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Model illustrating the possible interplay between estrogen signaling and DNA methylation mechanisms in the rat testicular germ-line. Dnmt1 complexed with PCNA and ER b, bound to ERE on Igf2/H19 locus could catalyze methylation of CpG island on H19 DMR. Tamoxifen being anti estrogenic at this locus could inhibit targeting of PCNA-Dnmt1 complex resulting into methylation error in spermatozoa either by interfering with maintenance or spreading activity of Dnmt1.