BIOL1020 Lecture Notes - Lecture 24: Natural Transformation, Noncoding Dna, Genome Size
Document Summary
Lecture 24: how genomics has sparked an evolution revolution. Phenotypes results from a complex mixture of inheritance units (genes) interacting with each other, with the external environment and, in eukaryotes, with non-genic parts of the genome ("messy" phenotypes) Prokaryote genomes are gene dense and always small, but in eukaryotes things get messier. Prokaryotes swap genes at high frequency to generate diversity and respond to changes in their environment. Critical mechanism is lateral gene transfer (lgt) among different bacterial types. The value of lgt is exemplified by the e. coli pan genome: coli genome encodes ~ 4000 genes - 2000 core genes in all individuals, 2000 accessary genes. There are ~20000 accessory genes in total across the species. No correlation between genome size and apparent organismal complexity - the c-value paradox. The c-value paradox exists because only a tiny percent of a multicellular eukaryote genome comprises protein-coding genes, the rest a highly variables amount of non-coding dna.
