skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Distinct parasegmental and imaginal enhancers and the establishment of the expression pattern of the Ubx gene

Abstract

The expression domain of the Ubx gene in Drosophila embryos is bounded by the product of the hb gene, acting as a repressor. We show that all Ubx fragments that bind Hb protein in vitro contain parasegmental enhancers active in the embryo in specific parasegmental patterns. We have found three new embryonic enhancer elements in the upstream region, in addition to the two previously identified. Each produces a pattern initially bounded at PS6 by Hb but sooner or later breaks down this boundary and begins to express in the anterior region. These enhancers do not respond to the long-term maintenance mediated by the Polycomb group of genes. They also cease functioning after germ band extension. Expression in imaginal tissues is due to a set of entirely separate and independent imaginal disc enhancers. These do not contain Hb binding sites and by themselves have no anterior/posterior positional information, although some distinguish between ventral and dorsal discs. A third kind of element, the Polycomb Response Element (PRE), has no enhancer activity but causes long-term maintenance of the expression domain of other enhancers present in the vicinity. The interaction of these elements results in the correct expression of Ubx in imaginal tissues. 40more » refs., 7 figs.« less

Authors:
; ; ;  [1]
  1. Univ. of Geneva (Switzerland)
Publication Date:
OSTI Identifier:
535346
Resource Type:
Journal Article
Resource Relation:
Journal Name: Genetics; Journal Volume: 141; Journal Issue: 4; Other Information: PBD: Dec 1995
Country of Publication:
United States
Language:
English
Subject:
55 BIOLOGY AND MEDICINE, BASIC STUDIES; DROSOPHILA; EMBRYOS; GENES; GENE REGULATION; GENE REPRESSORS; TRANSCRIPTION; DNA SEQUENCING; STRUCTURE-ACTIVITY RELATIONSHIPS; GENETIC MAPPING; TISSUE DISTRIBUTION; TRANSPOSONS

Citation Formats

Pirrotta, V., Chan, Chi Shing, McCabe, D., and Qian, Su. Distinct parasegmental and imaginal enhancers and the establishment of the expression pattern of the Ubx gene. United States: N. p., 1995. Web.
Pirrotta, V., Chan, Chi Shing, McCabe, D., & Qian, Su. Distinct parasegmental and imaginal enhancers and the establishment of the expression pattern of the Ubx gene. United States.
Pirrotta, V., Chan, Chi Shing, McCabe, D., and Qian, Su. Fri . "Distinct parasegmental and imaginal enhancers and the establishment of the expression pattern of the Ubx gene". United States. doi:.
@article{osti_535346,
title = {Distinct parasegmental and imaginal enhancers and the establishment of the expression pattern of the Ubx gene},
author = {Pirrotta, V. and Chan, Chi Shing and McCabe, D. and Qian, Su},
abstractNote = {The expression domain of the Ubx gene in Drosophila embryos is bounded by the product of the hb gene, acting as a repressor. We show that all Ubx fragments that bind Hb protein in vitro contain parasegmental enhancers active in the embryo in specific parasegmental patterns. We have found three new embryonic enhancer elements in the upstream region, in addition to the two previously identified. Each produces a pattern initially bounded at PS6 by Hb but sooner or later breaks down this boundary and begins to express in the anterior region. These enhancers do not respond to the long-term maintenance mediated by the Polycomb group of genes. They also cease functioning after germ band extension. Expression in imaginal tissues is due to a set of entirely separate and independent imaginal disc enhancers. These do not contain Hb binding sites and by themselves have no anterior/posterior positional information, although some distinguish between ventral and dorsal discs. A third kind of element, the Polycomb Response Element (PRE), has no enhancer activity but causes long-term maintenance of the expression domain of other enhancers present in the vicinity. The interaction of these elements results in the correct expression of Ubx in imaginal tissues. 40 refs., 7 figs.},
doi = {},
journal = {Genetics},
number = 4,
volume = 141,
place = {United States},
year = {Fri Dec 01 00:00:00 EST 1995},
month = {Fri Dec 01 00:00:00 EST 1995}
}
  • No abstract prepared.
  • To help elucidate the mechanisms by which nerve growth factor (NGF) regulates gene expression, the authors have identified and studied four genes (a-2, d-2, d-4, and d-5) that are positively regulated by NGF in PC12 cells, including one (d-2) which has previously been identified as a putative transcription factor (NGF I-A). Three of these genes, including d-2, were induced very rapidly at the transcriptional level, but the relative time courses of transcription and mRNA accumulation of each of these three genes were distinct. The fourth gene (d-4) displayed no apparent increase in transcription that corresponded to the increase in itsmore » mRNA, suggesting that NGF may regulate its expression at a posttranscriptional level. Thus NGF positively regulates gene expression by more than one mechanism. The study of the regulation of the expression of these and other NGF-inducible genes should provide valuable new information concerning how NGF and other growth factors cause neural differentiation.« less
  • Treatment of human promyelocytic leukemia cells U937 with phorbol 12-myristate 13-acetate (TPA) induces them to differentiate into monocytic cells. Here the authors investigated the effects of TPA on interleukin 1 gene expression and the possible role of protein kinase C (PKC) in this process. Addition of TPA to serum-starved U937 cells induced the expression of the interleukin 1{beta} (IL-1{beta}) gene. This effect was apparent as early as 2 h and peaked at 24 h in the presence of 5 {times} 10{sup {minus}8} M TPA. To determine the protein kinase C isozymes present in the control and TPA treated U937 cells,more » they prepared antipeptide antibodies that specifically recognize the {alpha}, {beta}, and {gamma} isoforms of protein kinase C in rat brain cytosol and U937 cell extracts. Upon TPA treatment, there was a time-dependent translocation (maximum 1 h) of PKC {alpha} to a particulate compartment, followed by its gradual disappearance, with no concomitant rise in the cytosolic form. PKC {beta} remained cytosolic during TPA treatment, while PKC {gamma} appeared at 6 h and continued to increase in abundance by 24 h, mostly in particulate form. Exposure of {sup 32}PO{sub 4}-labeled cells to TPA for 30 min enhanced the phosphorylation of several major substrates. Exposure of U937 cells to diC{sub 8} failed to induce PKC {alpha} translocation. The data suggest a potential role for PKC {alpha} mediated phosphorylation of substrates in the initial events leading to TPA-induced differentiation of a promonocytic cell to a monocyte/macrophage.« less
  • Several cell types are present in the intestinal epithelium that likely arise from a common precursor, the stem cell, and each mature cell type expresses a unique set of genes that characterizes its functional phenotype. Although the process of differentiation is intimately linked to the cessation of proliferation, the mechanisms that dictate intestinal cell fate determination are not well characterized. To investigate the reprogramming of gene expression during the cell lineage allocation/differentiation process, we took advantage of a unique system of two clonal derivatives of HT29 cells, Cl16E and Cl19A cells, which spontaneously differentiate as mucus producing goblet and chloride-secretingmore » cells, respectively, as a function of time. By profiling gene expression, we found that these two cell lines show remarkably similar kinetics of change in gene expression and common clusters of coordinately regulated genes. This demonstrates that lineage-specific differentiation of intestinal epithelial cells is characterized overall by the sequential recruitment of functionally similar gene sets independent of the final phenotype of the mature cells.« less
  • Purpose: Women who received irradiation for Hodgkin's lymphoma have a strong increased risk for developing breast cancer. Approximately 90% of the breast cancers in these patients can be attributed to their radiation treatment, rendering such series extremely useful to determine whether a common radiation-associated cause underlies the carcinogenic process. Methods and Materials: In this study we used gene expression profiling technology to assess gene expression changes in radiation-associated breast tumors compared with a set of control breast tumors of women unexposed to radiation, diagnosed at the same age. RNA was obtained from fresh frozen tissue samples from 22 patients whomore » developed breast cancer after Hodgkin's lymphoma (BfHL) and from 20 control breast tumors. Results: Unsupervised hierarchical clustering of the profile data resulted in a clustering of the radiation-associated tumors separate from the control tumors (p < 0.001). Using a supervised class prediction tool, a nearest centroid classifier of 198 probes was identified. The BfHL tumors were often of the intrinsic basal breast tumor subtype, and they showed a chromosomal instability profile and a higher expression of the proliferation marker Ki-67. Conclusion: These results indicate that radiation-associated tumors are different from other breast tumors on the basis of their expression profile and that they are mainly of one specific cause that is characterized by high proliferation and a more aggressive tumor type.« less