13 research outputs found
Vertical Resource Partitioning and Sexuality of Three Sympatric Species of Red Sea Sandfishes (Xyrichtys melanopus, Labridae; Trichonotus nikii, Trichonotidae; Gorgasia sp., Congridae)
Three species of marine sandfishes were studied from
1984 to 1986. Their inter- and intraspecific behavior
was monitored during the daylight hours to examine
interactions that could result in the vertical
stratification of the species over the sandy bottom
within the fringing and patch reefs in the north Red Sea.
Horizontal plankton tows were taken at three heights and
three times a day. These samples were compared to
stomach contents of the fishes to determine the trophic
relationships in the community and their affects on
spatial relations between the species . Prey
specificities of the fishes were determined by using an
electivity measure. Using paraffin histology, Xyrichtys
melanopus was determined to be a monandric protogynous
hermaphrodite and Trichonotus nikii, a gonochorist.
Previous work on the mating systems and territoriality of
all three sandfish species helped in part to explain the
vertical spatial arrangement of the sandfish species
within the community. Effects of pollution on the b iota
of the Northern Gulf of Aqaba are noted
STAT3 acts through pre-existing nucleosome-depleted regions bound by FOS during an epigenetic switch linking inflammation to cancer
Mml1,a New Common Integration Site in Murine Leukemia Virus-Induced Promonocytic Leukemias Maps to Mouse Chromosome 10
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STAT3 acts through pre-existing nucleosome-depleted regions bound by FOS during an epigenetic switch linking inflammation to cancer
Background: Transient induction of the Src oncoprotein in a non-transformed breast cell line can initiate an epigenetic switch to a cancer cell via a positive feedback loop that involves activation of the signal transducer and activator of transcription 3 protein (STAT3) and NF-ÎşB transcription factors. Results: We show that during the transformation process, nucleosome-depleted regions (defined by formaldehyde-assisted isolation of regulatory elements (FAIRE)) are largely unchanged and that both before and during transformation, STAT3 binds almost exclusively to previously open chromatin regions. Roughly, a third of the transformation-inducible genes require STAT3 for the induction. STAT3 and NF-ÎşB appear to drive the regulation of different gene sets during the transformation process. Interestingly, STAT3 directly regulates the expression of NFKB1, which encodes a subunit of NF-ÎşB, and IL6, a cytokine that stimulates STAT3 activity. Lastly, many STAT3 binding sites are also bound by FOS and the expression of several AP-1 factors is altered during transformation in a STAT3-dependent manner, suggesting that STAT3 may cooperate with AP-1 proteins. Conclusions: These observations uncover additional complexities to the inflammatory feedback loop that are likely to contribute to the epigenetic switch. In addition, gene expression changes during transformation, whether driven by pre-existing or induced transcription factors, occur largely through pre-existing nucleosome-depleted regions. Electronic supplementary material The online version of this article (doi:10.1186/1756-8935-8-7) contains supplementary material, which is available to authorized users