BIOLOGY 1A03 Lecture Notes - Lecture 1: Reverse Transcriptase, Intron, Escherichia Coli

• School: McMaster University
• Department: Biology
• Course: BIOLOGY 1A03
• Professor: Xudong Zhu

Document Summary

Eukaryotic genomes have several thousand loci called simple tandem repeats (strs) Microsatellites: simple sequence repeats, are repeating units of 1 to 5 bases. Minisatellites: variable number of terminal repeats (vntrs), are repeating units of 6 to 500 bases. Repeated sequences are hypervariable and vary among individuals much more than any other type of sequence. Thought to originate when dna pol skips or mistakenly adds extra bases during replication. One hypothesis for why microsatellites and minisatellites have so many diff alleles: highly repetitive stretches may misalign when chromosomes synapse during meiosis. Instead of lining up in exactly the same location, the two chromosomes pair up in a way that matches up bases in diff repeated segments= unequal crossing over. Chromosomes produced by unequal crossover contain diff number of repeats. If micro/mini-satellite locus has unique number of repeats= unique allele. How unique numbers of minisatellite repeats are generated! Using pcr to amplify minisatellite and microsatellite loci!