BIOLOGY 1A03 Lecture Notes - Gene Duplication, Alec Jeffreys, Meiosis

• School: McMaster University
• Department: Biology
• Course: BIOLOGY 1A03
• Professor: Lovaye Kajiura

Document Summary

In addition to containing repeated sequences from transposable elements, eukaryotic genomes have several thousand loci called simple tandem repeats (strs) These are small sequences repeated one after another down the length of a chromosome. Ac, giving the sequence acacacac : microsatellite sequences are thought to originate when dna polymerase skips or mistakenly adds extra bases during replication. Soon after these sequences were first characterized, alec jeffreys and co-workers established that microsatellite and minisatellite loci are hypervariable meaning that they vary among individuals much more than any other type of sequence does. One hypothesis for why both have so many different alleles: these highly repetitive stretches often align incorrectly when homologous chromosomes synapse and cross over during prophase of meiosis i. Dna fingerprinting refers to any technique for identifying individuals based on the unique features of their genomes. Because microsatellite and minisatellite loci vary so much among individuals, they are now the loci of choice for dna fingerprinting.