LUMP Is a Putative Double-Stranded RNA Binding Protein Required for Male Fertility in Drosophila melanogaster

In animals, male fertility requires the successful development of motile sperm. During Drosophila melanogaster spermatogenesis, 64 interconnected spermatids descended from a single germline stem cell are resolved into motile sperm in a process termed individualization. Here we identify a putative double-stranded RNA binding protein LUMP that is required for male fertility. lump1 mutants are male-sterile and lack motile sperm due to defects in sperm individualization. We show that one dsRNA binding domains (dsRBD) is essential for LUMP function in male fertility. These findings reveal LUMP is a novel factor required for late stages of male germline differentiation

Soil Moisture and Porosity Affects the Abundance and Distribution of Ageratum houstonianum

Introduction: Ageratum houstonianum is an herbaceous, drought-tolerant plant also known as Blue billygoat weed. It grows well in drained soil and shaded areas. Soil moisture and porosity are two abiotic factors that affect the abundance and distribution of A. houstonianum. An ideal condition for plants to grow includes a greater amount of soil moisture and porosity. Higher porosity would mean that there is a greater number of pores, which would result in more significant plant nutrients because of its ability to retain more water. The purpose of this research was to see how soil moisture and porosity based on the gradient with regards to distance from the tree impact the abundance and distribution of A. houstonianum. Materials and Methods: The belt transect method was used to test the soil moisture and porosity, and three belts with four quadrants in each were formed. For each of the belts, the first two quadrants closer to the tree were called zone 1, and the last two quadrants were labeled as zone 2. We hypothesized that there was an increase in abundance and distribution further away from the tree. Abundance was calculated by finding the density of the total number of species over each quadrant area. Soil samples were collected to test the soil moisture and porosity. Paired two-sample t-tests and ANOVA single factor tests were performed. Results and Conclusion: The t-tests showed a difference between the relationship of abundance/moisture, abundance/porosity, and moisture/porosity. The ANOVA test compared the means of density/moisture/porosity between zone 1 and 2 to see if they were statistically different from each other. Based on the results, there was a decrease in the density as the distance from the tree increased. Soil moisture and porosity also decreased as the distance from the tree increased, which rejected the hypothesis. Closer to the tree, there was an increase in moisture, density, and porosity, which led to the abundance of A. houstonianum species because the ideal conditions were met

The Role of Double-Stranded RNA Binding Protein R2D2 and Lump in Drosophila Gametogenesis

In Drosophila melanogaster, fertility requires the successful development of germline cells into mature gametes. This process is dependent on multiple factors that coordinate migration, proliferation, and differentiation of germline stem cells. Previous studies have shown dsRNA binding proteins have an important role in the induction and maintenance of germ cells. In this study, I investigated the requirement of dsRNA binding proteins, R2D2 and LUMP, in Drosophila melanogaster gametogenesis. I show R2D2 functions in the ovary, specifically in the somatic tissues giving rise to the stalk and other follicle cells critical for establishing the cellular architecture of the oocyte. Most interestingly, the female fertility defects in r2d21 are dramatically enhanced when one copy of the dcr-1 gene is missing. This indicates dicer-1 and r2d21 operate in the same fertility pathway. Furthermore, Dicer-1 protein coimmunoprecipitates with R2D2 antisera, indicating these proteins function in the same protein complex. Thus, r2d21 mutants have reduced viability and defective female fertility that stems from abnormal follicle cell function and Dicer-1 impacts this process. This is the first indication R2D2 functions beyond its known role in RNA interference to include ovarian development in Drosophila. I also studied a second putative double-stranded RNA binding protein (dsRBP). I found that lump is required for male fertility and there is an absence of motile sperm in lump mutant testes squash preparations and the seminal vesicles. The early stages of spermatogenesis, including mitosis, meiosis, and cytokinesis steps are unaffected in lump mutants. This indicated lump is likely required late in sperm development. The spermatid individualization complex is disrupted consistent with an individualization-deficient phenotype. A wildtype genomic rescuing transgene was able to rescue fertility and individualization. However, a lump transgene carrying a point mutation in the first dsRNA binding domain did not rescue fertility or individualization suggesting this domain is essential for lump function. Thus, it is likely that these two dsRNA binding proteins regulate gene expression in the ovary and testes and are essential for normal fertility