Experiment 1: Neuromuscular SHIRPA
The scores increased significantly from week 3 to week 24, indicating a decrease in muscle usage. The adult C22 mice were the most affected and C3-PMP mice were intermediate. The things that were most noticeable were in tremor, gait and tail elevation and escape strength. (Figure 1)
Experiment 2: Electrophysiology.
The mean NCV was lower in C3-PMP mice and in C22 mice. Than in wt mice. C22 mice had a lower amplitude compared to C3-PMP mice and wt. The mean CNAP was decreased significantly from 3 to 48 weeks in C22 mice. But not in C3-PMP mice. (table 1)
Experiment 3: Histology and morphology
In the C3 and CC22 and had numerous inappropriately thinly myelinated and unmyelinated fibers at 3 weeks compared to the control. The number of normally myelinated fibers increased in C3 and C22. There were more inappropriately myelinated in the motor branch compared to the peroneal nerve (Figure 3). Many amyelinated and thinly myelinated fibers and small diameter fibers that were hyper myelinated were found in both strains. There were occasional atrophic fibers and loss of Schwann cells at all ages of the C3 and C22 mice. All abnormalities were more frequent in C22 mice compared to the C3 PMP mice (figure 4). Macrophages were seen in C22 but not in C3 mice, which implies axonal damage. There were no regenerative fibers not identified with either the CC22 or C33 model(figure 3).
Putting it all together:
In adults, a higher neuromuscular SHIRPA score was associated with a lower number of fibers and lower CMAP amplitudes. Lower MNCV is associated with higher SHIRPA scores and lower number of axons. (figure 5)
Comments
The question that I posed in
The question that I posed in this experiment is where the mutation is in the unknown mutant yeast cells. To answer this question, the unknown yeast cells were crossed with each other and with ade mutant cells whose mutations are known. The resulting colonies were then copied on MV plate and MV plate that contain adenine.
Results section:
In the YED plate, there were two red diploid colonies and one pink colony (figure 1). The red colony was from unknown alpha 1 x ade2 a and unknown alpha 1 x unknown alpha 1. The pink colonies were from the cross between unknown alpha 1 and ade 1a. In the MV plate, the result was the exact same copy of those that were found inYED plate (figure 2). In the MV plate that contains adenine, all of the colonies were white (figure 3). The exact shade of the plates can be seen in the figure.