正牙基因受双体和干的调节,并指定了Drosophila头部发育
1Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115.
Nature
|August 2, 1990
概括
双体 (bcd) 基因对虫头部发育至关重要. 研究人员确定了正牙 (otd) 基因是bcd激活的关键参与者,对于头部结构形成至关重要.
科学领域:
- 发育生物学是发展生物学.
- 遗传学 是一个遗传学.
- 分子生物学分子生物学
背景情况:
- 果胚胎中的细胞命运是由双体 (bcd) 和体 (tor) 等母体基因决定的.
- bcd 指定了头部和胸部结构,而 tor 指定了缩写.
- 控制头部发育的遗传层次比腹部细分的理解要少.
研究的目的:
- 为了识别参与Drosophila头部发育的杂交基因.
- 为了研究正牙 (otd) 基因在头部特征中的作用.
- 了解母体基因与胚胎头部发育基因之间的调控关系.
主要方法:
- 在Drosophila胚胎中分析基因表达模式.
- 研究正指牙 (otd) 基因的功能.
- 研究双眼 (bcd) 和干 (tor) 母亲基因与生殖器基因表达之间的相互作用.
主要成果:
- 确定了homeobox基因orthodenticle (otd) 作为一个潜在的头部发育基因.
- otd表达是由双体 (bcd) 梯度激活的.
- 其他疾病表达也由前极的母体干 () 基因调节.
结论:
- 正牙 (otd) 是Drosophila头部发育所必需的关键细胞基因.
- 异位传染病作用于双体 (bcd) 的下游,也受到干 (tor) 信号的影响.
- 这一发现澄清了控制Drosophila胚胎前部模式的遗传层次的一部分.
相关概念视频
Determination
During embryogenesis, cells become progressively committed to different fates through a two-step process: specification followed by determination. Specification is demonstrated by removing a segment of an early embryo, “neutrally” culturing the tissue in vitro—for example, in a petri dish with simple medium—and then observing the derivatives. If the cultured region gives rise to cell types that it would normally generate in the embryo, this means that it is specified. In contrast, determination...
Cis-regulatory Sequences
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...
Master Transcription Regulators
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
The Ratio of X Chromosome to Autosomes
In most organisms, sex is determined by the ratio of X and Y chromosomes. However, in some organisms, such as Drosophila and C.elegans, sex is determined by the ratio of the number of X chromosomes to the number of sets of autosomes. The Y chromosome in Drosophila is active but does not determine sex. It contains genes responsible for the production of sperms in adult flies.
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Canonical Wnt Signaling Pathway
The gene encoding the main signaling molecules of the Wnt signaling pathways (the Wnt proteins) was discovered almost four decades ago by Nüsslein-Volhard and Wieschaus. They identified and originally named the gene "wingless" (wg) after a phenotype discovered during their landmark genetic screen in Drosophila for body pattern defects. At around the same time, another researcher named Harold Varmus found that a murine tumor virus activates the mammalian wg homolog, Int-1, which results in tumor...
Hedgehog Signaling Pathway
The Hedgehog gene (Hh) was first discovered due to its control of the growth of disorganized, hair-like bristles phenotype in Drosophila, much like hedgehog spines. Hh plays a crucial role in the development of organs and the maintenance of homeostasis in both invertebrates and vertebrates. However, while Drosophila has only one Hh protein, mammals have multiple functional Hedgehog proteins - Sonic (Shh), Desert (Dhh), and Indian Hedgehog (Ihh). All of these homologous proteins have adapted to...


