Feb 10, 2017

Mitochondrial Gene Transfer from Host to Parasitic Plants

Jia Tan '17

Recent studies have suggested that plant genomes have undergone horizontal gene transfer (HGT), especially in the mitochondrial genome. Horizontal gene transfer is a method of transferring foreign DNA that violate the common vertical descent pattern (i.e. from parents to offspring through sexual reproduction). Horizontal gene transfer has been shown to be an important factor in the evolution of many organism. It is also the primary reason for the spread of antibiotic resistance in bacteria. There are several mechanisms for horizontal gene transfer in bacteria: transformation, transduction, and conjugations. However, plants have a different mechanism for gene transfer. Research by Zhengxiang Xi, Yuguo Wang, Robert K. Bradley, M. Sugumaran, Christopher J. Marx, Joshua S. Rest and Charles C. Davis focused on parasitism, where horizontal gene transfer appears to be facilitated by intimate physical association between host and parasitic plants. Xi et al., selected 38 mitochondrial genes by using next-generation sequencing from host plants such as Tetrastigma cruciatum and Tetrastigma rafflesiae. Along with the parasitic Rafflesia cantleyi, Sapria himalayana and Rafflesia tuan-mudae. They wished to answer questions such as: what is the extent of horizontal gene transfer? Are the transgenes functional? Were those transgenes transferred together or one at a time? And where do those transgenes come from? By constructing phylogenetic trees, they were able to provide answers to those questions and validated their hypothesis. Results suggested that 24%-41% of the 38 selected mitochondrial gene sequences show evidence of horizontal gene transfer from host to parasitic plants. Additionally, most of the sequences were transferred one at a time, and appeared to be transcribable and translatable. More understanding of this process could potentially lead to effective parasitic weed controls and identifying the last common ancestor of different organisms.

Impact of Animal-Assisted Therapy for Patients with Fibromyalgia

Meagen Hamlin '17

Fibromyalgia affects about 5 million adults each year (2% of the population). When combined with rheumatoid conditions such as rheumatoid arthritis, systemic lupus erythematosus, and ankylosing spondylitis, the prevalence increases to 25-65% of the population. Fibromyalgia does not have a cure, therefore those affected often look for alternative therapies to help manage their pain. The objective of this study was to assess the effects of interacting with a therapy dog on fibromyalgia patients compared to patients in the waiting room, not interacting with the dog. Before and after visiting with the therapy dog, participants were to fill out a short questionnaire to screen for depression and anxiety (scale from 0-3). They were also asked to fill out a survey rating 10 symptoms (7 negative and 3 positive) on a scale from 0-10. This was compared against a waiting room control where participants filled out the survey before and after a waiting period without directions on what to do while waiting. In total, 106 therapy dog visits occurred and 49 waiting room controls participated in the study. The average time participants were with the dog was 12 minutes and the average waiting room time was 17 minutes. Results show that significant improvements were made for negative symptoms for the patients after the therapy dog visit, but no significant improvements were made for the waiting room control patients. Therefore, it can be concluded that therapy dog visits may be a beneficial alternative therapy for patients with fibromyalgia.