Klose RJ, Bird AP. Genomic DNA methylation：the mark and its mediators[J]. Trends in Biochemical Sciences, 2006, 31： 89-97.
[2]
Bogdanovic O, Veenstra GJC. DNA methylation and methyl-CpG binding proteins：developmental requirements and function[J]. Chromosoma, 2009, 118：549-565.
[3]
Cokus SJ, Feng S, Zhang X, et al. Shotgun bisulphite sequencing of the Arabidopsis genome reveals DNA methylation patterning[J]. Nature, 2008, 452：215-219.
[4]
Schaefer M, Lyko F. Lack of evidence for DNA methylation of Invader4 retroelements in Drosophila and implications for Dnmt2-mediated epigenetic regulation[J]. Nature Genetics, 2010, 42： 920-921.
[5]
Wang X, Wheeler D, Avery A, et al. Function and evolution of DNA methylation in Nasonia vitripennis[J]. PLoS Genetics, 2013, 9：e1003872.
[6]
Walsh TK, Brisson JA, Robertson HM, et al. A functional DNA methylation system in the pea aphid, Acyrthosiphon pisum[J]. Insect Molecular Biology, 2010, 19： 215-228.
[7]
Shimizu TS, Takahashi K, Tomita M. CpG distribution patterns in methylated and non-methylated species[J]. Gene, 1997, 205：103-107.
[8]
Elango N, Hunt BG, Goodisman MAD, et al. DNA methylation is widespread and associated with differential gene expression in castes of the honeybee, Apis mellifera[J], Proceedings of the National Academy of Sciences, USA, 2009, 106：11206-11211.
[9]
Sarda S, Zeng J, Hunt BG, et al. The evolution of invertebrate gene body methylation[J]. Molecular Biology and Evolution, 2012, 29：1907-1916.
[10]
Hunt BG, Brisson JA, Yi SV, et al. Functional conservation of DNA methylation in the pea aphid and the honeybee[J]. Genome Biology and Evolution, 2010, 2：719-728.
[11]
Herb BR, Wolschin F, Hansen KD, et al. Reversible switching between epigenetic states in honeybee behavioral subcastes[J]. Nature Neuroscience, 2012, 15： 1371-1373.
[12]
Schübeler D. Epigenetic islands in a genetic ocean[J]. Science, 2012, 338：756-757.
[13]
Roberts SB, Gavery MR. Is there a relationship between DNA methylation and phenotypic plasticity in invertebrates?[J]. Fronties in Physiology, 2012, 2：116.
[14]
Flores K, Wolschin F, Corneveaux JJ, et al. Genome-wide association between DNA methylation and alternative splicing in an invertebrate[J]. BMC Genomics, 2012, 13：480.
[15]
Maunakea AK, Chepelev I, Cui K, et al. Intragenic DNA methylation modulates alternative splicing by recruiting MeCP2 to promote exon recognition[J]. Cell Research, 2013, 11：1-14.
[16]
Zwier MV, Verhulst EC, Zwahlen RD, et al. DNA methylation plays a crucial role during early Nasonia development[J]. Insect Molecular Biology, 2012, 21：129-138.
[17]
Riviere G, Wu G, Fellous A, et al. DNA methylation is crucial for the early development in the Oyster Crassostrea gigas[J]. Marine Biotechnology, 2013, 15：739-753.
[18]
Marais G. Biased gene conversion：implications for genome and sex evolution[J]. Trends in Genetics, 2003, 19： 330-338.
[19]
Riggs AD. X inactivation, differentiation, and DNA methylation[J]. Cytogenetics and Cell Genetics, 1975, 14：9-25.
[20]
Holliday R, Pugh JE. DNA modification mechanisms and gene activity during development[J]. Science, 1975, 187：226-232.
[21]
Hata K, Okano M, Lei H, et al. Dnmt3L cooperates with the Dnmt3 family of de novo DNA methyltransferases to establish maternal imprints in mice[J]. Development, 2002, 129： 1983-1993.
[22]
Zemach A, McDaniel IE, Silva P, et al. Genome-wide evolutionary analysis of eukaryotic DNA methylation[J]. Science, 2010, 328：916-919.
[23]
Gadau J, Helmkampf M, Nygaard S, et al. The genomic impact of 100 million years of social evolution in seven ant species[J]. Trends in Genetics, 2012, 28：14-21.
[24]
Bestor TH. DNA methylation-evolution of a bacterial immune function into a regulator of gene-expression and genome structure in higher eukaryotes[J]. Biological Sciences Philosophical Transactions of the Royal Society of London Series B, 1990, 326： 179-187.
[25]
Jurkowski TP, Meusburger M, Phalke S, et al. Human DNMT2 methylates tRNA（Asp）molecules using a DNA methyltransferase-like catalytic mechanism[J]. RNA, 2008, 14： 1663-1670.
[26]
Collier J. Epigenetic regulation of the bacterial cell cycle[J]. Current Opinion in Microbiology, 2009, 12：722-729.
[27]
Zhang X, Yazaki J, Sundaresan A, et al. Genome-wide high-resolution mapping and functional analysis of DNA methylation in Arabidopsis[J]. Cell, 2006, 126：1189-1201.
[28]
Gavery MR, Roberts SB. Predominant intragenic methylation is associated with gene expression characteristics in a bivalve mollusk[J]. PeerJ, 2013, 1：e215.
[29]
Field LM. Methylation and expression of amplified esterase genes in the aphid Myzus persicae （Sulzer）[J]. Biochemical Journal, 2000, 349： 863-868.
[30]
Ono M, Swanson JJ, Field LM, et al. Amplification and methylation of an esterase gene associated with insecticide-resistance in greenbugs, Schizaphis graminum （Rondani）（Homoptera ： Aphididae）[J]. Insect Biochemistry and Molecular Biology, 1999, 29： 1065-1073.
[31]
Xiang H, Zhu J, Chen Q, et al. Single base-resolution methylome of the silkworm reveals a sparse epigenomic map[J]. Nature Biotechnology, 2010, 28：516-520.
[32]
Feng S, Cokus SJ, Zhang X, et al. Conservation and divergence of methylation patterning in plants and animals[J]. Proceedings of the National Academy of Science, USA, 2010, 107：8689-8694.
[33]
Elango N, Yi SV. DNA methylation and structural and functional bimodality of vertebrate promoters[J]. Molecular Biology Evolution, 2008, 25：1602-1608.
[34]
Glastad KM, Hunt BG, Yi SV, et al. DNA methylation in insects：on the brink of the epigenomic era[J]. Insect Molecular Biology, 2011, 20（5）：553-565.
[35]
Lyko F, Foret S, Kucharski R, et al. The honey bee epigenomes：differential methylation of brain DNA in queens and workers[J]. PLoS Biology, 2010, 8：e1000506.
[36]
Kucharski R, Maleszka J, Foret S, et al. Nutritional control of reproductive status in honeybees via DNA methylation[J]. Science, 2008, 319：1827-1830.
[37]
Weiner SA, Galbraith DA, Adams DC, et al. A survey of DNA methylation across social insect species, life stages, and castes reveals abundant and caste-associated methylation in a primitively social wasp[J]. Naturwissenschaften, 2013, 100：795-799.
[38]
Bonasio R, Li Q, Lian J, et al. Genome-wide and caste-specific DNA methylomes of the ants Camponotus floridanus and Harpegnathos saltator[J]. Current Biology, 2012, 22：1755-1764.
[39]
Terrapon N, Li C, Robertson HM, et al, Molecular traces of alternative social organization in a termite genome[J]. Nature Communications, 2014, 5：3636.
[40]
Rajasethupathy P, Antonov I, Sheridan R, et al. A role for neuronal piRNAs in the epigenetic control of memory-related synaptic plasticity[J]. Cell, 2012, 149：693-707.
[41]
Maunakea AK, Nagarajan RP, Bilenky M, et al. Conserved role of intragenic DNA methylation in regulating alternative promoters[J]. Nature, 2010, 466：253-257.
[42]
Riviere G. Epigenetic features in the oyster Crassostrea gigas suggestive of functionally relevant promoter DNA methylation in invertebrates[J]. Fronties in Physiology, 2014, 5：129.
[43]
Jouaux A, Heude-Berthelin C, Sourdaine P, et al. Gametogenic stages in triploid oysters Crassostrea gigas：irregular locking of gonial proliferation and subsequent reproductive effort[J]. Journal of Experimental Marine Biology and Ecology, 2010, 395：162-170.
[44]
Park J, Peng Z, Zeng J, et al. Comparative analyses of DNA methylation and sequence evolution using Nasonia genomes[J]. Molecular Biology and Evolution, 2011, 28：3345-3354.
[45]
Lister R, Pelizzola M, Dowen RH, et al. Human DNA methylomes at base resolution show widespread epigenomic differences[J]. Nature, 2009, 462：315-322.
[46]
Margueron R, Reinberg D. Chromatin structure and the inheritance of epigenetic information[J]. Nature Reviews Genetics, 2010, 11： 285-296.
