Exam 21: Genetics of Complex Traits

Correct Answer:

Verified

Genetic interaction maps from synthetic genetic arrays define associations as pairs of genes that show synthetic interactions;thus any two genes whose loss of function mutants are lethal or sick in combination but not individually,are connected by a line on the diagram.In protein interaction maps,nodes representing proteins are connected if they are found to physically interact either in yeast two-hybrid screens or in affinity capture experiments.Thus,the protein interaction maps indicate physical interactions between proteins,which like means that the proteins are part of the same pathway or complex.This contrasts with the genetic interaction maps,in which interacting proteins are often considered to be in parallel pathways and do not necessarily interact physically.

Correct Answer:

Verified

Budding yeast can easily be switched between either a diploid or haploid growth phase.Therefore mutations that would be lethal as haploids can be rescued (complemented)as diploids,and conversely,mutant genotypes can be assembled in the diploid phase and tested for lethality or other phenotypes in the haploid phase.Furthermore,the highly efficient homologous recombination system in yeast is an effective means of targeted gene replacement or gene deletion,even at a genomic scale.Indeed,collections of yeast strains each bearing a mutation in a gene of interest are commercially available.Yeast also has other advantages such as fast growth and compact size,which make it well-suited to automated high density screening.The major drawback of yeast is that it is unicellular.Thus,many genes and pathways specific to multicellularity cannot be studied in yeast.