scholarly journals Chromatin structure of a P-element-transduced hsp-28 gene in Drosophila melanogaster.

1986 ◽  
Vol 6 (11) ◽  
pp. 4126-4129 ◽  
Author(s):  
J C Eissenberg ◽  
S C Elgin

The Drosophila hsp-28 gene was heat inducible when transduced to novel chromosomal sites even when no direct selection for transduced gene expression was imposed. The pattern of DNase I-hypersensitive sites 5' to the wild type and transduced copy of hsp-28 was similar. In addition, DNase I-hypersensitive sites occurred within the P-element sequences flanking transduced loci.

1986 ◽  
Vol 6 (11) ◽  
pp. 4126-4129
Author(s):  
J C Eissenberg ◽  
S C Elgin

The Drosophila hsp-28 gene was heat inducible when transduced to novel chromosomal sites even when no direct selection for transduced gene expression was imposed. The pattern of DNase I-hypersensitive sites 5' to the wild type and transduced copy of hsp-28 was similar. In addition, DNase I-hypersensitive sites occurred within the P-element sequences flanking transduced loci.


1991 ◽  
Vol 11 (10) ◽  
pp. 5301-5311
Author(s):  
J A Brown ◽  
S G Holmes ◽  
M M Smith

The chromatin structures of two well-characterized autonomously replicating sequence (ARS) elements were examined at their chromosomal sites during the cell division cycle in Saccharomyces cerevisiae. The H4 ARS is located near one of the duplicate nonallelic histone H4 genes, while ARS1 is present near the TRP1 gene. Cells blocked in G1 either by alpha-factor arrest or by nitrogen starvation had two DNase I-hypersensitive sites of about equal intensity in the ARS element. This pattern of DNase I-hypersensitive sites was altered in synchronous cultures allowed to proceed into S phase. In addition to a general increase in DNase I sensitivity around the core consensus sequence, the DNase I-hypersensitive site closest to the core consensus became more nuclease sensitive than the distal site. This change in chromatin structure was restricted to the ARS region and depended on replication since cdc7 cells blocked near the time of replication initiation did not undergo the transition. Subsequent release of arrested cdc7 cells restored entry into S phase and was accompanied by the characteristic change in ARS chromatin structure.


2005 ◽  
Vol 25 (16) ◽  
pp. 7033-7041 ◽  
Author(s):  
Xiangdong Fang ◽  
Jin Sun ◽  
Ping Xiang ◽  
Man Yu ◽  
Patrick A. Navas ◽  
...  

ABSTRACT Deletion of the 234-bp core element of the DNase I hypersensitive site 3 (5′HS3) of the locus control region (LCR) in the context of a human beta-globin locus yeast artificial chromosome (β-YAC) results in profound effects on globin gene expression in transgenic mice. In contrast, deletion of a 2.3-kb 5′HS3 region, which includes the 234-bp core sequence, has a much milder phenotype. Here we report the effects of these deletions on chromatin structure in the beta-globin locus of adult erythroblasts. The 234-bp 5′HS3 deletion abolished histone acetylation throughout the β-globin locus; recruitment of RNA polymerase II (pol II) to the LCR and beta-globin gene promoter was reduced to a basal level; and formation of all the 5′ DNase I hypersensitive sites of the LCR was disrupted. The 2.3-kb 5′HS3 deletion mildly reduced the level of histone acetylation but did not change the profile across the whole locus; the 5′ DNase I hypersensitive sites of the LCR were formed, but to a lesser extent; and recruitment of pol II was reduced, but only marginally. These data support the hypothesis that the LCR forms a specific chromatin structure and acts as a single entity. Based on these results we elaborate on a model of LCR chromatin architecture which accommodates the distinct phenotypes of the 5′HS3 and HS3 core deletions.


1987 ◽  
Vol 7 (5) ◽  
pp. 1856-1864
Author(s):  
I Tratner ◽  
J L Nahon ◽  
J M Sala-Trepat ◽  
A Venetianer

We examined DNA methylation and DNase I hypersensitivity of the alpha-fetoprotein (AFP) and albumin gene region in hepatoma cell lines which showed drastic differences in the level of expression of these genes. We assayed for methylation of the CCGG sequences by using the restriction enzyme isoschizomers HpaII and MspI. We found two methylation sites located in the 5' region of the AFP gene and one in exon 1 of the albumin gene for which hypomethylation is correlated with gene expression. Another such site, located about 4,000 base pairs upstream from the AFP gene, seems to be correlated with the tissue specificity of the cells. DNase I-hypersensitive sites were mapped by using the indirect end-labeling technique with cloned genomic DNA probes. Three tissue-specific DNase I-hypersensitive sites were mapped in the 5' flanking region of the AFP gene when this gene was transcribed. Similarly, three tissue-specific DNase I-hypersensitive sites were detected upstream from the albumin gene in producing cell lines. In both cases, the most distal sites were maintained after cessation of gene activity and appear to be correlated with the potential expression of the gene. Interestingly, specific methylation sites are localized in the same DNA region as DNase I hypersensitive sites. This suggests that specific alterations of chromatin structure and changes in methylation pattern occur in specific critical regulatory regions upstream from the albumin and AFP genes in rat hepatoma cell lines.


1987 ◽  
Vol 368 (1) ◽  
pp. 111-120 ◽  
Author(s):  
Hans Peter FRITTON ◽  
Tibor IGO-KEMENES ◽  
Joachim NOWOCK ◽  
Ute STRECH-JURK ◽  
Manfred THEISEN ◽  
...  

1989 ◽  
Vol 9 (1) ◽  
pp. 296-302
Author(s):  
P Gönczy ◽  
W Reith ◽  
E Barras ◽  
B Lisowska-Grospierre ◽  
C Griscelli ◽  
...  

A defect in a trans-regulatory factor which controls major histocompatibility complex class II gene expression is responsible for an inherited form of immunodeficiency with a lack of expression of human leukocyte antigen (HLA) class II antigens. We have recently described and cloned an HLA class II promoter DNA-binding protein, RF-X, present in normal B cells and absent in these class II-deficient regulatory mutants. Here we report that these in vitro results correlate with a specific change in the chromatin structure of the class II promoter: two prominent DNase I-hypersensitive sites were identified in the promoter of the HLA-DRA gene in normal B lymphocytes and found to be absent in the class II-deficient mutant cells. The same two prominent DNase I-hypersensitive sites were observed in normal fibroblastic cells induced by gamma interferon to express class II genes. Interestingly, they were also observed in the uninduced class II-negative fibroblastic cells, which have also been shown to have a normal RF-X binding pattern. We conclude that the two DNase I-hypersensitive sites in the HLA-DRA promoter reflect features in chromatin structure which correlate with the binding of the trans-acting factor RF-X and which are necessary but not sufficient for the expression of class II genes.


2001 ◽  
Vol 21 (8) ◽  
pp. 2867-2879 ◽  
Author(s):  
Fang-Lin Sun ◽  
Matthew H. Cuaycong ◽  
Sarah C. R. Elgin

ABSTRACT We have used line HS-2 of Drosophila melanogaster, carrying a silenced transgene in the pericentric heterochromatin, to investigate in detail the chromatin structure imposed by this environment. Digestion of the chromatin with micrococcal nuclease (MNase) shows a nucleosome array with extensive long-range order, indicating regular spacing, and with well-defined MNase cleavage fragments, indicating a smaller MNase target in the linker region. The repeating unit is ca. 10 bp larger than that observed for bulkDrosophila chromatin. The silenced transgene shows both a loss of DNase I-hypersensitive sites and decreased sensitivity to DNase I digestion within an array of nucleosomes lacking such sites; within such an array, sensitivity to digestion by MNase is unchanged. The ordered nucleosome array extends across the regulatory region of the transgene, a shift that could explain the loss of transgene expression in heterochromatin. Highly regular nucleosome arrays are observed over several endogenous heterochromatic sequences, indicating that this is a general feature of heterochromatin. However, genes normally active within heterochromatin (rolled and light) do not show this pattern, suggesting that the altered chromatin structure observed is associated with regions that are silent, rather than being a property of the domain as a whole. The results indicate that long-range nucleosomal ordering is linked with the heterochromatic packaging that imposes gene silencing.


1984 ◽  
Vol 4 (9) ◽  
pp. 1853-1863 ◽  
Author(s):  
N Costlow ◽  
J T Lis

High-resolution analysis of the chromatin structure of the promoter regions of five Drosophila heat shock genes showed a similar location for the hypersensitive sequences relative to the start of transcription. For each of the five genes examined--those coding for hsp27, hsp26, hsp23, hsp70, and hsp83--the DNase I-hypersensitive sites in Drosophila melanogaster nuclei mapped to two regions upstream of the coding region. These sites occurred on the average, 115 and 17 base pairs upstream from the start of transcription of the five heat shock genes examined. This latter site corresponded to sequences at or near the TATA consensus sequence. Sites even further upstream of the hsp27, hsp26, and hsp83 genes were also evident. Additionally, for the two genes examined--hsp70 and hsp83--the DNase I-hypersensitive sites were preserved, at least within this level of resolution (+/- 10 base pairs), when the Drosophila genes were integrated into the Saccharomyces cerevisiae genome. This result indicates that the signals responsible for generating these hypersensitive sites are inherent in the DNA sequences and, in this case, are not highly species specific.


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