Genomes and their evolution Chapter 21

You must know How prokaryotic genomes compare to eukaryotic genomes Application of bioinformatics to medicine, evolution, and health The activity and role of transposable elements and retrotransposons in generating genetic diversity How evo-devo relates to our understanding of evolution of genomes The role of homeotic genes and homeoboxes in developmental patterns and sequences

Bioinformatics The use of computers, software, and mathematical models to process and integrate data from genome sequencing Proteomics = same thing for proteins

Genome variety There does not seem to be a correlation between the number of genes and complexity of the organism About 3700 genomes have been sequenced (mostly prokaryotes)

Noncoding dna Only about 1.5% of human DNA codes for proteins Repetitive sequences – form telomeres and many other noncoding regions

Transposable elements – repetitive DNA that is capable of moving from one location in a genome to another Requires enzyme called transposase Can interrupt normal gene function – can be inserted inside a gene or in a regulatory region https://www.youtube.com/watch?v=91vR-FKBMT4

Collections of 2 or more genes Multigene families Collections of 2 or more genes Example: human alpha and beta globin – on different chromosomes and have different versions that function at different times in life – fetal forms of hemoglobin have a higher affinity for oxygen than adult forms

Causes of Genome evolution Duplication events – creation of more than one version of a gene (like beta-globin) Mutations Transpositions

Sequence comparisons The more similar sequences are, the more recently two species had a common ancestor Can use this info to determine evolutionary relationships

Evo-devo – evolution of development – compares developmental processes to determine evolutionary changes

Homeotic genes – control placement and spatial organization of body parts Homeobox – 180-nucleotide sequence widely conserved in homeotic genes (found in many diverse species in the same form) – supports the relatedness and common evolution of all life forms