East Carolina University : Research and Creative Achievement Week 2011
be involved in the formation of replication forks and also in the recruitment of other DNA replication proteins. In Drosophila, mutations in Mcm10 have been linked to problems in endoreplication, chromosome formation and also progression in the cell cycle. Drosophila melanogaster is used as a genetic model organism for genetic crosses, because they are homologous to humans. Also Drosophila has high reproduction rates with a short generation time, and their chromosomes are easily manipulated. A mutant allele needs to be generated in order to study the role of MCM10 in regards to its involvement in DNA replication and replication fork formation. A strain of flies with a transposable element, also called a p-element, is inserted upstream of the gene and is crossed with a strain containing a transposase. The p-element is then mobilized by the transposase. The p-element is precisely excised leaving MCM10 intact about 90% of the time. A mutant allele is obtained when part of the gene is deleted, which occurs 10% of the time. The deletion is then screened using PCR and gel electrophoresis. The mutant strain can then be analyzed using common molecular techniques to further elucidating MCM10â€&#x;s role in DNA replication and replication fork formation.
Effect of PFOA on glycogen storage in an avian model, Ian Bryan, Department of Chemistry, East Carolina University, Greenville, NC 27858 As a result of their use in the manufacture of myriad commercial and industrial products, including firefighting foams, stain and water resistant coatings, and fluids used in electronics manufacturing, perfluorinated compounds (PFCs) are now part of the environmental milieu to which wildlife and humans are exposed. Studies with laboratory animal models indicate that PFCs are multisystem toxicants that induce liver, brain, reproductive, developmental, and immuno- toxicities. Of special concern are effects documented in developing organisms, including teratogenic changes and other more subtle and potentially deleterious developmental effects. We evaluated the developmental effects of a common PFC, perfluorooctanoic acid (PFOA), on chicken embryos. ²-oxidation of fatty acids is most active in the later part of incubation and glucose is derived from yolk fat. Glucose is generated from protein rather than yolk near the end of incubation and is stored in liver and muscles as glycogen. It is our hypothesis that increased ²-oxidation of fatty acids induced by developmental PFOA exposure forces the embryo to utilize protein as energy earlier in development and therefore decreases later glycogen stores, which can affect hatchability and survival. Fertile eggs were injected into the air cell prior to incubation with 0.5, 1, 2, or 5 mg PFOA/kg of egg weight and incubated. Control eggs received the vehicle (safflower oil) only. Embryos were removed from eggs after nineteen days of incubation, and immediately frozen. Glycogen was measured in prepared homogenates of each tissue. Liver glycogen levels did not differ by dose. Hatching muscle glycogen levels differed from controls by 43%, 36%, and 30% (0.5, 1, and 2 mg/kg doses, respectively). Our data indicate that PFOA decreases hatching muscle glycogen in 19-day-old embryos and there has been a marked increase in late embryo (days 18-20) death among treated groups. Additional studies are planned to evaluate glycogen stores in hatchling chickens.
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