rmmcdonald's blog

The dispersion of Emperors to the frontiers must have resulted in a significant shift in societal and cultural expectations. As revealed in Symmachus letter, Rome is in desperate need of financial assistance claiming "for some time now the provinces appointed for the purpose have contributed nothing of their usual revenues". Symmachus described how the people of Rome expect a certain lifestyle: "It is not greed that inspires the desires which the humanity of the age has aroused; rather, the precedents you have set are the source of our confident expectations". Symmachus flatters the emperors in this letter by making likely exaggerated claims that every Roman holds emperors in their hearts. He was likely trying to establish a connection between the emperors who prefer the frontiers to the people of Rome. If Symmachus was successfully able to establish this connection then he may have hoped the Emperors would send more aid. Symmachus seems to claim that the Romans were entitled to such riches because they were previously accustomed to it.

I was actually surprised about our results. I believed that seeds with a tampered seed coat would not germinate as well as a normal seed. However, the graphs reveal that for most types, seeds with a nicked coat germinated sooner and in greater numbers. From handling the seeds, I also believed that seeds with a thicker coat may actually germinate faster if they are nicked. Again, there was no distinct difference found between seeds of thick or thin coats. If we had more time to run this experiment again I would have liked to use seeds of more varying coat thickness. 

We wanted to figure out how important the seed coat is to the germination of a seed. For our experiment we focused on six types of seeds, ranging from green peas to chickpeas. We soaked 30 seeds of each type then removed the seed coat of 10 seeds, nicked another set of 10 seeds, and left the remaining 10 seeds alone. The seeds were then placed in petri dishes with a moist paper towel, all conditions being held constant. Over the course of four days we checked on the seeds every twelve hours. We noted the number of seeds germinated and any other traits that stood out to us.

Crotamine likely evolved from beta defensin genes through a combination of gene duplication, regulatory mutation, and coding sequence mutation. Gene duplication must have occurred first because the initial gene, beta defensin, is a gene critical to an organism's function therefore that gene must be conserved. When an ancestor had two copies of the beta defensin gene, one of the copies then had a spontaneous mutation in the regulatory sequence, expressing beta defensin in the fangs at higher concentration. This evolutionary step might have happened before, after, or at the same time as a series of mutations in the coding sequence of the copied beta defensin gene in order to code for a poisonous protein instead.

Gene Duplication: a spontaneous event such as a mutation or other factors may result in DNA polymerase or other mechanisms mistakenly duplicating a gene. Further mutations in the regulatory or coding region of one of the duplicated genes alters when, what, and how much of that gene may be expressed. These two copies of the same gene (found within a species) are called paralogs.

Regulatory mutation: mutations in the regulatory region of a gene will alter when and how much of a gene will be expressed. The genetic code of the gene itself will not be altered, preserving the phenotypic expression of the gene. However depending on the level of expression caused by a mutation in the regulatory sequence the phenotypic expression of the gene may also be altered.

Coding sequence mutation: Since the regulatory sequence remains the same, gene will be expressed at the same time, place, and level. However depending on the type of mutation in the gene it may be a nonsynonymous or synonymous. A nonsynonymous mutation may result in a loss of original function of the gene, but gain function in another pathway. If the protein is promiscuous it might not completely lose its original function, just alter one of its many active sites. 

Crotamine likely evolved from beta defensin genes through a combination of gene duplication, regulatory mutation, and coding sequence mutation. Gene duplication must have occurred first because the initial gene, beta defensin, is a gene critical to an organism's function therefore that gene must be conserved. When an ancestor had two copies of the beta defensin gene, one of the copies then had a spontaneous mutation in the regulatory sequence, expressing beta defensin in the fangs at higher concentration. This evolutionary step might have happened before, after, or at the same time as a series of mutations in the coding sequence of the copied beta defensin gene in order to code for a poisonous protein instead.

The resultant species must have a deep beak like the geospiza magnirostris because it must rip the bark from trees. The deep set beak will help the bird tear off the bark. Furthermore the bird will likely inherit the length of the geospitza conristris so that it may probe for insects. A sharp long beak will help it pick out the insect. Therefore, the beak will be deep set and long so that it may peel back the bark and pick at insects. I would expect the bird to express both Calmodulin and Bmp4 early on and at high amounts. An early and high expression of Calmodulin will lead to an elongated beak. Similarly, an early and high expression of Bmp4 will result in a deep set beak. 

Evolution may occur overtime through a succession of mutations or a gene that might be used for a different purpose than originally expressed. With that in mind, mountain goats with horns may have evolved from an ancestral population without horns through the following process. A goat that had a mutation for slight nubs where horns are located and due to genetic drift or selection that goat passed on that trait. Again another mutation might occur where the nubs grow more into smaller horns and that goat may pass on that trait due to drift or selection. This repeats until goats have full horns. Again this trait may be selected for due to mating reasons, influencing natural selection and making the trait have higher fitness. The trait may have also been influenced by genetic drift and been under no selection.

    Another possible theory in terms of genetics is that there could be a mutation in the promoter region specifically that codes for small horns resulting in over expression. Again the theory could be overexpression increased over time due to mutations until the fitness decreased when a goat had horns that were too large.

To accomplish this, we followed the protocol from ThermoFisher titled, “ER-Tracker™ Dyes for Live-Cell Endoplasmic Reticulum Labeling”.  Initially we incubated the plate of cells at 370C for 30 minutes. Following the incubation period, the cells were again rinsed with PBS and given media without CO2. The resultant cells appeared to over-fluoresce in unexpected locations so we repeated the procedure. We decided to incubated for 20 minutes in the staining mixture to prevent the overfluorescense. The cells incubated for 20 minutes appeared to clearly mark parts of the ER. These distinct sections of the ER marked by the tracker did not seem to distinctly overlap with the portions of the ER marked by the plasmid. However, we can confidently say that the plasmid marked the ER, just not the same aspects as the ER tracker did.

We nucleofected Sec61 beta plasmid labeled with mCherry into LLC-Pk1 cells in order to mark the endoplasmic reticulum. To verify that the plasmid marked the ER, we planned to use an ER tracker to stain the ER. Unfortunately, both the ER tracker and our labelled cells fluoresced mCherry. We thus chose to stain parental LLC-Pk1 cells with the ER tracker, with the understanding that if we stained our nucleofected cells with the marker, it would be difficult to distinguish between fluorescence signal from the plasmid or the tracker. We compared the overall ER morphology from each set of cells to determine if they mark relatively the same location.