《遗传学》课程教学资源（PPT课件，英文版）Is there any similarity between human and model organisms?

Is there any similarity between human and model organisms?

Is there any similarity between human and model organisms?

Human development

Human development

Drosophila embryos

Drosophila embryos

Using functional conservation to clone human genes Yeast with mutation Expose to human CDNA library Permissive growth conditions Human DNA (different human DNA in each cell) Restrictive Growth conditions Dies Dies Dies Only this cell grows Conclusion: Human DNA contains gene that was mutant(disfunctional) in yeast DNA

Using functional conservation to clone human genes

Using mutants to analyze the pathway or functions of genes Mutants have to be generated to analyze the pathway or functions of genes Saturation screening Overexpression Suppressor mutations Synthetic lethals Nonallelic noncomplementation

Using mutants to analyze the pathway or functions of genes • Mutants have to be generated to analyze the pathway or functions of genes • Saturation screening • Overexpression • Suppressor mutations • Synthetic lethals • Nonallelic noncomplementation

Gene 1 mutant No functional Proteins protein Gene f perform same function Functional protein Gene 2 mutant Functional proteIn Saturation No functional screening protein Cells still produce functional may not protein, even with a mutation recover all Wildtype gene Mutated gene g enes No functional Protein plays a role in proteIn early embryonic development Development arrested Protein plays a role wing development No adult, effects on wing development cannot be observed

Saturation screening may not recover all genes

Overexpression (a) Haploid cell Gene produces correct amount of protein to give normal function Promoter mutations overproduce protein, producing a mutant phenotype

Overexpression

Suppressor mutations (b) Haploid cell Protein complex Gene 1 Normal function Gene 2 Mutant gene ene 1 × Missing function Gene 2 Mutant gene Gene 1 Normal function Gene 2 compensating mutation

Suppressor mutations

Synthetic lethals (c) Haploid cell Gene 1 Normal function Gene 2 Redundant genes Mutant gene Genet (Defective protein Normal function Gene 2 Gene 1 (Defective protein) No function mutant phenotype C)(Defective protein is synthetic lethal Gene 2

Synthetic lethals

Nonallelic noncomplementation (d) Diploid cell Homologous 国■ chromosomes Functional proteins Gene 1 Gene 2 Reduced functional protein but still normal phenotype Gene 1 Gene 2 Reduced concentration of subunits leads to further reduction of functional protein, producing mutant Gene 1 Gene 2 phenotype

Nonallelic noncomplementation