Biology Commons^™

Coastal Marine Heatwaves In The Santa Barbara Channel: Decadal Trends And Ecological Implications, Kit Yu Karen Chan, L. Kui, A. M. Mcdonald, A. L. Ritger, G. E. Hofmann

Biology Faculty Works

Marine heatwaves (MHWs) are of increasing concern due to the emerging ecological and socioeconomic impacts on coastal ecosystems. Leveraging the data of the Santa Barbara Coastal Long-Term Ecological Research project, we analyzed the MHW event metrics observed in the kelp forest ecosystem and across Santa Barbara Channel, CA, USA. Not only was there a significant positive trend in the number of MHWs recorded, their duration and intensity were also increasing over time. MHWs were detected year-round, suggesting that marine organisms have exposure risks regardless of their phenology. Exposure at one life history stage could have a legacy effect on the …

Cultivation In Long-Term Simulated Microgravity Is Detrimental To Pyocyanin Production And Subsequent Biofilm Formation Ability Of Pseudomonas Aeruginosa, K. Z. M. Chen, L. M. Vu, Amy Cheng Vollmer

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Pseudomonas aeruginosa forms aggregates known as biofilms. Previous studies have shown that when P. aeruginosa is cultivated in space, thicker and structurally different biofilms are formed than from those grown on Earth. We investigated how microgravity, simulated in a laboratory setting, influenced the growth, colonization, and virulence potentials of a P. aeruginosa PA14 wild-type strain, as well as two surface attachment-defective (sad) mutants altered at crucial biofilm-forming steps: flgK and pelA. Using high-aspect ratio rotating-wall vessel (HARV) bioreactors, P. aeruginosa bacteria were grown to stationary phase under prolonged (6 days) exposure to simulated microgravity or normal gravity …

Inter-Kingdom Communication And The Sympoietic Way Of Life, Scott F. Gilbert

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Organisms are now seen as holobionts, consortia of several species that interact metabolically such that they sustain and scaffold each other’s existence and propagation. Sympoiesis, the development of the symbiotic relationships that form holobionts, is critical for our understanding the origins and maintenance of biodiversity. Rather than being the read-out of a single genome, development has been found to be sympoietic, based on multigenomic interactions between zygote-derived cells and symbiotic microbes. These symbiotic and sympoietic interactions are predicated on the ability of cells from different kingdoms of life (e.g., bacteria and animals) to communicate with one another and to have …

The Influence Of Resource Patch Condition And Size On Social Interactions, Reproductive Behaviors, And Oviposition In A Fungivorous Beetle, Lillian J. Fornoff , '21, C. A. Stahlmann Roeder, E. D. Brodie Iii, Vincent A. Formica

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Variation among resource patches can structure spatial patterns of social behavior. Individual preferences and requirements for heterogeneous resources can lead to differences in where behaviors take place and which kinds of individuals interact. In this study we examined whether properties of habitat patches predict presence of and interactions among wild forked fungus beetles (Bolitotherus cornutus). B. cornutus use shelf-like fruiting bodies of wood decaying fungi (brackets) as social arenas, courtship and mating sites, oviposition locations, and food sources. Brackets on a single log vary in size and condition and represent a dynamic resource as individual brackets decay over …

Random-Effects Substitution Models For Phylogenetics Via Scalable Gradient Approximations, A. F. Magee, A. J. Holbrook, J. E. Pekar, Itzue W. Caviedes-Solis, F. A. Matsen Iv, G. Baele, J. O. Wertheim, X. Ji, P. Lemey, M. A. Suchard

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Phylogenetic and discrete-trait evolutionary inference depend heavily on an appropriate characterization of the underlying character substitution process. In this paper, we present random-effects substitution models that extend common continuous-time Markov chain models into a richer class of processes capable of capturing a wider variety of substitution dynamics. As these random-effects substitution models often require many more parameters than their usual counterparts, inference can be both statistically and computationally challenging. Thus, we also propose an efficient approach to compute an approximation to the gradient of the data likelihood with respect to all unknown substitution model parameters. We demonstrate that this approximate …

How Neurobehavior And Brain Development In Alternative Whole-Organism Models Can Contribute To Prediction Of Developmental Neurotoxicity, Eva-Maria S. Collins, E. V. S. Hessel, S. Hughes

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No abstract provided.

Locus-Specific Differential Expression Of Human Satellite Sequences In The Nuclei Of Cancer Cells And Heat-Shocked Cells, Christina Rabeler, N. Paterna, Rajiv Potluri , '20, Lia R. D’Alessandro , '21, Anusha Bhatia , '24, Shu Yi Chen , '24, Johanna Lee , '23, Bereketab Abeje , '23, Benjamin Lipchin , '25, B. R. Carone, Dawn M. Carone

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Human satellites (HSats) are pericentric, tandemly repeating satellite DNA sequences in the human genome. While silent in normal cells, a subset of HSat2 noncoding RNA is expressed and accumulates in the nucleus of cancer cells. We developed a FISH-based approach for identification of the distribution of three subfamilies of HSat2 (A1, A2, B) sequences on individual human chromosomes. Further, using the HSat subfamily annotations in the T2T completed centromere satellite (CenSat) sequence, we isolated, defined and mapped differentially expressed sequence variants of nuclear-restricted HSat2 and HSat3 RNA from cancer cell lines and heat-shocked cells. We identified chromosome-specific and subfamily-specific expression …

The Iglon Family Of Cell Adhesion Molecules Expressed In Developing Neural Circuits Ensure The Proper Functioning Of The Sensory System In Mice, K. Singh, M. Jayaram, A. Hanumantharaju, T. Tõnissoo, T. Jagomäe, K. Mikheim, S. Muthuraman, Scott F. Gilbert, M. Plaas, M. K. E. Schäfer, J. Innos, K. Lilleväli, M.-A. Philips, E. Vasar

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Deletions and malfunctions of the IgLON family of cell adhesion molecules are associated with anatomical, behavioral, and metabolic manifestations of neuropsychiatric disorders. We have previously shown that IgLON genes are expressed in sensory nuclei/pathways and that IgLON proteins modulate sensory processing. Here, we examined the expression of IgLON alternative promoter-specific isoforms during embryonic development and studied the sensory consequences of the anatomical changes when one of the IgLON genes, Negr1, is knocked out. At the embryonal age of E12.5 and E13.5, various IgLONs were distributed differentially and dynamically in the developing sensory areas within the central and peripheral nervous …

Noise And Light Pollution Elicit Endocrine Responses In Urban But Not Forest Frogs, J. A. H. Smit, R. Vooijs, P. Lindenburg, Alexander T. Baugh, W. Halfwerk

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Urban areas are characterised by the presence of sensory pollutants, such as anthropogenic noise and artificial light at night (ALAN). Animals can quickly adapt to novel environmental conditions by adjusting their behaviour, which is proximately regulated by endocrine systems. While endocrine responses to sensory pollution have been widely reported, this has not often been linked to changes in behaviour, hampering the understanding of adaptiveness of endocrine responses. Our aim was, therefore, to investigate the effects of urbanisation, specifically urban noise and light pollution, on hormone levels in male urban and forest túngara frogs (Engystomops pustulosus), a species with …

Lhx3/4 Initiates A Cardiopharyngeal-Specific Transcriptional Program In Response To Widespread Fgf Signaling, C. J. Pickett, Hannah N. Gruner, Bradley Justin Davidson , '91

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Individual signaling pathways, such as fibroblast growth factors (FGFs), can regulate a plethora of inductive events. According to current paradigms, signal-dependent transcription factors (TFs), such as FGF/MapK-activated Ets family factors, partner with lineage-determining factors to achieve regulatory specificity. However, many aspects of this model have not been rigorously investigated. One key question relates to whether lineage-determining factors dictate lineage-specific responses to inductive signals or facilitate these responses in collaboration with other inputs. We utilize the chordate model Ciona robusta to investigate mechanisms generating lineage-specific induction. Previous studies in C. robusta have shown that cardiopharyngeal progenitor cells are specified through the …

Sediment Carbon Storage In Subtidal Beds Of The Invasive Seagrass Halophila Stipulacea Along An Extreme Water Depth Gradient, St. Thomas, U.S. Virgin Islands, Demian A. Willette, Kelsey M. Vaughn, Allie Durdall, Marilyn Brandt, Sophia Costa, Kristin Wilson Grimes

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Blue carbon ecosystems such as mangroves, salt marshes, and seagrass beds are found globally and are fundamental to fisheries production, storm surge protection, and carbon sequestration. The contribution of seagrass ecosystems to global carbon stocks is still not well understood, including in the United States Virgin Islands (USVI). No study has been published to-date assessing the sediment carbon density (SCD) in seagrass beds in the USVI. This study focused on the carbon storage ability of the invasive species, Halophila stipulacea, which is compact in size compared to common native seagrasses and has spread rapidly to become a dominant seagrass in …

Parentage Influence On Gene Expression Under Acidification Revealed Through Single-Embryo Sequencing, C. W. Fung, K. Y. Chau, D. C. S. Tong, C. Knox, S. S. T. Tam, S. Y. Tan, D. S. C. Loi, Z. Leung, Y. Xu, Y. Lan, P.-Y. Qian, Kit Yu Karen Chan, A. R. Wu

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The dissolution of anthropogenic carbon dioxide (CO2) in seawater has altered its carbonate chemistry in the process of ocean acidification (OA). OA affects the viability of marine species. In particular, calcifying organisms and their early planktonic larval stages are considered vulnerable. These organisms often utilize energy reserves for metabolism rather than growth and calcification as supported by bulk RNA-sequencing (RNA-seq) experiments. Yet, transcriptomic profiling of a bulk sample reflects the average gene expression of the population, neglecting the variations between individuals, which forms the basis for natural selection. Here, we used single-embryo RNA-seq on larval sea urchin Heliocidaris crassispina, which …

Fly-Cure, A Multi-Institutional Cure Using Drosophila, Increases Students' Confidence, Sense Of Belonging, And Persistence In Research, Julia A. Markle, Olivier Devergne, Seth M. Kelly, Paula A. Croonquist, Cory J. Evans, Melanie A. Hwalek, Victoria L. Straub, Danielle R. Hamill, Alexandra Peister, David P. Puthoff

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The Fly-CURE is a genetics-focused multi-institutional Course-Based Undergraduate Research Experience (CURE) that provides undergraduate students with hands-on research experiences within a course. Through the Fly-CURE, undergraduate students at diverse types of higher education institutions across the United States map and characterize novel mutants isolated from a genetic screen in Drosophila melanogaster. To date, more than 20 mutants have been studied across 20 institutions, and our scientific data have led to eleven publications with more than 500 students as authors. To evaluate the impact of the Fly-CURE experience on students, we developed and validated assessment tools to identify students’ perceived research …

Individual And Population Age Impact Social Behavior And Network Structure In A Long-Lived Insect, P. A. Cook, R. A. Costello, Vincent A. Formica, E. D. Brodie Iii

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Social behaviors vary among individuals, and social networks vary among groups. Understanding the causes of such variation is important for predicting or altering ecological processes such as infectious disease outbreaks. Here, we ask whether age contributes to variation in social behavior at multiple levels of organization: within individuals over time, among individuals of different ages, among local social environments, and among populations. We used experimental manipulations of captive populations and a longitudinal dataset to test whether social behavior is associated with age across these levels in a long-lived insect, the forked fungus beetle (Bolitotherus cornutus). In cross-sectional analyses, …

Brilliant Bird Brains: Object Recognition In Herring Gulls (Larus Argentatus Smithsonianus), Kristen M. Covino, F. Dylan Titmuss, Joseph E. Brosseau, Dora C. Donacik, Maddie E. Ellms, Alyssa R. Nowicki, Daphne Okuyama, Jessica M. Robinson, Katherine A. Schickfus, Eliza L. Stanley, Mary Elizabeth Everett

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The ability to recognize and associate objects with prior experiences has been demonstrated in several avian taxa. Corvids, for example, recognize visual stimuli associated with negative previous experiences and will modify their behavioral responses according to the level of perceived threat. However, the extent to which similar memory-based behaviors exist in seabirds is poorly understood. Our study investigated object recognition by Herring Gulls (Larus argentatus smithsonianus) on their breeding grounds, the site of a long-term monitoring project. When handling gulls and conducting field research, researchers wear standard bicycle helmets as a protective measure against physical aggression by nesting …

Cannabinoid Receptor Type 1 Regulates Sequential Stages Of Migration And Morphogenesis Of Neural Crest Cells And Derivatives In Chicken And Frog Embryos, Amira Mahomed, Daljit Girn, Afrin Pattani, Brian K. Wells, Chloe C. King, Sonya Patel, Harsimran Kaur, Christina M. Noravian, Jessica Sieminski, Chi Pham, Halley Dante, Maxellende Ezin, Tamira Elul

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The main cannabinoid receptor CB1R first shows expression during early neurula stage in chicken (Gallus gallus) embryos, and at early tailbud stage in the frog (Xenopus laevis) embryos. This raises the question of whether CB1R regulates similar or distinct processes during the embryonic development of these two species. Here, we examined whether CB1R influences the migration and morphogenesis of neural crest cells and derivatives in both chicken and frog embryos. Early neurula stage chicken embryos were exposed to arachidonyl-2ʹ-chloroethylamide (ACEA; a CB1R agonist), N-(Piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251; a CB1R inverse agonist) or Blebbistatin (nonmuscle Myosin II inhibitor) in ovo and examined during …

Corticosterone Alters Body Weight, But Not Metabolites, During Chronic Stress, Carolyn M. Bauer, M. A. Oranges, G. Firempong, L. M. Romero

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The stress response is partially mediated by increased levels of circulating glucocorticoids. While the stress response may be adaptive in the short term, chronically elevated levels of glucocorticoids can be pathological. We aimed to verify that chronic stress causes metabolic dysregulation via increased corticosterone (Cort) exposure by monitoring free fatty acid (FFA) concentrations (evidence of fat breakdown), uric acid concentrations (evidence of protein breakdown), and organ weights (furcular fat, abdominal fat, liver, and pectoralis muscle) in chronically stressed juvenile house sparrows (Passer domesticus). The sparrows were chronically stressed for 3 wk by applying a series of rotating mild psychological stressors. …

Generation Of Lexa Enhancer-Trap Lines In Drosophila By An International Scholastic Network, Cory J. Evans, Ella S. Kim, Arjun Rajan, Kathleen Chang, Sanath Govindarajan, Clara Gulick, Eva English, Bianca Rodriguez, Orion Bloomfield, Stella Nakada, Charlotte Beard, Sarah O’Connor, Sophia Mastroianni, Emma Downey, Matthew Feigenbaum, Caitlin Tolentino, Abigail Pace, Marina Khan, Soyoun Moon, Jordan Diprima, Amber Syed, Flora Lin, Yasmina Abukhadra, Isabella Bacon, John Beckerle, Sophia Cho, Nana Esi Donkor, Lucy Garberg, Ava Harrington, Mai Hoang, Nosa Lawani, Ayush Noori, Euwie Park

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Conditional gene regulation in Drosophila through binary expression systems like the LexA-LexAop system provides a superb tool for investigating gene and tissue function. To increase the availability of defined LexA enhancer trap insertions, we present molecular, genetic, and tissue expression studies of 301 novel Stan-X LexA enhancer traps derived from mobilization of the index SX4 line. This includes insertions into distinct loci on the X, II, and III chromosomes that were not previously associated with enhancer traps or targeted LexA constructs, an insertion into ptc, and seventeen insertions into natural transposons. A subset of enhancer traps was expressed in …

Early Chromosome Condensation By Xist Builds A-Repeat Rna Density That Facilitates Gene Silencing, M. Valledor, M. Byron, B. Dumas, Dawn M. Carone, L. L. Hall, J. B. Lawrence

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XIST RNA triggers chromosome-wide gene silencing and condenses an active chromosome into a Barr body. Here, we use inducible human XIST to examine early steps in the process, showing that XIST modifies cytoarchitecture before widespread gene silencing. In just 2–4 h, barely visible transcripts populate the large “sparse zone” surrounding the smaller “dense zone”; importantly, density zones exhibit different chromatin impacts. Sparse transcripts immediately trigger immunofluorescence for H2AK119ub and CIZ1, a matrix protein. H3K27me3 appears hours later in the dense zone, which enlarges with chromosome condensation. Genes examined are silenced after compaction of the RNA/DNA territory. Insights into this come …

Comparative Toxicity Assessment Of Glyphosate And Two Commercial Formulations In The Planarian Dugesia Japonica, S. Grace Fuselier , '25, Danielle Ireland, Nicholas Fu , '25, Christina Rabeler, Eva-Maria S. Collins

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Introduction: Glyphosate is a widely used, non-selective herbicide. Glyphosate and glyphosate-based herbicides (GBHs) are considered safe for non-target organisms and environmentally benign at currently allowed environmental exposure levels. However, their increased use in recent years has triggered questions about possible adverse outcomes due to low dose chronic exposure in animals and humans. While the toxicity of GBHs has primarily been attributed to glyphosate, other largely unstudied components of GBHs may be inherently toxic or could act synergistically with glyphosate. Thus, comparative studies of glyphosate and GBHs are needed to parse out their respective toxicity. Methods: We performed such a comparative …

A Simple Method For Quantifying Blastema Growth In Regenerating Planarians, Natali Campillo , '25, Danielle Ireland, Yashvi Patel , '24, Eva-Maria S. Collins

Biology Faculty Works

Due to their strong regenerative capabilities, freshwater planarians are a well-suited model system for studying the effects of chemicals on stem cell biology and regeneration. After amputation, a planarian will regenerate the missing body parts within 1 to 2 weeks. Because planarians have a distinct head morphology that can be easily identified, head and eye regeneration has been a popular qualitative measure of toxicity. However, qualitative measures can only detect strong defects. Here, we present protocols for quantifying the rate of blastema growth to measure regeneration defects for assessment of chemical toxicity. Following amputation, a regenerative blastema forms at the …

Six Decades Of North American Bird Banding Records Reveal Plasticity In Migration Phenology, Kyle G. Horton, Sara R. Morris, Benjamin M. Van Doren, Kristen M. Covino

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1. The timing of avian migration has evolved to exploit critical seasonal resources, yet plasticity within phenological responses may allow adjustments to interannual resource phenology. The diversity of migratory species and changes in underlying resources in response to climate change make it challenging to generalize these relationships.
2. We use bird banding records during spring and fall migration from across North America to examine macroscale phenological responses to interannual fluctuations in temperature and long-term annual trends in phenology.
3. In total, we examine 19 species of North American wood warblers (family Parulidae), summarizing migration timing from 2,826,588 banded birds from 1961 to 2018 …

Adult And Regenerating Planarians Respond Differentially To Chronic Drug Exposure, Kevin Bayingana , '23, Danielle Ireland, Elizabeth Rosenthal , '23, Christina Rabeler, Eva-Maria S. Collins

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There is a lack of data on the effects of chronic exposure to common drugs and stimulants on the developing nervous system. Freshwater planarians have emerged as a useful invertebrate model amenable to high-throughput behavioral phenotyping to assay chemical safety in adult and developing brains. Here, we leverage the unique strength of the system to test in parallel for effects on the adult and developing nervous system, by screening ten common drugs and stimulants (forskolin, clenbuterol, LRE-1, MDL-12,330A, adenosine, caffeine, histamine, mianserin, fluoxetine and sertraline) using the asexual freshwater planarian Dugesia japonica. The compounds were tested up to 100 …

Acetylcholinesterase Activity Staining In Freshwater Planarians, Christina Rabeler, Taixi Gong , '24, Danielle Ireland, O. Cochet-Escartin, Eva-Maria S. Collins

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The serine hydrolase acetylcholinesterase (AChE) is an important neuronal enzyme which catalyzes the hydrolysis of the neurotransmitter acetylcholine and other choline esters. The breakdown of acetylcholine by AChE terminates synaptic transmission and regulates neuromuscular communication. AChE inhibition is a common mode of action of various insecticides, such as carbamates and organophosphorus pesticides. Freshwater planarians, especially the species Dugesia japonica, have been shown to possess AChE activity and to be a suitable alternative model for studying the effects of pesticides in vivo. AChE activity can be quantified in homogenates using the Ellman assay. However, this biochemical assay requires specialized equipment …

Multilevel Selection On Social Network Traits Differs Between Sexes In Experimental Populations Of Forked Fungus Beetles, R. A. Costello, P. A. Cook, E. D. Brodie Iii, Vincent A. Formica

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Both individual and group behavior can influence individual fitness, but multilevel selection is rarely quantified on social behaviors. Social networks provide a unique opportunity to study multilevel selection on social behaviors, as they describe complex social traits and patterns of interaction at both the individual and group levels. In this study, we used contextual analysis to measure the consequences of both individual network position and group network structure on individual fitness in experimental populations of forked fungus beetles (Bolitotherus cornutus) with two different resource distributions. We found that males with high individual connectivity (strength) and centrality (betweenness) had …

Foreword: Symbiotic Perspectives On The Processes Of Biology And Art, Scott F. Gilbert

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No abstract provided.

Process Epistemologies For The Careful Interplay Of Art And Biology: An Afterword, S. R. Gilbert, Scott F. Gilbert

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No abstract provided.

New Worm On The Block: Planarians In (Neuro)Toxicology, Danielle Ireland, Eva-Maria S. Collins

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Traditional mammalian testing is too time- and cost-intensive to keep up with the large number of environmental chemicals needing assessment. This has led to a dearth of information about the potential adverse effects of these chemicals, especially on the developing brain. Thus, there is an urgent need for rapid and cost-effective neurotoxicity and developmental neurotoxicity testing. Because of the complexity of the brain, metabolically competent organismal models are necessary to understand the effects of chemicals on nervous system development and function on a systems level. In this overview, we showcase asexual freshwater planarians as an alternative invertebrate (“non-animal”) organismal model …

Pseudo-Embryology And Personhood: How Embryological Pseudoscience Helps Structure The American Abortion Debate, Scott F. Gilbert

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There is a pseudo-embryology flourishing today, well nourished by popular science, religious ideologies, and the public media. Just as eugenics was a pseudoscience that influenced (and still influences) American popular culture and which was responsible for racist anti-immigration laws (such as the Immigration Restriction Act of 1924), pseudo-embryology is also influencing popular culture and legislation. This new pseudoscience promotes the belief that science supports current zygotic and fetal personhood movements as well as anti-abortion legislation. However, what often passes for science are actually ideological myths, often grounded in and supporting male superiority. Indeed, the first myth of pseudo-embryology is that …

Bioactivation And Detoxification Of Organophosphorus Pesticides In Freshwater Planarians Shares Similarities With Humans, Danielle Ireland, Christina Rabeler, Taixi Gong , '24, Eva-Maria S. Collins

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Organophosphorus pesticides (OPs) are a chemically diverse class of insecticides that inhibit acetylcholinesterase (AChE). Many OPs require bioactivation to their active oxon form via cytochrome P450 to effectively inhibit AChE. OP toxicity can be mitigated by detoxification reactions performed by carboxylesterase and paraoxonase. The relative extent of bioactivation to detoxification varies among individuals and between species, leading to differential susceptibility to OP toxicity. Because of these species differences, it is imperative to characterize OP metabolism in model systems used to assess OP toxicity. We have shown that the asexual freshwater planarian Dugesia japonica is a suitable model to assess OP …