Chapter 2 From genes to genomes 莘大
Chapter 2 From Genes to Genomes
2.1Introduction We can think about mapping genes and genomes at several levels of resolution A genetic (or linkage) map identifies the distance between mutations in terms of recombination frequencies A linkage map can also be constructed by measuring recombination between sites in genomIc NA A restriction map is constructed by cleaving DNA into fragments with restriction enzymes and measuring the distances between the sites of cleavage The ultimate map is to determine the sequence of the DNA From the sequence, we can identity genes and the distances between them 消当
2.1 Introduction We can think about mapping genes and genomes at several levels of resolution: A genetic (or linkage) map identifies the distance between mutations in terms of recombination frequencies. A linkage map can also be constructed by measuring recombination between sites in genomic DNA. A restriction map is constructed by cleaving DNA into fragments with restriction enzymes and measuring the distances between the sites of cleavage. The ultimate map is to determine the sequence of the DNA. From the sequence, we can identify genes and the distances between them
2.1 Introduction 2.2 The nature of interrupted genes 2.3 Organization of interrupted genes may be conserved 2. 4 EXon sequences are conserved but introns vary 2.5 Genes can be isolated by the conservation of exons 2.6 Genes show a wide distribution of sizes 2. 7 Some DNA sequences code for more than one protein 2. 8 How did interrupted genes evolve? 2. 9 The scope of the paradigm 消当
2.1 Introduction 2.2 The nature of interrupted genes 2.3 Organization of interrupted genes may be conserved 2.4 Exon sequences are conserved but introns vary 2.5 Genes can be isolated by the conservation of exons 2.6 Genes show a wide distribution of sizes 2.7 Some DNA sequences code for more than one protein 2.8 How did interrupted genes evolve? 2.9 The scope of the paradigm
2.2 Genes can be mapped by restriction cleavage bp is an abbreviation for base pairs, distance along DNA IS measured in bi Restriction enzymes recognize specific short sequences of DNA and cleave the duplex (sometimes at target site, sometimes elsewhere depending on type) Restriction map is a linear array of sites on DNA cleaved by various restriction enzymes 消当
bp is an abbreviation for base pairs; distance along DNA is measured in bp. Restriction enzymes recognize specific short sequences of DNA and cleave the duplex (sometimes at target site, sometimes elsewhere, depending on type). Restriction map is a linear array of sites on DNA cleaved by various restriction enzymes. 2.2 Genes can be mapped by restriction cleavage
2.2 Genes can beCleave with Cleave with enzym enzyme B mapped by restriction cleavage Electrophorese Electro phorese Electrophorese A-fragments control dNa B-fragments FIgure 21 DNA can be 2500 2500 2100 cleaved by restriction 1400 enzymes into fragments 1000 1=18 500 50 that can be separated by gel electrophoresis Fragment sizes Control consists Fragment sizes 消当 compared of frag ments compared with control of known size with contr ol
Figure 2.1 DNA can be cleaved by restriction enzymes into fragments that can be separated by gel electrophoresis. 2.2 Genes can be mapped by restriction cleavage