Hitoshi Hiura

Learn More
Recent studies suggest that assisted reproductive technologies (ART), which involve the isolation, handling and culture of gametes and early embryos, are associated with an increased incidence of rare imprinting disorders. Major epigenetic events take place during this time and the process of ART may expose the epigenome to external influences, preventing(More)
DNA methylation is globally reprogrammed during mammalian preimplantation development, which is critical for normal development. Recent reduced representation bisulfite sequencing (RRBS) studies suggest that the methylome dynamics are essentially conserved between human and mouse early embryos. RRBS is known to cover 5-10% of all genomic CpGs, favoring(More)
Genomic imprinting causes parental origin-specific monoallelic gene expression through differential DNA methylation established in the parental germ line. However, the mechanisms underlying how specific sequences are selectively methylated are not fully understood. We have found that the components of the PIWI-interacting RNA (piRNA) pathway are required(More)
In mammals, some genes categorized as imprinted genes are exclusively expressed either from maternal or paternal allele. This parental-origin-specific gene expression is regulated by epigenetic modification of DNA methylation in differentially methylated region (DMR), which is independently imposed during oogenesis and spermatogenesis. It is known that(More)
There is an increased prevalence of imprinting disorders, such as Beckwith-Wiedemann syndrome, associated with human assisted reproductive technologies (ART). Work on animal models suggests that in vitro culture may be the source of these imprinting errors. However, in this study we report that, in some cases, the errors are inherited from the father. We(More)
BACKGROUND There is an increased incidence of rare imprinting disorders associated with assisted reproduction technologies (ARTs). The identification of epigenetic changes at imprinted loci in ART infants has led to the suggestion that the techniques themselves may predispose embryos to acquire imprinting errors and diseases. However, it is still unknown at(More)
Within the vertebrate groups, only mammals are subject to a specialized epigenetic process termed genomic imprinting in which genes are preferentially expressed from one parental allele. Imprinted expression has been reported for >100 mouse genes and, for approximately one-quarter of these genes, the imprinted expression is specific to the placenta (or(More)
Although ovarian theca cells play an indispensable role in folliculogenesis by providing follicular structural integrity and steroid substrates for estrogen production, little information is available about their recruitment, growth, and differentiation because their immature forms have not been identified. We have isolated putative thecal stem cells with(More)
The parent-of-origin specific expression of imprinted genes relies on DNA methylation of CpG-dinucleotides at differentially methylated regions (DMRs) during gametogenesis. To date, four paternally methylated DMRs have been identified in screens based on conventional approaches. These DMRs are linked to the imprinted genes H19, Gtl2 (IG-DMR), Rasgrf1 and,(More)
There has been an increase in incidence reports of rare imprinting disorders associated with assisted reproductive technology (ART). ART, including in vitro fertilization and intracytoplasmic sperm injections, is an important treatment for infertile people of reproductive age and increasingly produces children. The identification of epigenetic changes at(More)