Objective: I can explain how genes jumping between chromosomes can lead to evolution. Chapter 21; Sections ; Pgs Genomes: Connecting Advanced Genetics & Biotechnology to prove Evolution

Parts of the genome: collection of all DNA/genes in a given organism  Part of DNA that will encode for proteins =  Exons  Part of DNA that is transcribed, but…  …spliced out and recycled = introns  …utilized for regulation = ncRNA (help regulation)  Parts of DNA never transcribed =  Regulatory sequences (operons, enhancers: control elements, etc.)  All of the above = ~42.5% of genome

Types of DNA Most of DNA are sequences that do nothing but repeat or move around, but may have evolutionary significance

Types of ncDNA (non-coding DNA)  Pseudogenes: encoded for protein in past but gained mutations so non-functional  Repetitive DNA: multiple copies of segments of DNA …sounds like…? STR = short tandem repeats  Transposable elements: segments of DNA that move from one location to another “jumping genes”  Discovered by Barbara McClintock (nobel)

Types of Transposable Elements  Transposons: DNA intermediate…means…  Retrotransposons: RNA intermediate; requires  Reverse transcriptase (encoded by transposon)  How does transposition differ from translocation?  Copy & paste vs. Cut & paste

Multigene Families = collection of 2 or more identical/very similar genes based on sequence  If consist of identical DNA (usually tandem)  Usually for purpose of massive production (i.e. rRNA protein ribosomes)  If consist of nonidentical DNA (may be far apart)  Usually function together  can indicate evolutionary history

Genome Changes Lead to Evolution  Duplication of entire chromosome sets  Not just n or 2n, but 3n, 4n, 5n, etc. =  Polyploidy from Nondisjunction (LOTS)  Different chromosomes # = new species (more later)  Also, alteration of chromosome structure  new species…alteration comes from…?

Sources of Genome Evolution = Chromosomal Mutation  Duplications, Inversions, Deletions, Translocations AND Transpositions  If altered chromosomes are functional and provide advantage, then passed on  evolutionary history of genome

Tracking Evolution of Genes  Examine sequences to see how similar  Multigene family with green = pseudogene (similar sequences)

Result of “Jumping Genes” Transposons  Besides random mutations from polymerase  May inactivate gene if move to repressed…  May activate gene if move to promoted…  May reduce function if interrupt…  May enhance function if made more…  BUT only evolve if…

Summary of Biotechnology  WG1QmxnY WG1QmxnY  Consider the global and social impacts