QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 7 July 2004
doi: 10.1242/dev.01241

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in Development Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Mann, M. R. W. Articles by Bartolomei, M. S. Search for Related Content PubMed PubMed Citation Articles by Mann, M. R. W. Articles by Bartolomei, M. S. Social Bookmarking                         What's this?

Selective loss of imprinting in the placenta following preimplantation development in culture

¹ Howard Hughes Medical Institute and Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
² Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA

View larger version (36K): [in a new window]   Fig. 1. Allele-specific expression of the H19 imprinted gene in individual blastocysts. Gray bar height indicates the level of maternal expression, while black bar height represents the level of paternal-specific expression. The number of Whitten's cultured blastocysts with biallelic expression differed significantly from that of KSOMaa cultured (P=0.002), in vivo-derived (P=0.006), and B6XB6(CAST7) Whitten's cultured (P=0.0001) blastocysts as calculated by Fisher's exact test.

View larger version (37K): [in a new window]   Fig. 2. Methylation status of individual DNA strands in (A) the H19 upstream differentially methylated domain (DMD) (paternal strands shown) and (B) Snrpn promoter-exon 1 region (maternal strands shown) in cultured blastocysts as determined by bisulfite mutagenesis analysis. Unmethylated CpGs are represented as empty circles, while methylated CpGs are depicted as filled circles. Each line denotes an individual strand of DNA with the number of strands showing a given pattern indicated to the left. Bar height indicates the percentage of strands that have a methylated CpG at each specific site. Paternal and maternal alleles are depicted by black and gray bars, respectively. For H19, a base pair change in the paternal B6 allele eliminates CpG dinucleotide 8, while for Snrpn, CpG dinucleotide 1 is not present in the maternal CAST allele.

View larger version (42K): [in a new window]   Fig. 3. Loss of imprinted expression in embryonic day (E) 9.5 B6(CAST7)XB6 placentas following preimplantation culture in Whitten's medium. Embryos at the 2-cell stage were cultured to the blastocyst stage then transferred to recipient females. Postimplantation embryo-placental sets were recovered at E9.5. B6(CAST7)XB6 in vivo-derived controls (Vivo), B6XB6(CAST7) Whitten's cultured controls (BCW), the remaining samples are B6(CAST7)XB6 KSOMaa (K) or Whitten's (W) cultured conceptuses. Red bar height indicates the level of maternal expression, while blue bar height represents the level of paternal-specific expression.

View larger version (103K): [in a new window]   Fig. 4. Methylation status of individual DNA strands in (A) the H19 upstream DMD and (B) Snrpn promoter-exon 1 region in embryos and placentas recovered at embryonic day 9.5 as determined by bisulfite analysis. Details are as described in Fig. 2. A low level of sporadic methylation on the normally unmethylated allele was observed in samples perturbed by preimplantation culture (data not shown).

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

Twitter