Life Sciences Commons^™

A Novel Subcluster Of Closely Related Bacillus Phages With Distinct Tail Fiber/Lysin Gene Combinations, Rachel E. Loney, Veronique A. Delesalle, Brianne E. Chaudhry, Megan Czerpak, Alexandra A. Guffey, Leo Goubet-Mccall, Michael Mccarty, Madison S. Strine, Natalie T. Tanke, Albert C. Vill, Gregory P. Krukonis

Biology Faculty Publications

Bacteriophages (phages) are the most numerous entities on Earth, but we have only scratched the surface of describing phage diversity. We isolated seven Bacillus subtilis phages from desert soil in the southwest United States and then sequenced and characterized their genomes. Comparative analyses revealed high nucleotide and amino acid similarity between these seven phages, which constitute a novel subcluster. Interestingly, the tail fiber and lysin genes of these phages seem to come from different origins and carry out slightly different functions. These genes were likely acquired by this subcluster of phages via horizontal gene transfer. In conjunction with host range …

Dopamine Injections To The Midbrain Periaqueductal Gray Inhibit Vocal-Motor Production In A Teleost Fish, Alexander Allen, Elizabeth Heisler, James Matthew Kittelberger

Biology Faculty Publications

Across vertebrates, the midbrain periaqueductal gray (PAG) plays a critical role in social and vocal behavior. Dopaminergic neurotransmission also modulates these behaviors, and dopaminergic innervation of the PAG has been well documented. Nonetheless, the potential role of dopamine in shaping vocal production at the level of the PAG is not well understood. Here, we tested the hypothesis that dopamine modulates vocal production in the PAG, using a well-characterized vertebrate model system for the study of vocal communication, the plainfin midshipman fish, Porichthys notatus. We found that focal dopamine injections to the midshipman PAG rapidly and reversibly inhibited vocal production …

Ca2+ Entry Units In A Superfast Fish Muscle, James Matthew Kittelberger, Clara Franzini-Armstrong, Simona Boncompagni

Biology Faculty Publications

Over the past two decades, mounting evidence has demonstrated that a mechanism known as store-operated Ca2+ entry (SOCE) plays a crucial role in sustaining skeletal muscle contractility by facilitating Ca2+ influx from the extracellular space during sarcoplasmic reticulum (SR) Ca2+ depletion. We recently demonstrated that, in exercised fast-twitch muscle from mice, the incidence of Ca2+ entry units (CEUs), newly described intracellular junctions between dead-end longitudinal transverse tubular (T-tubule) extensions and stacks of sarcoplasmic reticulum (SR) flat cisternae, strictly correlate with both the capability of fibers to maintain contractions during fatigue and enhanced Ca2+ influx via SOCE. Here, we tested the …

Forty Years Without Family: Three Novel Bacteriophages With High Similarity To Spp1 Reveal Decades Of Evolutionary Stasis Since The Isolation Of Their Famous Relative, Veronique A. Delesalle, Brianne E. Tomko, Albert C. Vill, Katherine B. Lichty, Gregory P. Krukonis

Biology Faculty Publications

SPP1, an extensively studied bacteriophage of the Gram-positive Bacillus subtilis, is a model system for the study of phage–host interactions. Despite progress in the isolation and characterization of Bacillus phages, no previously fully sequenced phages have shared more than passing genetic similarity to SPP1. Here, we describe three virulent phages very similar to SPP1; SPP1 has greater than 80% nucleotide sequence identity and shares more that 85% of its protein coding genes with these phages. This is remarkable, given more than 40 years between the isolation of SPP1 and these phages. All three phages have somewhat larger genomes and more …

Complete Genome Sequences Of Two Temperate Bacillus Subtilis Phages Isolated At Tumamoc Hill Desert Laboratory, Gregory P. Krukonis, Amanda K. Kemp, Katie F. Storrie, Vivian R. Chavira, Hayden W. Lantrip, Victoria D. Perez, Desiree A. Reyes, Julian A. Truax, Rachel Loney, Veronique A. Delesalle

Biology Faculty Publications

Bacteriophages are important in structuring bacterial communities, including desert soils dominated by Bacillus species. Here, we describe two genetically similar temperate phages isolated on a Bacillus subtilis strain from soil in Tucson, Arizona. Their double-stranded DNA (dsDNA) genomes contain 98 and 102 genes, with a set of 4 genes being found in only one phage.

Developmental Basis Of Evolutionary Lung Loss In Plethodontid Salamanders, Zachary R. Lewis, Ryan R. Kerney, James Hanken

Biology Faculty Publications

One or more members of four living amphibian clades have independently dispensed with pulmonary respiration and lack lungs, but little is known of the developmental basis of lung loss in any taxon. We use morphological, molecular, and experimental approaches to examine the Plethodontidae, a dominant family of salamanders, all of which are lungless as adults. We confirm an early anecdotal report that plethodontids complete early stages of lung morphogenesis: Transient embryonic lung primordia form but regress by apoptosis before hatching. Initiation of pulmonary development coincides with expression of the lung-specification gene Wnt2b in adjacent mesoderm, and the lung rudiment expresses …

Cold Shock Induces A Terminal Investment Reproductive Response In C. Elegans, Leah Gulyas, Jennifer R. Powell

Biology Faculty Publications

Challenges from environmental stressors have a profound impact on many life-history traits of an organism, including reproductive strategy. Examples across multiple taxa have demonstrated that maternal reproductive investment resulting from stress can improve offspring survival; a form of matricidal provisioning when death appears imminent is known as terminal investment. Here we report a reproductive response in the nematode Caenorhabditis elegans upon exposure to acute cold shock at 2 °C, whereby vitellogenic lipid movement from the soma to the germline appears to be massively upregulated at the expense of parental survival. This response is dependent on functional TAX-2; TAX-4 cGMP-gated channels …

Complete Genome Sequences Of Four Phages Of The Horse Chestnut Phyllosphere, Gregory P. Krukonis, Sam J. Roth, Veronique A. Delesalle

Biology Faculty Publications

Bacteriophages play important roles in determining bacterial communities, including plant microbiota. Here, we describe four lytic phages, three Siphoviridae and one Podoviridae, isolated from four different bacterial species found on the leaves of horse chestnut trees. Their double-stranded DNA (dsDNA) genomes range from 39,095 to 46,062 bp and contain 51 to 70 genes.

Complete Genome Sequence Of The Pantoea Phage Ah07, Gregory P. Krukonis, Sam J. Roth, Veronique A. Delesalle

Biology Faculty Publications

Bacteriophages of the phyllosphere have not been extensively described, despite their role in bacterial communities on this plant organ. Here, we describe a temperate Pantoea phage, AH07, that was isolated from the leaves of horse chestnut trees. The 37,859-bp linear double-stranded DNA genome contains 58 putative genes, including an integration cassette.

Genome Sequences Of Erwinia Phyllophages Ah04 And Ah06, Gregory P. Krukonis, Sam J. Roth, Veronique A. Delesalle

Biology Faculty Publications

Although crucial in shaping bacterial communities, few bacteriophages of the phyllosphere have been described. We provide genome data for two Myoviridae phages, AH04 and AH06, isolated on Erwinia billingiae strains. AH04 shares limited genetic similarity with previously described phages, while AH06 shares over 75% similarity with various Erwinia phages.

Developing Inside A Layer Of Germs—A Potential Role For Multiciliated Surface Cells In Vertebrate Embryos, Ryan R. Kerney

Biology Faculty Publications

This paper reviews current research on the microbial life that surrounds vertebrate embryos. Several clades are believed to develop inside sterile—or near-sterile—embryonic microhabitats, while others thrive within a veritable zoo of microbial life. The occurrence of embryo-associated microbes in some groups, but not others, is an under-appreciated transition (possibly transitions) in vertebrate evolution. A lack of comparable studies makes it currently impossible to correlate embryo-associated microbiomes with other aspects of vertebrate evolution. However, there are embryonic features that should instruct a more targeted survey. This paper concludes with a hypothesis for the role of multiciliated surface cells in amphibian and …

Diversity And Substrate-Specificity Of Green Algae And Other Micro-Eukaryotes Colonizing Amphibian Clutches In Germany, Revealed By Dna Metabarcoding, Sten Anslan, Maria Sachs, Lois Rancilhac, Henner Brinkmann, Jörn Petersen, Sven Künzel, Anja Schwarz, Hartmut Arndt, Ryan R. Kerney, Miguel Vences

Biology Faculty Publications

Amphibian clutches are colonized by diverse but poorly studied communities of micro-organisms. One of the most noted ones is the unicellular green alga, Oophila amblystomatis, but the occurrence and role of other micro-organisms in the capsular chamber surrounding amphibian clutches have remained largely unstudied. Here, we undertook a multi-marker DNA metabarcoding study to characterize the community of algae and other micro-eukaryotes associated with agile frog (Rana dalmatina) clutches. Samplings were performed at three small ponds in Germany, from four substrates: water, sediment, tree leaves from the bottom of the pond, and R. dalmatina clutches. Sampling substrate strongly …

Comparative Study Of The Rates Of Dispersal Of Triadica Sebifera (Chinese Tallow) And Imperata Cylindrica (Japanese Blood Grass) In North America, Jamie W. Dinella, Meem Noshin Nawal Khan

Student Publications

Chinese Tallow (Triadica sebifera) and Japanese Blood Grass (Imperata cylindrica) are two invasive species that wreck havoc on their invaded areas by reducing the biodiversity of their new environments. We studied the rate of dispersal of these two species in North America to determine which species spreads faster. We hypothesized that Chinese Tallow spreads faster than Japanese Blood Grass since Chinese Tallow was introduced in North America long before Japanese Blood Grass and has a greater number of seed dispersal methods (e.g. wind, water, bird, etc.) than Japanese Blood Grass. To test our hypothesis, we collected the record of Chinese …

Heterotrophic Carbon Fixation In A Salamander-Alga Symbiosis, John A. Burns, Ryan Kerney, Solange Duhamel

Biology Faculty Publications

The unique symbiosis between a vertebrate salamander, Ambystoma maculatum, and unicellular green alga, Oophila amblystomatis, involves multiple modes of interaction. These include an ectosymbiotic interaction where the alga colonizes the egg capsule, and an intracellular interaction where the alga enters tissues and cells of the salamander. One common interaction in mutualist photosymbioses is the transfer of photosynthate from the algal symbiont to the host animal. In the A. maculatum–O. amblystomatis interaction, there is conflicting evidence regarding whether the algae in the egg capsule transfer chemical energy captured during photosynthesis to the developing salamander embryo. In experiments …

Embryonic Development Of The Pharyngeal Arch Arteries In Mammals, Megan E. Zierold

Student Publications

The pharyngeal arch arteries (PAAs) in mammals undergo asymmetric remodeling to give rise to the major blood vessels. The first and second PAAs form rudimentarily in mammalian embryos and eventually regress as the third, fourth, and sixth PAAs predominate. Cell migration, proliferation, and apoptosis drive the remodeling process, stimulated by a number of underlying molecular mechanisms. Sonic hedgehog, Hox genes, Tgfβ2, Tbx1, and a number of transcription regulators all influence PAA morphogenesis. Tbx1, which is found in the deleted region of Chromosome 22 in DiGeorge Syndrome patients, forms anterior-to-posterior and medial-tolateral gradients in the developing PAA system to promote remodeling. …

Artful Nature And The Legacy Of Maria Sibylla Merian, Emily N. Roush, Shannon R. Zeltmann, Felicia M. Else, Kay Etheridge, Shannon Egan

Schmucker Art Catalogs

The exhibition Artful Nature and the Legacy of Maria Sibylla Merian celebrates the skills and influences of a remarkable woman from seventeenth-century Europe. Curated by Emily Roush ’21 and Shannon Zeltmann ’21 with the guidance of Professors Kay Etheridge (Biology) and Felicia Else (Art History), Emily and Shannon selected the prints, organized them into categories, and carried out research on them, much of which was relatively obscure and would have been challenging even for graduate students.

Maria Sibylla Merian lived and worked in a time of vibrant intersections of art and science in Europe. Her images of insects and plants …

The Influence Of Signaling Conspecific And Heterospecific Neighbors On Eavesdropper Pressure, Paula A. Trillo, Christopher S. Benson, Michael S. Caldwell, Tiffany L. Lam, Oliver H. Pickering, David M. Logue

Biology Faculty Publications

The study of tradeoffs between the attraction of mates and the attraction of eavesdropping predators and parasites has generally focused on a single species of prey, signaling in isolation. In nature, however, animals often signal from mixed-species aggregations, where interactions with heterospecific group members may be an important mechanism modulating tradeoffs between sexual and natural selection, and thus driving signal evolution. Although studies have shown that conspecific signalers can influence eavesdropper pressure on mating signals, the effects of signaling heterospecifics on eavesdropper pressure, and on the balance between natural and sexual selection, are likely to be different. Here, we review …

Predicting The Future: Parental Progeny Investment In Response To Environmental Stress Cues, Leah Gulyas, Jennifer R. Powell

Biology Faculty Publications

Environmental stressors can severely limit the ability of an organism to reproduce as lifespan is decreased and resources are shifted away from reproduction to survival. Although this is often detrimental to the organism’s reproductive fitness, certain other reproductive stress responses may mitigate this effect by increasing the likelihood of progeny survival in the F1 and subsequent generations. Here we review three means by which these progeny may be conferred a competitive edge as a result of stress encountered in the parental generation: heritable epigenetic modifications to nucleotides and histones, simple maternal investments of cytosolic components, and the partially overlapping phenomenon …

Leonardo And The Whale, Kay Etheridge

Biology Faculty Publications

Around 1480, when he was 28 years old, Leonardo da Vinci recorded what may have been a seminal event in his life. In writing of his travels to view nature he recounted an experience in a cave in the Tuscan countryside:

Having wandered for some distance among overhanging rocks, I can to the entrance of a great cavern... [and after some hesitation I entered] drawn by a desire to see whether there might be any marvelous thing within..."

[excerpt]

Co-Cultures Of Oophila Amblystomatis Between Ambystoma Maculatum And Ambystoma Gracile Hosts Show Host-Symbiont Fidelity, Ryan R. Kerney, Jasper S. Leavitt, Elizabeth M. Hill, Huanjia Zhang, Eunsoo Kim, John Burns

Biology Faculty Publications

A unique symbiosis occurs between embryos of the spotted salamander (Ambystoma maculatum) and a green alga (Oophila amblystomatis). Unlike most vertebrate host-symbiont relationships, which are ectosymbiotic, A. maculatum exhibits both an ecto- and an endo-symbiosis, where some of the green algal cells living inside egg capsules enter embryonic tissues as well as individual salamander cells. Past research has consistently categorized this symbiosis as a mutualism, making this the first example of a “beneficial” microbe entering vertebrate cells. Another closely related species of salamander, Ambystoma gracile, also harbors beneficial Oophila algae in its egg capsules. However, our …

High-Resolution Identification Of Multiple Salmonella Serovars In A Single Sample By Using Crispr-Seroseq, Cameron P. Thompson, Alexandra N. Doak, Naufa Amirani, Erin A. Schroeder, Justin Wright, Subhashinie Kariyawasam, Regina Lamendella, Nikki Shariat

Biology Faculty Publications

Salmonella enterica is represented by >2,600 serovars that can differ in routes of transmission, host colonization, and in resistance to antimicrobials. S. enterica is the leading bacterial cause of foodborne illness in the United States, with well-established detection methodology. Current surveillance protocols rely on the characterization of a few colonies to represent an entire sample; thus, minority serovars remain undetected. Salmonella contains two CRISPR loci, CRISPR1 and CRISPR2, and the spacer contents of these can be considered serovar specific. We exploited this property to develop an amplicon-based and multiplexed sequencing approach, CRISPR-SeroSeq (serotyping by sequencing of the CRISPR loci), to …

Algae Living In Salamanders, Friend Or Foe?, John Burns, Ryan R. Kerney

Biology Faculty Publications

Roughly speaking, our bodies use energy from the sun, but we can't use sunlight directly. Instead, plants and algae collect sunlight and store it as chemical energy through the process of photosynthesis. We can access that fuel directly when we eat plants, or indirectly when we eat other animals that eat plants.

However, in some invertebrate animals (those without a backbone) the relationships to algae are more intimate. Tiny single-celled algal "symbionts" can actually live inside the cells of living corals and small animals like hydra that live in water. The algae live in a safe environment inside animal …

Early Limb Patterning In The Direct‐Developing Salamander Plethodon Cinereus Revealed By Sox9 And Col2a1, Ryan R. Kerney, James Hanken, David C. Blackburn

Biology Faculty Publications

Direct‐developing amphibians form limbs during early embryonic stages, as opposed to the later, often postembryonic limb formation of metamorphosing species. Limb patterning is dramatically altered in direct‐developing frogs, but little attention has been given to direct‐developing salamanders. We use expression patterns of two genes, sox9and col2a1, to assess skeletal patterning during embryonic limb development in the direct‐developing salamander Plethodon cinereus. Limb patterning in P. cinereus partially resembles that described in other urodele species, with early formation of digit II and a generally anterior‐to‐posterior formation of preaxial digits. Unlike other salamanders described to date, differentiation of preaxial zeugopodial …

Characterization Of Pax3 And Sox10 Transgenic Xenopus Laevis Embryos As Tools To Study Neural Crest Development, Mansour Alkobtawi, Heather Ray, Elias H. Barriga, Mauricio Moreno, Ryan R. Kerney, Anne-Helene Monsoro-Burq, Jean-Pierre Saint-Jeannet, Roberto Mayor

Biology Faculty Publications

The neural crest is a multipotent population of cells that originates a variety of cell types. Many animal models are used to study neural crest induction, migration and differentiation, with amphibians and birds being the most widely used systems. A major technological advance to study neural crest development in mouse, chick and zebrafish has been the generation of transgenic animals in which neural crest specific enhancers/promoters drive the expression of either fluorescent proteins for use as lineage tracers, or modified genes for use in functional studies. Unfortunately, no such transgenic animals currently exist for the amphibians Xenopus laevis and tropicalis, …

Ryan Kerney, Assistant Professor Of Biology, Musselman Library, Ryan R. Kerney

Next Page

In this last Next Page column of 2017, Ryan Kerney, Assistant Professor of Biology, shares some of his favorite science writers in the field of “evo devo;” his go-to science news sources and podcasts (note: “This Week in Parasitism” is a must-listen!); what he would ask Charles Darwin if given the chance; which books he likes to give as gifts; his favorite author of all time; and where he finds great recommendations for what to read next.

Differential Uptake Of Gold Nanoparticles By 2 Species Of Tadpole, The Wood Frog (Lithobates Sylvaticus) And The Bullfrog (Lithobates Catesbeianus), Lucas B. Thompson, Gerardo L.F. Carfagno, Kurt Andresen, Andrea J. Sitton, Taylor B. Bury, Laura L. Lee, Kevin T. Lerner, Peter P. Fong

Biology Faculty Publications

Engineered nanoparticles are aquatic contaminants of emerging concern that exert ecotoxicological effects on a wide variety of organisms. We exposed cetyltrimethylammonium bromide–capped spherical gold nanoparticles to wood frog and bullfrog tadpoles with conspecifics and in combination with the other species continuously for 21 d, then measured uptake and localization of gold. Wood frog tadpoles alone and in combination with bullfrog tadpoles took up significantly more gold than bullfrogs. Bullfrog tadpoles in combination with wood frogs took up significantly more gold than controls. The rank order of weight-normalized gold uptake was wood frogs in combination > wood frogs alone > bullfrogs in combination …

Transciptome Analysis Illuminates The Nature Of The Intracellular Interaction In A Vertebrate-Algal Symbiosis, John A. Burns, Huanjia Zhang, Elizabeth M. Hill, Eunsoo Kim, Ryan R. Kerney

Biology Faculty Publications

During embryonic development, cells of the green alga Oophila amblystomatis enter cells of the salamander Ambystoma maculatum forming an endosymbiosis. Here, using de novo dual-RNA seq, we compared the host salamander cells that harbored intracellular algae to those without algae and the algae inside the animal cells to those in the egg capsule. This two-by-two-way analysis revealed that intracellular algae exhibit hallmarks of cellular stress and undergo a striking metabolic shift from oxidative metabolism to fermentation. Culturing experiments with the alga showed that host glutamine may be utilized by the algal endosymbiont as a primary nitrogen source. Transcriptional changes in …

Mating Patterns And Post-Mating Isolation In Three Cryptic Species Of The Engystomops Petersi Species Complex, Paula A. Trillo, Andrea E. Narvaez, Santiago R. Ron, Kim L. Hoke

Biology Faculty Publications

Determining the extent of reproductive isolation in cryptic species with dynamic geographic ranges can yield important insights into the processes that generate and maintain genetic divergence in the absence of severe geographic barriers. We studied mating patterns, propensity to hybridize in nature and subsequent fertilization rates, as well as survival and development of hybrid F₁ offspring for three nominal species of the Engystomops petersi species complex in Yasuní National Park, Ecuador. We found at least two species in four out of six locations sampled, and 14.3% of the wild pairs genotyped were mixed-species (heterospecific) crosses. We also found reduced …

Comparative Postembryonic Skeletal Ontogeny In Two Sister Lineages Of Old World Tree Frogs (Rhacophoridae: Taruga, Polypedates), Gayani Senevirathne, Ryan R. Kerney, Madhava Meegaskumbura

Biology Faculty Publications

Rhacophoridae, a family of morphologically cryptic frogs, with many genetically distinct evolutionary lineages, is understudied with respect to skeletal morphology, life history traits and skeletal ontogeny. Here we analyze two species each from two sister lineages, Taruga and Polypedates, and compare their postembryonic skeletal ontogeny, larval chondrocrania and adult osteology in the context of a well-resolved phylogeny. We further compare these ontogenetic traits with the direct-developing Pseudophilautus silus. For each species, we differentially stained a nearly complete developmental series of tadpoles from early postembryonic stages through metamorphosis to determine the intraspecific and interspecific differences of cranial and postcranial …

The Feasibility Of Counting Songbirds Using Unmanned Aerial Vehicles, Andrew M. Wilson, Janine M. Barr, Megan E. Zagorski

Environmental Studies Faculty Publications

Obtaining unbiased survey data for vocal bird species is inherently challenging due to observer biases, habitat coverage biases, and logistical constraints. We propose that combining bioacoustic monitoring with unmanned aerial vehicle (UAV) technology could reduce some of these biases and allow bird surveys to be conducted in less accessible areas. We tested the feasibility of the UAV approach to songbird surveys using a low-cost quadcopter with a simple, lightweight recorder suspended 8 m below the vehicle. In a field experiment using playback of bird recordings, we found that small variations in UAV altitude (it hovered at 28, 48, and 68 …