1 / 8

molecular revolution

molecular revolution. The first molecular markers: allozymes. Allozymes Enzymes that diifer in amino acid sequence yet catalyze the same reaction -visible as a band on a gel -may exist at several gene loci Isozyme: allelic form of allozyme (same locus). +. enzyme. Visible

magdalena-fajardo
Download Presentation

molecular revolution

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. molecular revolution

  2. The first molecular markers: allozymes Allozymes Enzymes that diifer in amino acid sequence yet catalyze the same reaction -visible as a band on a gel -may exist at several gene loci Isozyme: allelic form of allozyme (same locus)

  3. + enzyme Visible Product - Substrate Allozyme assay • Gel electrophoresis • Current • Charge • Gel matrix • Starch or other medium • Protein variation • Charge • depends on pH • Size • different length of AA chain • Shape • Tertiary and quaternary structure • Visualization • Uses enzyme reactions • Specific substrate for each allozyme

  4. Lab assay of isozymes

  5. Isozyme gels

  6. Quaternary Structure and Allozymes Genotype AA AB BB • Enzymes can consist of several subunits • Monomer • One subunit • Dimer • Two subunits • Tetramer • Four subunits

  7. Disparate viewpoints about true levels of genetic variation • classical + + + m + ... + + + ============== + + + + + ... + + + • balanced A1 B2 C3... X1 Y1 Z3 ================= A4 B2 C7... X1 Y1 Z2 Allozymes revealed unexpectedly high levels of genetic variation

  8. Allozyme questions • What type of DNA variation can you detect with isozymes? • What is the ascertainment bias? • Why were they wildly popular in the 1970’s and 1980’s, then disappeared by 2000?

More Related