Genetics Commons^™

Reproductive Isolation In The Elegans-Group Of Caenorhabditis, Scott Everet Baird, Sara Rose Seibert

Biological Sciences Faculty Publications

Reproductive isolation is the basis of the Biological Species Definition and can be a driving force of speciation. Theoretical studies have provided models of how reproductive isolation can arise within individual species. Genetic tests of these models are limited to populations in which reproductive isolation is present but not complete. Here, reproductive isolation in the Elgans-Group of the nematode genus Caenorhabditis is reviewed. Pre-mating barriers, assortative fertilization and post-zygotic barriers all have been observed in this clade. In some combinations of species, fertile F1 hybrids can be obtained. Therefore, the Elegans-Group of Caenorhabditis is poised to become an important experimental …

A Path To Success? A Review Of Evolution, Development, And The Predictable Genome By David L. Stern, Hope Hollocher, Charles H. Pence, Grant Ramsey, Michelle M. Wirth

Faculty Publications

No abstract provided.

Staffan Müller-Wille And Hans-Jörg Rheinberger, A Cultural History Of Heredity, Charles H. Pence

Faculty Publications

No abstract provided.

Genetic Population Structure Of Us Atlantic Coastal Striped Bass (Morone Saxatilis), David T. Gauthier, Corinne A. Audemard, Jeanette E. L. Carlsson, Tanya L. Darden, Michael R. Denson, Kimberly S. Reece, Jens Carlsson

Biological Sciences Faculty Publications

Genetic population structure of anadromous striped bass along the US Atlantic coast was analyzed using 14 neutral nuclear DNA microsatellites. Young-of-the-year and adult striped bass (n = 1114) were sampled from Hudson River, Delaware River, Chesapeake Bay, North Carolina, and South Carolina. Analyses indicated clear population structure with significant genetic differentiation between all regions. Global multilocus F-ST was estimated at 0.028 (P < 0.001). Population structure followed an isolation-by-distance model and temporal sampling indicated a stable population structure more than 2 years at all locations. Significant structure was absent within Hudson River, whereas weak but significant genetic differences were observed between northern and southern samples in Chesapeake Bay. The largest and smallest effective striped bass population sizes were found in Chesapeake Bay and South Carolina, respectively. Coalescence analysis indicated that the highest historical gene flow has been between Chesapeake Bay and Hudson River populations, and that exchange has not been unidirectional. Bayesian analysis of contemporary migration indicated that Chesapeake Bay serves as a major source of migrants for Atlantic coastal regions from Albemarle Sound northward. In addition to examining population genetic structure, the data acquired during this project were capable of serving as a baseline for assigning fish with unknown origin to source region.

Family Matters: An Analysis Of Genetic Relatedness Of Tetraclita Rubescens (The Pink Volcano Barnacle) Over Several Spatial Scales At Monterey And Bodega Bay, California, Kelly N. Chang

Scripps Senior Theses

Inbreeding involves the mating of closely related individuals at a higher frequency than at random; this can decrease the average fitness of populations and individuals by reducing the presence of heterozygotes and augmenting the expression of deleterious genes. Since marine invertebrates exhibit widespread dispersal, their potential for inbreeding is often disregarded. The adult sessile state of barnacles creates the potential for inbreeding as a result of necessary copulation between neighboring individuals. Depending on the degree of mixing that occurs during dispersal, closely related individuals or siblings may settle in close proximity, generating the possibility of kin aggregation and consequent inbreeding. …

The Causes And Consequences Of Individual Variation In Parental Care Behavior, Daniel P. Wetzel

Theses and Dissertations--Biology

Behavioral traits can be remarkably flexible depending on the conditions in which they are expressed, yet, in spite of this flexibility, persistent differences between individuals appear to limit the potential expression of behaviors. For example, despite evidence that parents provide variable amounts of parental care in response to changing environmental conditions, they also differ in the overall level of care they provide. I used a behavioral reaction norm approach to study individual variation in parental care behavior in free-living house sparrows (Passer domesticus). I investigated the nature of this variation by studying the relationship between different forms of …

Genetic Diversity Of North American Captive-Born Gorillas (Gorilla Gorilla Gorilla), Noah D. Simmons, Ronald S. Wagner, Joseph G. Lorenz

All Faculty Scholarship for the College of the Sciences

Western lowland gorillas (Gorilla gorilla gorilla) are designated as critically endangered and wild populations are dramatically declining as a result of habitat destruction, fragmentation, diseases (e.g., Ebola) and the illegal bushmeat trade. As wild populations continue to decline, the genetic management of the North American captive western lowland gorilla population will be an important component of the long‐term conservation of the species. We genotyped 26 individuals from the North American captive gorilla collection at 11 autosomal microsatellite loci in order to compare levels of genetic diversity to wild populations, investigate genetic signatures of a population bottleneck and identify …

Phylogeography Of The Christmas Tree Worm Spirobranchus Corniculatus (Annelida, Serpulidae) From The Coral Triangle, Australia, And Fiji, Abril Iñiguez, Craig J. Starger, Elena Kupriyanova, Demian Willette, Tristan Varman, Joshua A. Drew, Abdul Hamid Toha, Benedict Maralit, Kent E. Carpenter, Paul H. Barber

Biological Sciences Faculty Publications

Christmas Tree Woms is a common name given to a group of large and colourful serpulid polychaetes of the genus Spirobranchus that are obligate symbionts of hermatypic corals commonly found in tropical and subtropical regions world-wide. While current taxonomic species delimitations of these worms are based almost exclusively on the morphology of opercular structures, particularly the number and shape of calcareous opercular horns, high levels of intraspecific variation in this morphological feature have made species boundaries within the genus difficult to resolve. Molecular work to differentiate serpulid worms has long been hampered by the availability of informative markers. Recent work …

Genetic Diversity In Populations Of Epiphanes Chihuahuaensis (Rotifera: Monogononta) In The Northern Chihuahuan Desert, Diego E. Reyes

Open Access Theses & Dissertations

1. Cryptic speciation in zooplankton is a phenomenon that has been recently gaining much attention. This is due in part to advances in molecular techniques which help in the identification of morphologically indistinct species. Organisms that have been traditionally believed to have cosmopolitan distributions are being found to be composed of cryptic species complexes with high levels of genetic divergence among lineages.

2. Epiphanes chihuahuaensis is a member in the Epiphanes senta species complex. In a previous study by Schröder & Walsh (2007), genetic data, along with morphological and reproductive isolation data were employed to help delineate four species within …

Phylogenetics Links Monster Larva To Deep-Sea Shrimp., Heather D Bracken-Grissom, Darryl L Felder, Nicole L Vollmer, Joel W Martin, Keith A Crandall

Computational Biology Institute

Mid-water plankton collections commonly include bizarre and mysterious developmental stages that differ conspicuously from their adult counterparts in morphology and habitat. Unaware of the existence of planktonic larval stages, early zoologists often misidentified these unique morphologies as independent adult lineages. Many such mistakes have since been corrected by collecting larvae, raising them in the lab, and identifying the adult forms. However, challenges arise when the larva is remarkably rare in nature and relatively inaccessible due to its changing habitats over the course of ontogeny. The mid-water marine species Cerataspis monstrosa (Gray 1828) is an armored crustacean larva whose adult identity …

A Tale Of Two Haplotypes: The Eda2r/Ar Intergenic Region Is The Most Divergent Genomic Segment Between Africans And East Asians In The Human Genome, Amanda M. Casto, Brenna M. Henn, Jeffery M. Kidd, Carlos D. Bustamante, Marcus W. Feldman

Human Biology Open Access Pre-Prints

Single nucleotide polymorphisms (SNPs) with large allele frequency differences between human populations are relatively rare. The longest run of SNPs with an allele frequency difference of one between the Yoruba of Nigeria and the Han Chinese is found on the long arm of the X chromosome in the intergenic region separating the EDA2R and AR genes. It has been proposed that the unusual allele frequency distributions of these SNPs are the result of a selective sweep affecting African populations that occurred after the Out-of-Africa migration. To investigate the evolutionary history of the EDA2R/AR intergenic region, we characterized the haplotype structure …

A Genetic Survey Of English Sole Populations In The Salish Sea, Elizabeth S. Gutierrez, Gary A. Winans, Jon Baker, Amanda Cope

STAR Program Research Presentations

This summer I interned at the Northwest Fisheries Science Center in Seattle, WA and participated in NOAA’s Salish Sea Project. The Salish Sea Project’s goal is to identify genetically distinctive groups of species in the Salish Sea that may have unique evolutionary and/or adaptive backgrounds. These findings will allow NOAA to promote and monitor the natural production of species in the Salish Sea, to select representative populations for experimental work regarding pollution, ocean acidification and climate change, to contribute to managing the ecosystem for intra- and inter-species diversity, and to help make informed decisions about adaptive management and marine protected …

Two Boundaries Separate Borrelia Burgdorferi Populations In North America, Gabriele Margos, Jean I. Tsao, Santiago Castillo-Ramirez, Yvette A. Girard, Anne G. Hoen

Dartmouth Scholarship

Understanding the spread of infectious diseases is crucial for implementing effective control measures. For this, it is important to obtain information on the contemporary population structure of a disease agent and to infer the evolutionary processes that may have shaped it. Here, we investigate on a continental scale the population structure of Borrelia burgdorferi, the causative agent of Lyme borreliosis (LB), a tick-borne disease, in North America. We test the hypothesis that the observed d population structure is congruent with recent population expansions and that these were preceded by bottlenecks mostly likely caused by the near extirpation in the 1900s …

Widespread Diversity In African Toads (Anura: Amietophrynus), Nancy P. Conkey ^, Eli Greenbaum *

COURI Symposium Abstracts, Spring 2012

No abstract provided.

How Roads Affect The Population Genetic Structure Of The Lizard Uta Stansburiana In The Northern Chihuahuan Desert, Priscilla D. Duran ^, Kevin W. Floyd, Elizabeth J. Walsh *

COURI Symposium Abstracts, Spring 2012

Urbanization can have significant ecological effects on natural populations, including habitat fragmentation through increased road density. Roads may isolate populations, causing disruption of gene flow, inbreeding, and decreased genetic diversity. In this study we investigate how two roads, interstate highway I-10 and rural country road NM-9, affect population genetic structure of ideblotched lizards (Uta stansburiana) in the northern Chihuahuan Desert of New Mexico. Lizards were trapped on both sides of each road, plus one control site/road. Nine microsatellite loci were amplified to determine signatures of disrupted gene flow. Genotypes were obtained for 144 individuals from three sites, I-10 …

Microgeographic Differentiation In Historical Yemen Inferred By Morphometric Distances, Maria Enrica Danubio, Emanuele Sanna, Fabrizio Rufo, Domenico Martorella, Elvira Vecchi, Alfredo Coppa

Human Biology Open Access Pre-Prints

This study analysed the variations in space of 8 body dimensions and 11 measures of the head of 1,244 adult Yemenite males, collected in 1933/34 by Coon in Yemen and in Hadhramawt. The aim was to evaluate the presence of geographic microdifferentiation of the populations settled in the different regions of Yemen at the time. Coon sub-divided the sample into 6 geographical areas according to birthplace and ethnicity of the individuals: Tihamah, the Western Mountains, the Central Plateau, the South Coast, the Eastern Mountains and Hadhramawt. The results of ANCOVA (age as covariate) show that the observed differences of all …

Modeling The Dispersion Of Eastern Oyster Larvae (Crassostrea Virginica) And Its Effects On The Movement Of Disease Resistant Genes In The Delaware Bay Estuary, Diego A. Narvaez

OES Theses and Dissertations

This study combines several models to address two primary research questions. How does the interaction of larval biology and environmental variability determine the spatial distribution of oyster larvae in Delaware Bay? What is the role of larval dispersion in the transference of disease-resistant genes? The particle-tracking module in the Regional Ocean Modeling System (ROMS) was converted into an Individual-Based model representing Eastern oyster larvae that has growth and vertical migration. Exchange of larvae between natural oyster reefs was estimated and used in an Individual-Based genetic model that simulates the genetic structure of eastern oysters. Particles were released from a number …

A High Density Snp Array For The Domestic Horse And Extant Perissodactyla: Utility For Association Mapping, Genetic Diversity, And Phylogeny Studies, Molly E. Mccue, Danika L. Bannasch, Jessica Lynn Petersen, Jessica Gurr, Ernie Bailey, Matthew M. Binns, Ottmar Distl, Gérard Guérin, Telhisa Hasegawa, Emmeline W. Hill, Tosso Leeb, Gabriella Lindgren, M. Cecilia T. Penedo, Knut H. Røed, Oliver A. Ryder, June E. Swinburne, Teruaki Tozaki, Stephanie J. Valberg, Mark Vaudin, Kerstin Lindblad-Toh, Claire M. Wade, James R. Mickelson

Department of Animal Science: Faculty Publications

An equine SNP genotyping array was developed and evaluated on a panel of samples representing 14 domestic horse breeds and 18 evolutionarily related species. More than 54,000 polymorphic SNPs provided an average inter-SNP spacing of ~43 kb. The mean minor allele frequency across domestic horse breeds was 0.23, and the number of polymorphic SNPs within breeds ranged from 43,287 to 52,085. Genome-wide linkage disequilibrium (LD) in most breeds declined rapidly over the first 50–100 kb and reached background levels within 1–2 Mb. The extent of LD and the level of inbreeding were highest in the Thoroughbred and lowest in the …

The Role Of Epigenetics In Evolution: The Extended Synthesis, Aaron W. Schrey, Christina L. Richards, Victoria Meller, Vincent Sollars, Douglas M. Ruden

Integrative Biology Faculty and Staff Publications

No abstract provided.

Epigenetic Variation May Compensate For Decreased Genetic Variation With Introductions: A Case Study Using House Sparrows (Passer Domesticus) On Two Continents, Aaron W. Schrey, Courtney A. C. Coon, Michael T. Grispo, Mohammed Awad, Titus Imboma, Earl D. Mccoy, Henry R. Mushinsky, Christina L. Richards, Lynn B. Martin

Integrative Biology Faculty and Staff Publications

Epigenetic mechanisms impact several phenotypic traits and may be important for ecology and evolution. The introduced house sparrow (Passer domesticus) exhibits extensive phenotypic variation among and within populations. We screened methylation in populations from Kenya and Florida to determine if methylation varied among populations, varied with introduction history (Kenyan invasion < 50 years old, Florida invasion ~150 years old), and could potentially compensate for decrease genetic variation with introductions. While recent literature has speculated on the importance of epigenetic effects for biological invasions, this is the first such study among wild vertebrates. Methylation was more frequent in Nairobi, and outlier loci suggest that populations may be differentiated. Methylation diversity was similar between populations, in spite of known lower genetic diversity in Nairobi, which suggests that epigenetic variation may compensate for decreased genetic diversity as a source of phenotypic variation during introduction. Our results suggest that methylation differences may be common among house sparrows, but research is needed to discern whether methylation impacts phenotypic variation.

Successful Genotyping Of Microsatellites In The Woolly Mammoth, Yasuko Ishida, Alfred L. Roca, Stephen Fratpietro, Alex D. Greenwood

Biological Sciences Faculty Publications

Genetic analyses using ancient DNA from Pleistocene and early Holocene fossils have largely relied on mitochondrial DNA (mtDNA) sequences. Among woolly mammoths, Mammuthus primigenius, mtDNA analyses have identified 2 distinct clades (I and II) that diverged 1-2 Ma. Here, we establish that microsatellite markers can be effective on Pleistocene samples, successfully genotyping woolly mammoth specimens at 2 loci. Although significant differentiation at the 2 microsatellite loci was not detected between 16 clade I and 4 clade II woolly mammoths, our results demonstrate that the nuclear population structure of Pleistocene species can be examined using fast-evolving nuclear microsatellite markers.

Expansion Dating: Calibrating Molecular Clocks In Marine Species From Expansions Onto The Sunda Shelf Following The Last Glacial Maximum, Eric D. Crandall, Elizabeth J. Sbrocco, Timery S. Deboer, Paul H. Barber, Kent E. Carpenter

Biological Sciences Faculty Publications

The rate of change in DNA is an important parameter for understanding molecular evolution and hence for inferences drawn from studies of phylogeography and phylogenetics. Most rate calibrations for mitochondrial coding regions in marine species have been made from divergence dating for fossils and vicariant events older than 1-2 My and are typically 0.5-2% per lineage per million years. Recently, calibrations made with ancient DNA (aDNA) from younger dates have yielded faster rates, suggesting that estimates of the molecular rate of change depend on the time of calibration, decaying from the instantaneous mutation rate to the phylogenetic substitution rate. aDNA …

Comparative Developmental Transcriptomics Of Echinoderms, Roy Vaughn

USF Tampa Graduate Theses and Dissertations

The gastrula stage represents the point in development at which the three primary germ layers diverge. At this point the gene regulatory networks that specify the germ layers are established and the genes that define the differentiated states of the tissues have begun to be activated. These networks have been well characterized in sea urchins, but not in other echinoderms. Embryos of the brittle star Ophiocoma wendtii share a number of developmental features with sea urchin embryos, including the ingression of mesenchyme cells that give rise to an embryonic skeleton. Notable differences are that no micromeres are formed during cleavage …

High Connectivity In The Deepwater Snapper Pristipomoides Filamentosus (Lutjanidae) Across The Indo-Pacific With Isolation Of The Hawaiian Archipelago, Michelle R. Gaither, Shelley A. Jones, Christopher Kelley, Stephen J. Newman, Laurie Sorenson, Brian W. Bowen

Fisheries Research Articles

In the tropical Indo-Pacific, most phylogeographic studies have focused on the shallow-water taxa that inhabit reefs to approximately 30 m depth. Little is known about the large predatory fishes, primarily snappers (subfamily Etelinae) and groupers (subfamily Epinephelinae) that occur at 100–400 m. These long-lived, slow-growing species support fisheries across the Indo-Pacific, yet no comprehensive genetic surveys within this group have been conducted. Here we contribute the first range-wide survey of a deepwater Indo-Pacific snapper, Pristipomoides filamentosus, with special focus on Hawai'i. We applied mtDNA cytochrome b and 11 microsatellite loci to 26 samples (N = 1,222) collected across …

The Y-Str Genetic Diversity Of An Idaho Basque Population, With Comparison To European Basques And Us Caucasians, Josu Zubizarreta, Michael C. Davis, Greg Hampikian

Human Biology Open Access Pre-Prints

Fifty unrelated Basque males from southwest Idaho were typed for the 17 Y-STR loci in the Yfiler multiplex kit (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, YGATA_H4.1 and DYS385a/b). A total of 42 haplotypes were identified, with no more than two individuals sharing a single haplotype. The haplotype diversity (HD) was 0.9935, and gene diversity (D) over loci was 0.457 ± 0.137. The Idaho Basque population was compared to the source population from the Basque autonomous region of Northern Spain and Southern France, as well as a US Caucasian population. The haplotype diversity …

Integration Versus Apartheid In Post-Roman Britain: A Response To Thomas Et Al. (2008), John E. Pattison

Human Biology Open Access Pre-Prints

The genetic surveys of the population of Britain conducted by Weale et al. and Capelli et al. produced estimates of the Germani immigration into Britain during the early Anglo-Saxon period, c.430-c.730. These estimates are considerably higher than the estimates of archaeologists. A possible explanation suggested that an apartheid-like social system existed in the early Anglo-Saxon kingdoms resulting in the Germani breeding more quickly than the Britons. Thomas et al. attempted to model this suggestion and showed that it was a possible explanation if all Anglo-Saxon kingdoms had such a system for up to 400 yrs. I noted that their explanation …

Systematics Of African Skink In The Panaspis Wahlbergi Complex, Ma. Fernanda Medina^, Eli Greenbaum*

COURI Symposium Abstracts, Summer 2011

No abstract provided.

Herbicide-Resistant Risk Assessment: Response Of Common Nebraska Weeds To Dicamba Dose, Roberto J. Crespo

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Dicamba-resistant soybeans are being developed to provide an additional herbicide mechanism of action that can be used in soybean, and to provide a tool to help manage or mitigate the evolution of other herbicide-resistant weed populations. The objectives of this thesis were to assess the risk of common Nebraska weeds developing resistance to dicamba, quantify baseline dose-response to dicamba of high-risk weed species, and survey the variability in dicamba dose-response among populations of those species. Twenty-five weed scientists were asked to estimate the risk likelihood of ten weed species evolving resistance to dicamba following the commercialization of dicamba-resistant soybean. Palmer …

Phylogeography Of The Reef Fish Cephalopholis Argus(Epinephelidae) Indicates Pleistocene Isolation Across The Indo-Pacific Barrier With Contemporary Overlap In The Coral Triangle, Michelle R. Gaither, Brian W. Bowen, Tiana-Rae Bordenave, Luiz A. Rocha, Stephen J. Newman, Juan A. Gomez, Lynne Van Herwerden, Matthew T. Craig

Fisheries Research Articles

Background

The Coral Triangle (CT), bounded by the Philippines, the Malay Peninsula, and New Guinea, is the epicenter of marine biodiversity. Hypotheses that explain the source of this rich biodiversity include 1) the center of origin, 2) the center of accumulation, and 3) the region of overlap. Here we contribute to the debate with a phylogeographic survey of a widely distributed reef fish, the Peacock Grouper (Cephalopholis argus; Epinephelidae) at 21 locations (N = 550) using DNA sequence data from mtDNA cytochrome b and two nuclear introns (gonadotropin-releasing hormone and S7 ribosomal protein).

Results

Population structure was significant …

Evolutionary Patterns In Deep-Sea Mollusks, Elizabeth Ellen Boyle

Graduate Doctoral Dissertations

The evolution of deep-sea fauna is poorly known. We know little about the scales of population differentiation, radiation and colonization of the deep sea. This dissertation explores evolution in the deep sea at the level of population differentiation on ocean-wide scales in a gastropod species Benthonella tenella and phylogeny of a deep-sea subfamily of protobranch bivalves, Ledellinae. While working on the phylogeny of the Ledellinae the presence of mitochondrial heteroplasmy was discovered.

Genetic variation was quantified within and among populations of deep-sea gastropod Benthonella tenella to identify the extent of population differentiation and potential mechanisms that might isolate gene pools. …