DNA Methylation in Mouse Testes

DNA methylation of retrotransposons and imprinted genes is accurately regulated in spermatogenesis. In particular, CpG methylation of long interspersed elements-1 (LINE1 or L1) and intracisternal A-particle (IAP) retrotransposons during spermatogenesis has been well characterized. CpG methylation of the regulatory regions of retrotransposons is acquired during embryonic testis development; however, reductions of DNA methylation in LINE1 and/or IAP and/or Rasgrf1, which is an imprinted gene, are observed in defi cient mice of piRNA biogenesis concerning. Here, we describe two methods, bisulfi te sequencing and Southern blotting using a methylation-sensitive restriction enzyme, for analysis of DNA methylation of LINE1, IAP, and imprinted genes in mouse testes.