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Full-Text Articles in Life Sciences

Quantifying Planarian Behavior As An Introduction To Object Tracking And Signal Processing, Nicole C. Stowell, T. Goel, Vir Shetty , '22, Jocelyne Noveral, Eva-Maria S. Collins Dec 2021

Quantifying Planarian Behavior As An Introduction To Object Tracking And Signal Processing, Nicole C. Stowell, T. Goel, Vir Shetty , '22, Jocelyne Noveral, Eva-Maria S. Collins

Biology Faculty Works

Answers to mechanistic questions about biological phenomena require fluency in a variety of molecular biology techniques and physical concepts. Here, we present an interdisciplinary approach to introducing undergraduate students to an important problem in the areas of animal behavior and neuroscience—the neuronal control of animal behavior. In this lab module, students explore planarian behavior by quantitative image and data analysis with freely available software and low-cost resources. Planarians are ∼1–2-cm-long aquatic free-living flatworms famous for their regeneration abilities. They are inexpensive and easy to maintain, handle, and perturb, and their fairly large size allows for image acquisition with a webcam, …


Let It Rip: The Mechanics Of Self-Bisection In Asexual Planarians Determines Their Population Reproductive Strategies, T. Goel, Danielle Ireland, Vir Shetty , '22, Christina Rabeler, P. H. Diamond, Eva-Maria S. Collins Nov 2021

Let It Rip: The Mechanics Of Self-Bisection In Asexual Planarians Determines Their Population Reproductive Strategies, T. Goel, Danielle Ireland, Vir Shetty , '22, Christina Rabeler, P. H. Diamond, Eva-Maria S. Collins

Biology Faculty Works

Asexual freshwater planarians reproduce by transverse bisection (binary fission) into two pieces. This process produces a head and a tail, which fully regenerate within 1–2 weeks. How planarians split into two offspring—using only their musculature and substrate traction—is a challenging biomechanics problem. We found that three different species, Dugesia japonica, Girardia tigrina and Schmidtea mediterranea, have evolved three different mechanical solutions to self-bisect. Using time lapse imaging of the fission process, we quantitatively characterize the main steps of division in the three species and extract the distinct and shared key features. Across the three species, planarians actively alter …


Corticosterone's Roles In Avian Migration: Assessment Of Three Hypotheses, Carolyn M. Bauer, H. E. Watts Sep 2021

Corticosterone's Roles In Avian Migration: Assessment Of Three Hypotheses, Carolyn M. Bauer, H. E. Watts

Biology Faculty Works

While corticosterone (CORT) is often suggested to be an important hormone regulating processes necessary for avian migration, there has been no systematic assessment of CORT's role in migration. Prior to migration, birds increase fat stores and flight muscle size to prepare for the high energetic costs associated with long-distance flight. After attaining sufficient energetic stores, birds then make the actual decision to depart from their origin site. Once en route birds alternate between periods of flight and stopovers, during which they rest and refuel for their next bouts of endurance flight. Here, we evaluate three non-mutually exclusive hypotheses that have …


Synthesis Of Thresholds Of Ocean Acidification Impacts On Echinoderms, N. Bednaršek, P. Calosi, R. A. Feely, R. Ambrose, M. Byrne, Kit Yu Karen Chan, S. Dupont, J. L. Padilla-Gamiño, J. I. Spicer, F. Kessouri, M. Roethler, M. Sutula, S. B. Weisberg May 2021

Synthesis Of Thresholds Of Ocean Acidification Impacts On Echinoderms, N. Bednaršek, P. Calosi, R. A. Feely, R. Ambrose, M. Byrne, Kit Yu Karen Chan, S. Dupont, J. L. Padilla-Gamiño, J. I. Spicer, F. Kessouri, M. Roethler, M. Sutula, S. B. Weisberg

Biology Faculty Works

Assessing the vulnerability of marine invertebrates to ocean acidification (OA) requires an understanding of critical thresholds at which developmental, physiological, and behavioral traits are affected. To identify relevant thresholds for echinoderms, we undertook a three-step data synthesis, focused on California Current Ecosystem (CCE) species. First, literature characterizing echinoderm responses to OA was compiled, creating a dataset comprised of >12,000 datapoints from 41 studies. Analysis of this data set demonstrated responses related to physiology, behavior, growth and development, and increased mortality in the larval and adult stages to low pH exposure. Second, statistical analyses were conducted on selected pathways to identify …


Social Communication Across Reproductive Boundaries: Hormones And The Auditory Periphery Of Songbirds And Frogs, M. D. Gall, Alexander T. Baugh, J. R. Lucas, M. A. Bee May 2021

Social Communication Across Reproductive Boundaries: Hormones And The Auditory Periphery Of Songbirds And Frogs, M. D. Gall, Alexander T. Baugh, J. R. Lucas, M. A. Bee

Biology Faculty Works

Most animals experience reproductive transitions in their lives; for instance, reaching reproductive maturity or cycling in and out of breeding condition. Some reproductive transitions are abrupt, while others are more gradual. In most cases, changes in communication between the sexes follow the time course of these reproductive transitions and are typically thought to be coordinated by steroid hormones. We know a great deal about hormonal control of communication behaviors in birds and frogs, as well as the central neural control of these behaviors. There has also been significant interest in the effects of steroid hormones on central nervous system structures …


Choosing Life Stories: Body As Teacher, .O Love, S. M. Curry, Scott F. Gilbert May 2021

Choosing Life Stories: Body As Teacher, .O Love, S. M. Curry, Scott F. Gilbert

Biology Faculty Works

Biological science and the larger society interact with each other. Biologists tell stories--stories such as fertilization, body development, and evolution--using the narrative structures given to them by the larger society. These stories have to be consistent with the scientific data; but what data are collected is also a social judgement. The stories that biologists have told have often emphasized competition and have often marginalized cooperative efforts. New research has shown that these competitive stories offer a very incomplete version of what is happening in our bodies, and that mutual cooperation is a major part of how the body develops and …


A Tail’S Tale: Biomechanical Roles Of Dorsal Thoracic Spine Of Barnacle Nauplii, Emily Branam , '21, J. Y. Wong, B. K. K. Chan, Kit Yu Karen Chan Apr 2021

A Tail’S Tale: Biomechanical Roles Of Dorsal Thoracic Spine Of Barnacle Nauplii, Emily Branam , '21, J. Y. Wong, B. K. K. Chan, Kit Yu Karen Chan

Biology Faculty Works

Many marine invertebrates have complex life histories that begin with a planktonic larval stage. Similar to other plankton, these larval invertebrates often possess protruding body extensions, but their function beyond predator deterrence is not well-documented. For example, the planktonic nauplii of crustaceans have spines. Using the epibiotic pedunculate barnacle Octolasmis spp., we investigated how the dorsal thoracic spine affects swimming and fluid disturbance by comparing nauplii with their spines partially removed against those with intact spines. Our motion analysis showed that amputated Octolasmis spp. swam slower, in jerkier trajectories, and were less efficient per stroke cycle than those with intact …


Moderately Elevated Glucocorticoids Increase Mate Choosiness But Do Not Affect Sexual Proceptivity Or Preferences In Female Gray Treefrogs, Alexander T. Baugh, M. D. Gall, Stewart C. Silver , '20, M. A. Bee Apr 2021

Moderately Elevated Glucocorticoids Increase Mate Choosiness But Do Not Affect Sexual Proceptivity Or Preferences In Female Gray Treefrogs, Alexander T. Baugh, M. D. Gall, Stewart C. Silver , '20, M. A. Bee

Biology Faculty Works

Glucocorticoids (GCs) are rarely studied in the context of female mate choice, despite the expression of receptors for these products in sexual, sensory and decision-making brain areas. Here we investigated the effects of GC concentrations on three aspects of female sexual behavior in breeding Cope's gray treefrogs (Hyla chrysoscelis): proceptivity—a measure of sexual motivation, intraspecific mate preferences, and mate choosiness. To our knowledge this is the first experimental study on the endocrine basis of mate choosiness. We predicted that mate choosiness—forfeiting an initial mate preference to pursue a suddenly more attractive mate—would be particularly impacted by elevated GCs with moderate …


Plant-Derived Drug Discovery In An Introductory Biology Laboratory Course, Tatiana Kuzmenko, Ashwarya Sharma, Demian A. Willette Apr 2021

Plant-Derived Drug Discovery In An Introductory Biology Laboratory Course, Tatiana Kuzmenko, Ashwarya Sharma, Demian A. Willette

Biology Faculty Works

Hands-on, inquiry-based laboratory activities are excellent opportunities to introduce first-year undergraduate students to the lab environment and to catalyze new interest in topics they may not yet know or be as enthusiastic about studying. We describe a multisession introductory laboratory activity that couples the research areas of medicinal drug discovery and plant biology. Selecting from a diversity of native California plants and broadly recognized medicinal plants, students learn and apply an assortment of basic phytochemical assays, analyze preliminary data, and then formulate hypothesis-driven follow-up experiments. Working in small groups, students develop shared project management and collaboration skills, and present activity …


Male Competition Reverses Female Preference For Male Chemical Cues, Z. Vilella-Pacheco, L. D. Mitchem, Vincent A. Formica, E. D. Brodie Iii Mar 2021

Male Competition Reverses Female Preference For Male Chemical Cues, Z. Vilella-Pacheco, L. D. Mitchem, Vincent A. Formica, E. D. Brodie Iii

Biology Faculty Works

Females must choose among potential mates with different phenotypes in a variety of social contexts. Many male traits are inherent and unchanging, but others are labile to social context. Competition, for example, can cause physiological changes that reflect recent wins and losses that fluctuate throughout time. We may expect females to respond differently to males depending on the outcome of their most recent fight. In Bolitotherus cornutus (forked fungus beetles), males compete for access to females, but copulation requires female cooperation. In this study, we use behavioral trials to determine whether females use chemical cues to differentiate between males and …


Ectopic Expression Of Pericentric Hsatii Rna Results In Nuclear Rna Accumulation, Mecp2 Recruitment, And Cell Division Defects, C. C. Landers, C. A. Rabeler , '20, E. K. Ferrari, Lia R. D'Alessandro , '21, D. D. Kang, J. Malisa, Safia M. Bashir , '20, Dawn M. Carone Mar 2021

Ectopic Expression Of Pericentric Hsatii Rna Results In Nuclear Rna Accumulation, Mecp2 Recruitment, And Cell Division Defects, C. C. Landers, C. A. Rabeler , '20, E. K. Ferrari, Lia R. D'Alessandro , '21, D. D. Kang, J. Malisa, Safia M. Bashir , '20, Dawn M. Carone

Biology Faculty Works

Within the pericentric regions of human chromosomes reside large arrays of tandemly repeated satellite sequences. Expression of the human pericentric satellite HSATII is prevented by extensive heterochromatin silencing in normal cells, yet in many cancer cells, HSATII RNA is aberrantly expressed and accumulates in large nuclear foci in cis. Expression and aggregation of HSATII RNA in cancer cells is concomitant with recruitment of key chromatin regulatory proteins including methyl-CpG binding protein 2 (MeCP2). While HSATII expression has been observed in a wide variety of cancer cell lines and tissues, the effect of its expression is unknown. We tested the effect …


From Coast To Coast To Coast: Ecology And Management Of Eelgrass Systems Across Canada, Sarah Joy Bittick Feb 2021

From Coast To Coast To Coast: Ecology And Management Of Eelgrass Systems Across Canada, Sarah Joy Bittick

Biology Faculty Works

Seagrass meadows are among the most productive and diverse marine ecosystems, providing essential structure, functions, and services. They are also among the most impacted by human activities and in urgent need of better management and protection. In Canada, eelgrass (Zostera marina) meadows are found along the Atlantic, Pacific, and Arctic coasts, and thus occur across a wide range of biogeographic conditions. Here, we synthesize knowledge of eelgrass ecosystems across Canada’s coasts, highlighting commonalities and differences in environmental conditions, plant, habitat, and community structure, as well as current trends and human impacts. Across regions, eelgrass life history, phenology, and general species …


Cyclin-Dependent Kinase 1 And Aurora Kinase Choreograph Mitotic Storage And Redistribution Of A Growth Factor Receptor, C. D. Cota, M. S. Dreier , '20, W. Colgan, A. Cha, Twan Sia , '21, Bradley Justin Davidson , '91 Jan 2021

Cyclin-Dependent Kinase 1 And Aurora Kinase Choreograph Mitotic Storage And Redistribution Of A Growth Factor Receptor, C. D. Cota, M. S. Dreier , '20, W. Colgan, A. Cha, Twan Sia , '21, Bradley Justin Davidson , '91

Biology Faculty Works

Endosomal trafficking of receptors and associated proteins plays a critical role in signal processing. Until recently, it was thought that trafficking was shut down during cell division. Thus, remarkably, the regulation of trafficking during division remains poorly characterized. Here we delineate the role of mitotic kinases in receptor trafficking during asymmetric division. Targeted perturbations reveal that Cyclin-dependent Kinase 1 (CDK1) and Aurora Kinase promote storage of Fibroblast Growth Factor Receptors (FGFRs) by suppressing endosomal degradation and recycling pathways. As cells progress through metaphase, loss of CDK1 activity permits differential degradation and targeted recycling of stored receptors, leading to asymmetric induction. …


A Functional Genomics Screen Identifying Blood Cell Development Genes In Drosophila By Undergraduates Participating In A Course-Based Research Experience, Cory Evans Jan 2021

A Functional Genomics Screen Identifying Blood Cell Development Genes In Drosophila By Undergraduates Participating In A Course-Based Research Experience, Cory Evans

Biology Faculty Works

Undergraduate students participating in the UCLA Undergraduate Research Consortium for Functional Genomics (URCFG) have conducted a two-phased screen using RNA interference (RNAi) in combination with fluorescent reporter proteins to identify genes important for hematopoiesis in Drosophila. This screen disrupted the function of approximately 3500 genes and identified 137 candidate genes for which loss of function leads to observable changes in the hematopoietic development. Targeting RNAi to maturing, progenitor, and regulatory cell types identified key subsets that either limit or promote blood cell maturation. Bioinformatic analysis reveals gene enrichment in several previously uncharacterized areas, including RNA processing and export and vesicular …


Characterizing Industrial And Artisanal Fishing Vessel Catch Composition Using Environmental Dna And Satellite-Based Tracking Data, Demian A. Willette, Gabriela Navarrete-Forero, Zachary Gold, Apollo Marco D. Lizano, Leonardo Gonzalez-Smith, Giovanna Sotil Jan 2021

Characterizing Industrial And Artisanal Fishing Vessel Catch Composition Using Environmental Dna And Satellite-Based Tracking Data, Demian A. Willette, Gabriela Navarrete-Forero, Zachary Gold, Apollo Marco D. Lizano, Leonardo Gonzalez-Smith, Giovanna Sotil

Biology Faculty Works

The decline in wild-caught fisheries paired with increasing global seafood demand is pushing the need for seafood sustainability to the forefront of national and regional priorities. Validation of species identity is a crucial early step, yet conventional monitoring and surveillance tools are limited in their effectiveness because they are extremely time-consuming and require expertise in fish identification. DNA barcoding methods are a versatile tool for the genetic monitoring of wildlife products; however, they are also limited by requiring individual tissue samples from target specimens which may not always be possible given the speed and scale of seafood operations. To circumvent …


Alternative Promoter Use Governs The Expression Of Iglon Cell Adhesion Molecules In Histogenetic Fields Of The Embryonic Mouse Brain, T. Jagomäe, K. Singh, M.-A. Philips, M. Jayaram, K. Seppa, T. Tekko, Scott F. Gilbert, E. Vasar, K. Lilleväli Jan 2021

Alternative Promoter Use Governs The Expression Of Iglon Cell Adhesion Molecules In Histogenetic Fields Of The Embryonic Mouse Brain, T. Jagomäe, K. Singh, M.-A. Philips, M. Jayaram, K. Seppa, T. Tekko, Scott F. Gilbert, E. Vasar, K. Lilleväli

Biology Faculty Works

The members of the IgLON superfamily of cell adhesion molecules facilitate fundamental cellular communication during brain development, maintain functional brain circuitry, and are associated with several neuropsychiatric disorders such as depression, autism, schizophrenia, and intellectual disabilities. Usage of alternative promoter-specific 1a and 1b mRNA isoforms in Lsamp, Opcml, Ntm, and the single promoter of Negr1 in the mouse and human brain has been previously described. To determine the precise spatiotemporal expression dynamics of Lsamp, Opcml, Ntm isoforms, and Negr1, in the developing brain, we generated isoform-specific RNA probes and carried out in situ hybridization in the developing (embryonic, E10.5, E11.5, …