Problem Set # 3 - Answers

PHR 647

 


1) Calculate the percentage of phenotypically mutant offspring generated by the mating cross of 2 heterozygotes for mutation, m - M/m x M/m: 
a) if m is an autosomal recessive mutation?

The geneotype of these mutant is __m/m__.
The phenotype of the parent is __normal__.

b) m is an autosomal dominant mutation?

The genotype of these mutant is __M/m or m/m__.
The phenotype of the parents is __affected__.

2) Indicate what type of nucleic acid molecules and method is used to screen for:
a) positive transgenic founders?
PCR, Southern hybridization, dot blot
DNA isolated from any cells in the mouse


b) positive transgenic expressers?
RT-PCR, Northern hybridization, RPA, dot blot
RNA isolated from tissues that normally express the promoter
.

3) A transgenic founder is bred to establish a transgenic mouse line. If none of the founders offspring carry the transgene, the founder is__ mosaic__. If the founder
carries the transgene but does not express the transgene, will his offspring express the transgene? No


4) Mice generated by ES cell knock-out mutations are called __chimeras__. The knock-out mutation is only passed on to offspring if the mutation is in __germ__ cells.
The offspring will be __mozaic__ for the mutation with a genotype of __heterozygotes__ . Coat color is used to distinguish the F1 generations with __mixed or agouti__
coats and the F2 generation with __solid__coats.