Matching Items (18)
Filtering by
- All Subjects: Biology
- Creators: Rutowski, Ronald
Description
Though it is a widespread adaptation in humans and many other animals, parental care comes in a variety of forms and its subtle physiological costs, benefits, and tradeoffs related to offspring are often unknown. Thus, I studied the hydric, respiratory, thermal, and fitness dynamics of maternal egg-brooding behavior in Children's pythons (Antaresia childreni). I demonstrated that tight coiling detrimentally creates a hypoxic developmental environment that is alleviated by periodic postural adjustments. Alternatively, maternal postural adjustments detrimentally elevate rates of egg water loss relative to tight coiling. Despite ventilating postural adjustments, the developmental environment becomes increasingly hypoxic near the end of incubation, which reduces embryonic metabolism. I further demonstrated that brooding-induced hypoxia detrimentally affects offspring size, performance, locomotion, and behavior. Thus, parental care in A. childreni comes at a cost to offspring due to intra-offspring tradeoffs (i.e., those that reflect competing offspring needs, such as water balance and respiration). Next, I showed that, despite being unable to intrinsically produce body heat, A. childreni adjust egg-brooding behavior in response to shifts in nest temperature, which enhances egg temperature (e.g., reduced tight coiling during nest warming facilitated beneficial heat transfer to eggs). Last, I demonstrated that A. childreni adaptively adjust their egg-brooding behaviors due to an interaction between nest temperature and humidity. Specifically, females' behavioral response to nest warming was eliminated during low nest humidity. In combination with other studies, these results show that female pythons sense environmental temperature and humidity and utilize this information at multiple time points (i.e., during gravidity [egg bearing], at oviposition [egg laying], and during egg brooding) to enhance the developmental environment of their offspring. This research demonstrates that maternal behaviors that are simple and subtle, yet easily quantifiable, can balance several critical developmental variables (i.e., thermoregulation, water balance, and respiration).
ContributorsStahlschmidt, Zachary R (Author) / DeNardo, Dale F (Thesis advisor) / Harrison, Jon (Committee member) / McGraw, Kevin (Committee member) / Rutowski, Ronald (Committee member) / Walsberg, Glenn (Committee member) / Arizona State University (Publisher)
Created2011
Description
Land management practices such as domestic animal grazing can alter plant communities via changes in soil structure and chemistry, species composition, and plant nutrient content. These changes can affect the abundance and quality of plants consumed by insect herbivores with consequent changes in population dynamics. These population changes can translate to massive crop damage and pest control costs. My dissertation focused on Oedaleus asiaticus, a dominant Asian locust, and had three main objectives. First, I identified morphological, physiological, and behavioral characteristics of the migratory ("brown") and non-migratory ("green") phenotypes. I found that brown morphs had longer wings, larger thoraxes and higher metabolic rates compared to green morphs, suggesting that developmental plasticity allows greater migratory capacity in the brown morph of this locust. Second, I tested the hypothesis of a causal link between livestock overgrazing and an increase in migratory swarms of O. asiaticus. Current paradigms generally assume that increased plant nitrogen (N) should enhance herbivore performance by relieving protein-limitation, increasing herbivorous insect populations. I showed, in contrast to this scenario, that host plant N-enrichment and high protein artificial diets decreased the size and viability of O. asiaticus. Plant N content was lowest and locust abundance highest in heavily livestock-grazed fields where soils were N-depleted, likely due to enhanced erosion and leaching. These results suggest that heavy livestock grazing promotes outbreaks of this locust by reducing plant protein content. Third, I tested for the influence of dietary imbalance, in conjunction with high population density, on migratory plasticity. While high population density has clearly been shown to induce the migratory morph in several locusts, the effect of diet has been unclear. I found that locusts reared at high population density and fed unfertilized plants (i.e. high quality plants for O. asiaticus) had the greatest migratory capacity, and maintained a high percent of brown locusts. These results did not support the hypothesis that poor-quality resources increased expression of migratory phenotypes. This highlights a need to develop new theoretical frameworks for predicting how environmental factors will regulate migratory plasticity in locusts and perhaps other insects.
ContributorsCease, Arianne (Author) / Harrison, Jon (Thesis advisor) / Elser, James (Thesis advisor) / DeNardo, Dale (Committee member) / Quinlan, Michael (Committee member) / Sabo, John (Committee member) / Arizona State University (Publisher)
Created2012
Description
Skeletal muscles arise from the myotome compartment of the somites that form during vertebrate embryonic development. Somites are transient structures serve as the anlagen for the axial skeleton, skeletal muscle, tendons, and dermis, as well as imposing the metameric patterning of the axial musculoskeletal system, peripheral nerves, and vasculature. Classic studies have described the role of Notch, Wnt, and FGF signaling pathways in controlling somite formation and muscle formation. However, little is known about the transformation of myotome compartments into identifiable post-natal muscle groups. Using a mouse model, I have undertaken an evaluation of morphological events, including hypertrophy and hyperplasia, related to the formation of several muscles positioned along the dorsal surface of the vertebrae and ribs. Lunatic fringe (Lfng) deficient embryos and neonates were also examined to further understand the role of the Notch pathway in these processes as it is a modulator of the Notch receptor and plays an important role in defining somite borders and anterior-posterior patterning in many vertebrates. Lunatic fringe deficient embryos showed defects in muscle fiber hyperplasia and hypertrophy in the iliocostalis and longissimus muscles of the erector spinae group. This novel data suggests an additional role for Lfng and the Notch signaling pathway in embryonic and fetal muscle development.
ContributorsDe Ruiter, Corinne (Author) / Rawls, J. Alan (Thesis advisor) / Wilson-Rawls, Jeanne (Committee member) / Kusumi, Kenro (Committee member) / Fisher, Rebecca E. (Committee member) / Arizona State University (Publisher)
Created2012
Description
Conditions during development can shape the expression of traits at adulthood, a phenomenon called developmental plasticity. In this context, factors such as nutrition or health state during development can affect current and subsequent physiology, body size, brain structure, ornamentation, and behavior. However, many of the links between developmental and adult phenotype are poorly understood. I performed a series of experiments using a common molecular currency - carotenoid pigments - to track somatic and reproductive investments through development and into adulthood. Carotenoids are red, orange, or yellow pigments that: (a) animals must acquire from their diets, (b) can be physiologically beneficial, acting as antioxidants or immunostimulants, and (c) color the sexually attractive features (e.g., feathers, scales) of many animals. I studied how carotenoid nutrition and immune challenges during ontogeny impacted ornamental coloration and immune function of adult male mallard ducks (Anas platyrhynchos). Male mallards use carotenoids to pigment their yellow beak, and males with more beaks that are more yellow are preferred as mates, have increased immune function, and have higher quality sperm. In my dissertation work, I established a natural context for the role that carotenoids and body condition play in the formation of the adult phenotype and examined how early-life experiences, including immune challenges and dietary access to carotenoids, affect adult immune function and ornamental coloration. Evidence from mallard ducklings in the field showed that variation in circulating carotenoid levels at hatch are likely driven by maternal allocation of carotenoids, but that carotenoid physiology shifts during the subsequent few weeks to reflect individual foraging habits. In the lab, adult beak color expression and immune function were more tightly correlated with body condition during growth than body condition during subsequent stages of development or adulthood. Immune challenges during development affected adult immune function and interacted with carotenoid physiology during adulthood, but did not affect adult beak coloration. Dietary access to carotenoids during development, but not adulthood, also affected adult immune function. Taken together, these results highlight the importance of the developmental stage in shaping certain survival-related traits (i.e., immune function), and lead to further questions regarding the development of ornamental traits.
ContributorsButler, Michael (Author) / McGraw, Kevin J. (Thesis advisor) / Chang, Yung (Committee member) / Deviche, Pierre (Committee member) / DeNardo, Dale (Committee member) / Rutowski, Ronald (Committee member) / Arizona State University (Publisher)
Created2012
Description
Triops (Branchiopoda: Notostraca) and Streptocephalus (Branchiopoda: Anostraca) are two crustaceans which cohabitate in ephemeral freshwater pools. They both lay desiccation resistant eggs that disperse passively to new hydrologically isolated environments. The extent of genetic distance among regions and populations is of perennial interest in animals that live in such isolated habitats. Populations in six natural ephemeral pool habitats located in two different regions of the Sonoran Desert and a transition area between the Sonoran and Chihuahuan Deserts were sampled. Sequences from Genbank were used for reference points in the determination of species as well as to further identify regional genetic distance within species. This study estimated the amount of within and between genetic distance of individuals from each region and population through the use of a neutral marker, cytochrome oxidase I (COI). We concluded that, although the method of passive dispersal may differ between the two genera, the differences do not results in different patterns of genetic distances between regions and populations. Furthermore, we only found the putative species, Triops longicaudatus "short", with enough distinct speciation. Although Triops longicaudatus "long" and Triops newberryi may be in the early stages of speciation, this study does not find enough support to conclude that they have separated.
ContributorsMurphy Jr., Patrick Joseph (Author) / Rutowski, Ronald (Thesis director) / Cartwright, Reed (Committee member) / Lessios, Nikos (Committee member) / School of Life Sciences (Contributor) / School of Human Evolution and Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The giant green sea anemone, Anthopleura xanthogrammica, hosts two different endosymbiotic algae. One is a unicellular chlorophyte, Elliptochloris marina; the other is Symbiodinium muscatinei, a dinoflagellate. Hosting these different symbionts influences the life history strategy of A. xanthogrammica's congener A. elegantissima, directly impacting its reproductive strategy (asexual vs. sexual). My study sought to examine whether the type and density of symbiont also affects the reproductive condition of A. xanthogrammica, which reproduces only sexually. Gonad development was measured in anemones from Slip Point, Clallam Bay, WA and Tongue Point, WA along with symbiont type and density per mg of anemone protein. The results indicate a trend towards brown anemones having more developed gonads, especially in males. This may mean that A. xanthogrammica anemones that host zooxanthellae are more reproductively fit than zoochlorellate anemones. Thus, it may be favorable for anemones to host zooxanthellae. This is especially true in summer months when the high temperatures and mid-day low tides coincide with the period of most rapid gonad development.
ContributorsGasbarro, Ryan Patrick (Author) / Neuer, Susanne (Thesis director) / Rutowski, Ronald (Committee member) / Bingham, Brian (Committee member) / Barrett, The Honors College (Contributor) / School of Earth and Space Exploration (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Pollinator populations globally have declined at concerning rates in recent years, which is problematic given that roughly a third of all food production depends on them. Managed honey bee colony losses in particular have alarmed beekeepers and scientists, especially in the United States. Widespread agrochemical use has been implicated as one of the major causes of these colony losses. While the lethal effects of agrochemicals often receive the most attention, sublethal effects can occur at lower doses and can substantially weaken colonies over time. Impaired associative learning ability is a sublethal effect of a number of agrochemicals, and is particularly concerning, as it may hinder the abilities of bees to forage for food or find their way back to the colony. Here, I focus on the fungicide Pristine® (active ingredients: 25.2% boscalid, 12.8% pyraclostrobin), which is sprayed on honey bee-pollinated crops during bloom and is known to poison bee mitochondria at ppm levels. First, I show that Pristine® impairs performance on an associative learning assay in the laboratory. Next, I show that Pristine® alters carbohydrate absorption in honey bees, providing a possible mechanism underlying this impaired learning performance. Finally, I demonstrate that Pristine® interacts with high temperatures to induce homing failure in exposed bees. My results raise concerns that this common fungicide may not be safe for pollinators and will be relevant to policymakers as they make decisions surrounding the regulation of fungicide use in agriculture.
ContributorsDesJardins, Nicole (Author) / Harrison, Jon F (Thesis advisor) / Smith, Brian H (Thesis advisor) / DeGrandi-Hoffman, Gloria (Committee member) / DeNardo, Dale (Committee member) / Pratt, Stephen (Committee member) / Arizona State University (Publisher)
Created2023
Description
Wound healing is a complex tissue response that requires a coordinated interplay of multiple cells in orchestrated biological processes to restore the skin's barrier function post-injury. Proteolytic enzymes, in particular matrix metalloproteinases (MMPs), contribute to all phases of the healing process by regulating immune cell influx, clearing out the extracellular matrix (ECM), and remodeling scar tissue. As a result of these various functions in the healing of skin wounds, uncontrolled activities of MMPs are associated with impaired wound healing. The MMP gene family consists of a highly conserved set of genes. Deleterious mutations in MMP genes cause developmental phenotypes that affect the heart, skeleton, and immune system response.
The availability of contiguous draft genomes of non-model organisms enables the study of gene families through analysis of synteny and sequence identity. My project is aimed at conducting a comparative genomic analysis of the MMP gene family from the genomes of 29 tetrapod species—with an emphasis on reptiles. Results regarding the similarities and differences among MMP protein sequences can be further investigated to shed light on the causes which give rise to various adaptive mutations for specific species groups.
ContributorsYu, Alexander (Author) / Kusumi, Kenro (Thesis director) / Dolby, Greer (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2022-12
Description
Structural Equation Modeling (SEM) is a multivariate analysis methodology that could potentially be utilized to examine the barrier effect that river systems have on genetic differentiation. In this project, river systems are split into the variables of Daily Average Discharge, Average River Width, and Seasonality measurements and regressed onto the genetic differentiation, measured as Fst. This data was collected from the USGS database (U.S. Geological Survey, 2020), sequencing files from differing literature, or Google Earth measurements. Different Structural Equation Modeling models are used to model different system structures as well as compare it to more traditional methodologies like Generalized Linear Modeling and Generalized Linear Mixed Modeling. Ultimately results were limited by the small sample size, however, interesting patterns still emerged from the models. The SE models indicate that Discharge plays a primary role in the genetic differentiation of adjacent river populations. In addition to this, the results demonstrate how quantification of indirect effects, particularly those relating to discharge, give more informative interpretations than traditional multivariate statistics alone. These findings prompt further investigations into this potential methodology.
ContributorsMaag, Garett (Author) / Dolby, Greer A. (Thesis advisor) / Kusumi, Kenro (Thesis advisor) / Stokes, Maya F. (Committee member) / Barly, Anthony (Committee member) / Arizona State University (Publisher)
Created2023
Description
Body size plays a pervasive role in determining physiological and behavioral performance across animals. It is generally thought that smaller animals are limited in performance measures compared to larger animals; yet, the vast majority of animals on earth are small and evolutionary trends like miniaturization occur in every animal clade. Therefore, there must be some evolutionary advantages to being small and/or compensatory mechanisms that allow small animals to compete with larger species. In this dissertation I specifically explore the scaling of flight performance (flight metabolic rate, wing beat frequency, load-carrying capacity) and learning behaviors (visual differentiation visual Y-maze learning) across stingless bee species that vary by three orders of magnitude in body size. I also test whether eye morphology and calculated visual acuity match visual differentiation and learning abilities using honeybees and stingless bees. In order to determine what morphological and physiological factors contribute to scaling of these performance parameters I measure the scaling of head, thorax, and abdomen mass, wing size, brain size, and eye size. I find that small stingless bee species are not limited in visual learning compared to larger species, and even have some energetic advantages in flight. These insights are essential to understanding how small size evolved repeatedly in all animal clades and why it persists. Finally, I test flight performance across stingless bee species while varying temperature in accordance with thermal changes that are predicted with climate change. I find that thermal performance curves varied greatly among species, that smaller species conform closely to air temperature, and that larger bees may be better equipped to cope with rising temperatures due to more frequent exposure to high temperatures. This information may help us predict whether small or large species might fare better in future thermal climate conditions, and which body-size related traits might be expected to evolve.
ContributorsDuell, Meghan (Author) / Harrison, Jon F. (Thesis advisor) / Smith, Brian H. (Thesis advisor) / Rutowski, Ronald (Committee member) / Wcislo, William (Committee member) / Conrad, Cheryl (Committee member) / Arizona State University (Publisher)
Created2018