Sequences in the H19 ICR that are transcribed as small RNA in oocytes are dispensable for methylation imprinting in YAC transgenic mice.
Allele-specific methylation of the endogenous H19 imprinting control region (ICR) is established in sperm. We previously showed that the paternal H19 ICR in yeast artificial chromosome (YAC) transgenic mice (TgM) was preferentially methylated in somatic cells, but not in germ cells, suggesting that differential methylation could be established after fertilization. In this report, we discovered small RNA molecules in growing oocytes, the nucleotide sequences of which mapped to the H19 ICR. To test if these small RNA sequences play a role in the establishment of differential methylation, we deleted the sequences from the H19 ICR DNA and generated YAC TgM. In somatic cells of these mice, methylation imprinting of the transgene was normally established. In addition, the mutant fragment was not methylated in sperm and eggs. These data demonstrate that sequences in the H19 ICR that correspond to the small RNA sequences are dispensable for methylation imprinting in YAC TgM.
Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan. t-takahashi@tara.tsukuba.ac.jp
Takuya
T
Takahashi
Hitomi
H
Matsuzaki
Shin-Ichi
S
Tomizawa
Eiichi
E
Okamura
Tomoko
T
Ichiyanagi
Akiyoshi
A
Fukamizu
Hiroyuki
H
Sasaki
Keiji
K
Tanimoto
D000818:Animals; D015139:Blotting, Southern; D002478:Cells, Cultured; D018244:Chromosomes, Artificial, Yeast; D019175:DNA Methylation; D005260:Female; D005306:Fertilization / Q000235:genetics; D018392:Genomic Imprinting; D019901:Locus Control Region / Q000235:genetics*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009865:Oocytes / Q000378:metabolism; D062085:RNA, Long Noncoding; D058727:RNA, Small Untranslated / Q000235:genetics / Q000378:metabolism*; D022661:RNA, Untranslated / Q000235:genetics* / Q000378:metabolism*; D013737:Testis / Q000378:metabolism
C094335:H19 long non-coding RNA; D062085:RNA, Long Noncoding; D058727:RNA, Small Untranslated; D022661:RNA, Untranslated