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

Although DNA replication, repair, homologous recombination occur with high fidelity to ensure the genome identity between generations, there are genetic processes that rearrange DNA sequences and thus lead to a more dynamic genome structure Two classes of genetic recombination for DNA rearrangement: • Conservative site-specific recombination (CSSR): recombination between two defined sequence elements • Transpositional recombination (Transposition): recombination between specific sequences and nonspecific DNA sites

1. Please define the term “mutation”, and list the major types of DNA mutations and their corresponding phenotypic effects. (20 points) 2. Please define the term “DNA lesion”. Please list the three types of DNA lesions and the chemical or physical mutagens cause these lesions. (20 points)

Q1. Prokaryotic cell E. coli consists of a single closed-circular DNA molecule of 4.6 x 106 bp long. This DNA molecule would be 1.6 mm if the double helix is relaxed. Please describe what strategies does E. coli use to pack such a long molecules into its nucleoid less than a micrometer (mm) in diameter. (20 points)

（1）不离开自己的座位。（2）合上书和笔记。（3） 个人只能看和写自己的试卷（4）老师宣布停的时候， 所有学生必须放下自己的笔，眼睛 向前看。（5）老师 宣布收试卷时，试卷必须快速由每排的最左边传向右边， 每排最右边的同学负责把试卷交给当堂助教

2.不许离开自己的座位，不许看他人试卷，不许讲话 (有问题举手） 3.老师宣布收试卷时，试卷必须快速由每排的最左边传向右边，每排最右边的同学负责把试 卷交给当堂助教。迟交者不收！

（1）桌上只许有笔，答题纸和英文课本。（2）不许 离开自己的座位。（3）不许偷看，不许讲话 (有问题 举手）（4）老师宣布停的时候，必须放下自己的笔。 （5）老师宣布收试卷时，试卷必须快速由每排的最左 边传向右边，每排最右边的同学负责把试卷交给当堂 助教

The principle of the polymerase chain reaction (PCR) was first reported in 1971 (Kleppe et al., 1971), but it was only after the dis￾covery of the thermostable Taq DNA polymerase (Saiki et al., 1988; Lawyer et al., 1989) that this technology became easy to use

What Do You Know About Your Target? The sensitivity needs of your system are primarily determined by the abundance of your target, which can be approximated according to its origin. Plasmids, cosmids, phagemids as colony lifts or dot blots, and PCR products are usually intermediate to high-abundance targets. Genomic DNA is considered an intermediate to low-abundance target. Most prokaryotic genes are present as single copies, while genes from higher eukaryotes

What Are the Symptoms of Acrylamide Poisoning? The initial symptoms of acrylamide poisoning on the skin are peeling of the skin at the point of contact, followed by tingling and numbness in the exposed area. If exposure by any means (touch, ingestion, inhalation) continues, muscular weakness, difficulty maintaining balance