The purpose of this study was to determine if the width of the Achilles tendon differs among different types of athletes and non-athletes. The forty participants in this study were 18 to 25 years old and did not have any known Achilles tendon pathologies or current lower limb injuries. Each participant filled out a survey that consisted of demographic questions and questions about their performance in athletics and other physical activities. This information was used to categorize participants into different athletic and non-athletic groups: sprinters, jumpers, agility athletes, endurance athletes, non-athletes that are active, and non-active subjects. Additionally, the width of the Achilles tendon was measured using ultrasonography at three locations in each leg: the insertion on the calcaneus, and the musculotendinous junctions of the tendon with the gastrocnemius and soleus muscles. The mean widths of the two legs within an individual were calculated for each measurement location and then divided by the weight of the participant. A repeated measures analysis of variance with one among-subject factor (athletic/non-althetic type) and one within-subjects factor (width measurement location) will be performed to determine if there is a difference in mean relative tendon widths among and within subjects. Additionally, confidence intervals for each grouping and measurement will be calculated. It is expected that sprinters, jumpers, and agility athletes will have a wider tendons than endurance, non-athletic but active, and non-active subjects.
Dept of Biology and Environmental Science, Marietta College, Marietta, OH
P103 • Vanessa Y. Rubio, Cynthia C. Bennington
Genetic Variability and Gender Specialization in Passiflora incarnata
Plants possess a diversity of breeding systems that have evolved in response to selection favoring outcrossing or optimal resource allocation during growth and development. Andromonoecy is a breeding system where individual plants produce both staminate and hermaphroditic (bisexual) flowers. In the andromonoecious vine, Passiflora incarnata, prior studies have examined fitness traits of hermaphroditic and staminate flowers. In our study, we compared male fitness traits (e.g., nectar quantity, nectar quality, and pollen tube growth) between hermaphroditic and staminate flowers, accounting for potential differences between genotypes. We conducted these experiments using 30 potted plants of P. incarnata, representing six clonally-replicated genotypes originally obtained from natural populations. There was significant genetic variability in traits such as nectar sucrose concentration and pollen diameter, but little evidence that staminate and hermaphroditic flowers differed in male fitness. Ultimately, male fitness is best measured as the number of seeds successfully sired, a variable that is difficult to quantify.
Dept of Biology, Stetson University, DeLand, FL
P104 • John R. Massey1, Miranda Camp1, Allyson M. Fenwick1, Andrew L. Sheldon2, Alicia S. Schultheis1
Genetic Structure and Phylogeography of Great Basin Populations of the Stonefly Hesperoperla pacifica Using Novel Nuclear Loci
Genetic diversity is an important component of biodiversity. Thus, understanding the geographic patterns of genetic diversity and the historical and contemporary processes which led to those patterns can help create a better understanding of biodiversity. The Great Basin’s sky island topography has resulted in genetic isolation of montane populations of plants and animals, including the aquatic insect Doroneuaria baumanni. In this study, our goal was to determine whether this pattern holds for other perlid stoneflies, namely Hesperoperla pacifica.We hypothesized that H. pacifica populations would be less structured than those of D. baumanni because H. pacifica has less stringent habitat requirements. We tested our hypothesis in several Great Basin populations using three nuclear loci that were obtained from transcriptome data. FST estimates from these nuclear loci suggest H. pacifica populations are less structured than the previously studied stonefly Doroneuria baumanni, which had three geographically non-overlapping clades. H. pacifica populations commonly share haplotypes and have lower FST values. Thus, the degree of isolation of stonefly populations may be dependent upon species-specific life history characteristics. Our results underscore the benefits of a comparative approach to understanding the phylogeography of the Great Basin. The contrasting patterns of genetic structure in these two stoneflies highlight the need for studying multiple species to identify potential hotspots of genetic diversity.
1 Dept of Biology, Stetson University, DeLand, FL; 2 Professor Emeritus, University of Montana
Phylogenetic Studies Reveal the Evolutionary History of the Structure of 5S Ribosomal RNA
As an integral component of the large subunit of ribosome, 5S rRNA carries out fundamentally important functions during protein synthesis. Due to its associations with the large rRNA subunit and several ribosomal proteins, 5S rRNA has been used as a model molecule for studies on RNA structure, RNA-RNA, and RNA-protein interactions. Structurally, 5S rRNAs are folded into a conserved secondary structure. Despite being a model for the study of RNA structure and RNA-protein interactions, the evolutionary history of the universally conserved 5S rRNA molecule remains unclear. Here, we apply an award-winning phylogenetic method to reconstruct the evolutionary histories of molecules and substructures of 5S rRNA directly from its molecular structure, and to identify the ancestral functional and structural components that were crucial during its early life. Trees of molecules revealed the tripartite nature of life; superkingdom Archaea formed a paraphyletic basal group, while Bacteria and Eukarya were monophyletic and derived. Trees of molecular substructures support an origin of the molecule in a segment that is homologous to helix I, its initial enhancement with helix III, and the early formation of the three-domain structure typical of modern 5S rRNA in Archaea, while the delayed formation of the 3-branched structure in Bacteria and Eukarya supports the archaeal rooting of the tree of life. The evolution of molecular interactions between 5S rRNA and ribosomal proteins suggested that 5S rRNA represents an evolutionarily late addition to the ribosomal ensemble that occurred prior to the early diversification of Archaea.
1 School of Science and Technology, Georgia Gwinnett College, Lawrenceville, GA; 2Dept of Crop Science, University of Illinois at Urbana-Champaign, Urbana, IL
