Entomology Commons^™

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

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 …

Analysis Of Gene Expression During Embryonic Development In Mulberry Silkworm Bombyx Mori, Amit Singh, K. P. Gopinathan

Amit Singh

We have developed a method for dechorionation and devitellinization of the silkworm eggs without damage, to facilitate the analysis of gene expression during embryonic development of Bombyx mori. Making use of antibodies available from heterologous systems, the spatio-temporal expression patterns of peroxidase and proliferating cell nuclear antigen have been directly visualized in whole mount embryos at various stages of development without the need for generating transformed ·lines carrying specific reporter constructs. The B. mori system, previously unamenable for such studies, could thus serve as an attractive model for molecular analysis of insect development. The attention lavished on Drosophila melanogaster as …

Characterization Of The Role Of Alpha-Arylphorin In The Heliothis Virescens Midgut Response To Cry1ac Toxin From Bacillus Thuringiensis, Jerreme Jamael Jackson

Doctoral Dissertations

Homeostasis of the intestinal epithelium in Heliothis virescens is mediated by the proliferation and differentiation of multipotent intestinal stem cells (ISCs) that lie adjacent to the basal lamina. In response to extrinsic and intrinsic signals, ISC proliferation and differentiation promotes epithelial growth and regeneration following the loss of integrity. We tested the in vivo effects of the ISC mitogen, a [alpha]-arylphorin, on ISC proliferation and the morphological changes of the midgut during larval development. Additionally, we examined how these changes affected the intestinal epithelium response to Cry1Ac toxin from Bacillus thuringiensis. Histological and in vitro evidence supported two distinct …

Investigating Notch Signaling And Sequential Segmentation In The Fairy Shrimp, Thamnocephalus Platyurus, Sara Izzat Khalil

Senior Theses and Projects

Segmentation is a key feature of arthropod diversity and evolution. In the standard model for arthropod development, Drosophila melanogaster, segments develop simultaneously by a progressive subdivision of the embryo. By contrast, most arthropods add segments sequentially from a posterior region called the growth zone and in a manner similar to vertebrates.

Recent work, mainly focused on insects, suggests that Notch signaling might play a role in arthropods that segment sequentially. These studies document a potential regulatory similarity between sequentially segmenting arthropods and vertebrates. In vertebrates, somite formation involves a molecular oscillator that functions as a pacemaker, driving periodic expression …

(R)-Desmolactone Is A Sex Pheromone Or Attractant For The Endangered Valley Elderberry Longhorn Beetle Desmocerus Californicus Dimorphus And Several Congeners (Cerambycidae: Lepturinae), A. M. Ray, R. A. Arnold, I. Swift, P. A. Schapker, S. Mccann, C. J. Marshall, J. S. Mcelfresh, J. G. Millar

Faculty Scholarship

We report here that (4R,9Z)-hexadec-9-en-4-olide [(R)-desmolactone] is a sex attractant or sex pheromone for multiple species and subspecies in the cerambycid genus Desmocerus. This compound was previously identified as a female-produced sex attractant pheromone of Desmocerus californicus californicus. Headspace volatiles from female Desmocerus aureipennis aureipennis contained (R)-desmolactone, and the antennae of adult males of two species responded strongly to synthetic (R)-desmolactone in coupled gas chromatography-electroantennogram analyses. In field bioassays in California, Oregon, and British Columbia, traps baited with synthetic (R)-desmolactone captured males of several Desmocerus species and subspecies. Only male beetles were captured, indicating that this compound acts as a …

Editorial Overview: Environmental Physiology: Insect Environmental Physiology, Brent J. Sinclair

Biology Publications

No abstract provided.

Beyond Race And Place: Distal Sociological Determinants Of Hiv Disparities, J. R. Robbins, M. Buot, J. P. Docena

Faculty Scholarship

Informed behavior change as an HIV prevention tool has yielded unequal successes across populations. Despite decades of HIV education, some individuals remain at high risk. The mainstream media often portrays these risk factors as products of race and national borders; however, a rich body of recent literature proposes a host of complex social factors that influence behavior, including, but not limited to: poverty, income inequality, stigmatizing social institutions and health care access. We examined the relationship between numerous social indicators and HIV incidence across eighty large U.S. cities in 1990 and 2000. During this time, major correlating factors included income …

Choosing And Using Diversity Indices: Insights For Ecological Applications From The German Biodiversity Exploratories, Kathyrn Morris, T Caruso, F. Buscot

Faculty Scholarship

Biodiversity, a multidimensional property of natural systems, is difficult to quantify partly because of the multitude of indices proposed for this purpose. Indices aim to describe general properties of communities that allow us to compare different regions, taxa, and trophic levels. Therefore, they are of fundamental importance for environmental monitoring and conservation, although there is no consensus about which indices are more appropriate and informative. We tested several common diversity indices in a range of simple to complex statistical analyses in order to determine whether some were better suited for certain analyses than others. We used data collected around the …

Evaluation Of Antibiotic Resistance Emerging From Use Of Antibiotics In Cafos, J. R. Robbins, D. Hellman, N. Pease, M. Costello

Faculty Scholarship

No abstract provided.

Doublesex Target Genes In The Red Flour Beetle, Tribolium Castaneum, Jayendra Nath Shukla, Subba Reddy Palli

Entomology Faculty Publications

Sex determination cascade in insects terminates with the production of sex-specific protein, Doublesex (Dsx). We identified the dsx homolog (Tcdsx) in Tribolium castaneum. The pre-mRNA of Tcdsx is sex-specifically spliced into three female (Tcdsxf1, Tcdsxf2 and Tcdsxf3) and one male-specific (Tcdsxm) isoforms. Cis-regulatory elements potentially involved in sex-specific splicing of the Tcdsx pre-mRNA were identified in the female-specific exon and the adjoining intronic sequences. All the three female-specific TcDsx proteins share common OD1 and OD2 domains and differ in their C-terminal sequences. Knockdown of Tcdsx resulted in a reduction in the oocyte development, egg production and hatching of eggs laid. …

Comparing The Midgut Regenerative Responses In Bacillus Thuringiensis-Susceptible And Resistant Heliothis Virescens Larvae, Anais Severiana Castagnola

Doctoral Dissertations

The crystal (Cry) toxins from Bacillus thuringiensis (Bt) display high specificity and toxicity against relevant insect pests and the use of Bt-based products continues to contribute to insect pest management. To protect this investment, further its potential, and investigate possible unintended effects, various research questions have been proposed. One issue related to Bt usage is the evolution of pest resistance to Bt toxins. The midgut epithelium is targeted by Cry toxins killing enterocytes, facilitating invasion of the hemocoel, leading to septicemia and mortality. While resistance may emerge from alterations to these steps, most research efforts have been focused on reduced …

Role Of Ecdysone Signaling In Fat Body Remodeling, Marsha Kristel Bernardo, N. Bond, Allen G. Gibbs

Undergraduate Research Opportunities Program (UROP)

Climate change is fundamentally connected to animal development and survival, and the life history of an organism must be coordinated with predictable seasonal changes of the environment. Climate change affects the life cycle of plants, a major food source for insects. If photoperiod, the primary environmental queue that insects utilize to determine the proper emergence time, and food availability becomes out of sync, many populations of insects and other animals could be threatened. Understanding animal development can provide insight into this issue and could provide clues that may help the scientific community predict how insect populations may respond to climate …

Ecological Correlates Of Buggy Creek Virus Infection In Oeciacus Vicarius, Southwestern Nebraska, 2004, Amy T. Moore, Eric A. Edwards, Mary Bomberger Brown, Nicholas Komar, Charles R. Brown

School of Natural Resources: Faculty Publications

Buggy Creek virus (family Togaviridae, genus Alphavirus, BCRV) is an alphavirus within the western equine encephalitis virus complex whose primary vector is the swallow bug, Oeciacus vicarius Horvath (Hemiptera: Cimicidae), an ectoparasite of the colonially nesting cliff swallow, Petrochelidon pyrrhonota, that is also a frequent host for the virus.We investigated ecological correlates of BCRV infection in 100-bug pools at 14 different swallow colony sites in southwestern Nebraska from summer 2004, by using plaque assay on Vero cells to identify cytopathic virus and reverse transcription-polymerase chain reaction to identify noncytopathic viral RNA. We found 26.7% of swallow bug pools …

The Effects Of Nematode Infection And Mi-Mediated Resistance In Tomato (Solanum Lycopersicum) On Plant Fitness, Brandon P. Corbett

Inquiry: The University of Arkansas Undergraduate Research Journal

The Mi gene in tomato (Solanum lycopersicum) is a single, dominant resistance (R) gene that confers resistance against several species of insects and root-knot nematodes. Tis study examined the impact of root-knot nematode infestation and the plant growth and reproduction of near-isogenic tomato cultivars with and without Mi. The objectives of this experiment were to examine the potential fitness costs and benefits of the R gene-mediated herbivore resistance, and to explore the role of nematodes as a selection pressure favoring plants that carry Mi. Mi-mediated resistance dramatically reduced nematode reproduction on tomato. In the presence of nematodes, plants that carried …

Exogenous Expression Of Human Na, K-Atpase Isoforms In Insect Cells, Christal Renee' Carpenter

McCabe Thesis Collection

The Na-K-ATPase or Na pump is a membrane bound enzyme that maintains a high concentration of K+ and low concentration of Na+ in most animal cells. Three subunits constitute the Na pump, named alpha (ex), beta (~). and gamma (y). The ex subunit is responsible for the catalytic and transport of the enzyme, the ~ subunit is important for bringing the ex to the plasma membrane of the cell, and y is a regulatory subunit of the Na pump. In addition, there are several molecular variants or isoforms of the ex and ~ subunits. At present four different ex (ex …

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

Biology Faculty Publications

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 …

Analysis Of Gene Expression During Embryonic Development In Mulberry Silkworm Bombyx Mori, Amit Singh, K. P. Gopinathan

Biology Faculty Publications

We have developed a method for dechorionation and devitellinization of the silkworm eggs without damage, to facilitate the analysis of gene expression during embryonic development of Bombyx mori. Making use of antibodies available from heterologous systems, the spatio-temporal expression patterns of peroxidase and proliferating cell nuclear antigen have been directly visualized in whole mount embryos at various stages of development without the need for generating transformed ·lines carrying specific reporter constructs. The B. mori system, previously unamenable for such studies, could thus serve as an attractive model for molecular analysis of insect development.

The attention lavished on Drosophila melanogaster as …

Survivorship And Growth Of Sexually And Asexually Derived Larvae Of Alsophila Pometaria (Lepidoptera: Geometridae), Lawrence G. Harshman, Douglas J. Futuyma

School of Biological Sciences: Faculty Publications

A substantial body of theory is devoted to understanding the relative advantages of sexual and asexual reproduction. It is generally understood that asexual forms potentially have a higher rate of reproduction because they save the cost of producing males. The micro-evolutionary consequences of sexual and asexual reproduction are less clear. Sexual reproduction generates abundant genotypic diversity which may be adaptively advantageous (Williams 1975; Maynard Smith 1978). Asexual reproduction may perpetuate combinations of genes that are co-adapted (Templeton 1979), heterotic (Suomalainen et al. 1976; White 1979), or specialized (Vrijenhoek 1979, 1984). Thus, it is possible that the fitness of a sexual …

Characterization Of The Dna And Chromosonal Analysis Of Embryonic Dermacentor Variabilis (Say) Cells In Culture, Stanley Nicholas Mason

Biological Sciences Theses & Dissertations

Cultured embryonic Dermacentor variabilis cells were examined by spectrophotometric techniques to determine total cellular DNA concentration and guanine-cytosine content of the DNA and by differential staining procedures to define the karyotype further. The cells were found to have a mean DNA content of 16.98 pg and a DNA guanine-cytosine content of 49%. Chromosome banding attempts resulted in the specific characterization of four chromosomes and differential grouping of the seven remaining chromosomes. A previously unreported submetacentric chromosome was identified.

Fine Structure Of The Nucleus And Cytoplasmic Feulgen-Positive Areas In The Developing Oocyte Of Argus (Persicargas) Radiatus, Bonnie J. Harding

Biological Sciences Theses & Dissertations

A transmission electron microscope analysis of the changes that occur in the nuclear chromatin and the Feulgen-positive areas of the oocyte cytoplasm as the female develops, feeds and mates is described. The description includes analysis of oocytes from three types of females: unfed, unmated; fed, unmated; and fed, mated. In all types, dense material passes through the extremely porous nuclear membrane where it accumulates in the cytoplasm.

Nuclei of previtellogenic oocytes appear the same in all females studied. Fibrillar bodies and up to four large nucleoli are seen. No typical chromatin is seen, but structures resembling nucleosomes appear throughout the …

A Histochemical Study Of The Ovary Of The Milkweed Bug Oncopeltus Fasciatus (Dallas), With Special Reference To The "Intermediate" Cell, Khian Kioe Liem

Masters Theses

No abstract provided.

The Relation Of Temperature To The Embryonic And Nymphal Development Of The Differential Grasshopper Melanoplus Differentialis Thomas, Myron H. Swenk, Charles H. Bratt

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

Temperature plays the major role in the regulation of the rate of embryonic development of the differential grasshopper (Melanoplus differentialis Thomas).

Spermatogenesis Of The Butterfly, Papilio Rutulus, John P. Munson

All Faculty Scholarship for the College of the Sciences

For a number of years I have been studying the spermatogenesis of Papilio rutulus (pl. 12, fig. 1) not ,with any one single problem especially in view, but with the aim of ascertaining the entire life history of its sperm cell, its various phases of development, its mode of growth and differentiation, the history of its several parts, and its relation to the organism.