在一个活跃的Balbiani环基因上存在素H1
C Ericsson1, U Grossbach, B Björkroth
1Department of Molecular Genetics, Medical Nobel Institute, Karolinska Institutet, Stockholm, Sweden.
Cell
|January 12, 1990
概括
基因组H1仍然与活跃的Balbiani环基因结合,即使DNA被扩展用于转录. 这种蛋白质在活跃的基因中更容易获得,这表明它在整个基因活动周期中存在.
科学领域:
- 分子生物学分子生物学
- 染色体生物学 染色体生物学
- 发育生物学 发展生物学
背景情况:
- 在Chironomus tentans中的Balbiani环基因是活跃基因表达的模型.
- 基因组H1在活跃转录的基因中的作用尚未完全理解.
- 染色体结构,包括基因素修饰,调节基因活动.
研究的目的:
- 调查活跃的Balbiani环基因上素H1的存在和可访问性.
- 为了确定基因转录过程中,基因组H1是否仍然结合.
- 为了比较活跃与抑制的基因状态中的基因素H1关联.
主要方法:
- 免疫电子显微镜被用来检测 histone H1.
- 作为生物模型,使用了Chironomus tentans的唾液腺.
- 基因在最大激活和抑制的构造中进行了分析.
主要成果:
- 在Balbiani环基因中检测到活跃和抑制状态的histon H1.
- 基因组H1的免疫信号在活性基因上显著更强.
- 在未折叠的染色质中增加了组素H1的可访问性,这可能解释了更强的信号.
结论:
- 在转录过程中,基因组H1仍然与DNA模板结合.
- 核细胞在RNA聚合酶中被破坏,但核心基因组和基因组H1仍然存在.
- 即使当染色质被解密以获得高的转录活性时,也保持了基因组H1关联.
相关概念视频
02:32Position-effect Variegation
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
02:04Polytene Chromosomes
Polytene chromosomes are giant interphase chromosomes with several DNA strands placed side by side. They were discovered in the year 1881 by Balbiani in salivary glands, intestine, muscles, malpighian tubules, and hypoderm of larvae Chironomus plumosus. Hence, these are also called "Salivary gland chromosomes." These are found in insects of the order Diptera and Collembola; in certain organs of mammals; and synergids, antipodes of flowering plants. Polytene chromosomes are also regularly...
02:30Histone Variants at the Centromere
Histone variants are the histone proteins with structural and sequence variations. These variants may be regarded as “mutant” forms that replace their canonical histone counterparts in the nucleosomes. Specific post-translational modifications on the histone variants enable further chromatin complexity and regulate tissue-specific gene expression. The most common histone variants are from histone H2A, H2B, and linker histone H1 families. However, several variants of histone H3 variants are also...
02:38Heterochromatin
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
02:38Heterochromatin
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
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02:32Histone Modification
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Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...