Biology Reference
In-Depth Information
CHAPTER 2
Transcription, Translation, and
Regulation of Eukaryotic DNA
Chapter Outline
2.1 Overview 37
2.2 Introduction 38
2.3 RNA Synthesis is Gene Transcription 41
2.4 Transcription Involves Binding, Initiation, Elongation, and Termination
43
2.5 RNA Transcripts of Protein-Coding Genes 45
2.6 RNA of Protein-Coding Genes Must Be Modified and Processed in Eukaryotes
45
2.7 Splicing Out the Introns 47
2.8 Translation Involves Protein Synthesis 48
2.9 RNA Surveillance: Damage Control 52
2.10 Import and Export from the Nucleus 53
2.11 Transport of Proteins within the Cytoplasm
54
2.12 mRNA Stability 55
2.13 Chaperones and the Proteosome 56
2.14 RNA Silencing or Interference and miRNAs
56
2.15 Gene Regulation in Eukaryotes
58
2.16 Insulators and Boundaries 63
2.17 Chromosome or Gene Imprinting in Insects
64
2.18 Eukaryotic Genomes and Evolution
66
References Cited
67
2.1 Overview
Genetic information in an organism is expressed in three classes of genes: 1) struc-
tural (protein-coding) genes that are transcribed into messenger RNA (mRNA) and
translated into polypeptides; 2) genes that code for ribosomal RNA (rRNA), transfer
RNA (tRNA), or other classes of small RNAs, in which the transcription product is used
directly; and 3) regulatory sites that are not transcribed but that serve as recognition
sequences for proteins involved in DNA replication, transcription, and repair.
Protein-coding genes in eukaryotic organisms are transcribed from DNA
into pre-messenger RNAs (pre-mRNAs) that then are processed into mRNA.
