Project description:When sampling many samples at locations with poor laboratory facilities, the ability of freezing samples for later processising is crucial. ATAC-seq on fresh tissue is still considered the star method. Freezing has shown to affect chromatin architecture and nucleosome pattern. However, the freezing method might determine the chromatin integrity. We therefore ask whether or not slow frozen samples give the same results as fresh samples when assaying tissues for transposase accessible chromatin?
Project description:Surplus tissues from multiple solid human cancers directly slow-frozen after resection can subsequently be used for different types of methods including the establishment of 2D, 3D, and ex vivo cultures as well as single cell RNA sequencing (scRNAseq) with similar results when compared to freshly analyzed material.
Project description:This study aimed to compare the transcriptome of vitrified and slow frozen embryos with the untreated control. Bovine embryos (compact morulae) were vitrified or slow frozen and post-warm embryos were cultured to expanded blastocyst stage. The vitrified- and slow frozen-derived were subjected to microarray analysis and compared with untreated control embryos for differential gene expression. Morula to blastocyst conversion rate was higher (P<0.05) in control (72%) and vitrified (77%) embryos compared to slow frozen (34%) embryos. Total 20 genes were upregulated and 44 genes were downregulated in the vitrified embryos (fold change ≥ +-2, P<0.05). In slow frozen embryos, 102 genes were upregulated and 63 genes were downregulated (fold change ≥ +-1.5, P<0.05) in comparison with untreated embryos. Vitrified embryos exhibited significant changes in gene expression mainly involving embryo implantation (PTGS2, CALB1), lipid peroxidation and ROS generation (HSD3B1, AKR1B1, APOA1) and cell differentiation (KRT19, CLDN23). The slow frozen embryos, however, showed significant changes in the expression of genes related to cell signaling (SPP1), cell structure and differentiation (DCLK2, JAM2 and VIM), and lipid metabolism (PLA2R1 and SMPD3). In silico comparison between vitrified and slow-frozen (reference) embryos revealed similar changes in gene expression as between vitrified and untreated embryos. In conclusion, the vitrified bovine embryos demonstrated better post-warming embryo development than slow-frozen bovine embryos but their gene expression related to lipid metabolism, steroidogenesis, cell differentiation and placentation changed significantly. Slow freezing killed more embryos than vitrification, and the survived embryos did not express significant change in their gene expression.
Project description:This study aimed to compare the transcriptome of vitrified and slow frozen embryos with the untreated control. Bovine embryos (compact morulae) were vitrified or slow frozen and post-warm embryos were cultured to expanded blastocyst stage. The vitrified- and slow frozen-derived were subjected to microarray analysis and compared with untreated control embryos for differential gene expression. Morula to blastocyst conversion rate was higher (P<0.05) in control (72%) and vitrified (77%) embryos compared to slow frozen (34%) embryos. Total 20 genes were upregulated and 44 genes were downregulated in the vitrified embryos (fold change ≥ +-2, P<0.05). In slow frozen embryos, 102 genes were upregulated and 63 genes were downregulated (fold change ≥ +-1.5, P<0.05) in comparison with untreated embryos. Vitrified embryos exhibited significant changes in gene expression mainly involving embryo implantation (PTGS2, CALB1), lipid peroxidation and ROS generation (HSD3B1, AKR1B1, APOA1) and cell differentiation (KRT19, CLDN23). The slow frozen embryos, however, showed significant changes in the expression of genes related to cell signaling (SPP1), cell structure and differentiation (DCLK2, JAM2 and VIM), and lipid metabolism (PLA2R1 and SMPD3). In silico comparison between vitrified and slow-frozen (reference) embryos revealed similar changes in gene expression as between vitrified and untreated embryos. In conclusion, the vitrified bovine embryos demonstrated better post-warming embryo development than slow-frozen bovine embryos but their gene expression related to lipid metabolism, steroidogenesis, cell differentiation and placentation changed significantly. Slow freezing killed more embryos than vitrification, and the survived embryos did not express significant change in their gene expression.
Project description:This study aimed to compare the transcriptome of vitrified and slow frozen embryos with the untreated control. Bovine embryos (compact morulae) were vitrified or slow frozen and post-warm embryos were cultured to expanded blastocyst stage. The vitrified- and slow frozen-derived were subjected to microarray analysis and compared with untreated control embryos for differential gene expression. Morula to blastocyst conversion rate was higher (P<0.05) in control (72%) and vitrified (77%) embryos compared to slow frozen (34%) embryos. Total 20 genes were upregulated and 44 genes were downregulated in the vitrified embryos (fold change ≥ +-2, P<0.05). In slow frozen embryos, 102 genes were upregulated and 63 genes were downregulated (fold change ≥ +-1.5, P<0.05) in comparison with untreated embryos. Vitrified embryos exhibited significant changes in gene expression mainly involving embryo implantation (PTGS2, CALB1), lipid peroxidation and ROS generation (HSD3B1, AKR1B1, APOA1) and cell differentiation (KRT19, CLDN23). The slow frozen embryos, however, showed significant changes in the expression of genes related to cell signaling (SPP1), cell structure and differentiation (DCLK2, JAM2 and VIM), and lipid metabolism (PLA2R1 and SMPD3). In silico comparison between vitrified and slow-frozen (reference) embryos revealed similar changes in gene expression as between vitrified and untreated embryos. In conclusion, the vitrified bovine embryos demonstrated better post-warming embryo development than slow-frozen bovine embryos but their gene expression related to lipid metabolism, steroidogenesis, cell differentiation and placentation changed significantly. Slow freezing killed more embryos than vitrification, and the survived embryos did not express significant change in their gene expression.
Project description:The aim of the present study was to perform an additional global miRNA microarray analysis of tubular and tubulovillous adenoma biopsy specimen completed with colorectal adenocarcinomas using fresh frozen tisse
Project description:Background: The main bottleneck for genomic studies of tumors is the limited availability of fresh frozen (FF) samples collected from patients, coupled with comprehensive long-term clinical follow-up. This shortage could be alleviated by using existing large archives of routinely obtained and stored Formalin-Fixed Paraffin-Embedded (FFPE) tissues. However, since these samples are partially degraded, their RNA sequencing is technically challenging. Results: In an effort to establish a reliable and practical procedure, we compared three protocols for RNA sequencing using pairs of FF and FFPE samples, both taken from the same breast tumor. In contrast to previous studies, we compared the expression profiles obtained from the two matched sample types, using the same protocol for both. Three protocols were tested on low initial amounts of RNA, as little as 100 ng, to represent the possibly limited availability of clinical samples. For two of the three protocols tested, poly(A) selection (mRNA-seq) and ribosomal-depletion, the total gene expression profiles of matched FF and FFPE pairs were highly correlated. For both protocols, differential gene expression between two FFPE samples was in agreement with their matched FF samples. Notably, although expression levels of FFPE samples by mRNA-seq were mainly represented by the 3'-end of the transcript, they yielded very similar results to those obtained by ribosomal-depletion protocol, which produces uniform coverage across the transcript. Further, focusing on clinically relevant genes, we showed that the high correlation between expression levels persists at higher resolutions. Conclusions: Using the poly(A) protocol for FFPE exhibited, unexpectedly, similar efficiency to the ribosomal-depletion protocol, with the latter requiring much higher (2-3 fold) sequencing depth to compensate for the relative low fraction of reads mapped to the transcriptome. The results indicate that standard poly(A)-based RNA sequencing of archived FFPE samples is a reliable and cost-effective alternative for measuring mRNA-seq on FF samples. Expression profiling of FFPE samples by mRNA-seq can facilitate much needed extensive retrospective clinical genomic studies.
Project description:The influence of GH transgenesis on liver gene expression in coho salmon was examined. Gene expression in livers of transgenic salmon on a restricted ration (R) was compared to that in livers of nontransgenic control salmon (C). Keywords: Transcript profile