Biology 1002B Lecture Notes - Lecture 21: Alternative Splicing, Gene Duplication, Non-Homologous End Joining
3 Apr 2016
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Lecture 21 outcomes: strategies for annotation of genome sequence (finding orfs) Look for mrna and see if orf produces a message. Genes are lined up one after another organized into operons. Most of the double stranded sequence is being used. Percent of coding dna is higher in prokaryote. Introns are the majority of the sequence that is transcribed have multiples of them. Have regions between genes that code for nothing. Don"t use much of genome for protein coding genes: mechanism for the origin of (spliceosomal) introns in eukaryotic genes. Think introns came from endosymbiosis: bacteria that were taken up and eventually became mitochondria, had in their genomes a kind of mobile element that was transferred to the nucleus by lateral gene transfer then they copied themselves. Introns in bacteria are not like the introns we have, they move around and splice themselves. Some of our introns do this: prokaryotic introns splice themselves have secondary structure.
