1993 — 1997 |
Dowling, Thomas |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Phylogenetic Analysis of Reproductive Isolation in Cyprinid Fishes @ Arizona State University
Biodiversity is generated by the process of speciation and maintained by factors preventing interbreeding of distinct species (i.e. reproductive isolation). Reproductive isolation is most readily studied in situations like that involving the minnow species, Luxilus cornutus and Luxilus chrysocephalus, which interbreed extensively in the eastern United States. Dr. Thomas Dowling of Arizona State University has been studying genetic interactions between these two hybridizing species, and he has identified geographic variation in the effectiveness of factors maintaining reproductive discontinuity. This study expands upon Dr. Dowling's previous research by examining eastern locations where the two species co-occur and adjacent areas to the west and south, providing complete characterization of geographic variation in reproductive isolation. Sequence variation of the mitochondrial DNA control region is being used to infer phylogenetic relationships of cornutus and chrysocephalus populations and identify the importance of pre- and post-Pleistocene effects in structuring of genetic variation within these species. Comparisons of these relationships with the pattern of reproductive isolation will allow for tests of the role of ancestry, dispersal, and geological history in geographic variation of reproductive isolation. Likewise, population phylogenies will allow for examination of the role of hydrographic history and dispersal on the distribution of genetic variation within each of these species, providing a test of hypotheses concerning the origin of species diversity in the Central Highlands region, one of the most diverse faunas in North America.
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0.915 |
1995 — 1997 |
Trelease, Richard (co-PI) [⬀] Dowling, Thomas Vermaas, Willem [⬀] Stout, Valerie (co-PI) [⬀] Blankenship, Robert (co-PI) [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
A Dna Sequencing Facility For Interdisciplinary Biological Research @ Arizona State University
DNA sequence determinations are of fundamental importance for studies in many areas of the biosciences. including functional biochemistry, cell and molecular biology, population genetics, and molecular systematics. The purpose of this proposal is to streamline DNA sequencing at Arizona State University by seeking funds to establish a DNA sequencing facility. The major piece of equipment for this facility will be an automated DNA sequencer, which currently is not available at our University and which is requested in this proposal. About 20 groups at Arizona State University routinely use DNA sequencing in their research, and a large number of graduate students, undergraduates, postdoctoral fellows, staff, and faculty will benefit from the establishment of a DNA sequencing facility with an automated sequencer. The sequencer requested utilizes an infrared laser diode to excite fluorophor-labeled DNA that is size-separated by gel electrophoresis. Fluorescence from the fluorophor is detected, and simultaneous scanning of four sequencing lanes over time can provide a DNA sequence of 800 nucleotides or more with over 99% accuracy in a highly cost-effective manner. With the equipment requested, 22 samples can be sequenced simultaneously. Apart from providing a 30% cost-share in purchasing this equipment, the University also will create a staff-level position for an individual to run the DNA sequencing facility and will bear most of the personnel cost involved. A Ph.D.-level research scientist (already on staff) will supervise the facility. Nominal user fees (about $5 per sequence) will be charged to cover the cost of chemicals, the DNA sequencer service contract, and a small part (about 20%) of the technician's salary. This facility will provide a highly effective and economic mechanism to obtain and analyze DNA sequence information. An additional benefit is that DNA sequencing becomes accessible to a large number of graduate students who work in research areas (for examp le, systematics and population biology) that would benefit from DNA analysis, but for whom DNA sequencing facilities currently are not readily available. Also, many undergraduate projects, which usually preclude use of radioactivity, could include DNA sequencing. Another significant advantage of acquisition of an automated DNA sequencer is that when DNA sequencing becomes more efficient, students will be able to gather and analyze sequence information more expediently, leaving more room for emphasis on training in other important areas.
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0.915 |
2003 — 2008 |
Collins, James (co-PI) [⬀] Jacobs, Bertram (co-PI) [⬀] Dowling, Thomas Bingham, Scott (co-PI) [⬀] Blankenship, Robert (co-PI) [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
A Capillary Dna Sequencer and Denaturing Hplc For Molecular Genetics, Ecogenomics, and Experimental Bioinformatics @ Arizona State University
A grant has been awarded to Arizona State University under the direction of Dr. Thomas Dowling for the acquisition of a 48-capillary DNA sequencer/genetic analyzer, and an HPLC genotyping and DNA fragment purification system. This instrumentation is essential for efficient completion of the diversity of projects being conducted at ASU, including molecular, evolutionary, ecological, genomic, and bioinformatic studies. Acquisition of this equipment is necessary to handle both increasing demands (number of samples) by existing and new faculty, and will permit investigators to address questions not currently approachable with the existing systems. Research areas that will utilize the instrumentation include: (1) molecular genetics and the evolution of photosynthesis, (2) molecular systematics and evolution of a diversity of organisms (e.g., bacteria, fungi, plants, animals), (3) genetics and management of endangered species, (4) introgressive hybridization and evolutionary genomics, and (5) population biology. The equipment will become part of the DNA sequencing facility at the university. This facility provides support to several educational programs, such as the NSF REU and UMEB programs, which introduce students of diverse backgrounds to careers in science. Central to training these students is exposure to the newest techniques that allow us to obtain previously unobtainable answers. Therefore, addition of this equipment will allow us to better serve the undergraduates and graduates working in our laboratories by exposing them to state of the art technology and techniques.
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0.915 |
2006 — 2009 |
Dowling, Thomas Faeth, Stanley [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
The Ecological Consequences of Hybridization of Asexual Microbial Symbionts @ Arizona State University
Hybridization between species is a well-known biological process that rapidly creates new species and varieties of living organisms. For example, approximately 95% of fern species and 70% of flowering plant species and have arisen from hybridization (combining genes from two species). Hybrid plants include important crop plants such as modern wheat. Many species of animals are also the result of hybridization between two parental species. Much less is known about hybridization between microbial species, although the ecological consequences can be dramatic. For example, the aggressive and pathogenic fungus that causes Dutch elm disease and devastated American forests resulted from hybridization of two benign fungal strains. This research studies the ecological effects of hybridization of a fungal endophyte that lives internally in both agronomic and native grasses. Endophytes are symbiotic fungi that live inside plants and do not usually cause disease. Instead, these endophytes improve growth, competitive abilities and resistance to herbivores that consume the plant. This research will examine how hybridization of the endophyte alters the growth, reproduction and survival of the grass in which it lives.
This research has important implications for the welfare of pasture, turf and native grasses, all of which are often infected with endophytes. Furthermore, hybridization opportunities have dramatically increased as microbes are transported globally by human activities. These microbial hybridization events may result in either positive or negative (e.g., pathogenic) effects on their hosts, including crops, humans and livestock. Understanding how hybrid microbial partners influence their native host grasses and agronomic crops is therefore essential.
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0.915 |