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2022

Population genetics

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Full-Text Articles in Life Sciences

Population Genomics Provide Insights Into The Global Genetic Structure Of Colletotrichum Graminicola, The Causal Agent Of Maize Anthracnose, Flávia Rogério, Riccardo Baroncelli, Francisco Borja Cuevas-Fernández, Sioly Becerra, Joanne Crouch, Wagner Bettiol, M. Andrea Azcárate-Peril, Martha Malapi-Wight, Veronique Ortega, Javier Betran, Albert Tenuta, José S. Dambolena, Paul D. Esker, Pedro Revilla, Tamra A. Jackson-Ziems, Jürg Hiltbrunner, Gary Munkvold, Ivica Buhiniček, José L. Vicente-Villardón, Serenella A. Sukno, Michael R. Thon Dec 2022

Population Genomics Provide Insights Into The Global Genetic Structure Of Colletotrichum Graminicola, The Causal Agent Of Maize Anthracnose, Flávia Rogério, Riccardo Baroncelli, Francisco Borja Cuevas-Fernández, Sioly Becerra, Joanne Crouch, Wagner Bettiol, M. Andrea Azcárate-Peril, Martha Malapi-Wight, Veronique Ortega, Javier Betran, Albert Tenuta, José S. Dambolena, Paul D. Esker, Pedro Revilla, Tamra A. Jackson-Ziems, Jürg Hiltbrunner, Gary Munkvold, Ivica Buhiniček, José L. Vicente-Villardón, Serenella A. Sukno, Michael R. Thon

Department of Plant Pathology: Faculty Publications

Understanding the genetic diversity and mechanisms underlying genetic variation in pathogen populations is crucial to the development of effective control strategies. We investigated the genetic diversity and reproductive biology of Colletotrichum graminicola isolates which infect maize by sequencing the genomes of 108 isolates collected from 14 countries using restriction site-associated DNA sequencing (RAD-seq) and wholegenome sequencing (WGS). Clustering analyses based on single-nucleotide polymorphisms revealed three genetic groups delimited by continental origin, compatible with short-dispersal of the pathogen and geographic subdivision. Intra- and intercontinental migration was observed between Europe and South America, likely associated with the movement of contaminated germplasm. Low …


Population Genetics Of Populus Trichocarpa For Targeted Breeding As A Biofuel Crop, Cai John Aug 2022

Population Genetics Of Populus Trichocarpa For Targeted Breeding As A Biofuel Crop, Cai John

Doctoral Dissertations

Populus trichocarpa (poplar) is a woody species native to the western U.S. and Canada. As a fast-growing crop, it has been under investigation by the Department of Energy as a resource for liquid biofuel production. Having recently expanded the collection of poplar whole-genome sequences so that it spans the entire natural species range, we have the novel opportunity to study adaptive responses across this range. This work starts with an initial proof of concept study in a well-studied portion of the species range that has complete whole-genome sequences and RNA expression. The completeness of these data allow robust validation of …


Invasion Of The Northeastern United States By The Southern Pine Beetle, Dendroctonus Frontalis, And The Impacts On Signatures Of Isolation By Distance Assessed Using Mitochondrial Dna, Lora Grace Holman May 2022

Invasion Of The Northeastern United States By The Southern Pine Beetle, Dendroctonus Frontalis, And The Impacts On Signatures Of Isolation By Distance Assessed Using Mitochondrial Dna, Lora Grace Holman

Honors Theses

The southern pine beetle (SPB) is a small, black beetle that parasitizes pine trees across the United States and Central America. Recently it has been recognized that the range of SPB is not limited to the southern United States, but rather extends northward across the eastern United States, which raises concerns for pine trees that have never encountered the pest before. Using mitochondrial DNA sequences from a section of the cytochrome oxidase I gene and four different measures of genetic distance compared to geographic distance, we tested for evidence of isolation by distance (IBD) among sampled SPB to see whether …


Molecular Evolution And Biogeography Of The New World Eptesicus Bats, Xueling Yi May 2022

Molecular Evolution And Biogeography Of The New World Eptesicus Bats, Xueling Yi

Theses and Dissertations

Molecular evolution refers to a broad field of studies ranging from microevolution (e.g., population genetics) to macroevolution (e.g., phylogeny), including the bridging field of phylogeography. In natural populations, molecular studies are also combined with biogeography that links biological diversity with geographic distributions to provide a comprehensive understanding of evolutionary processes. The field of molecular evolution has been largely advanced from early exploratory descriptions to statistical tests on biological hypotheses and integrative analyses using sophisticated modeling. However, studies of molecular evolution still face some unresolved questions and challenges, especially in non-model systems. For example, the application of new technology has largely …


Evaluating Population Genetic Structure And Potential Genomic Signals Of Natural Selection In A Migratory Songbird (Protonotaria Citrea), Tyler A. Hohenstein Jan 2022

Evaluating Population Genetic Structure And Potential Genomic Signals Of Natural Selection In A Migratory Songbird (Protonotaria Citrea), Tyler A. Hohenstein

Theses and Dissertations

In this study I attempted to further resolve the population genetic structure in the Prothonotary Warbler (Protonotaria citrea), and conducted an outlier SNP analysis and exploratory gene ontology analysis to investigate potential ongoing natural selection in the species. This analysis of population structure confirms previous work by DeSaix et al. (2019), where weak population structure was observed between eastern sites along the Atlantic Coastal Plain, and western sites in the Mississippi Alluvial Valley, possibly due to a genetic discontinuity across the Appalachian Mountains. I conducted two forms of outlier SNP analyses, a principal component analysis (PCA)-based approach to identify SNPs …


An Analysis Of The Spatial Genetic Structure Of A Hybrid Zone Between Two Species Of Killifish, Fundulus Heteroclitus And F. Grandis, Andrew Lee Hardy Jan 2022

An Analysis Of The Spatial Genetic Structure Of A Hybrid Zone Between Two Species Of Killifish, Fundulus Heteroclitus And F. Grandis, Andrew Lee Hardy

UNF Graduate Theses and Dissertations

Hybridization offers unique insight into the evolutionary process of speciation and the forces that maintain barriers to reproduction. In northeast Florida, a hybrid zone between two species of killifish, Fundulus heteroclitus and F. grandis, has been identified near Flagler Beach, FL, although the exact boundaries of the hybrid zone remain unknown (Gonzalez et al. 2009). This study aims to determine the fine-scale spatial genetic patterns of the hybrid zone and test the hypothesis that species ranges are influenced by changes in dominant vegetation. Results from an ADMIXTURE analysis and FST data indicated the boundary of the area of …


Florida Sand Skink And Blue-Tailed Mole Skink: Expanding Geographic Coverage Of Genetic Analysis For Conservation, Emma Simpson Jan 2022

Florida Sand Skink And Blue-Tailed Mole Skink: Expanding Geographic Coverage Of Genetic Analysis For Conservation, Emma Simpson

Electronic Theses and Dissertations

The Lake Wales Ridge is important scrub habitat that has been increasingly altered since the post-Columbian settlement in Florida. This loss of habitat has caused extreme anthropogenic fragmentation within the Lake Wales Ridge resulting in isolation among extant scrub patches. To expand the geographic scope of previous studies and answer questions concerning population connectivity, we characterized genetic diversity and differentiation using cytochrome-b and microsatellite genetic markers for two endemic skink species: the Florida Sand Skink (Plestiodon reynoldsi) and Blue-tailed Mole Skink (Plestiodon egregius lividus). Both species display historical isolation between central and southern Lake Wales Ridge …


Genetic Variation At The Olr1, Anxa9, Myf5, Ltf, Igf1, Lgb, Csn3, Pit1, Mbl1,Cacna2d1, And Abcg2 Loci In Turkish Grey Steppe, Anatolian Black, And Eastanatolian Red Cattle, Özden Çobanoğlu, Sena Ardiçli Jan 2022

Genetic Variation At The Olr1, Anxa9, Myf5, Ltf, Igf1, Lgb, Csn3, Pit1, Mbl1,Cacna2d1, And Abcg2 Loci In Turkish Grey Steppe, Anatolian Black, And Eastanatolian Red Cattle, Özden Çobanoğlu, Sena Ardiçli

Turkish Journal of Veterinary & Animal Sciences

Native breeds are excellent sources of genetic variation. Anatolian native breeds are relatives of the first cattle domesticated and are ancestors of many European breeds. Therefore, this study aimed to evaluate the genetic variation of OLR1, ANXA9, MYF5, LTF, IGF1, LGB, CSN3, PIT1, MBL1, CACNA2D1, and ABCG2 markers in Turkish Grey Steppe, Anatolian Black, and East Anatolian Red cattle. The analysis included 367 cattle and the genotyping was performed by the PCR-RFLP. Population genetics indices including heterozygosity, the number of effective alleles, the polymorphism information content, fixation index, and the level of possible variability realization, and moreover, the genetic diversity …


Population Genomics Of Redbreast Sunfish (Lepomis Auritus): Exploring Gene Flow And Local Adaptation In A Widely Distributed Freshwater Fish, Garret J. Strickland Jan 2022

Population Genomics Of Redbreast Sunfish (Lepomis Auritus): Exploring Gene Flow And Local Adaptation In A Widely Distributed Freshwater Fish, Garret J. Strickland

Electronic Theses and Dissertations

Little information is available concerning the distribution of genetic diversity in non-salmonid, non-imperiled, freshwater fish. In order to fill in this knowledge gap, I conducted a population genomics survey in Redbreast Sunfish (Lepomis auritus; RBS), a widespread, generalist species distributed along the Atlantic slope rivers of eastern North America. I sampled four basins (ACF, Savannah, Roanoke, and James) at eight sites each with a factorial experimental design. Sites were distributed among coastal plain, Piedmont, or mountain ecoregions in order to capture the greatest range of environmental states experienced by RBS, with the intention of finding evidence for local adaptation to …


Applying Conservation Genomic Techniques To Guide Management Of The Reticulated Flatwoods Salamander (Ambystoma Bishopi), Miranda Gaupp Jan 2022

Applying Conservation Genomic Techniques To Guide Management Of The Reticulated Flatwoods Salamander (Ambystoma Bishopi), Miranda Gaupp

Electronic Theses and Dissertations

The Reticulated flatwoods salamander (Ambystoma bishopi) is a federally endangered amphibian endemic to the longleaf-pine ecosystem of the southeastern U.S. This study used analyses of single-nucleotide polymorphism (SNP) data, collected from 2,255 unique individuals across 5 breeding seasons, spread across the known extant range of A. bishopi, to characterize the genetic diversity and demographics of populations, genetic relationships among populations, and patterns and spatial extents of gene flow, and to evaluate potential effects of management on A. bishopi’s resiliency. Population structure was strongly hierarchical, with individual breeding ponds (n = 38) acting as semi-connected subpopulations …


Investigating The Genetic Diversity Of Immune Genes In Non-Native Populations Of American Bullfrogs (Rana Catesbeiana), Luisa Nereyda Segovia Jan 2022

Investigating The Genetic Diversity Of Immune Genes In Non-Native Populations Of American Bullfrogs (Rana Catesbeiana), Luisa Nereyda Segovia

Cal Poly Humboldt theses and projects

The American Bullfrog (Rana catesbeiana) is a highly invasive species that has successfully colonized habitats around the world. The genetic variability of immune genes within invasive populations, like that of bullfrogs, may contribute to how resistant a population is to pathogens. The objective of this project was to characterize the genetic diversity of an immune gene in invasive bullfrog populations in California to better understand how persistent these populations might be over time. To characterize immune gene variability, I isolated exon 2 of the Major Histocompatibility Complex (MHC) Class II Beta chain gene and a neutral mitochondrial marker, …


Implications Of Population Genetics And Physiological Responses On The Conservation Of Moose (Alces Alces Americana), Elias Rosenblatt Jan 2022

Implications Of Population Genetics And Physiological Responses On The Conservation Of Moose (Alces Alces Americana), Elias Rosenblatt

Graduate College Dissertations and Theses

Wildlife populations around the globe are facing numerous, complex challengesto their persistence, yet conservation efforts are hindered by limited information about these populations and the anthropogenic pressures they face. North American moose (Alces alces americana), despite being of ecological, cultural, and economical importance, inhabit remote landscapes, making population monitoring difficult. At the same time, many moose populations, including in Vermont and eastern North America, have experienced recent declines mainly due to winter tick (Dermacentor albipictus) epizootics. Anthropogenic landscape change and climate-mediated pressures pose future challenges for moose across the southern extent of their distribution. Though impacts of winter tick infestation …


Elements Of Biocontrol Strategies For Pheretimoid Earthworms, Maryam Nouri-Aiin Jan 2022

Elements Of Biocontrol Strategies For Pheretimoid Earthworms, Maryam Nouri-Aiin

Graduate College Dissertations and Theses

Jumping worms (Megascolecidae) in the pheretimoid complex, have raisedconsiderable environmental concerns with conservationists, ecologists, policy makers, and the public. Their impacts on North American forests and high density is distinct from earthworms in other families. Most of the infested forests are near horticultural settings. Practicable options to manage their dispersal into forests do not exist. This dissertation examines the potential of an entomopathogenic fungus to control them in horticulture. It also investigates major barriers to managing their spread and studying their ecology including species identification, phenology, and genetic diversity. First, to discover the best time to apply biocontrol agents, I …