Researchers are using the CRISPR-Cas9 system to genetically engineer organisms in order to study gene function and to attempt to help patients with genetic diseases. In 2016, a research team used the CRISPR-Cas9 system to genetically alter pig zygotes so that they would have muscular dystrophy, a type of genetic disease that results in muscle wasting and loss of muscle mass. This disease often results from a lack of the protein dystrophin in skeletal muscle tissue. Researchers sometimes develop animal models of diseases so that they can develop therapies to treat the human version of the disease.
The researchers compared the molecular biology and physiology of two types of pigs: healthy, normal pigs (WT) and those that were modified when they were zygotes with the CRISPR-Cas9 system (CRISPR). The data below show the dystrophin levels in various tissues from both types of pigs.
Source: Adapted from Yu, H. H., Zhao, H., Qing, Y. B., Pan, W. R., Jia, B. Y., Zhao, H. Y., Huang, X. X., et al. (2016). Porcine zygote injection with Cas9/sgRNA results in DMD-modified pig with muscle dystrophy. International Journal of Molecular Sciences,17(10): 1668. MDPI AG. Retrieved from http://dx.doi.org/10.3390/ijms17101668.
-In this study, what would have been true of the guide RNA that was used in the CRISPR-Cas9 system?
A) The guide RNA was complementary in sequence to a region of the dystrophin gene.
B) The guide RNA was injected into skeletal muscle cells, heart cells, and intestinal cells.
C) The guide RNA helped target the Cas9 enzyme to the dystrophin protein.

Question

Researchers are using the CRISPR-Cas9 system to genetically engineer organisms in order to study gene function and to attempt to help patients with genetic diseases. In 2016, a research team used the CRISPR-Cas9 system to genetically alter pig zygotes so that they would have muscular dystrophy, a type of genetic disease that results in muscle wasting and loss of muscle mass. This disease often results from a lack of the protein dystrophin in skeletal muscle tissue. Researchers sometimes develop animal models of diseases so that they can develop therapies to treat the human version of the disease.
The researchers compared the molecular biology and physiology of two types of pigs: healthy, normal pigs (WT) and those that were modified when they were zygotes with the CRISPR-Cas9 system (CRISPR). The data below show the dystrophin levels in various tissues from both types of pigs.
  Source: Adapted from Yu, H. H., Zhao, H., Qing, Y. B., Pan, W. R., Jia, B. Y., Zhao, H. Y., Huang, X. X., et al. (2016). Porcine zygote injection with Cas9/sgRNA results in DMD-modified pig with muscle dystrophy. International Journal of Molecular Sciences,17(10): 1668. MDPI AG. Retrieved from http://dx.doi.org/10.3390/ijms17101668.
-In this study, what would have been true of the guide RNA that was used in the CRISPR-Cas9 system?
A) The guide RNA was complementary in sequence to a region of the dystrophin gene. 
B) The guide RNA was injected into skeletal muscle cells, heart cells, and intestinal cells. 
C) The guide RNA helped target the Cas9 enzyme to the dystrophin protein.

Quizplus · Accepted Answer

The researchers used the CRISPR-Cas9 system to genetically alter pig zygotes so that they would have muscular dystrophy, which often results from a lack of the protein dystrophin in skeletal muscle tissue. Therefore, it can be assumed that the guide RNA used in the CRISPR-Cas9 system was complementary in sequence to a region of the dystrophin gene.

Researchers Are Using the CRISPR-Cas9 System to Genetically Engineer Organisms