Chapter 14 Recombination and repair 莘大
Chapter 14 Recombination and repair
14.1 Introduction 14.2 Breakage and reunion involves heteroduplex dnA 14.3 Double-strand breaks initiate recombination 14.4 Double-strand breaks initiate snapsis 14.5 Bacterial recombination involves single-strand assimilation 14.6 Gene conversion accounts for interallelic recombination 14.7 Topological manipulation of dna 4.8 Specialized recombination involves breakage and reunion at specific sites 14.9 Repair systems correct damage to DNA 14.10 Excision repair systems in E coli 14.11 Controlling the direction of mismatch repair 14.12 Retrieval systems in E coli 14.13 Reca triggers the sos system 14.14 Eukaryotic repair systems 消当
14.1 Introduction 14.2 Breakage and reunion involves heteroduplex DNA 14.3 Double-strand breaks initiate recombination 14.4 Double-strand breaks initiate snapsis 14.5 Bacterial recombination involves single-strand assimilation 14.6 Gene conversion accounts for interallelic recombination 14.7 Topological manipulation of DNA 14.8 Specialized recombination involves breakage and reunion at specific sites 14.9 Repair systems correct damage to DNA 14.10 Excision repair systems in E. coli 14.11 Controlling the direction of mismatch repair 14.12 Retrieval systems in E. coli 14.13 RecA triggers the SOS system 14.14 Eukaryotic repair systems
14.1Introduction Bivalent is the structure containing all four chromatids(two representing each homologue )at the start of meiosis Breakage and reunion describes the mode of genetic recombination, in which two dna duplex molecules are broken at corresponding points and then rejoined crosswise(involving formation of a length of heteroduplex dNa around the site of joining) Site-specific recombination occurs between two specific(not necessarily homologous)sequences, as in phage integration/excision or resolutionof cointegrate structures during transposition Synapsis describes the association of the two pairs of sister chromatids representing homologous chromosomes that occurs at the start of meiosis resulting structure is called a bivalent Synaptonemal complex describes the morphological structure of synapsed chromosomes Transposition refers to the movement of a transposon to a new site in the genome 消当
Bivalent is the structure containing all four chromatids (two representing each homologue) at the start of meiosis. Breakage and reunion describes the mode of genetic recombination, in which two DNA duplex molecules are broken at corresponding points and then rejoined crosswise (involving formation of a length of heteroduplex DNA around the site of joining). Site-specific recombination occurs between two specific (not necessarily homologous) sequences, as in phage integration/excision or resolution of cointegrate structures during transposition. Synapsis describes the association of the two pairs of sister chromatids representing homologous chromosomes that occurs at the start of meiosis; resulting structure is called a bivalent. Synaptonemal complex describes the morphological structure of synapsed chromosomes. Transposition refers to the movement of a transposon to a new site in the genome. 14.1 Introduction
P rogress through m eiosis 14.1 M ole cular interactions M Each chrom osome has chrom somes Introduction AN replicated, and consists of become visible, often 2 sister chromatid s attached to nuclear envelope A MVV Figure 14.1 Recombination Zygotene A Initiation Chromosom es begin occurs during the first meiotic reglon or regions AAAAA prophase. The stages of N prophase are defined by the P achytene appearance of the Synaptonem al complex extends chromosomes each of which along entire length of bosom es consists of two replicas(sister ) /VA Strand exchange NUM VA Single strands exchange chromatids), although the Diplotene duplicated state becomes Chromosomes A人A in of exchange separate but are held visible only at the end. The together by hastata N molecular interactions of any individual crossing-over event Diakinesis involve two of the four duplex Chromosom es A Resolution condense, detach from envelope DNAS chiasmata remain. a 八 4 chromatids becom 请莘大
Figure 14.1 Recombination occurs during the first meiotic prophase. The stages of prophase are defined by the appearance of the chromosomes, each of which consists of two replicas (sister chromatids), although the duplicated state becomes visible only at the end. The molecular interactions of any individual crossing-over event involve two of the four duplex DNAs. 14.1 Introduction
A antigen gaNAdo. 1 14.1 alp1-R Fuon 1 Introduction A transfer A gene 4 amino a anges Fuca B transferas 小 Figure 1.22 The ABO blood group locus codes for a B antigen Fuoo1 galactosyltransferase whose Deletion specificity determines the A blood group gene Phenotype Genotype Activity 00 No AO or AA N-Ac- gal transferase 消当 BO or BB Gal transferase N-Ac- gal& gal-transferast
Figure 1.22 The ABO blood group locus codes for a galactosyltransferase whose specificity determines the blood group. 14.1 Introduction