X inactivation-specific transcript expression in mouse oocytes and zygotes.
Expression of the X inactivation-specific transcript (XIST:) gene has previously been shown by reverse transcription-polymerase chain reaction (RT-PCR) to be present at the 4-cell stage of female mouse embryos. This early expression, which is followed by X inactivation in the extra-embryonic tissues, is maternally imprinted. By the blastocyst stage, as the embryonic lineages begin to form, the imprint is lost and expression becomes random. By applying in-situ RT-PCR, we showed that XIST: is expressed even earlier in development, in unfertilized mouse oocytes as well as in pronuclei stage zygotes. Our data demonstrate XIST: expression in oocytes and suggest that XIST: transcripts may occur in both XX and XY zygotes. A difference in the pattern of expression (rod-like or rounded punctate signal) is found among pronuclear-stage embryos. Early expression is in agreement with findings reported in human embryos.
Avner
R
R
Unit for Development of Molecular Biology and Genetic Engineering, The Hebrew University, Hadassah Medical School, Jerusalem.
Wahrman
J
J
Richler
C
C
Ayoub
N
N
Friedmann
A
A
Laufer
N
N
Mitrani-Rosenbaum
S
S
D000818:Animals; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D051379:Mice; D009865:Oocytes / Q000502:physiology*; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D014960:X Chromosome / Q000235:genetics; D015053:Zygote / Q000502:physiology*
D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D014157:Transcription Factors; C077885:XIST non-coding RNA