Project description:BACKGROUND:The increasing demand of single-cell RNA-sequencing (scRNA-seq) experiments, such as the number of experiments and cells queried per experiment, necessitates higher sequencing depth coupled to high data quality. New high-throughput sequencers, such as the Illumina NovaSeq 6000, enables this demand to be filled in a cost-effective manner. However, current scRNA-seq library designs present compatibility challenges with newer sequencing technologies, such as index-hopping, and their ability to generate high quality data has yet to be systematically evaluated. RESULTS:Here, we engineered a dual-indexed library structure, called TruDrop, on top of the inDrop scRNA-seq platform to solve these compatibility challenges, such that TruDrop libraries and standard Illumina libraries can be sequenced alongside each other on the NovaSeq. On scRNA-seq libraries, we implemented a previously-documented countermeasure to the well-described problem of index-hopping, demonstrated significant improvements in base-calling accuracy on the NovaSeq, and provided an example of multiplexing twenty-four scRNA-seq libraries simultaneously. We showed favorable comparisons in transcriptional diversity of TruDrop compared with prior inDrop libraries. CONCLUSIONS:Our approach enables cost-effective, high throughput generation of sequencing data with high quality, which should enable more routine use of scRNA-seq technologies.
Project description:CD34+ hematopoietic stem progenitor cells (HSPCs) from cryo-preserved blood or bone marrow were FACS sorted in TriZol and RNA was isolated according to the manufacturer’s protocol. SMARTer Ultra Low Input RNA kit for sequencing (Clontech, v4 Cat# 634891) was used to generate cDNA. Sequencing libraries were generated using TruSeq Nano DNA Sample Preparation kits (Illumina, Cat# 20015964), according to the low sample protocol and paired-end sequenced on a HiSeq 2500 or Novaseq 6000 (both Illumina).
Project description:The characterization of biodiversity is a crucial element of ecological investigations as well as environmental assessment and monitoring activities. Increasingly, amplicon-based environmental DNA metabarcoding (alternatively, marker gene metagenomics) is used for such studies given its ability to provide biodiversity data from various groups of organisms simply from analysis of bulk environmental samples such as water, soil or sediments. The Illumina MiSeq is currently the most popular tool for carrying out this work, but we set out to determine whether typical studies were reading enough DNA to detect rare organisms (i.e., those that may be of greatest interest such as endangered or invasive species) present in the environment. We collected sea water samples along two transects in Conception Bay, Newfoundland and analyzed them on the MiSeq with a sequencing depth of 100,000 reads per sample (exceeding the 60,000 per sample that is typical of similar studies). We then analyzed these same samples on Illumina's newest high-capacity platform, the NovaSeq, at a depth of 7 million reads per sample. Not surprisingly, the NovaSeq detected many more taxa than the MiSeq thanks to its much greater sequencing depth. However, contrary to our expectations this pattern was true even in depth-for-depth comparisons. In other words, the NovaSeq can detect more DNA sequence diversity within samples than the MiSeq, even at the exact same sequencing depth. Even when samples were reanalyzed on the MiSeq with a sequencing depth of 1 million reads each, the MiSeq's ability to detect new sequences plateaued while the NovaSeq continued to detect new sequence variants. These results have important biological implications. The NovaSeq found 40% more metazoan families in this environment than the MiSeq, including some of interest such as marine mammals and bony fish so the real-world implications of these findings are significant. These results are most likely associated to the advances incorporated in the NovaSeq, especially a patterned flow cell, which prevents similar sequences that are neighbours on the flow cell (common in metabarcoding studies) from being erroneously merged into single spots by the sequencing instrument. This study sets the stage for incorporating eDNA metabarcoding in comprehensive analysis of oceanic samples in a wide range of ecological and environmental investigations.
Project description:Stripe rust (Puccinia striiformis f. sp. tritici; Pst) and powdery mildew (Blumeria graminis f. sp. tritici; Bgt) are important diseases of wheat (Triticum aestivum) worldwide. Similar mechanisms and gene transcripts are assumed to be involved in the host defense response because both pathogens are biotrophic fungi. The main objective of our study was to identify co-regulated mRNAs that show a change in expression pattern after inoculation with Pst or Bgt, and to identify mRNAs specific to the fungal stress response. In the present study, cDNA libraries were constructed from leaves inoculated with Pst or Bgt at 0, 1, 2 and 3 days post-inoculation (dpi) with three biological replicates, and then sequenced using the Illumina HiSeq™ 2000 platform. Note: Samples in SRA were assigned the same sample accession. This is incorrect as there are different samples, hence “Source Name” was replaced with new values. Comment[ENA_SAMPLE] contains the original SRA sample accessions.
Project description:In present study, digital gene expression (DGE) profiling was performed to obtain a general picture of the transcriptomic implicated in the early development of R. venosa. Eighteen DGE libraries at six developmental stages of R. venosa were constructed, sequenced by IIIumina HiSeq 2500 platform. RNA from six developmental stages of R. venosa was sequenced using Illumina Hi-seq 2500. Each stage have three replicates
Project description:The goal of the experiment was to understand the epigenetic effects of PU.1 haploinsufficiency on pro-B cells. The RS4:11 cell line was edited both mono and biallelicaly via electroporation of Cas9 and guides. Following editing, aliquots of unedited (SPI1 +/+), mono (SPI1 +/-) and biallellicaly edited (SPI1 -/-) cells were lysed before undergoing the transposition reaction. After transposition, the ATAC-seq libraries were purified and then amplified via PCR. Libraries were sequenced using the Illumina Novaseq platform.
Project description:A time course of the macrophage response to Salmonella exposure analyzing the effects of input cell number as a control for single cell studies Mouse macrophages were exposed to Salmonella enterica for different lengths of time. Libraries were constructed using either approximately 500,00 macrophages lysed directly on a tissue culture dish (bulk) or using only 150 cells isolated using FACS (sorted). All libraries were constructed in duplicate (bulk) or triplicate (sorted). All replicates are biological replicates
Project description:To address how CSF3R mutations affect hematopoiesis in a severe congenital neutropenia (SCN) background we used SCN patient, or control, derived induced pluripotent stem cells (iPSC). HPCs were generated from CRISPR-Cas9 genome edited CSF3R-d715 SCN or control-derived iPSCs with the STEMdiff™ Hematopoietic Kit (STEMCELL Technologies). Floating cells were harvested at Day 12 of the hematopoietic induction protocol. CD34+CD45+ HPCs were FACS sorted in TRIzol and RNA was isolated according to the manufacturer’s protocol. SMARTer Ultra Low Input RNA kit for sequencing (Clontech, v4 Cat# 634891) was used to generate cDNA. Sequencing libraries were generated using TruSeq Nano DNA Sample Preparation kits (Illumina, Cat# 20015964), according to the low sample protocol and paired-end sequenced on a HiSeq 2500 or Novaseq 6000 (both Illumina).