Expression of the Snurf-Snrpn IC transcript in the oocyte and its putative role in the imprinting establishment of the mouse 7C imprinting domain.
The human chromosome 15q11-q13, or mouse chromosome 7C, is an imprinting domain controlled by bipartite imprinting centers (ICs): Prader-Willi syndrome (PWS)-IC and Angelman syndrome (AS)-IC. PWS-IC functions to maintain the paternal epigenotype on the paternal chromosome in somatic cells, while AS-IC plays a role in the establishment of the maternal epigenetic mark at PWS-IC in the female germline or early embryos. Several alternative exons and promoters of Snurf-Snrpn (SNRPN upstream reading frame-small nuclear ribonucleoprotein polypeptide N) are expressed as "IC transcripts". Previous studies have shown that IC-transcript expression is restricted to the brain. We studied expression of the mouse IC-transcript in tissues including brain and oocytes as well as in cultured neurons and glia cells by RT-PCR and by in situ hybridization (ISH) in oocytes. The IC transcript was strongly expressed in brain (especially in neurons) and ovary (especially in oocytes and granulosa cells), while no expression was found in other tissues. This was confirmed by quantitative analysis and ISH. Expression levels in the brain were 7-fold higher compared to those in ovaries. ISH signals were observed in oocytes and granulosa cells of the secondary and developing follicles. These findings, together with previous data, suggest that the IC transcript may be associated with the establishment of PWS-IC methylation on the maternal chromosome as an AS-IC cis-acting element.
Mapendano
Christophe K
CK
Department of Human Genetics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.|CREST, Japan Science and Technology Agency, Kawaguchi, Japan.
Kishino
Tatsuya
T
CREST, Japan Science and Technology Agency, Kawaguchi, Japan.|Division of Functional Genomics, Center for Frontier Life Sciences, Nagasaki University, Nagasaki, Japan.
Miyazaki
Kazumi
K
CREST, Japan Science and Technology Agency, Kawaguchi, Japan.|Division of Functional Genomics, Center for Frontier Life Sciences, Nagasaki University, Nagasaki, Japan.
Kondo
Shinji
S
CREST, Japan Science and Technology Agency, Kawaguchi, Japan.|Division of Functional Genomics, Center for Frontier Life Sciences, Nagasaki University, Nagasaki, Japan.
Yoshiura
Koh-Ichiro
KI
Department of Human Genetics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.|CREST, Japan Science and Technology Agency, Kawaguchi, Japan.
Hishikawa
Yoshitaka
Y
Department of Histology and Cell Biology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
Koji
Takehiko
T
Department of Histology and Cell Biology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
Niikawa
Norio
N
Department of Human Genetics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.|CREST, Japan Science and Technology Agency, Kawaguchi, Japan.
Ohta
Tohru
T
CREST, Japan Science and Technology Agency, Kawaguchi, Japan. ohta@hoku-iryo-u.ac.jp.|Institute of Personalized Health Sciences, Health Science University of Hokkaido, Kanazawa 1757, Ishikari-Tohbetsu, Hokkaido 061-0293, Japan. ohta@hoku-iryo-u.ac.jp.
D017398:Alternative Splicing; D000818:Animals; D001324:Autoantigens; D001483:Base Sequence; D017931:DNA Primers; D005260:Female; D018392:Genomic Imprinting; D017403:In Situ Hybridization; D008297:Male; D051379:Mice; D009687:Nuclear Proteins / Q000235:genetics*; D009865:Oocytes / Q000378:metabolism*; D010053:Ovary / Q000166:cytology / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017411:Ribonucleoproteins, Small Nuclear / Q000235:genetics*; D055517:snRNP Core Proteins
D001324:Autoantigens; D017931:DNA Primers; D009687:Nuclear Proteins; D012333:RNA, Messenger; D017411:Ribonucleoproteins, Small Nuclear; C526417:SNRPN protein, human; C486713:SNURF protein, mouse; D055517:snRNP Core Proteins