telomeric nap1l4 and osbpl5 of the kcnq1 cluster, and the decorin gene are not imprinted in human trophoblast stem cells端粒的nap1l4和osbpl5 kcnq1集群,decorin基因不是印在人类滋养层干细胞.pdfVIP

Telomeric NAP1L4 and OSBPL5 of the KCNQ1 Cluster, and the DECORIN Gene Are Not Imprinted in Human Trophoblast Stem Cells 1,2 3 3 1 Jennifer M. Frost *, Ramya Udayashankar , Harry D. Moore , Gudrun E. Moore 1 Clinical and Molecular Genetics Unit, Institute of Child Health, University College London, London, United Kingdom, 2 Institute of Reproductive and Developmental Biology, Imperial College London, London, United Kingdom, 3 Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom Abstract Background: Genomic imprinting of the largest known cluster, the Kcnq1/KCNQ1 domain on mChr7/hChr11, displays significant differences between mouse and man. Of the fourteen transcripts in this cluster, imprinting of six is ubiquitous in mice and humans, however, imprinted expression of the other eight transcripts is only found in the mouse placenta. The human orthologues of the latter eight transcripts are biallelically expressed, at least from the first trimester onwards. However, as early development is less divergent between species, placental specific imprinting may be present in very early gestation in both mice and humans. Methodology/Principal Findings: Human embryonic stem (hES) cells can be differentiated to embryoid bodies and then to trophoblast stem (EB-TS) cells. Using EB-TS cells as a model of post-implantation invading cytotrophoblast, we analysed allelic expression of two telomeric transcripts whose imprinting is placental specific in the mouse, as well as the ncRNA KCNQ1OT1, whose imprinted expression is ubiquitous in early human and mouse development. KCNQ1OT1 expression was monoallelic in all samples but OSBPL5 and NAP1L4 expression was biallelic in EB-TS cells, as w