Project description:Purpose: In Drosophila, we tried to determine the neural activity-dependent transcription controlled by Kdm4B. We conducted nuclear RNA-seq analysis in mushroom body in Drosophila, either in naive state or after optogenetic activation. Methods: The nuclei of mushroom body were collected by immunoprecipitation-based method (Hirano Y., et al, 2016, Nature Communications, also see extraction protocol below). mRNA was purified from the mushroom body nuclei with oligo dT magnetic beads, and used to prepare library. After deep sequencing in triplicate using illumine Hiseq X, the adaptors were trimmed via Trimommatic, followed by mapping to the Drosophila reference genome, dm6 from UCSC using STAR. The reads with low mapping quality below 8 and the non-primary mapped reads were eliminated. The filtered reads were analyzed with HTSeq-count to obtain numbers of the reads mapped on exons, which was further analyzed on R using DESeq2 Results: Using an optimized data analysis workflow, we mapped about 9-18 million reads for ChIP-seq, and 30-40 million reads for nuclear RNA-seq to Drosophila reference genome, dm6 In ChIP-seq, binding of all proteins was enriched nearby the transcriptional start site (TSS). The binding sites determined were 1,237 for CoRest-C, 2,717 for Rpd3, and 6,684 for CBP. Importantly, among CoRest-C binding sites, overlapping sites of CoRest-C and CBP were 1,038/1,237 (83.9%), those of CoRest-C and Rpd3 were 789/1,237 (63.8%), and those of CoRest-C, Rpd3, and CBP were 704/1,237 (56.9%), suggesting that these three proteins colocalize on the specific genomic regions In nuclear RNA-seq, we found that upregulation of gene expression is robust at 10-min after 5-min optogenetic activation. The genes showing significant difference were 2,702 at this time point, in which 1,582 genes showed increase, and the rest showed decrease in the expression. Among the 1,582 increased genes, 1,055 genes were bound by CBP, supporting the idea that CBP is an important factor in activity-dependent transcription. Furthermore, 338 was bound by CoRest-C, 254 of which showed colocalization with CBP and Rpd3. Conclusions: Our study represents activity-dependent transcription in mushroom body in Drosophila, which is mediated by Kdm4B.

Project description:Purpose: Exploring the alteration in histone acetylation colocalized with CREB/CRTC binding, which are important for long-term memory maintenance Methods: The nuclei of Drosophila mushroom bodies were purified and the histone acetylation and CREB/CRTC binding were examined by ChIP-seq using specific antibodies. The sequencing was performed using SOLiD, and aligned to dm3 using Lifescope..The sequence reads that passed quality filters were analyzed by peak calling using PICS and ERD equipped on Strand NGS software. This method using two algorisms excludes false-positive calling of peaks. The PICS and ERD were run using a default setting except for the following parameters; for PICS, 120 bp as an average fragment length, 10 bp as a minimum distance between forward and reverse reads, 200 bp as a minimum distance between forward and reverse reads, 100 bp as a window width, with 5% false discovery rate; for ERD, 2 as an enrichment factor, 100 bp as a window size, 10 bp as a window slide size, 100 bp as a minimum region size. The peaks obtained by ERD analysis were filtered by an enrichment factor of 1.5, and a density of reads at 0.3 for H3K9Ac, 0.15 for H4K16Ac, 0.18 for CREB and 0.15 for CRTC. To determine the histone acetylation-increased sites, the peaks determined from 3 replicates of the trained samples were summed to analyze all peaks. Then the centers of the H3K9Ac and H4K16Ac peaks were extracted, and then used to create neighboring 400 bp windows. The mapped reads were counted in these 400 bp windows for each biological replicate of ChIP-seq analysis. The counted read numbers in individual regions were normalized by elav for H3K9Ac ChIP-seq, and gapdh2 for H4K16Ac ChIP. The normalized read numbers in individual windows obtained from the spaced trained flies and the naïve flies were analyzed by Student’s t test (p < 0.05). Standard deviations of the normalized read numbers in individual windows from 3 replicates of naïve flies were 0.07 in H3K9Ac-ChIP-seq and 0.10 in H4K16Ac-ChIP-seq. Significantly increased peaks showing a more than 1.2-fold increase (>2SD) were determined as sites with an increase in H3K9Ac or H4K16Ac. Results: Using an optimized data analysis workflow, the filtered reads amounted to 12-15 million reads for H3K9Ac in each of 3 replicates, 5-7 million reads for H4K16 in each of 3 replicates, 2.4 million reads for CREB, 2 million reads for CRTC, and 2.9 million reads for input. Using anti-H3K9Ac antibody, we found significant increases in H3K9Ac 1 day after training, and 75.0% of these mapped within 500bps of the transcriptional start sites (TSSs) of 1766 genes. Using anti-H4K16Ac antibody, we found significant increases in H4K16Ac 1 day after spaced training, and 61.6% of these mapped within 500bps of the TSSs of 1320 genes. Epigenetic changes in the vicinity of TSSs suggests that expression of these genes may be increased in LTM maintenance. We also examined CRTC and CREB binding 1 day after training. We identified 2390 CRTC binding sites, of which 79.6% of these were close to CREB binding sites. These CREB/CRTC binding sites mapped to 1394 genes, and were predominately located within 500bp from TSSs (55.4%). Of the 1394 CREB/CRTC target genes, 346 genes showed increases in H3K9Ac, 319 showed increases in H4K16Ac, and 135 showed increases in both. Conclusions: Our study represents the first detailed analysis of chromatin state related to memory in Drosophila mushroom bodied. The optimized data analysis workflows reported here should provide a framework for comparative investigations of tissue-specific epigenetic alterations.

Project description:Purpose: In Drosophila, we determined that neural activity-dependent transcription is controlled by CBP, Rpd3, and CoRest-C. To investigate the dynamics of those binding to the chromatin, and the relationship with activity-dependent transcription, we conducted the ChIP-seq assay for the three proteins, and nuclear RNA-seq analysis in mushroom body in Drosophila, either in naive state or after optogenetic activation. Methods: The nuclei of mushroom body were collected by immunoprecipitation-based method (Hirano Y., et al, 2016, Nature Communications, also see extraction protocol below). The chromatin prepared from the collected mushroom body was used for ChIP-seq with antibody for CBP, Rpd3 or CoRest-C. For CBP and Rpd3, antibody was raised against the endogenous proteins. For CoRest-C, which was tagged by myc, anti-myc antibody was used. In nuclear RNA-seq, mRNA was purified from the mushroom body nuclei with oligo dT magnetic beads, and used to prepare library. After deep sequencing in triplicate using illumine Hiseq X, the adaptors were trimmed via Trimommatic, followed by mapping to the Drosophila reference genome, dm6 from UCSC using STAR. The reads with low mapping quality below 8 and the non-primary mapped reads were eliminated. MACS was used for peak calling in ChIP-seq on Strand NGS software, using a default setting except for the following parameters; 10-4 as a P-value cutoff, and 3 as a enrichment factor. The binding sites were determined when the peaks were overlapped in at least 2 out of 3 biological replicates, using the optogenetically activated samples. For RNA-seq, the filtered reads were analyzed with HTSeq-count to obtain numbers of the reads mapped on exons, which was further analyzed on R using DESeq2 Results: Using an optimized data analysis workflow, we mapped about 9-18 million reads for ChIP-seq, and 30-40 million reads for nuclear RNA-seq to Drosophila reference genome, dm6 In ChIP-seq, binding of all proteins was enriched nearby the transcriptional start site (TSS). The binding sites determined were 1,237 for CoRest-C, 2,717 for Rpd3, and 6,684 for CBP. Importantly, among CoRest-C binding sites, overlapping sites of CoRest-C and CBP were 1,038/1,237 (83.9%), those of CoRest-C and Rpd3 were 789/1,237 (63.8%), and those of CoRest-C, Rpd3, and CBP were 704/1,237 (56.9%), suggesting that these three proteins colocalize on the specific genomic regions In nuclear RNA-seq, we found that upregulation of gene expression is robust at 10-min after 5-min optogenetic activation. The genes showing significant difference were 2,702 at this time point, in which 1,582 genes showed increase, and the rest showed decrease in the expression. Among the 1,582 increased genes, 1,055 genes were bound by CBP, supporting the idea that CBP is an important factor in activity-dependent transcription. Furthermore, 338 was bound by CoRest-C, 254 of which showed colocalization with CBP and Rpd3. Conclusions: Our study represents the first detailed analysis of activity-dependent transcription in mushroom body in Drosophila, with biologic replicates, generated by ChIP-seq and RNA-seq technology. We found the rapid response of transcription after optogenetic activation, and its colocalization with CBP, Rpd3 and CoRest-C binding sites. These data strongly support the idea that these three proteins control activity-dependent transcription.

Project description:Purpose: Exploring the alteration in CREB/CRTC binding related to long-term memory Methods: The nuclei of Drosophila mushroom bodies were purified and the histone acetylation and CREB/CRTC binding were examined by ChIP-seq using specific antibodies. The sequencing was performed using Miseq, and aligned to dm3 using CLCbio. The sequence reads that passed quality filters were analyzed by peak calling using PICS and ERD equipped on Strand NGS software. This method using two algorisms excludes false-positive calling of peaks. The PICS and ERD were run using a default setting except for the following parameters; for PICS, 120 bp as an average fragment length, 10 bp as a minimum distance between forward and reverse reads, 200 bp as a minimum distance between forward and reverse reads, 100 bp as a window width, with 5% false discovery rate; for ERD, 1.5 as an enrichment factor, 100 bp as a window size, 10 bp as a window slide size, 100 bp as a minimum region size. The peaks obtained by ERD analysis were filtered by an enrichment factor of 2, and a density of reads at 0.12 for CREB and 0.2 for CRTC. The CREB and the CRTC binding sites were determined as the peak-called region in at least 2 samples out of the three replicates. The CREB and the CRTC binding sites located 200 bp vicinity to each other were defined as the CREB/CRTC binding sites. In parallel, the read counts were obtained in the 1 kb window covering entire genome and analyzed by DESeq2, to determine the region enriched with CREB/CRTC in a specific group of samples. The region with increased or decreased CREB/CRTC binding were determined if the region were defined by the CREB/CRTC binding sites in the above criteria. Results: Using an optimized data analysis workflow, the filtered reads amounted to 8-11million reads for CREB in each of 3 replicates, 8-17 million reads for CRTC in each of 3 replicates, and 4.4 million reads for input. Using anti-CREB antibody, we found 239 significant increases in CREB binding out of 4995 CREB/CRTC binding sites 1 day after training. Using anti-CRTC antibody, we found 4989 significant increases in CRTC binding out of 4995 CREB/CRTC binding sites 1 day after spaced training. Conclusions: Our study shows that, although CREB binding is mostly unchanged, CRTC binding is significantly increased after long-term memory formation in Drosophila mushroom bodies.

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Mushroom Body Ethanol RNA-seq

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