern of the need of studies in further detail about real impact of nanomaterials in the environment.
Project description:Soybean and fish contains various active components that were reported to prevent cardiovasucular diseases. Epidemiological studies indicated that Asian eating patterns, consisting of daily seafood and/or soy consumption, confer protection against cardiovascular diseases. In this context, we expected that simultaneous intake of soybean and fish may be greatly beneficial in a manner different from the ingestion of the individual food. To understand the detailed mechanism for modulating the lipid metabolism by co-ingestion of a soy food (tofu) and fish oil, we investigated the global changes in hepatic mRNA expression in rats by using a microarray analysis. Generally, ingestion of tofu contributed to prevent the mRNA expressions involved in hepatic lipogenesis, whereas fish oil facilitated the mRNA expressions related to the degradation of hepatic fatty acids. In terms of mRNA expression, the interaction of two dietary factors was limited. The expression data was normalized and summarized by using SuperNORM data service (Skylight Biotech Inc.). Significance of expressional change among groups was tested by 2-way ANOVA on the normalized CEL data, which was deposited in a tab-separated ASCII text format. Principal components were identified on the summarized gene data. Rats were divided into four groups each with similar average body weights and assigned experimental diets for 21 days as follows: casein and soybean oil diet (CS); casein and fish oil diet (CF); tofu and soybean oil diet (TS); tofu and fish oil diet (TF). Total protein and fat content of each diet was 200 and 150 g/kg, respectively. Soybean oil diets (CS and TS) contain 150 g/kg diet of soybean-derived fat (i.e. soybean oil and freeze-dried tofu), and 50 g/kg of fish oil was replaced with the same amount of soybean-derived fat for fish oil diets (CF and TF). Animals were allowed free access to food and water.
Project description:Halophilic microorganisms have long been known to survive within the brine inclusions of salt crystals, as evidenced by their pigmentation. However, the molecular mechanisms allowing this survival has remained an open question for decades. While protocols for the surface sterilization of halite (NaCl) have enabled isolation of cells and DNA from within halite brine inclusions, “-omics” based approaches have faced two main technical challenges: (1) removal of all contaminating organic biomolecules (including proteins) from halite surfaces, and (2) performing selective biomolecule extractions directly from cells contained within halite brine inclusions with sufficient speed to avoid modifications in gene expression during extraction. In this study, we present methods to resolve these two technical challenges. In addition, we apply these methods to perform the first examination of the early acclimation of a model haloarchaeon (Halobacterium salinarum NRC-1) to halite brine inclusions. Examinations of the proteome of Halobacterium cells two months post-evaporation revealed a high degree of similarity with stationary phase liquid cultures, but with a sharp down-regulation of ribosomal proteins. Low quantities of RNA from halite brine inclusions corroborate the hypothesis of low transcriptional and translational activities. While proteins for central metabolism were part of the shared proteome between liquid cultures and halite brine inclusions, proteins involved in cell mobility (archaellum, gas vesicles) were either absent or less abundant in halite samples. Proteins unique to cells within brine inclusions included transporters, suggesting modified interactions between cells and the surrounding brine inclusions microenvironment. The methods and hypotheses presented here enable future studies of the survival of halophiles in both culture model and natural halite systems.
Project description:Piwi-interacting RNAs (piRNAs) play significant roles in suppressing transposons and nonself nucleic acids, maintaining genome integrity, and defending against viral infections, and are essential for fertility in a variety of organisms. In C. elegans, most piRNA precursors are transcribed by RNA polymerase II in the nucleus and are subjected to a number of processing and maturation steps. However, the biogenesis of piRNAs is still not fully understood. We used functional proteomics to study piRNA biogenesis in C. elegans and identified a piRNA processing and chromosome segregation (PICS) complex. The PICS complex contains two known piRNA biogenesis factors, TOFU-6 and PID-1, and three new proteins PICS-1, TOST-1, and ERH-2, which exhibit dynamic localization among different subcellular compartments. In the germlines of gravid animals, the PICS complex contains TOFU-6/PICS-1/ERH-2/PID-1, is largely concentrated at the perinuclear granule zone and engages in piRNA processing. During early embryogenesis, the TOFU-6/PICS-1/ERH-2/TOST-1 complex accumulates in the nucleus and plays essential roles in chromosome segregation and cell division. Interestingly, the functions of these factors in mediating chromosome segregation are independent of piRNA production. Therefore, we speculate that differential compositions of PICS factors may help cells coordinate distinct cellular processes.
Project description:The effects of freeze-dried tofu, a traditional Japanese soy food, were compared with those of major active soy components, protein and isoflavone, by observing physiological differences and global transcriptomes in the liver of male rats. The GeneChip data was normalized and summarized by using SuperNORM data service (Skylight Biotech Inc.). Significance of expressional change among groups was tested by 2-way ANOVA on the normalized CEL data, which was deposited in a tab-separated ASCII text format. Principal components were identified on the summarized gene data. Rats were randomly divided into 6 groups of 5 samples and assigned experimental diets for 14 days. The experimental diets were as follows: casein diet (C); C containing isoflavone (CI) soy protein diet (S); S containing isoflavone (SI); a diet containing 100 g/kg each of protein derived from casein and freeze-dried tofu (T10); a diet containing 200 g/kg of protein derived from freeze-dried tofu (T20). CI and SI were supplemented with a mixture of isoflavones to match the isoflavone level of T20.