3 May 2019
Potential Mechanism for Epigenetic Inheritance in Mammals
Amberlyn Bergmann '19
Genes are passed down through DNA mediated methods, and the genes do not change. But there is a newer concept, epigenetics inheritance, that is possibly through RNA mediated methods. One way that this is happening is through paramutations. This usually occurs in plants, like maize, but it slowly starting to show up in mammals. One mutation that is happening is the Kit mutation, where mice feet and tails were turning white. But when looking at their genotype, they should have been a normal color. While looking for an answer they looked at Dnmt2 methyltransferase in RNA, to see if that had any connection to why this paramutation was happening. First they looked at a cross between a heterozygote (Kit*/+) and a wild type (Kit+/+).They did microinjection of oligoribonucleotide from the Kit gene into either two Dnmt2-/- or wild type parents. Then with that they looked at how much RNA methylation occurred to see if there was a difference in different regions. They also used methylated DNA to see how see the status of the Kit loci in testis of the three different genotypic mice. The results show from the cross of the two mice that Dnmt2 is needed to get the white tail on the mice. Looking at the DNA methylation, there was no significant differences in any of the regions. But when looking at the RNA methylation, there was a major difference in the amount of RNA methylation between the control and the injected mice. So this shows that Dnmt2 is required for epigenetic inheritance and that it is not DNA methylation but RNA methylation that occurs.
A proposal to Inadequate Physical Activity in Minneapolis Public Schools
Becca Heer '19
This case study was a simulated situation and I was to come up with a solution. The problem that I was given was that the superintendent of the Minneapolis public school district has recently noticed a major decline in the test scores of schools as well as the behavior of the students. Recently the Minneapolis school district has decreased the amount of time spent in gym class and recess in order to increase the amount of time learning in the classrooms. The superintendent wants to see if incorporating physical activity in the classroom will help to increase better behavior and test scores of the students. A two-week trial will take place in a third grade classroom at a school in a lower income part of north Minneapolis called Nellie Stone Johnson.
The research question that I was trying to answer was: by adding physical activity into the 3rd grade curriculum will improve the academic achievement and behavior of students in a classroom. To figure out whether or not this was possible I reviewed multiple literature sources to create a 2-week trial to implement in a 3rd grade classroom. In studies that I found it showed that adding in 30 minutes of physical activity 3 times a week it is equivalent to adding in 4 extra months of learning into the normal 9 months of learning.
Children aged 6-17 years old should be getting 60 minutes or more of physical activity every single day. If we add this into the classroom it will help students to be healthier and it will help them learn better while in the classroom.
Exploring Microbial Diversity in the Rhizosphere of Non-Nodulating and Nodulating Legumes
Mahida Adan '19
Rhizobia are agricultural bacteria that form a symbiotic relationship with legumes. This symbiosis facilitates the production of up 60% of the world’s bioavailable nitrogen through nitrogen fixation. Nitrogen is fixed through a reaction catalyzed by nitrogenase (NifH), an enzyme which converts atmospheric nitrogen to ammonia. While there is vast information about the microbial communities associated with agricultural legumes, little is known about the bacterial populations present in leguminous trees of the same family. The purpose of this project was to assess diversity amongst the microbial communities associated with the roots of nodulating and non-nodulating leguminous trees, and to investigate the abundance of nifH in these environments. We hypothesized that nodulating and non-nodulating trees associate with similar bacterial populations that contain the nitrogenase gene, nifH. Soil samples from the roots of nodulating and non-nodulating trees were examined to determine the presence of nifH using the polymerase chain reaction (PCR). Microbial diversity was evaluated by using 16S ribosomal RNA analysis. Bioinformatics and statistical tools such as Qiime, Principal Coordinate Analysis, and BLASTX were employed to interpret and compare the DNA sequencing results. Abundant bacterial phyla present in all the plants examined included Proteobacteria (35%), Actinobacteria (20%) and Acidobacteria (10%). Bacterial families common to all samples included Bradyrhizobiaceae, Chitinophagaceae, Chthoniobacteraceae and Flavobacteriaceae. Despite common bacterial phyla and families, Principle Coordinate Analysis showed dissimilarities amongst the microbial communities associated with nodulating and non-nodulating legumes. These results were supported by statistical analysis through ANOSIM (R=0.978875; P<.001) and AMOVA (Fs=16.547; P<.001). In summary, the data suggest that similar bacterial phyla are associated with leguminous trees, however, nodulating and non-nodulating species contain distinctive microbial communities. The presence of nifH in all the plants analyzed indicates the potential for nitrogen-fixation within the non-nodulating leguminous trees.