Comparison of gene expression in male and female mouse blastocysts revealed imprinting of the X-linked gene, Rhox5/Pem, at preimplantation stages.
Mammalian male preimplantation embryos develop more quickly than females . Using enhanced green fluorescent protein (EGFP)-tagged X chromosomes to identify the sex of the embryos, we compared gene expression patterns between male and female mouse blastocysts by DNA microarray. We detected nearly 600 genes with statistically significant sex-linked expression; most differed by 2-fold or less. Of 11 genes showing greater than 2.5-fold differences, four were expressed exclusively or nearly exclusively sex dependently. Two genes (Dby and Eif2s3y) were mapped to the Y chromosome and were expressed in male blastocysts. The remaining two (Rhox5/Pem and Xist) were mapped to the X chromosome and were predominantly expressed in female blastocysts. Moreover, Rhox5/Pem was expressed predominantly from the paternally inherited X chromosome, indicating sex differences in early epigenetic gene regulation.
Kobayashi
Shin
S
Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Isotani
Ayako
A
Mise
Nathan
N
Yamamoto
Masamichi
M
Fujihara
Yoshitaka
Y
Kaseda
Kazuhiro
K
Nakanishi
Tomoko
T
Ikawa
Masahito
M
Hamada
Hiroshi
H
Abe
Kuniya
K
Okabe
Masaru
M
D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism*; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D050172:Genes, X-Linked; D018392:Genomic Imprinting; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D008297:Male; D051379:Mice; D012737:Sex Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation
D018398:Homeodomain Proteins; C498048:Rhox5 protein, mouse; D014157:Transcription Factors