Project description:DNA N6-methyladenine (6mA) is the most widespread type of DNA methylation in prokaryotes. However, the prevalence of 6mA in eukaryotes has recently been challenged due to the limitations of current 6mA detection techniques. Here, we present a chemical-based sequencing method, Nitrite-assisted Amino MEthylation sequencing (NAME-seq), for quantitative, whole-genome mapping of 6mA at single-base resolution. NAME-seq combines nitrite conversion of 6mA to nitrosylated-6mA (6mA-NO) with Klenow Fragment (3'→5' exo-) random priming to induce a 6mA-to-T transversion specifically. We apply NAME-seq to two bacterial species and show that, compared to SMRT-seq, NAME-seq results in a more specific and robust detection of 6mA. NAME-seq can also accurately map 6mA in the C. reinhardtii genome at single-base resolution. Additionally, we show that NAME-seq can be combined with conventional DIP-seq to detect 6mA in the Dam-methylated human genome with high specificity. Therefore, we further perform DIP-NAME-seq to profile 6mA in WT and TASOR KO K562 cell line and revealed that 6mA is enriched at specific motifs (HYYHAG and CACACA) and H3K9me3 regions. In summary, we demonstrate NAME-seq is a specific and sensitive sequencing method for quantitative 6mA mapping at single base resolution across different model organisms.
Project description:DNA N6-methyladenine (6mA) is the most widespread type of DNA methylation in prokaryotes. However, the prevalence of 6mA in eukaryotes has recently been challenged due to the limitations of current 6mA detection techniques. Here, we present a chemical-based sequencing method, Nitrite-assisted Amino MEthylation sequencing (NAME-seq), for quantitative, whole-genome mapping of 6mA at single-base resolution. NAME-seq combines nitrite conversion of 6mA to nitrosylated-6mA (6mA-NO) with Klenow Fragment (3'→5' exo-) random priming to induce a 6mA-to-T transversion specifically. We apply NAME-seq to two bacterial species and show that, compared to SMRT-seq, NAME-seq results in a more specific and robust detection of 6mA. NAME-seq can also accurately map 6mA in the C. reinhardtii genome at single-base resolution. Additionally, we show that NAME-seq can be combined with conventional DIP-seq to detect 6mA in the Dam-methylated human genome with high specificity. Therefore, we further perform DIP-NAME-seq to profile 6mA in WT and TASOR KO K562 cell line and revealed that 6mA is enriched at specific motifs (HYYHAG and CACACA) and H3K9me3 regions. In summary, we demonstrate NAME-seq is a specific and sensitive sequencing method for quantitative 6mA mapping at single base resolution across different model organisms.
Project description:By sequencing small RNAs from uninfected Arabidopsis roots and from galls seven and 14 days post infection with Meloidogyne incognita, we sequenced by SOLiD technology the RNA fraction below 50nt. We identified 24 miRNAs differentially expressed in gall as putative regulators of gall development.
Project description:High-coverage whole genome sequencing of 11 Brazilian isolates of the root-knot nematode Meloidogyne incognita, presenting different host plant preferences and different geographical origins. Four M. incognita host races had been proposed in the past, based on host (in)compatibility on four different plant strains. The objective was to assess whether genomic variations (SNP) correlate with host range compatibility, geographical origin and host plant of origin.
Project description:To interrogate single-base resolution 6mA sites in the genome-wide, we develop DA-6mA-seq (DpnI-Assisted N6-methylAdenine sequencing), an optimized sequencing method taking advantage of restriction enzyme DpnI, which exclusively cleaves methylated adenine sites. We find DpnI also recognizes other sequence motifs besides the canonical GATC restriction sites, largely expanding the application range of this method. DA-6mA-seq requires less starting material and lower sequencing depth than previous methods, but achieves higher sensitivity, providing a good strategy to identify 6mA in large genome with a low abundance of 6mA. We rebuild the 6mA maps of Chlamydomonas by DA-6mA-seq and then apply this method to another two eukaryotic organisms, Plasmodium and Penicillium. Further analysis reveals most 6mA sites are symmetric at various sequence contexts, suggesting 6mA may function as a new heritable epigenetic mark in eukaryotes. A new sequencing method is developed to detect 6mA in eukaryotes
