title: Single base-resolution methylome of the silkworm reveals a sparse epigenomic map.
abstract: Epigenetic regulation in insects may have effects on diverse biological processes. Here we survey the methylome of a model insect, the silkworm Bombyx mori, at single-base resolution using Illumina high-throughput bisulfite sequencing (MethylC-Seq). We conservatively estimate that 0.11% of genomic cytosines are methylcytosines, all of which probably occur in CG dinucleotides. CG methylation is substantially enriched in gene bodies and is positively correlated with gene expression levels, suggesting it has a positive role in gene transcription. We find that transposable elements, promoters and ribosomal DNAs are hypomethylated, but in contrast, genomic loci matching small RNAs in gene bodies are densely methylated. This work contributes to our understanding of epigenetics in insects, and in contrast to previous studies of the highly methylated genomes of Arabidopsis and human, demonstrates a strategy for sequencing the epigenomes of organisms such as insects that have low levels of methylation.
authors.affiliation: CAS-Max Planck Junior Research Group, State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, The Chinese Academy of Sciences, Kunming, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xiang
authors.forename: Jingde
authors.initials: J
authors.lastname: Zhu
authors.forename: Quan
authors.initials: Q
authors.lastname: Chen
authors.forename: Fangyin
authors.initials: F
authors.lastname: Dai
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Muwang
authors.initials: M
authors.lastname: Li
authors.forename: Hongyu
authors.initials: H
authors.lastname: Zhang
authors.forename: Guojie
authors.initials: G
authors.lastname: Zhang
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.forename: Yang
authors.initials: Y
authors.lastname: Dong
authors.forename: Li
authors.initials: L
authors.lastname: Zhao
authors.forename: Ying
authors.initials: Y
authors.lastname: Lin
authors.forename: Daojun
authors.initials: D
authors.lastname: Cheng
authors.forename: Jian
authors.initials: J
authors.lastname: Yu
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Sun
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Zhou
authors.forename: Kelong
authors.initials: K
authors.lastname: Ma
authors.forename: Yinghua
authors.initials: Y
authors.lastname: He
authors.forename: Yangxing
authors.initials: Y
authors.lastname: Zhao
authors.forename: Shicheng
authors.initials: S
authors.lastname: Guo
authors.forename: Mingzhi
authors.initials: M
authors.lastname: Ye
authors.forename: Guangwu
authors.initials: G
authors.lastname: Guo
authors.forename: Yingrui
authors.initials: Y
authors.lastname: Li
authors.forename: Ruiqiang
authors.initials: R
authors.lastname: Li
authors.forename: Xiuqing
authors.initials: X
authors.lastname: Zhang
authors.forename: Lijia
authors.initials: L
authors.lastname: Ma
authors.forename: Karsten
authors.initials: K
authors.lastname: Kristiansen
authors.forename: Qiuhong
authors.initials: Q
authors.lastname: Guo
authors.forename: Jianhao
authors.initials: J
authors.lastname: Jiang
authors.forename: Stephan
authors.initials: S
authors.lastname: Beck
authors.forename: Qingyou
authors.initials: Q
authors.lastname: Xia
authors.forename: Wen
authors.initials: W
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D012831:Bombyx / Q000235:genetics*; D019295:Computational Biology / Q000379:methods*; D019175:DNA Methylation / Q000235:genetics*; D044127:Epigenesis, Genetic; D005786:Gene Expression Regulation; D049750:Genome, Insect; D017422:Sequence Analysis, DNA