武汉大学生命科学学院：《分子生物学》（英文版）Part II：Maintenance of the Genome CHAPTER 7 Chromosomes, chromatin, and the nucleosome

Molecular biology of the Gene 5/E - Watson et al. ( 2004) Part l: chemistry and genetics Part l: Maintenance of the Genome Part l: Expression of the Genome Part IV: Regulation Part v: Methods 3/1105 刻博来字 Wuhan Universit

Molecular Biology of the Gene, 5/E --- Watson et al. (2004) Part I: Chemistry and Genetics Part II: Maintenance of the Genome Part III: Expression of the Genome Part IV: Regulation Part V: Methods 3/11/05

Part ll: Maintenance of the genome Dedicated to the structure of DNa and the processes that propagate, maintain and alter it from one cell generation to the next @博共字 Wuhan University

Part II: Maintenance of the Genome Dedicated to the structure of DNA and the processes that propagate, maintain and alter it from one cell generation to the next

Ch 6: The structures of dna and rna ch 7: chromosomes, chromatins and the nucleosome Ch 8: The replication of DNA Ch 9: The mutability and repair of DNA Ch 10: Homologous recombination at the molecular level Ch 11: Site-specific recombination and transposition of dNA 3/1105

Ch 6: The structures of DNA and RNA Ch 7: Chromosomes, chromatins and the nucleosome Ch 8: The replication of DNA Ch 9: The mutability and repair of DNA Ch 10: Homologous recombination at the molecular level Ch 11: Site-specific recombination and transposition of DNA 3/11/05

CHAPTER A Chromosomes chromatin, and the nucleosome .4o kb DNA Looos secured at base b unknown mechanism nop consists of auplex DNA condensed by basic proteins in unknown 劣溪字 Wuhan University

CHAPTER 7: Chromosomes, chromatin, and the nucleosome

Consider the structure of dna within the cell, and the biological relevance of the structure DNA is associated with proteins in cells, both prokaryotes and eukaryotes even viruses Each dna and its associated proteins is called a chromosome

Consider the structure of DNA within the cell, and the biological relevance of the structure. ◼DNA is associated with proteins in cells, both prokaryotes and eukaryotes, even viruses ◼Each DNA and its associated proteins is called a chromosome

vocabulary Nucleus:胞核; Nucleolus:核仁 Nucleoid:类核 Mitosis:o丝分裂;Meos:减数分裂 interphase:分裂间期 Histone:组蛋白; Nucleosome:核小体 Chromotasome:染色小体 Chromosome:染色体; Chromatin:、染色质;eu-; hetero Centromere(中心粒) Telomere(端粒) Repetitive dna(重复DNA) Tandem gene cluster(串联基因簇)

Nucleus: 细胞核; Nucleolus: 核仁 Nucleoid: 类核 Mitosis: 有丝分裂；Meiosis：减数分裂 interphase：分裂间期 Histone: 组蛋白；Nucleosome: 核小体 Chromotasome: 染色小体 Chromosome: 染色体； Chromatin: 染色质；eu-; hetero￾Centromere (中心粒） Telomere（端粒） Repetitive DNA (重复DNA) Tandem gene cluster（串联基因 簇） Vocabulary

The importance of packing of dNa into chromosomes 1> Chromosome is a compact form of the dNa that readily fits inside the cell? >To protect DNA from damage >DNA in a chromosome can be transmitted efficiently to both daughter cells during cell division Chromosome confers an overall organization to each molecule of DNA, which facilitates gene expression as welll as recombination

The importance of packing of DNA into chromosomes ➢Chromosome is a compact form of the DNA that readily fits inside the cell [?] ➢To protect DNA from damage ➢DNA in a chromosome can be transmitted efficiently to both daughter cells during cell division ➢Chromosome confers an overall organization to each molecule of DNA, which facilitates gene expression as well as recombination

Proteins in chromosome(1) Half of the molecular mass of eukaryotic chromosome is protein >In eukaryotic cells a given region of DNA with its associated proteins is called chromatin The majority of the associated proteins are small, basic proteins called histones > Other proteins associated with the chromosome are referred to as non-histone proteins, including numerous dNA binding proteins that regulate the transcription, replication, repair and recombination of DNA

Half of the molecular mass of eukaryotic chromosome is protein ➢In eukaryotic cells a given region of DNA with its associated proteins is called chromatin ➢The majority of the associated proteins are small, basic proteins called histones. ➢Other proteins associated with the chromosome are referred to as non-histone proteins, including numerous DNA binding proteins that regulate the transcription, replication, repair and recombination of DNA. Proteins in chromosome (1)

Proteins in chromosome(2) >Nucleosomes: regular association of DNA With histones to form a structure effectively compacting DNA

➢Nucleosomes: regular association of DNA with histones to form a structure effectively compacting DNA Proteins in chromosome (2)

CHAPTER 7: Chromosomes, chromatin, and the nucleosome 1. What is the cost (challenge)of compaction of DNA into chromosome? [De-compaction is required when DNA needs to be accessible by other proteins for cellular activities such as replication, transcription, 2. How the challenge could be resolved? TThe interaction between DNA and histones is dynamic, chromosome remodeling, chromosome modification 3. What are the advantage of the challenge? [Add a large layer of gene regulation

1. What is the cost (challenge) of compaction of DNA into chromosome? [De-compaction is required when DNA needs to be accessible by other proteins for cellular activities such as replication, transcription. ] 2. How the challenge could be resolved? [The interaction between DNA and histones is dynamic, chromosome remodeling, chromosome modification] 3. What are the advantage of the challenge? [Add a large layer of gene regulation] CHAPTER 7: Chromosomes, chromatin, and the nucleosome