Mutation

mutation - change in genome that's not genetic recombination

either at the chromosome level or nucleotide level:
spotaneous/induced
mutagens


nucleotide level mutation:
point mutation- change 1 base pair
e.g., base-pair mutation - 1 bair pair swap (e.g., at to gc=transition, at to ta =transversion)
missense mutation occurs in aa coding region e.g., sickle cell anemia = 1aa change in hemoglobin
neutral = no change in aa function
silent = no change in aa (could change a promoter thought)
end of base-pair

point mutation type 2 = insertition/deletion of base-pair
frameshift mutation or nonframeshift
frameshift = deletions/insertions in non-multiples of 3 >usually bad prot
nonframeshift = deletion/insertions in multiples of 3 >partial/complete functional prot

nonsense mutation results either point or insertion/deletion > new stop codon



chromosomal level
deletion/duplication/translocation/inversion
deletion = break off or lost during homologous recombination/crosssing over
duplication = dna fragment break off and incorporates into homologous chromosome
aneuploidy = delete/dup of entire chromosome (e.g., down = 3 copies chrom21)
polyploidy = delete/dup of sets of chromosomes

translocation = dna from one chromosome inserted into another chromosome
inversion = orientation change on one chromosome
these are cause by transposition (eu and prokaryotes)-transposon excise from chrom & reinsert
transposon - can 1+ genes or control element
can copy before moving
allow cell to change genetics without meiosis

mutation
forward or back (change move or revert to original state)
wild type - original
e.g., his + (wt) and his- (forward) to revert (back) and to further change (forward)