exam 4

• RNAi • homologous recombination to create mutations • P-elements/transposons (insertional mutagenesis) • CRISPR-Cas9

• transgenes to over-express or mis-express genes (forced gene expression)

DNA sequencing - mutant allele - phenotype

loss of function method, creates mutations, changes genetic sequence by replacing target gene with heterologous or exogenous DNA

common way to mutate genes through the use of transposons (transposons)

used to introduce mutations to study the effects on the phenotype

causing mutations to identify the genes responsible for specific phenotypes

technology used for DNA and RNA sequencing and mutation detection, can determine nucleotide sequence. forward genetics

(P1) M1M1 x (P2) M2M2 = (F1) M1M2

inhibit

promote

different genes

the gene carries that mutation

phenotype - mutant allele - DNA sequencing

• X-ray (physical) • p-elements (insertional) • EMS (chemical) • RNAi

• tumor suppressors • proto-oncogenes • caretaker

• inhibit cell survival/proliferation • loss of function • keywords: apoptosis, DNA/chromosomal damage • recessive

• promote cell survival/proliferation • gain of function • keywords: signaling, transcription factors • dominant

• repair/prevent DNA damage • loss of function • keywords: DNA repair enzymes • recessive

each mutation is a progression towards a cancer cell - 1st mutation inactivates negative cell cycle regulator - 2nd mutation inactivates positive cell cycle regulator - 3rd mutation inactivates genome stability factor, cancer cells develop after the 3rd mutation

• higher rate of proliferation: evades normal controls on cell growth • dedifferentiated: cancer cells behave more like stem cells • structural abnormalities: larger structures than normal cells • poorly organized: abnormally interacts with body/tissue, overgrown normal confines

highly repetitive sequences

introns

transposons