Discovery of a novel imprinted gene by transcriptional analysis of parthenogenetic embryonic stem cells.
BACKGROUND
Parthenogenetic embryonic stem cells (PESCs) may have future utilities in cell replacement therapies since they are closely related to the female from which the activated oocyte was obtained. Furthermore, the avoidance of parthenogenetic development in mammals provides the most compelling rationale for the evolution of genomic imprinting, and the biological process of parthenogenesis raises complex issues regarding differential gene expression.


RESULTS
We describe here homozygous rhesus monkey PESCs derived from a spontaneously duplicated, haploid oocyte genome. Since the effect of homozygosity on PESCs pluripotency and differentiation potential is unknown, we assessed the similarities and differences in pluripotency markers and developmental potential by in vitro and in vivo differentiation of homozygous and heterozygous PESCs. To understand the differences in gene expression regulation between parthenogenetic and biparental embryonic stem cells (ESCs), we conducted microarray analysis of genome-wide mRNA profiles of primate PESCs and ESCs derived from fertilized embryos using the Affymetrix Rhesus Macaque Genome array. Several known paternally imprinted genes were in the highly down-regulated group in PESCs compared with ESCs. Furthermore, allele-specific expression analysis of other genes whose expression is also down-regulated in PESCs, led to the identification of one novel imprinted gene, inositol polyphosphate-5-phosphatase F (INPP5F), which was exclusively expressed from a paternal allele.


CONCLUSIONS
Our findings suggest that PESCs could be used as a model for studying genomic imprinting, and in the discovery of novel imprinted genes.
Sritanaudomchai
Hathaitip
H
Oregon National Primate Research Center, Beaverton, OR 97006, USA.
Ma
Hong
H
Clepper
Lisa
L
Gokhale
Sumita
S
Bogan
Randy
R
Hennebold
Jon
J
Wolf
Don
D
Mitalipov
Shoukhrat
S
D000483:Alleles; D000818:Animals; D002460:Cell Line; D019175:DNA Methylation; D053595:Embryonic Stem Cells / Q000378:metabolism*; D044127:Epigenesis, Genetic; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006580:Genetic Carrier Screening; D018392:Genomic Imprinting; D006801:Humans; D000072181:Inositol Polyphosphate 5-Phosphatases; D008253:Macaca mulatta; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics; D039904:Pluripotent Stem Cells / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*
D012333:RNA, Messenger; D010744:Phosphoric Monoester Hydrolases; C000606431:INPP5F protein, human; D000072181:Inositol Polyphosphate 5-Phosphatases