The cholinergic gene locus in amphioxus: Molecular characterization and developmental expression patterns

Identification and characterisation of differentially regulated genes in preimplantation human embryonic development are required to improve embryo quality and pregnancy rates in IVF. In this study, we examined expression of a number of genes known to be critical for early development and compared expression profiles in individual preimplantation human embryos to establish any differences in gene expression in fresh compared to frozen–thawed embryos used routinely in IVF. We analysed expression of 19 genes by cDNA amplification followed by quantitative real-time PCR in a panel of 44 fresh and frozen–thawed human preimplantation embryos. Fresh embryos were obtained from surplus early cleavage stage embryos and frozen–thawed embryos from cryopreserved 2PN embryos. Our aim was to determine differences in gene expression between fresh and frozen–thawed human embryos, but we also identified differences in developmental expression patterns for particular genes. We show that overall gene expression among embryos of the same stage is highly variable and our results indicate that expression levels between groups did differ and differences in expression of individual genes was detected. Our results show that gene expression from frozen–thawed embryos is more consistent when compared with fresh, suggesting that cryopreserved embryos may represent a reliable source for studying the molecular events underpinning early human embryo development.

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Molecular characterization, expression patterns, and promoter activity analysis of PGM1 in pigs

Genetics and Molecular Research ◽

10.4238/2015.march.31.12 ◽

2015 ◽

Vol 14 (1) ◽

pp. 2816-2824

Author(s):

J.Y. Yu ◽

S.M. Shao ◽

Y.Z. Xiong

Keyword(s):

Molecular Characterization ◽

Promoter Activity ◽

Expression Patterns ◽

Activity Analysis ◽

Promoter Activity Analysis

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S-Phase Progression Mediates Activation of a Silenced Gene in Synthetic Nuclei

Molecular and Cellular Biology ◽

10.1128/mcb.20.11.4169-4180.2000 ◽

2000 ◽

Vol 20 (11) ◽

pp. 4169-4180 ◽

Cited By ~ 5

Author(s):

Alison J. Crowe ◽

Julie L. Piechan ◽

Ling Sang ◽

Michelle C. Barton

Keyword(s):

Dna Replication ◽

Developmental Stage ◽

Expression Patterns ◽

Marker Gene ◽

Nuclear Extract ◽

S Phase ◽

Developmental Expression ◽

Aberrant Expression ◽

Transcription Repressors

ABSTRACT Aberrant expression of developmentally silenced genes, characteristic of tumor cells and regenerating tissue, is highly correlated with increased cell proliferation. By modeling this process in vitro in synthetic nuclei, we find that DNA replication leads to deregulation of established developmental expression patterns. Chromatin assembly in the presence of adult mouse liver nuclear extract mediates developmental stage-specific silencing of the tumor marker gene alpha-fetoprotein (AFP). Replication of silenced AFP chromatin in synthetic nuclei depletes sequence-specific transcription repressors, thereby disrupting developmentally regulated repression. Hepatoma-derived factors can target partial derepression of AFP, but full transcription activation requires DNA replication. Thus, unscheduled entry into S phase directly mediates activation of a developmentally silenced gene by (i) depleting developmental stage-specific transcription repressors and (ii) facilitating binding of transactivators.

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