Differential DNA methylation in discrete developmental stages of the parasitic nematode Trichinella spiralis.
BACKGROUND
DNA methylation plays an essential role in regulating gene expression under a variety of conditions and it has therefore been hypothesized to underlie the transitions between life cycle stages in parasitic nematodes. So far, however, 5'-cytosine methylation has not been detected during any developmental stage of the nematode Caenorhabditis elegans. Given the new availability of high-resolution methylation detection methods, an investigation of life cycle methylation in a parasitic nematode can now be carried out.


RESULTS
Here, using MethylC-seq, we present the first study to confirm the existence of DNA methylation in the parasitic nematode Trichinella spiralis, and we characterize the methylomes of the three life-cycle stages of this food-borne infectious human pathogen. We observe a drastic increase in DNA methylation during the transition from the new born to mature stage, and we further identify parasitism-related genes that show changes in DNA methylation status between life cycle stages.


CONCLUSIONS
Our data contribute to the understanding of the developmental changes that occur in an important human parasite, and raises the possibility that targeting DNA methylation processes may be a useful strategy in developing therapeutics to impede infection. In addition, our conclusion that DNA methylation is a mechanism for life cycle transition in T. spiralis prompts the question of whether this may also be the case in any other metazoans. Finally, our work constitutes the first report, to our knowledge, of DNA methylation in a nematode, prompting a re-evaluation of phyla in which this epigenetic mark was thought to be absent.
Fei
F
Gao
Xiaolei
X
Liu
Xiu-Ping
XP
Wu
Xue-Lin
XL
Wang
Desheng
D
Gong
Hanlin
H
Lu
Yudong
Y
Xia
Yanxia
Y
Song
Junwen
J
Wang
Jing
J
Du
Siyang
S
Liu
Xu
X
Han
Yizhi
Y
Tang
Huanming
H
Yang
Qi
Q
Jin
Xiuqing
X
Zhang
Mingyuan
M
Liu
D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D003596:Cytosine / Q000378:metabolism*; D004247:DNA / Q000032:analysis*; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D018507:Gene Expression Regulation, Developmental; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D008969:Molecular Sequence Data; D009132:Muscles / Q000378:metabolism; D010802:Phylogeny; D012333:RNA, Messenger / Q000378:metabolism; D017422:Sequence Analysis, DNA / Q000379:methods*; D017160:Trichinella spiralis / Q000235:genetics / Q000254:growth & development*
D012333:RNA, Messenger; D003596:Cytosine; D004247:DNA; D004248:DNA (Cytosine-5-)-Methyltransferases