You isolate mouse stem cells from a blastocyst that was produced the old-fashioned way by two mice with black fur. In cell culture, you introduce a transgene into these cells by transfection. You then inject the stem cells into a blastocyst removed from a foster mom with white fur. The injected blastocyst is then placed back into a foster mom. When the baby mouse is born what will it look like? Which cells contain the transgene?
A) Black. All cells have the transgene.
B) White with black patches. The cells that are capable of producing white fur have the transgene.
C) White with black patches. The cells that are capable of producing black fur have the transgene.
D) White. There is no way to identify which cells have the transgene.
stem cells are injected to blastocyst of white mice, so chimera mice will be produced, with black and white patches, the black stem cells have the transgene so black cells will have transgene so the answer is
C) White with black patches. The cells that are capable of producing black fur have the transgene.
You isolate mouse stem cells from a blastocyst that was produced the old-fashioned way by two...
You have isolated mouse C57BL6 trophoblast stem cells and have propagated them on MEFs with heparin. To test for the success of your culture protocol, you are injecting the cells into a mouse C57BL6 blastocyst. Once the pups are born, you notice that your experiment failed. Why? What was the expected outcome of this injection?
2. A dominant allele H reduces the number of body bristles that Drosophila flies have, giving rise to a “hairless” phenotype. In the homozygous condition, H is lethal. An independently assorting dominant allele S has no effect on bristle number except in the presence of H, in which case a single dose of S suppresses the hairless phenotype, thus restoring the "hairy" phenotype. However, S also is lethal in the homozygous (S/S) condition. What ratio of hairy to hairless flies...