<h2>CRISPR/Cas9</h2>
Explanation:
CRISPR can be used to reintroduce dystrophin back into the KO mouse
- CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats and is used to for gene editing
- CRISPR/Cas-mediated genome editing has been shown to permanently correct DMD mutations and restore dystrophin function in mouse models
- Germline editing by injecting zygotes with CRISPR/Cas9 editing component was first done in mdx mice by correcting the mutated exon 23
- Postnatal editing of mdx mice was then achieved using recombinant adeno-associated virus to deliver CRISPR/Cas9 genome editing components and correct the dystrophin gene by skipping or deleting the mutated exon 23 in vivo
- Germline and postnatal CRISPR/Cas9 editing approaches both successfully restored dystrophin function in the mice and same technique can be used for KO mouse model
The hormone described above is the hormone Melatonin.
Melatonin is a hormone secreted by the pineal gland in the brain, which helps regulate other hormones and maintains the body's circadian rhythm. This rhythm is an internal 24 hour clock that plays a critical role when we fall asleep and when awake. When it is dark the body releases more melatonin.
Complete question:
In a separate study, 68 rock pocket mice were collected from four different, widely separated areas of dark lava rock. One collecting site was in Sonora, Mexico. The other three were in Chihuahua, Mexico. Dr. Nachman and colleagues observed no significant differences in the color of the rocks in the four locations sampled. However, the dark-colored mice from the three Chihuahua locations were slightly darker than the dark-colored mice from the Sonora population. The entire Mc1r gene was sequenced in all 68 of the mice collected. The mutations responsible for the dark fur color in the Sonora mice were absent from the three different populations of Chihuahua mice. No Mc1r mutations were associated with dark fur color in the Chihuahua populations. These findings suggest that adaptive dark coloration has occurred at least twice in the rock pocket mouse and that these similar phenotypic changes have different genetic bases.
How does this study support the concept that natural selection is not random?
Answer:
The study supports the concept that natural selection is not random because in different areas with the same or very similar environmental characteristics, the same phenotype was produced by different types of mutations.
Explanation:
All of the sampled animals are inhabiting dark substrate. Probably animals needed to camouflage to survive. Natural selection must have driven them to produce dark color, similar to the substrate color. So animals from the different regions suffered different mutations that drove them to have almost the same dark fur color. The environmental condition is favoring the same phenotype.
Different stars are different colors depending on the temperature. So, for example, a blue star is hotter than a yellow star such as our Sun.
