NELF-A controls Drosophila healthspan by regulating heat-shock protein-mediated cellular protection and heterochromatin maintenance [ChIP-seq]

Comparison of differential H3K9me2 enrichment in Day 50 adult heterozygous NELF-A*/+ mutant (BX) and control sibling (Sib) fly heads (2 biological replicates). Read quality check was performed using FASTQC and adaptors were trimmed. Reads were mapped to Drosophila reference genome (BDGP6.22.98) using STAR (v2.5) with following parameters: (--alignEndsType EndToEnd --alignIntronMax 1). Downstream analysis was performed using Galaxy platform. Peak calling was performed using MACS2 (v2.1.1), using an effective genome size of 120000000 --no model --extsize 200 --broad --keep-dup auto --bdg. Differential peaks between NELF-A*/+ (BX) and control siblings (Sib) was performed using MACS2 bdgdiff with following parameters: -g 100 -l 200. Alignment files (bam format) were transformed into read coverage files (bigwig format) using DeepTools: bamCompare (v3.3.2), normalized by readcount, scores representing ChIP minus Input.

本数据集旨在比较第50日龄成年杂合NELF-A*/+突变体（BX）与对照同胞（Sib）果蝇头部的组蛋白H3赖氨酸9二甲基化（H3K9me2）差异富集水平，共包含2个生物学重复。首先使用FASTQC对测序读段进行质量检测并完成接头序列修剪，随后采用STAR（v2.5）将读段比对至果蝇参考基因组（BDGP6.22.98），比对参数为：--alignEndsType EndToEnd --alignIntronMax 1。后续分析基于Galaxy平台开展，使用MACS2（v2.1.1）进行峰识别，设置有效基因组大小为120000000，采用参数--no model --extsize 200 --broad --keep-dup auto --bdg；继而通过MACS2的bdgdiff工具分析BX与对照同胞间的差异峰，参数为-g 100 -l 200。最后使用DeepTools的bamCompare（v3.3.2）将比对生成的BAM格式文件转换为读段覆盖度文件（BigWig格式），以读段计数进行归一化，所得得分代表ChIP信号与Input信号的差值。