概括
研究人员分离了四个贝塔型球蛋白基因,揭示了与胚胎基因在集群末的独特基因组排列. 这一发现有助于我们更好地理解脊椎动物的全球蛋白基因调节.
科学领域:
- 基因组学就是基因组学.
- 分子生物学分子生物学
- 发育生物学 发展生物学
背景情况:
- 全球蛋白基因对氧气运输至关重要,在发育过程中表达的不同类型.
- 了解全球蛋白基因集群的组织,可以了解它们的调节和演变.
研究的目的:
- 为了隔离和表征贝塔型全球蛋白基因的完整组.
- 为了确定这些基因在基因组中的物理组织和联系.
主要方法:
- 使用lambda Charon 4A重组细菌分离的DNA.
- 含有β型环球蛋白基因的重组细菌菌体的特征.
- 绘制和测序以确定基因顺序和物理距离.
主要成果:
- 鉴定和分离了四种的β型环球蛋白基因 (epsilon,βH,rho和β).
- 这些基因紧密联系在一起,并从相同的DNA链转录.
- 物理顺序被确定为5' ... rho-beta H-beta-epsilon ... 3',其中的排列在脊椎动物中是唯一的.
结论:
- 与其他脊椎动物相比,的β型环球蛋白基因集群表现出明显的组织.
- 这种独特的安排,胚胎基因在极端,成年/化基因在中心,可能反映了专门的调节机制.
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.
01:51Lampbrush Chromosomes
In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, Rückert observed LBCs in shark egg cells and coined the term "lampbrush chromosomes" because they looked like brushes used to clean kerosene lamps.
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the...
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the...
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...
02:38Heterochromatin
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...
01:30General Transcription Factors
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
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...