MGY277H1 Lecture Notes - Lecture 6: Whole Genome Sequencing, Phylogenetics, Serology
23 Oct 2018
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Document Summary
Prokaryotes classification systems: current classification system is a three-domain system that was developed by comparing ribosomal rna nucleotide sequences, three-domain system is based on evolutionary relatedness. Replaces five-kingdom system which is based on obvious morphological differences but does not reflect recent genetic insights of ribosomal rna data indicating plants, animals more closely related than archaea, Informal groupings also used: phylogenetic tree shows evolutionary relatedness, horizontal (lateral) gene transfer complicates dna comparisons. What are strains: sub-species and strains are levels of categorization underneath species. Strain names are very arbitrary usually given by an inventory system or the first person to work with that isolate. Methods of prokaryotic classification to determine species relatedness: there are 5 methods, phenotypic methods: relied on predicting relatedness based on phenotypic properties (gram-stain, size, morphology, biochemical tests, aerobic/anaerobic, etc, not used as much as dna sequencing. Strategies to identify prokaryotes identifying microbes often an important goal: food manufacturer important to identify food contaminant.
