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Full-Text Articles in Genetics and Genomics

Tal Effector-Nucleotide Targeter (Tale-Nt) 2.0: Tools For Tal Effector Design And Target Prediction, Erin L. Doyle, Nicholas J. Booher, Daniel S. Standage, Daniel F. Voytas, Volker P. Brendel, John K. Vandyk, Adam J. Bogdanove Oct 2019

Tal Effector-Nucleotide Targeter (Tale-Nt) 2.0: Tools For Tal Effector Design And Target Prediction, Erin L. Doyle, Nicholas J. Booher, Daniel S. Standage, Daniel F. Voytas, Volker P. Brendel, John K. Vandyk, Adam J. Bogdanove

Nicholas J. Booher

Transcription activator-like (TAL) effectors are repeat-containing proteins used by plant pathogenic bacteria to manipulate host gene expression. Repeats are polymorphic and individually specify single nucleotides in the DNA target, with some degeneracy. A TAL effector-nucleotide binding code that links repeat type to specified nucleotide enables prediction of genomic binding sites for TAL effectors and customization of TAL effectors for use in DNA targeting, in particular as custom transcription factors for engineered gene regulation and as site-specific nucleases for genome editing. We have developed a suite of web-based tools called TAL Effector-Nucleotide Targeter 2.0 (TALE-NT 2.0;https://boglab.plp.iastate.edu/) that enables design …


Inferring Processes Of Coevolutionary Diversification In A Community Of Panamanian Strangler Figs And Associated Pollinating Wasps, Jordan D. Satler, Edward Allen Herre, K. Charlotte Jandér, Deren A. R. Eaton, Carlos A. Machado, Tracy A. Heath, John D. Nason Mar 2019

Inferring Processes Of Coevolutionary Diversification In A Community Of Panamanian Strangler Figs And Associated Pollinating Wasps, Jordan D. Satler, Edward Allen Herre, K. Charlotte Jandér, Deren A. R. Eaton, Carlos A. Machado, Tracy A. Heath, John D. Nason

Tracy Heath

The fig and pollinator wasp obligate mutualism is diverse (~750 described species), ecologically important, and ancient (~80-90 Ma), providing model systems for generating and testing many questions in evolution and ecology. Once thought to be a prime example of strict one-to-one cospeciation, current thinking suggests that genera of pollinator wasps coevolve with corresponding subsections of figs, but the degree to which cospeciation or other processes contributes to the association at finer scales is unclear. Here we use genome-wide sequence data from a community of Panamanian strangler figs (Ficus subgenus Urostigma, section Americana) and associated fig wasp pollinators …


The Wings Of Bombyx Mori Develop From Larval Discs Exhibiting An Early Differentiated State: A Preliminary Report, Madhuri Kango-Singh, Amit Singh, K. P. Gopinathan Jul 2015

The Wings Of Bombyx Mori Develop From Larval Discs Exhibiting An Early Differentiated State: A Preliminary Report, Madhuri Kango-Singh, Amit Singh, K. P. Gopinathan

Madhuri Kango-Singh

Lepidopteran insects present a complex organization of appendages which develop by various mechanisms. In the mulberry silkworm, Bombyx mori, a pair of meso- and meta-thoracic discs located on either side in the larvae gives rise to the corresponding fore- and hind-wings of the adult. These discs do not experience massive cell rearrangements during metamorphosis and display the adult wing vein pattern. We have analysed wing development in B. mori by two approaches, viz., expression of patterning genes in larval wing discs, and regulatory capacities of larval discs following explantation or perturbation. Expression of Nubbin is seen all over the presumptive …


The Wings Of Bombyx Mori Develop From Larval Discs Exhibiting An Early Differentiated State: A Preliminary Report, Madhuri Kango-Singh, Amit Singh, K. P. Gopinathan Jul 2015

The Wings Of Bombyx Mori Develop From Larval Discs Exhibiting An Early Differentiated State: A Preliminary Report, Madhuri Kango-Singh, Amit Singh, K. P. Gopinathan

Amit Singh

Lepidopteran insects present a complex organization of appendages which develop by various mechanisms. In the mulberry silkworm, Bombyx mori, a pair of meso- and meta-thoracic discs located on either side in the larvae gives rise to the corresponding fore- and hind-wings of the adult. These discs do not experience massive cell rearrangements during metamorphosis and display the adult wing vein pattern. We have analysed wing development in B. mori by two approaches, viz., expression of patterning genes in larval wing discs, and regulatory capacities of larval discs following explantation or perturbation. Expression of Nubbin is seen all over the presumptive …


Tal Effector-Nucleotide Targeter (Tale-Nt) 2.0: Tools For Tal Effector Design And Target Prediction, Erin L. Doyle, Nicholas J. Booher, Daniel S. Standage, Daniel F. Voytas, Volker P. Brendel, John K. Vandyk, Adam J. Bogdanove Oct 2014

Tal Effector-Nucleotide Targeter (Tale-Nt) 2.0: Tools For Tal Effector Design And Target Prediction, Erin L. Doyle, Nicholas J. Booher, Daniel S. Standage, Daniel F. Voytas, Volker P. Brendel, John K. Vandyk, Adam J. Bogdanove

John K. VanDyk

Transcription activator-like (TAL) effectors are repeat-containing proteins used by plant pathogenic bacteria to manipulate host gene expression. Repeats are polymorphic and individually specify single nucleotides in the DNA target, with some degeneracy. A TAL effector-nucleotide binding code that links repeat type to specified nucleotide enables prediction of genomic binding sites for TAL effectors and customization of TAL effectors for use in DNA targeting, in particular as custom transcription factors for engineered gene regulation and as site-specific nucleases for genome editing. We have developed a suite of web-based tools called TAL Effector-Nucleotide Targeter 2.0 (TALE-NT 2.0;https://boglab.plp.iastate.edu/) that enables design of custom …


Construction And Sequence Sampling Of Deep-Coverage Large-Insect Bac Libraries For Three Model Lepidopteran Species, Chengcang Wu, Dina Proestou, Dorothy Carter, Erica Nicholson, Filippe Santos, Shaying Zhao, Hong-Bin Zhang, Marian R. Goldsmith Dec 2012

Construction And Sequence Sampling Of Deep-Coverage Large-Insect Bac Libraries For Three Model Lepidopteran Species, Chengcang Wu, Dina Proestou, Dorothy Carter, Erica Nicholson, Filippe Santos, Shaying Zhao, Hong-Bin Zhang, Marian R. Goldsmith

Marian R Goldsmith

Background: Manduca sexta, Heliothis virescens, and Heliconius erato represent three widely-used insect model species for genomic and fundamental studies in Lepidoptera. Large-insert BAC libraries of these insects are critical resources for many molecular studies, including physical mapping and genome sequencing, but not available to date. Results: We report the construction and characterization of six large-insert BAC libraries for the three species and sampling sequence analysis of the genomes. The six BAC libraries were constructed with two restriction enzymes, two libraries for each species, and each has an average clone insert size ranging from 152–175 kb. We estimated that the genome …


Extensive Conserved Synteny Of Genes Between The Karyotypes Of Manduca Sexta And Bombyx Mori Revealed By Bac-Fish Mapping, Yuji Yasukochi, Makiko Tanaka-Okuyama, Fukashi Shibata, Atsuo Yoshido, Frantisek Marec, Chengcang Wu, Hongbin Zhang, Marian R. Goldsmith, Ken Sahara Dec 2012

Extensive Conserved Synteny Of Genes Between The Karyotypes Of Manduca Sexta And Bombyx Mori Revealed By Bac-Fish Mapping, Yuji Yasukochi, Makiko Tanaka-Okuyama, Fukashi Shibata, Atsuo Yoshido, Frantisek Marec, Chengcang Wu, Hongbin Zhang, Marian R. Goldsmith, Ken Sahara

Marian R Goldsmith

Background: Genome sequencing projects have been completed for several species representing four highly diverged holometabolous insect orders, Diptera, Hymenoptera, Coleoptera, and Lepidoptera. The striking evolutionary diversity of insects argues a need for efficient methods to apply genome information from such models to genetically uncharacterized species. Constructing conserved synteny maps plays a crucial role in this task. Here, we demonstrate the use of fluorescence in situ hybridization with bacterial artificial chromosome probes as a powerful tool for physical mapping of genes and comparative genome analysis in Lepidoptera, which have numerous and morphologically uniform holokinetic chromosomes. Methodology/Principal Findings: We isolated 214 clones …


Kaikobase: An Integrated Silkworm Genome Database And Data Mining Tool, Michihiko Shimomura, Hiroshi Minami, Yoshitaka Suetsugu, Hajime Ohyanagi, Chikatada Satoh, Baltazar Antonio, Yoshiaki Nagamura, Keiko Kadono-Okuda, Hideyuki Kajiwara, Hideki Sezutsu, Javaregowda Nagaraju, Marian R. Goldsmith, Qingyou Xia, Kimiko Yamamoto, Kazuei Mita Dec 2012

Kaikobase: An Integrated Silkworm Genome Database And Data Mining Tool, Michihiko Shimomura, Hiroshi Minami, Yoshitaka Suetsugu, Hajime Ohyanagi, Chikatada Satoh, Baltazar Antonio, Yoshiaki Nagamura, Keiko Kadono-Okuda, Hideyuki Kajiwara, Hideki Sezutsu, Javaregowda Nagaraju, Marian R. Goldsmith, Qingyou Xia, Kimiko Yamamoto, Kazuei Mita

Marian R Goldsmith

Background: The silkworm, Bombyx mori, is one of the most economically important insects in many developing countries owing to its large-scale cultivation for silk production. With the development of genomic and biotechnological tools, B. mori has also become an important bioreactor for production of various recombinant proteins of biomedical interest. In 2004, two genome sequencing projects for B. mori were reported independently by Chinese and Japanese teams; however, the datasets were insufficient for building long genomic scaffolds which are essential for unambiguous annotation of the genome. Now, both the datasets have been merged and assembled through a joint collaboration between …


Comparison Of Two Gelling Agents For Screwworm (Diptera: Calliphoridae) Larval Diets, David B. Taylor Feb 2012

Comparison Of Two Gelling Agents For Screwworm (Diptera: Calliphoridae) Larval Diets, David B. Taylor

David B. Taylor

A sodium polyacrylamide polyacrylate gelling agent, Water-Lock G-400, and a galactan polysaccharide agent, carrageenan, were compared for solidifying larval diets of the screwworm, Cochliomyia hominivorax (Coquerel). Water-Lock diet produced larger pupae with less larval mortality than did carrageenan diet. Pupae from larvae reared on the Water-Lock diet exhibited higher emergence and produced adults with higher fecundity. Water-Lock diet also produced larger larvae at 56 h after oviposition. Densities in excess of 300 mg of eggs (16,200 eggs) per liter of Water-Lock gelled diet did not increase larval yield but did reduce larval weight and survival.


Mitochondrial Dna Variation Among Muscidifurax Spp. (Hymenoptera: Pteromalidae), Pupal Parasitoids Of Filth Flies (Diptera), David B. Taylor, Richard D. Peterson Ii, Allen L. Szalanski, James J. Petersen Feb 2012

Mitochondrial Dna Variation Among Muscidifurax Spp. (Hymenoptera: Pteromalidae), Pupal Parasitoids Of Filth Flies (Diptera), David B. Taylor, Richard D. Peterson Ii, Allen L. Szalanski, James J. Petersen

David B. Taylor

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing analyses were used to characterize an amplicon of ~625 bp in 4 of the 5 nominate species of Muscidifurax Girault & Sanders, pupal parasitoids of muscoid flies. A single polymorphic nucleotide site was observed among 2 samples of M. raptor Girault & Sanders. No sequence variation was observed among 3 samples of M. raptorellus Kogan & Legner. The sequence of M. uniraptor Kogan & Legner was identical to that of M. raptorellus. Nucleotide divergence among the Muscidifurax spp. ranged from 0.14 to 0.18 substitutions per nucleotide. Muscidifurax zaraptor Kogan & Legner …


Identification Of Screwworm Species By Polymerase Chain Reaction-Restriction Fragment Length Polymorphism, David B. Taylor, Allen L. Szalanski, Richard D. Peterson Ii Feb 2012

Identification Of Screwworm Species By Polymerase Chain Reaction-Restriction Fragment Length Polymorphism, David B. Taylor, Allen L. Szalanski, Richard D. Peterson Ii

David B. Taylor

Restriction fragment length polymorphisms in polymerase chain reaction amplified fragments (PCR-RFLP) of mitochondrial DNA were used to differentiate species of New World screwworms (Diptera : Calliphoridae) . Twenty-seven restriction enzymes were screened on five regions of mtDNA . Eleven restriction fragment length patterns differentiated New World screwworm, Cochliomyia hominivorax (Coquerel), from secondary screwworm, Cochliomyia macellaria (F.) . Five restriction fragment length patterns were polymorphic in C. hominivorax while all fragment patterns were fixed in C. macellaria. Diagnostic restriction fragment length patterns were used for species diagnosis, whereas intraspecific variable patterns were used to characterize field samples and laboratory strains . …


Population Genetics And Gene Variation In Primary And Secondary Screwworm (Diptera : Calliphoridae), David B. Taylor, Richard D. Peterson Ii Feb 2012

Population Genetics And Gene Variation In Primary And Secondary Screwworm (Diptera : Calliphoridae), David B. Taylor, Richard D. Peterson Ii

David B. Taylor

Allozyme variation in screwworm, Cochliomyia hominivorax (Coquerel), and secondary screwworm, C. macellaria (F.), populations from northwest Costa Rica was examined . Variability was observed in 11 of 13 enzyme loci and the frequency of the most common allele was <0.95 for 5 loci in screwworm . In secondary screwworm, 12 of 13 loci were variable and the frequency of the most common allele was <0.95 for 6 loci . Expected heterozygosities were 0.149 and 0.160 for screwworm and secondary screwworm, respectively. Goodness-of-fit statistics for Hardy-Weinberg equilibrium and Wrights F statistics indicated that both species are panmictic with no evidence of …


Genetic And Morphological Comparisons Of New And Old World Populations Of Spalangia Species (Hymenoptera: Pteromalidae), David B. Taylor, Roger Moon, Gary Gibson, Allen L. Szalanski Feb 2012

Genetic And Morphological Comparisons Of New And Old World Populations Of Spalangia Species (Hymenoptera: Pteromalidae), David B. Taylor, Roger Moon, Gary Gibson, Allen L. Szalanski

David B. Taylor

The genetic similarity of New and Old World samples of Spalangia spp. (Hymenoptera: Pteromalidae) was examined using two ribosomalDNAregions. The species examined were Spalangia cameroni Perkins, Spalangia endius Walker, Spalangia gemina Bouček, Spalangia nigra Latreille, Spalangia nigroaenea Curtis, and Spalangia slovaca Bouček. Two species of Muscidifurax, Muscidifurax raptor Girault & Sanders and Muscidifurax zaraptor Kogan & Legner (Hymenoptera: Pteromalidae) were included as outgroup taxa. The internal transcribed spacer (ITS)-1 region was highly variable among Spalangia species with many insertions/deletions making alignment of the sequences difÞcult. The D2-D3 region of the 28s ribosomal gene and the nuclear rDNA 18s gene were …


Assessing Nuclear And Mitochondrial Dna Sequence Variation Within Steinernema (Rhabditida: Steinernematidae), Allen L. Szalanski, David B. Taylor, Peter G. Mullin Feb 2012

Assessing Nuclear And Mitochondrial Dna Sequence Variation Within Steinernema (Rhabditida: Steinernematidae), Allen L. Szalanski, David B. Taylor, Peter G. Mullin

David B. Taylor

DNA sequence analysis was used to characterize the nuclear ribosomal DNA ITS1 region and a portion of the COII and 16S rDNA genes of the mitochondrial genome from Steinernema entomopathogenic nematodes. Nuclear ITS1 nucleotide divergence among seven Steinernema spp. ranged from 6 to 22%, and mtDNA divergence among five species ranged from 12 to 20%. No intraspecific variation was observed among three S. feltiae strains. Phylogenetic analysis of both nuclear and mitochondrial DNA sequences confirms the existing morphological relationships of several Steinernema species. Both the rDNA ITS1 and mtDNA sequences were useful for resolving relationships among Steinernema taxa.


Mitochondrial Dna Variation In Screwworm, David B. Taylor, Allen L. Szalanski, Richard D. Peterson Ii Feb 2012

Mitochondrial Dna Variation In Screwworm, David B. Taylor, Allen L. Szalanski, Richard D. Peterson Ii

David B. Taylor

Polymerase chain reaction-restriction fragment length polymorphism (PCRRFLP) analysis was used to characterize mitochondrial DNA (mtDNA) variation in screwworms, Cochliomyia hominivorax, and secondary screwworm, C. macellaria, from the Caribbean, North America and South America. Four amplicons, totaling 7.1 kb, were analysed with sixteen restriction enzymes. A total of 133 restriction sites was observed in the two species, 104 in C. hominivorax, of which nineteen were variable, and ninety-five in C. macellaria, none of which was variable. Fourteen mtDNA haplotypes were observed among eighteen C. hominivorax examined. Mean divergence between C. hominivorax haplotypes (d) was 0.0064 …


Population Genetics And Gene Variation Of Stable Fly Populations (Diptera: Muscidae) In Nebraska, Allen L. Szalanski, David B. Taylor, Richard D. Peterson Ii Feb 2012

Population Genetics And Gene Variation Of Stable Fly Populations (Diptera: Muscidae) In Nebraska, Allen L. Szalanski, David B. Taylor, Richard D. Peterson Ii

David B. Taylor

Genetic variation in stable fly, Stomoxys calcitrans (L.),populations from Nebraska, Canada, and Texas was sampled. Four of 12 allozyme loci were polymorphic, with an average of 1.7 alleles per locus. Observed and expected heterozygosities were 0.086 and 0.070,respectively. Nei's genetic distance between populations averaged 0.001 and ranged from 0.000 to 0.005. Wright's F statistics revealed greater variation within than among populations. Allele frequencies were homogeneous among temporal samples from a single population. Polymerasechain reaction—restriction fragment length polymorphism (PCR—RFLP) analysis of 6.4 kb of the mitochondrial DNA genome with 16 restriction enzymes revealed no variation in stable fly populations from Canada, …


Genetics Of The Screwworm Fly, David B. Taylor, Estela Martinez Cuevas Feb 2012

Genetics Of The Screwworm Fly, David B. Taylor, Estela Martinez Cuevas

David B. Taylor

Three spontaneous eye mutants of Cochliomyia hominivorax, the screwworm fly, are described and characterized. The mutants, yellow eye (ye), orange eye (or), and white eye (wh), segregate independently and are recessive. Yellow eye is recessively epistatlc to orange eye and dominantly epistatic to white eye. All three mutants have complete penetrance, are autosomal, and have little effect on fly viabillty under laboratory conditions.


Comparison Of Gelled And Meat Diets For Rearing Screwworm, Cochliomyia Hominivorax (Diptera: Calliphoridae), Larvae, David B. Taylor, Robert L. Mangan Feb 2012

Comparison Of Gelled And Meat Diets For Rearing Screwworm, Cochliomyia Hominivorax (Diptera: Calliphoridae), Larvae, David B. Taylor, Robert L. Mangan

David B. Taylor

A liquid diet solidified with an acrylamide-acrylate polymer gelling agent (Water-Lock) was compared with a standard meat diet for rearing screwworm, Cochliomyia hominivorax (Coquerel), larvae. Size and yield of larvae reared on gel diet were equal to, or greater than, those of larvae reared on meat diet. Duration of larval development was increased by ca. 13 h on gel diet; however, variability of pupal weight and larval survival over generations were reduced when gel diet was used. Larval size was also more uniform over the 3-d period when larvae leave the rearing medium to pupate (crawl-off). Gelled diet was more …


Susceptibility Of House Fly (Diptera: Muscidae) Larvae To Entomopathogenic Nematodes (Rhabditida: Heterorhabditidae, Steinernematidae, David B. Taylor, Allen L. Szalanski, Byron J. Adams, Richard D. Peterson Ii Feb 2012

Susceptibility Of House Fly (Diptera: Muscidae) Larvae To Entomopathogenic Nematodes (Rhabditida: Heterorhabditidae, Steinernematidae, David B. Taylor, Allen L. Szalanski, Byron J. Adams, Richard D. Peterson Ii

David B. Taylor

The potential for entomopathogenic nematodes to control flies in cattle feedlots was determined by screening 40 strains representing 8 species of Heterorhabditis Poinar and 5 species of Steinernema Travassos for virulence toward 3rd-instar house flies (maggots), Musca domestica L. None of the 22 strains of Heterorhabditis infecting maggots caused significant levels of mortality in a filter paper assay. Ten strains of Steinernema infected maggots, of which 7 strains--4 S. carpocapsa (Weiser), 2 S. feltiae (Filipjev), and 1 S. scapterisci (Nguyen & Smart) caused significant mortality. Ten Heterorhabditis strains and 10 Steinernema strains successllly reproduced for 22 generations in maggots. No …


Gelled Diet For Screwworm (Diptera: Calliphoridae) Mass Production, David B. Taylor, Jimmy C. Bruce, Rene Garcia Feb 2012

Gelled Diet For Screwworm (Diptera: Calliphoridae) Mass Production, David B. Taylor, Jimmy C. Bruce, Rene Garcia

David B. Taylor

A rearing system based on a diet gelled with Water-Lock G400, a synthetic superabsorbent (poly(2-propenamide-co-2-propenoic acid, sodium salt))( WL), was compared with the standard rearing system (liquid diet suspended in acetate fibers) for the mass production of screwworms, Cochlomyia hominivorax (Coquerel). The WL rearing system yielded 2% heavier pupae, 32% higher egg to pupa survival, and required 54% less diet and 88% less labor than the standard rearing system. Other advantages of the WL system include reduced susceptibility to suboptimal environmental conditions and labor practices, and characteristics conducive to centralization and mechanization of rearing procedures.


Response Of Screwworms (Diptera: Calliphoridae) To Changes In The Concentration Of Blood, Egg, And Milk In The Larval Diet, David B. Taylor Feb 2012

Response Of Screwworms (Diptera: Calliphoridae) To Changes In The Concentration Of Blood, Egg, And Milk In The Larval Diet, David B. Taylor

David B. Taylor

Larvae of screwworm, Cochliomyia hominivorax (Coquerel), were reared on diets with varying concentrations of whole dried bovine blood, whole dried egg, and nonfat dried milk. Pupal weight, egg to pupal survival, adult emergence, sex ratio, fecundity, and fertility were significantly affected by one or more of the dietary components. Curvilinear models for the effect of dietary component concentration on life history parameters were derived by multiple regression. Most models resulted in bell-shaped curves that were used to calculate optimal diet component concentrations. Biomass, survival, emergence, and fecundity were maximized at 6% blood, 5% egg, and 1.3% milk.


Economic Impact Of Stable Flies (Diptera: Muscidae) On Cattle Production., David Taylor, Roger Moon, Darrell Mark Dec 2011

Economic Impact Of Stable Flies (Diptera: Muscidae) On Cattle Production., David Taylor, Roger Moon, Darrell Mark

David B. Taylor

Stable flies, Stomoxys calcitrans (L.), are among the most damaging arthropod pests of cattle worldwide. The last estimate of their economic impact on United States cattle production was published 20 yr ago and placed losses at $608 million. Subsequently, several studies of effects of stable flies on beef cattle weight gain and feed efficiency have been published, and stable flies have become increasingly recognized as pests of cattle on pasture and range. We analyzed published studies and developed yield-loss functions to relate stable fly infestation levels to cattle productivity, and then estimated the economic impact of stable flies on cattle …


Dispersal Of Stable Flies (Diptera: Muscidae) From Larval Developmental Sites., David B. Taylor, Roger D. Moon, John B. Campbell, Dennis R. Berkebile, Philip J. Scholl, Alberto B. Broce, Jerome A. Hogsette Dec 2009

Dispersal Of Stable Flies (Diptera: Muscidae) From Larval Developmental Sites., David B. Taylor, Roger D. Moon, John B. Campbell, Dennis R. Berkebile, Philip J. Scholl, Alberto B. Broce, Jerome A. Hogsette

David B. Taylor

Seven mark-recapture studies were conducted over 3 yr to assess dispersal of newly emerging adult stable flies, Stomoxys calcitrans L., from larval development sites in a mixed agricultural environment in northeastern Nebraska. Infested hay debris piles were marked by dusting their surfaces with fluorescent pigments, adults were captured with surrounding grids of Alsynite sticky traps, and specimens were dissected to determine feeding histories and reproductive age. Distances and directions of 3,889 marked specimens indicated males and females dispersed equally and in all directions. Midguts of males and females were equally likely to contain blood-meal remnants. Percentage with blood remnants and …


Polyphyly Of The Pikeminnows (Teleostei: Cyprinidae) Inferred Using Mitochondrial Dna Sequences, T. Heath Ogden Dec 2009

Polyphyly Of The Pikeminnows (Teleostei: Cyprinidae) Inferred Using Mitochondrial Dna Sequences, T. Heath Ogden

T. Heath Ogden

The phylogenetic relationships of the Colorado pikeminnow Ptychocheilus lucius, northern pikeminnow P. oregonensis, Sacramento pikeminnow P. grandis, Umpqua pikeminnow P. umpquae, and hardhead Mylopharodon conocephalus were examined by using molecular data to investigate monophyly of the genus Ptychocheilus. Phylogenies generated using DNA sequence data from the cytochrome b and 16S ribosomal DNA genes of the mitochondrial genome reveal that Ptychocheilus is a polyphyletic genus and suggest that the taxonomy of the group is in need of further revision. These data yield insights into the evolution of the pikeminnows and help place the significant evolutionary events in context with the geological …


Towards A New Paradigm In Mayfly Phylogeny (Ephemeroptera): Combined Analysis Of Morphological And Molecular Data, T. Heath Ogden Dec 2008

Towards A New Paradigm In Mayfly Phylogeny (Ephemeroptera): Combined Analysis Of Morphological And Molecular Data, T. Heath Ogden

T. Heath Ogden

This study represents the first formal morphological and combined (morphological and molecular) phylogenetic analyses of the order Ephemeroptera. Taxonomic sampling comprised 112 species in 107 genera, including 42 recognized families (all major lineages of Ephemeroptera). Morphological data consisted of 101 morphological characters. Molecular data were acquired from DNA sequences of the 12S, 16S, 18S, 28S and H3 genes. The Asian genus Siphluriscus (Siphluriscidae) was supported as sister to all other mayflies. The lineages Carapacea, Furcatergalia, Fossoriae, Pannota, Caenoidea and Ephemerelloidea were supported as monophyletic, as were many of the families. However, some recognized families (for example, Ameletopsidae and Coloburiscidae) and …


Combined Morphological And Molecular Phylogeny Of Ephemerellidae (Ephemeroptera), T. Heath Ogden Dec 2008

Combined Morphological And Molecular Phylogeny Of Ephemerellidae (Ephemeroptera), T. Heath Ogden

T. Heath Ogden

This study represents the first combined molecular and morphological analysis for the mayfly family Ephemerellidae (Ephemeroptera), with a focus on the relationships of genera and species groups of the subfamily Ephemerellinae. The phylogeny was constructed based on DNA sequence data from 3 nuclear (18S rDNA, 28S rDNA, histone H3) and 2 mitochondrial (12S rDNA, 16S rDNA) genes, and 23 morphological characters. Taxon sampling for Ephemerellidae included exemplars from all 25 extant genus groups and additional representatives from those genera with the highest diversity. Ephemerellidae appears to consist of three major clades. Ephemerella, the largest genus of Ephemerellidae, and Serratella were …


Pisciforma, Setisura, And Furcatergalia (Order: Ephemeroptera) Are Not Monophyletic Based On 18s Rdna Sequences: A Reply To Sun Et Al. (2006), T. Heath Ogden Dec 2007

Pisciforma, Setisura, And Furcatergalia (Order: Ephemeroptera) Are Not Monophyletic Based On 18s Rdna Sequences: A Reply To Sun Et Al. (2006), T. Heath Ogden

T. Heath Ogden

No abstract provided.


Molecules, Morphology And Fossils: A Comprehensive Approach To Odonate Phylogeny And The Evolution Of The Odonate Wing, T. Heath Ogden Dec 2007

Molecules, Morphology And Fossils: A Comprehensive Approach To Odonate Phylogeny And The Evolution Of The Odonate Wing, T. Heath Ogden

T. Heath Ogden

We undertook a comprehensive morphological and molecular phylogenetic analysis of dragonfly phylogeny, examining both extant and fossil lineages in simultaneous analyses. The legitimacy of higher-level family groups and the phylogenetic relationship between families were tested. Thirteen families were supported as monophyletic (Aeshnidae, Calopterygidae, Chlorocyphidae, Euphaeidae, Gomphidae, Isostictidae, Lestidae, Libellulidae, Petaluridae, Platystictidae, Polythoridae, Pseudostigmatidae and Synthemistidae) and eight as non-monophyletic (Amphipterygidae, Coenagrionidae, Corduliidae, Megapodagrionidae, Protoneuridae and Synlestidae), although Perilestidae and Platycnemididae were recovered as monophyletic under Bayesian analyses. Nine families were represented by one species, thus monophyly was not tested (Epiophlebiidae, Austropetaliidae, Chlorogomphidae, Cordulegastridae, Macromiidae, Chorismagrionidae, Diphlebiidae, Lestoideidae and Pseudolestidae). Epiprocta …


Stable Fly Population Dynamics In Eastern Nebraska In Relation To Climatic Variables., David B. Taylor, Dennis R. Berkebile, Philip J. Scholl Dec 2006

Stable Fly Population Dynamics In Eastern Nebraska In Relation To Climatic Variables., David B. Taylor, Dennis R. Berkebile, Philip J. Scholl

David B. Taylor

Stable flies, Stomoxys calcitrans (L.), are among the most economically important arthropod pests of livestock in North America. In this study, we monitored the seasonal dynamics of a stable fly population in eastern Nebraska for 5 yr. Models based upon temperature and precipitation were developed to determine the affects of these variables on population levels as well as to project population trends. Stable flies appear in eastern Nebraska in late March to early April, and they build to a peak population during the last week of June and first week of July. In most years, the population decreases in midsummer, …


Does Direct Optimization Produce More Accurate Alignments And Topologies? Poy Vs. Clustalw+Paup*, T. Heath Ogden Dec 2006

Does Direct Optimization Produce More Accurate Alignments And Topologies? Poy Vs. Clustalw+Paup*, T. Heath Ogden

T. Heath Ogden

Direct optimization frameworks for simultaneously estimating alignments and phylogenies have recently been developed. One such method, implemented in the program POY, is becoming more common for analyses of variable length sequences (e.g., analyses using ribosomal genes) and for combined evidence analyses (morphology + multiple genes). Simulation of sequences containing insertion and deletion events was performed in order to directly compare a widely used method of multiple sequence alignment (ClustalW) and subsequent parsimony analysis in PAUP* with direct optimization via POY. Data sets were simulated for pectinate, balanced, and random tree shapes under different conditions (clocklike, non-clocklike, and ultrametric). Alignment accuracy …