Autonomous regulation of sex-specific developmental programming in mouse fetal germ cells.
In mice, unique events regulating epigenetic programming (e.g., genomic imprinting) and replication state (mitosis versus meiosis) occur during fetal germ cell development. To determine whether these processes are autonomously programmed in fetal germ cells or are dependent upon ongoing instructive interactions with surrounding gonadal somatic cells, we isolated male and female germ cells at 13.5 days postcoitum (dpc) and maintained them in culture for 6 days, either alone or in the presence of feeder cells or gonadal somatic cells. We examined allele-specific DNA methylation in the imprinted H19 and Snrpn genes, and we also determined whether these cells remained mitotic or entered meiosis. Our results show that isolated male germ cells are able to establish a characteristic "paternal" methylation pattern at imprinted genes in the absence of any support from somatic cells. On the other hand, cultured female germ cells maintain a hypomethylated status at these loci, characteristic of the normal "maternal" methylation pattern in endogenous female germ cells before birth. Further, the surviving female germ cells entered first meiotic prophase and reached the pachytene stage, whereas male germ cells entered mitotic arrest. These results indicate that mechanisms controlling both epigenetic programming and replication state are autonomously regulated in fetal germ cells that have been exposed to the genital ridge prior to 13.5 dpc.
Iwahashi
Kazuhiro
K
Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96813, USA.
Yoshioka
Hirotaka
H
Low
Eleanor W
EW
McCarrey
John R
JR
Yanagimachi
Ryuzo
R
Yamazaki
Yukiko
Y
D000483:Alleles; D000818:Animals; D001324:Autoantigens / Q000235:genetics; D002478:Cells, Cultured; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism; D019175:DNA Methylation; D005260:Female; D005333:Fetus / Q000166:cytology* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018392:Genomic Imprinting; D005854:Germ Cells / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D006066:Gonads / Q000166:cytology / Q000196:embryology; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics; D017411:Ribonucleoproteins, Small Nuclear / Q000235:genetics; D012733:Sex Differentiation / Q000235:genetics*; D046468:Sexual Development / Q000235:genetics*; D055517:snRNP Core Proteins
D001324:Autoantigens; C094335:H19 long non-coding RNA; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins; D004248:DNA (Cytosine-5-)-Methyltransferases