Section outline

  • General

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  • Eukaryatic 基因规范

    What will you learn
    ::你会学到什么

    • How is regulated in eukaryotes
      ::在eukaryotes中如何管理
    • The role of regulatory elements in eukaryotic gene regulation
      ::调控要素在安眠基因调控中的作用
    • How regulation is important during the of an organism
      ::生物体的监管如何重要
    • How develops by altering gene regulation
      ::如何通过改变基因管制而发展

    Four light switches, showing different positions of 'ON' and 'OFF' settings.

    On or Off? On or Off? On or Off?
    ::开还是走 开还是走 开还是走 开还是走?

    That is the key question. Gene regulation in eukaryotes is a highly regulated process usually involving many , which either bind to each other or bind to the .
    ::这是关键问题。 eukaryotes的基因监管是一个监管严密的过程,通常涉及许多,相互约束或相互约束。

    Eukaryotic Gene Regulation
    ::Eukaryatic 基因规范

    In eukaryotic cells , the start of transcription is one of the most complicated parts of gene regulation. There may be many regulatory proteins and regulatory elements involved. Regulation may also involve enhancers . Enhancers are distant regions of DNA that can loop back to interact with a gene’s promoter .
    ::在尿道细胞中,转录的开始是基因监管中最复杂的部分之一。 可能涉及许多监管性蛋白和监管要素。 监管也可能涉及增强剂。 增强剂是遥远的DNA区域,可以与基因促进者回转。

    The TATA Box
    ::TATATA 框框

    Different types of have unique patterns of regulatory elements that result in only the necessary genes being transcribed. That’s why a skin cell and nerve cell, for example, are so different from each other. However, some patterns of regulatory elements are common to all genes, regardless of the cells in which they occur. An example is the TATA box , so named because it has a core sequence of TATAAA . This is a regulatory element that is part of the promoter of most eukaryotic genes. A number of regulatory proteins bind to the TATA box, forming a multi-protein complex. It is only when all of the appropriate proteins are bound to the TATA box that RNA polymerase recognizes the complex and binds to the promoter. Once RNA polymerase binds, transcription begins. 
    ::不同种类的监管要素都有独特的模式,它们只导致必要的基因被转录。这就是为什么皮肤细胞和神经细胞彼此如此不同的原因。然而,某些监管要素的模式对所有基因都是共同的,不管它们发生在哪个细胞中。一个例子是TATA框,它的名字是因为它有TATAA的核心序列。这是一个监管要素,它是大多数尿道基因的促进者的一部分。一些监管蛋白与TATA盒捆绑在一起,形成多蛋白复合体。只有当所有的合适的蛋白都与TATA盒捆绑在一起时,RNA聚合酶才承认复杂和与促销者捆绑在一起。一旦RNA聚合酶捆绑在一起,转录就会开始。

    Regulation During Development
    ::制定期间的规章条例

    The regulation of gene expression is extremely important during the development of an organism. Regulatory proteins must turn on certain genes in particular cells at just the right time so the organism develops normal organs and organ systems . Homeobox genes are an example of genes that regulate development. They code for regulatory proteins that switch on whole series of major developmental genes. In , homeobox genes called hox genes ensure that body parts such as limbs develop in the correct place. The Figure shows how a in a hox gene can affect an insect’s development. Other organisms, including humans, also have hox genes. 
    ::基因表达的调控在生物体发育期间极为重要。 调节性蛋白必须在正确的时间转向某些基因, 特别是细胞, 以便生物体发展正常的器官和器官系统。 软骨基因是基因调节发展的一个例子。 它们为调控性蛋白编码, 转换成一系列主要的发育基因。 在 被称为 hox 基因的软骨基因确保肢体等身体部分在正确的地方发育。 图中显示了荷骨基因如何影响昆虫的发育。 其他生物, 包括人类, 也有Hox 基因 。

    Close-up of fruit flies showing developmental anomaly due to hox gene mutation affecting leg growth.
    Effect of Hox Gene Mutation. Scientists caused a mutation in a hox gene of this fruit fly. As a result of the mutation, a leg grew out of its head where an antenna should have developed.

    Gene Expression and Cancer
    ::基因表达与癌症

    The mutations that cause cancer generally occur in two types of regulatory genes: tumor-suppressor genes and proto-oncogenes (see the Figure ). These genes produce regulatory proteins that control the . When the genes mutate, cells with mutations divide rapidly and without limits, potentially resulting in a tumor and cancer.
    ::导致癌症的突变一般发生在两类监管基因中:肿瘤抑制基因和原生致癌基因(见图 ) 。 这些基因产生控制肿瘤的监管蛋白质。 当基因突变时,突变细胞会迅速和无限制地分裂,可能导致肿瘤和癌症。

    Flow chart depicting mutations in genes leading to cancer development through cell proliferation.
    How Cancer Develops. This flow chart shows how a series of mutations in tumor-suppressor genes and proto-oncogenes leads to cancer.

     

    Summary
    ::摘要

    • Regulation of transcription in eukaryotes is generally more complex than in prokaryotes. It involves unique regulatory elements in different cells as well as common regulatory elements such as the TATA box.
      ::eukaryotes的转录规范一般比prokaryotes更为复杂,涉及不同单元的独特监管要素以及共同监管要素,如TATA框。
    • Regulation is especially important during development. It may involve regulatory genes such as homeobox genes that switch other regulatory genes on or off.
      ::监管在开发过程中尤其重要,可能涉及调控基因,如调换其他调控基因开关或开关的波音箱基因。
    • Mutations in regulatory genes that normally control the cell cycle cause cancer.
      ::通常控制细胞循环的管制基因的变异导致癌症。

    Review
    ::回顾

    1. Identify the TATA box and its function in transcription.
      ::识别TATA框及其在抄录中的功能。
    2. What is a homeobox gene?
      ::什么是原声盒基因?
    3. Why is gene regulation especially important during development?
      ::为什么基因监管在发展过程中特别重要?
    4. What are tumor-suppressor genes and proto-oncogenes?
      ::什么是肿瘤抑制基因和原致癌基因?
    5. Sketch how an insect with a mutated hox gene might look. Explain your sketch. 
      ::用变异的荷克斯基因的昆虫看起来有多像 解释一下你的草图