Project description:To demonstrate the tolerance of mammalian sperm nucleus against extreme environments, mouse spermatozoa were freeze-dried and treated with 95 °C for 1 h or irradiated at over 5 Gy. Although all sperm were ostensibly dead after rehydration, healthy offspring were obtained from recovered sperm nuclei. The normality of those offspring were examined by microarray, and no difference were detected compare to fresh control offspring.
Project description:The zebrafish embryo has repeatedly proved to be a useful model for the analysis of effects by environmental toxicants. This study was performed to investigate if an approach combining mechanism-specific bioassays with microarray techniques can obtain more in-depth insights into the ecotoxicity of complex pollutant mixtures as present, e.g., in freeze-dried whole sediment samples and their corresponding organic extracts in parallel. To this end, altered gene expression was compared to data from established bioassays as well as to results from chemical analysis. Microarray analysis revealed several classes of significantly regulated genes which could to a considerable extent be related to the hazard potential. Results indicate that potential classes of contaminants can be assigned to sediment extracts by both classical biomarker genes and corresponding expression profile analyses of known substances. However, it is difficult to distinguish between specific responses and more universal detoxification of the organism. Additionally, different gene expression was shown to be less influenced by the sampling site than by the method of exposure, which could be attributed to differential bioavailability of contaminants. Microarray analyses were performed with early life stages of zebrafish exposed to sediment extracts or freeze-dried sediment from three sampling sites (Ehingen, Lauchert, Sigmaringen) along the Upper part of the Danube River, Germany. The expression profiles were compared within the sampling sites, between the exposure scheme and to the expression pattern of model toxicants, such as 4-chloroaniline, Cadmium, DDT, TCDD, and Valproic acid (Gene Expression Omnibus Series GSE9357). Additionally, mechanism-specific bioassays and chemical analysis of the sediments have been combined and compared to the present gene expression data.
Project description:The zebrafish embryo has repeatedly proved to be a useful model for the analysis of effects by environmental toxicants. This study was performed to investigate if an approach combining mechanism-specific bioassays with microarray techniques can obtain more in-depth insights into the ecotoxicity of complex pollutant mixtures as present, e.g., in freeze-dried whole sediment samples and their corresponding organic extracts in parallel. To this end, altered gene expression was compared to data from established bioassays as well as to results from chemical analysis. Microarray analysis revealed several classes of significantly regulated genes which could to a considerable extent be related to the hazard potential. Results indicate that potential classes of contaminants can be assigned to sediment extracts by both classical biomarker genes and corresponding expression profile analyses of known substances. However, it is difficult to distinguish between specific responses and more universal detoxification of the organism. Additionally, different gene expression was shown to be less influenced by the sampling site than by the method of exposure, which could be attributed to differential bioavailability of contaminants.
Project description:We report the human homologous microRNA profiles in food-grade, bovine-sourced sirloin, heart and adrenal tissue (raw, cooked, and laboratory-prepared pasteurized, freeze-dried extracts) Deep miRNA sequencing of sirloin (raw and cooked), heart tissue (raw, cooked, and pastuerized, freeze-dried extracts) and adrenal tissue (raw, cooked, and laboratory-prepared pasteurized, freeze-dried extracts), 3 replicates each process group
Project description:We report the human homologous microRNA profiles in food-grade, bovine-sourced sirloin, heart and adrenal tissue (raw, cooked, and laboratory-prepared pasteurized, freeze-dried extracts)
Project description:Purpose: The goal of this study was to determine the microRNA (miRNA) content of extracellular vesicles (EVs) derived from murine mesenchymal stem cells (mMSC), and evaluate reproducibility among distinct EV productions. We also aimed at assessing the effect of freeze-drying on EV miRNA content, by performing sequencing on freeze-dried EVs and calculating statistical difference between unmodified and freeze-dried EVs. Methods: mMSC-derived EVs were obtained from mMSC in culture in reduced serum medium Opti-MEM by differential centrifugation, with a final step at 100,000 g for 110 min at 4°C. EV pellets (freeze-dried (n=3) or not (n=2)) were resuspended in Qiazol lysis buffer and RNA was extracted following RNeasy Micro kit. cDNA libraries for sequencing were prepared using the TruSeq Small RNA Sample Preparation Kit. Amplified cDNA constructs were purified on 6 % PAGE gel and DNA molecules corresponding to 15–50 nucleotide transcripts were excised, eluted from gel, and concentrated. Image analyses and base calling were performed using the HiSeq Control Software and Real-Time Analysis component (Illumina). Before statistical analysis, genes with less than 15 reads (cumulating all the analysed samples) were filtered out. Differentially expressed miRNA were identified using three Bioconductor packages: edgeR, DESeq and DESeq2. Results: Considering miRNAs detected with at least 5 counts (in terms of normalised counts), 339 miRNAs were identified and miRNA content was highly conserved among the two batches tested, with 237 miRNAs out of the 339 present in both batches (70%). Statistical analysis did not evidence statistical difference between unmodified EVs (n=2) and freeze-dried EVs (n=3) (DESeq2, p<0.05). No statistical difference was found using other Bioconductor packages DESeq and edgeR. These results indicated conservation of miRNA content following freeze-drying. Conclusion: mMSC-EV miRNA content was comparable between the two EV productions analysed, indicating reproducibility. Some of the miRNAs identified were consistent with previously published results on MSC-derived EVs. Freeze-drying conserved miRNA content.
Project description:It has long been believed that tolerance against extreme environments is possible only for 'lower' groups, such as archaea, bacteria or tardigrades, and not for more 'advanced' species. Here, we demonstrated that the mammalian sperm nucleus also exhibited strong tolerance to cold and hot temperatures. When mouse spermatozoa were freeze-dried (FD), similar to the anhydrobiosis of Tardigrades, all spermatozoa were ostensibly dead after rehydration. However, offspring were obtained from recovered FD sperm nuclei, even after repeated treatment with conditions from liquid nitrogen to room temperature. Conversely, when FD spermatozoa were heated at 95 °C, although the birth rate was decreased with increasing duration of the treatment, offspring were obtained even for FD spermatozoa that had been heat-treated for 2 h. This period was improved up to 6 h when glucose was replaced with trehalose in the freeze-drying medium, and the resistance temperature was extended up to 150 °C for short periods of treatment. Randomly selected offspring grew into healthy adults. Our results suggest that, when considering the sperm nucleus/DNA as the material that is used as a blueprint of life, rather than cell viability, a significant tolerance to extreme temperatures is present even in 'higher' species, such as mammals.
Project description:Few invertebrates can survive cryopreservation in liquid nitrogen, and the mechanisms by which some species do survive are underexplored, despite high application potential. Here, we turn to the drosophilid Chymomyza costata to strengthen our fundamental understanding of extreme freeze tolerance and gain insights about potential avenues for cryopreservation of biological materials. We first use RNAseq to generate transcriptomes of three C. costata larval phenotypic variants: those warm-acclimated in early or late diapause (weak capacity to survive cryopreservation), and those undergoing cold acclimation after diapause entry (extremely freeze tolerant, surviving cryopreservation). We identify mRNA transcripts representing genes and processes that accompany the physiological transition to extreme freeze tolerance and relate cryopreservation survival to the transcriptional profiles of select candidate genes using extended sampling of phenotypic variants. Enhanced capacity for protein folding, refolding and processing appears to be a central theme of extreme freeze tolerance and may allow cold-acclimated larvae to repair or eliminate proteins damaged by freezing (thus mitigating the toxicity of denatured proteins, endoplasmic reticulum stress and subsequent apoptosis). We also find a number of candidate genes (including both known and potentially novel, unannotated sequences) whose expression profiles tightly mirror the change in extreme freeze tolerance status among phenotypic variants.