Introduction
In a scientific research paper, researchers should put across different sections for the benefits of elaborating the work done. These components differ from one another and they include title, abstract, introduction, materials and methods, results, discussion, and figure legends among others.
The purpose of title is to give the reader an idea on what is contained in the research paper. It contains captivating information about the research carried out, nomenclature of the field, the subject, and scope of the paper and variables used. The abstract re-establishes the research topic, gives its objective, points out the methodologies used, and gives main findings and a conclusion. Introduction gives the importance of the study, defends the model used in the study, and states the hypothesis and description of the experimental design. Additionally, it states how the stated objectives were accomplished.
Materials and methods section gives a documentation of all materials, methods, and procedures used in the study. The purpose is to enable other people use the same materials and methods in subsequent studies or to evaluate the credibility of the work done. On its part, the results section functions to present and illustrate findings of the study. This includes a summary of the findings, description of the findings and data analysis. It also contains summary of control experiments and observations not presented in figures. Discussion offers a precise interpretation of results together with strong support for all conclusions made. Evidence from the experiment coupled with generally accepted knowledge is used to support the findings. Discussion also states whether the hypothesis is null or valid. Finally, figures contain data that is described in the study while legends give details about the data shown in the figures and tables.
Content of the Paper
In the body system of Drosophila melanogaster, different enzymes perform different functions. For instance, enzyme DNase II is involved in the degradation of ingested DNA in phagolysosomes. Therefore, mutation or absence of this enzyme would result into increased ingested DNA in phagocytic cells. The researchers in this paper were dealing with the effects of reduced or mutated DNase II activity on the immune system of Drosophila melanogaster. They wanted to determine what happens when the activity of DNase II in Drosophila melanogaster is reduced or eliminated.
The hypothesis in this study was, “severe reduction of DNase II activity would result in diminished immune function and viability”. In this study, the researchers used RNAi to knock down enzyme DNase II from Drosophila melanogaster. Additionally, after knocking down this enzyme, they infected the DNase II-deficient flies with gram-negative bacteria to test the level of infection.
The techniques used in this study varied even though they worked in harmony to achieve the desired results. The activity of the DNase II enzyme derived from the flies was determined by use of radical diffusion assay. Other techniques used included construction of RNAi vector by cloning its fragments into pGEM –T vector. Inverse Polymerase Chain Reaction (PCR) was used to verify the site of integration and to sequence the region adjacent to the RNAi transposon. Quantitative real-time PCR was then performed to synthesis cDNA. The other test involved was testing survival of the flies after knocking out the DNase II enzyme and the subsequent infection of gram-negative bacteria. After this, the researchers generated polyclonal antibodies against the carboxyl terminal of the enzyme and carried out a western blot to determine the amount of DNase II enzyme and mRNA in the DNase II-deficient flies. The final test was to determine the effects of DNase II-RNAi expression on dDNase II levels and hemocyte numbers by use of immunoflourescence microscopy.
The researchers found interesting results. Contrary to the common belief that mutation or degradation of DNase II in Drosophila melanogaster leads to increase in un-degraded DNA in phagocytic cells, they established this statement is null. The study revealed that this is not the case. Despite the fact that these researchers knocked out enzyme DNase II from the flies, the amount of un-degraded DNA in phagocytic cells remained low. One of the explanations put forward here is that, residue effect of nuclease activity in DNase II-deficient flies is sufficient to degrade DNA in these phagocytic cells.
These researchers also indicated that a recent study, although not documented, showed that some strains of DNase II-deficient flies had increased expression of antibacterial genes, diptericin, and attacin and this explains partly why the immune system of the flies did not become compromised even after knocking off DNase II. These findings are perplexing because it has been established that accumulation of ingested DNA in phagocytes leads to severely impaired immune system. The conclusion here is that, degradation or mutation of DNase II does not lead to accumulation of ingested DNA in phagocytic cells. Moreover, absence of DNase II does not lead to severely impaired immune system in Drosophila melanogaster.
Therefore, the future direction of the research discussed here is to find out how a defect in bacterial DNA degradation leads to a severely impaired immune system. This question should be addressed in subsequent future researchers.