BT 210

Lecture Outline- Week 4

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Mapping the Genome: Part I

Restriction Enzymes and Physical Mapping

A. Introduction

1) Most modern biotechnology research revolves around physical

isolation and manipulation of particular genes of interest (review

from first week)

2) Genes are composed of DNA (review material from last week's lecture

3) Problem: there's a huge amount of DNA inside even the simplest organism, so how do you go about finding a particular gene of interest?

4) You need to have a map.

B. Restriction Enzymes cut DNA into reproducible, discrete fragments

1) Origin of restriction enzymes

2) Action of restriction enzymes

- blunt end cutters

- sticky end cutters

- diversity

C. Restriction enzymes can be used to generate a physical map of the genome. Three steps are involved:

1) Generation and resolution of fragments

- restriction digestions

- agarose gel electrophoresis

2) Determination of fragment lengths

- gel calibration

3) Ordering of fragments

- double digest mapping