Life Sciences Commons^™

Divergent Functions Of The Myotubularin (Mtm) Homologs Atmtm1 And Atmtm2 In Arabidopsis Thaliana: Evolution Of The Plant Mtm Family, Yong Ding, Ivan Ndamukong, Yang Zhao, Yuannan Xia, Jean-Jack Riethoven, David R. Jones, Nullin Divecha, Zoya Avramova

School of Biological Sciences: Faculty Publications

Myotubularin and myotubularin-related proteins are evolutionarily conserved in eukaryotes. Defects in their function result in muscular dystrophy, neuronal diseases, and leukemia in humans. In contrast to the animal lineage, where genes encoding both active and inactive myotubularins (phosphoinositide 3-phosphatases) have appeared and proliferated in the basal metazoan group, myotubularin genes are not found in the unicellular relatives of green plants. However, they are present in land plants encoding proteins highly similar to the active metazoan enzymes. Despite their remarkable structural conservation, plant and animal myotubularins have significantly diverged in their functions. While loss of myotubularin function causes severe disease phenotypes …

Inbreeding-Stress Interactions: Evolutionary And Conservation Consequences, David H. Reed, Charles W. Fox, Laramy S. Enders, Torsten N. Kristensen

Department of Entomology: Faculty Publications

The effect of environmental stress on the magnitude of inbreeding depression has a long history of intensive study. Inbreeding-stress interactions are of great importance to the viability of populations of conservation concern and have numerous evolutionary ramifications. However, such interactions are controversial. Several meta-analyses over the last decade, combined with omic studies, have provided considerable insight into the generality of inbreeding-stress interactions, its physiological basis, and have provided the foundation for future studies. In this review, we examine the genetic and physiological mechanisms proposed to explain why inbreeding-stress interactions occur. We specifically examine whether the increase in inbreeding depression with …

Genome Sequencing Of Ovine Isolates Of Mycobacterium Avium Subspecies Paratuberculosis Offers Insights Into Host Association, John Bannantine, Chia-Wei Wu, Chungyi Hsu, Shiguo Zhou, David C. Schwartz, Darrell O. Bayles, Michael L. Paustian, David P. Alt, Srinand Sreevatsan, Vivek Kapur, Adel M. Talaat

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Background: The genome of Mycobacterium avium subspecies paratuberculosis (MAP) is remarkably homogeneous among the genomes of bovine, human and wildlife isolates. However, previous work in our laboratories with the bovine K-10 strain has revealed substantial differences compared to sheep isolates. To systematically characterize all genomic differences that may be associated with the specific hosts, we sequenced the genomes of three U.S. sheep isolates and also obtained an optical map.

Results: Our analysis of one of the isolates, MAP S397, revealed a genome 4.8 Mb in size with 4,700 open reading frames (ORFs). Comparative analysis of the MAP S397 isolate showed …

Natural Selection: A Concept In Need Of Some Evolution?, Charles H. Smith

DLPS Faculty Publications

In some respects natural selection is a quite simple theory, arrived at through the logical integration of three propositions (the presence of variation within natural populations, an absolutely limited resources base, and procreation capacities exceeding mere replacement numbers) whose individual truths can hardly be denied. Its relation to the larger subject of evolution, however, remains problematic. It is suggested here that a scaling-down of the meaning of natural selection to “the elimination of the unfit,” as originally intended by Alfred Russel Wallace (1823-1913), might ultimately prove a more effective means of relating it to larger-scale, longer-term, evolutionary processes.

Evolving Possibilities: Postembryonic Axial Elongation In Salamanders With Biphasic (Eurcyea Cirrigera, Eurycea Longicauda, Eurycea Quadridigitata) And Paedomorphic Life Cycles (Eurycea Nana And Ambystoma Mexicanum), Janet L. Vaglia, Kurt White '09, Alison Case '09

Biology Faculty publications

Typically, the number of vertebrae an organism will have postembryonically is determined during embryogenesis via the development of paired somites. Our research investigates the phenomenon of postembryonic vertebral addition in salamander tails. We describe body and tail growth and patterns of postsacral vertebral addition and elongation in context with caudal morphology for four plethodontids ( Eurycea) and one ambystomatid. Eurycea nana and Ambystoma mexicanum have paedomorphic life cycles; Eurcyea cirrigera, Eurycea longicauda and Eurycea quadridigitata are biphasic. Specimens were collected, borrowed and/or purchased, and cleared and stained for bone and cartilage. Data collected include snout-vent length (SVL), tail length (TL), …

Analysis Of The Lactobacilluscasei Supragenome And Its Influence In Species Evolution And Lifestyle Adaptation, Jeff Broadbent, E. C. Neeno-Eckwall, B. Stahl, K. Tandee, H. Cai, W. Morovic, P. Horvath, J. Heidenreich, N. T. Perna, R. Barrangou, J. L. Steele

Nutrition, Dietetics, and Food Sciences Faculty Publications

The broad ecological distribution of L. casei makes it an insightful subject for research on genome evolution and lifestyle adaptation. To explore evolutionary mechanisms that determine genomic diversity of L. casei, we performed comparative analysis of 17 L. casei genomes representing strains collected from dairy, plant, and human sources. Results Differences in L. casei genome inventory revealed an open pan-genome comprised of 1,715 core and 4,220 accessory genes. Extrapolation of pan-genome data indicates L. casei has a supragenome approximately 3.2 times larger than the average genome of individual strains. Evidence suggests horizontal gene transfer from other bacterial species, particularly lactobacilli, …

Prospects For The Study Of Evolution In The Deep Biosphere, Jennifer F. Biddle, Jason B. Sylvan, William J. Brazelton, Katina J. Edwards, Craig L. Moyer, John F. Heidelberg, William C. Nelson

Biology Faculty and Staff Publications

Since the days of Darwin, scientists have used the framework of the theory of evolution to explore the interconnectedness of life on Earth and adaptation of organisms to the ever-changing environment. The advent of molecular biology has advanced and accelerated the study of evolution by allowing direct examination of the genetic material that ultimately determines the phenotypes upon which selection acts. The study of evolution has been furthered through examination of microbial evolution, with large population numbers, short generation times, and easily extractable DNA. Such work has spawned the study of microbial biogeography, with the realization that concepts developed in …

Observed And Simulated Time Evolution Of Hcl, Clono2, And Hf Total Column Abundances, R Kohlhepp, R Ruhnke, M P Chipperfield, M De Maziere, J Notholt, S Barthlott, R L. Batchelor, R D. Blatherwick, Th Blumenstock, M T. Coffey, P Demoulin, H Fast, W Feng, A Goldman, D W. T Griffith, K Hamann, J W. Hannigan, F Hase, N B. Jones, A Kagawa, I Kaiser, Y Kasai, O Kirner, W Kouker, R Lindenmaier, E Mahieu, R L. Mittermeier, B Monge-Sanz, I Morino, I Murata, H Nakajima, M Palm, Clare Paton-Walsh, U Raffalski, Th Reddmann, M Rettinger, C P. Rinsland, E Rozanov, M Schneider, C Senten, C Servais, B M. Sinnhuber, D Smale, K Strong, R Sussmann, J R. Taylor, G Vanhaelewyn, T Warneke, C Whaley, M Wiehle, S W. Wood

Faculty of Science - Papers (Archive)

Time series of total column abundances of hydrogen chloride (HCl), chlorine nitrate (ClONO2), and hydrogen fluoride (HF) were determined from ground-based Fourier transform infrared (FTIR) spectra recorded at 17 sites belonging to the Network for the Detection of Atmospheric Composition Change (NDACC) and located between 80.05° N and 77.82° S. By providing such a near-global overview on ground-based measurements of the two major stratospheric chlorine reservoir species, HCl and ClONO2, the present study is able to confirm the decrease of the atmospheric inorganic chlorine abundance during the last few years. This decrease is expected following the 1987 Montreal Protocol and …

Placing Birds On A Dynamic Evolutionary Map: Using Digital Tools To Update The Evolutionary Metaphor Of The "Tree Of Life", Sonia Stephens

Electronic Theses and Dissertations

This dissertation describes and presents a new type of interactive visualization for communicating about evolutionary biology, the dynamic evolutionary map. This web-based tool utilizes a novel map-based metaphor to visualize evolution, rather than the traditional "tree of life." The dissertation begins with an analysis of the conceptual affordances of the traditional tree of life as the dominant metaphor for evolution. Next, theories from digital media, visualization, and cognitive science research are synthesized to support the assertion that digital media tools can extend the types of visual metaphors we use in science communication in order to overcome conceptual limitations of traditional …

Analysis Of A Wound-Induced Gene Family In Glycine Max, Gena Robertson

Masters Theses

Gene families in plants are important in understanding genome evolution indicating when and where genome duplications and segmental duplications occurred as well as subsequent divergence and subfunctionalization. A gene family in Glycine max that encodes a WI12 protein, wound-induced protein, was found to consist of ten genes on five chromosomes. Wound-induced proteins are activated in response to wounding in plants, and the WI12 protein in particular is thought to be involved in cell wall modifications at the wound site. A variety of bioinformatics tools have been used to analyze the expansion of this family in soybean as well as identify …

Intra And Interhost Dynamics Shaping Arbovirus Adaptation And Evolution, Alexander T. Ciota

Legacy Theses & Dissertations (2009 - 2024)

Arthropod-borne viruses (arboviruses), which are predominately mosquito-borne and almost exclusively RNA viruses, are maintained in nature in complex transmission cycles involving blood sucking invertebrates and vertebrate hosts. Although over 120 arboviruses are human pathogens responsible for causing a significant and expanding global health burden, a detailed understanding of the complex interactions between these pathogens and their hosts, particularly invertebrate hosts, is lacking. Defining these interactions is necessary if we are to understand the selective pressures and, therefore, evolutionary, adaptive, and epidemiological potential of arboviruses. This requires experimental infection and evolution studies, particularly in vivo, with natural hosts. The results presented …

Evolution And Diversity Of Periplasmic Proteins Involved In Copper Homeostasis In Gamma Proteobacteria., José Argüello, Georgina Hernandez-Montes, Brenda Valderrama

José M. Argüello

Background: Different systems contributing to copper homeostasis in bacteria have been described in recent years involving periplasmic and transport proteins that provide resistance via metal efflux to the extracellular media (CopA/Cue, Cus, Cut, and Pco). The participation of these proteins in the assembly of membrane, periplasmic and secreted cuproproteins has also been postulated. The integration and interrelation of these systems and their apparent redundancies are less clear since they have been studied in alternative systems. Based on the idea that cellular copper is not free but rather it is transferred via protein-protein interactions, we hypothesized that systems would coevolve and …