◼ All DNA is recombinant DNA. ◼ Genetic exchange works constantly to blend and rearrange chromosomes, most obviously during meiosis, when homologous chromosomes pair prior to the first nuclear division. ◼ During this pairing, genetic exchange between the chromosomes occurs. This exchange, classically termed crossing over, is one of the results of homologous recombination
TOPIC 1 Principles of Transcriptional Regulation [watch the animation] TOPIC 2 Regulation of Transcription Initiation: Examples from Bacteria (Lac operon, alternative s factors, NtrC,MerR, Gal rep, araBAD operon) TOPIC 3 Examples of Gene Regulation after Transcription Initiation (Trp operon) TOPIC 4 The Case of Phage λ: Layers of Regulation
Similarity of regulation between eukaryotes and prokaryote 1.Principles are the same: • signals (信号), • activators and repressors (激活蛋白和阻 遏蛋白) • recruitment and allostery, cooperative binding (招募，异构和协同结合) 2. The gene expression steps subjected to regulation are similar, and the initiation of transcription is the most pervasively regulated step
◼ What are the main challenges of translation and how do organisms overcome them? ◼ What is the organization of nucleotide sequence information in mRNA? ◼ What is the structure of tRNAs, and how do aminoacyl tRNA synthetases recognize and attach the correct amino acids to each tRNA? ◼ How does the ribosome orchestrate the translation process?
