Publications by authors named "Danika Johnston"

Article Synopsis
  • The study explores how gene-expression patterns are maintained during the cell cycle, focusing on the role of epigenetic marks in preserving chromatin structure from parent to daughter cells.
  • Researchers analyzed potential epigenetic marks in Drosophila embryos during DNA replication, finding that while certain histones (H3) are typically methylated during transcription, they are replaced by nonmethylated versions after DNA replication.
  • The study suggests that specific enzymes responsible for histone modifications may be crucial for re-establishing the histone code on newly formed unmethylated histones, implying their role as epigenetic marks.
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The Drosophila ecdysone receptor (EcR/Usp) is thought to activate or repress gene transcription depending on the presence or absence, respectively, of the hormone ecdysone. Unexpectedly, we found an alternative mechanism at work in salivary glands during the ecdysone-dependent transition from larvae to pupae. In the absense of ecdysone, both ecdysone receptor subunits localize to the cytoplasm, and the heme-binding nuclear receptor E75A replaces EcR/Usp at common target sequences in several genes.

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This study aimed to (a) determine if DNA methylation is a mechanism of WWOX (WW domain containing oxidoreductase) and FHIT (fragile histidine triad) inactivation in lung, breast and bladder cancers; (b) examine distinct methylation patterns in neoplastic and adjacent tissues and (c) seek correlation of methylation patterns with disease status. Protein expression was detected by immunohistochemistry, and methylation status by methylation-specific PCR (MSP) and sequencing, in lung squamous cell carcinomas and adjacent tissues, invasive breast carcinomas, adjacent tissues and normal mammary tissues and bladder transitional cell carcinomas. Wwox and Fhit expression was reduced in cancers in association with hypermethylation.

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