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UC Merced Previously Published Works

Cover page of Genome sequences of four novel Endozoicomonas strains associated with a tropical octocoral in a long-term aquarium facility.

Genome sequences of four novel Endozoicomonas strains associated with a tropical octocoral in a long-term aquarium facility.

(2025)

We report the genome sequences of four Endozoicomonas sp. strains isolated from the octocoral Litophyton maintained long term at an aquarium facility. Our analysis reveals the coding potential for versatile polysaccharide metabolism; Type II, III, IV, and VI secretion systems; and the biosynthesis of novel ribosomally synthesized and post-translationally modified peptides.

Cover page of VISTA Enhancer browser: an updated database of tissue-specific developmental enhancers

VISTA Enhancer browser: an updated database of tissue-specific developmental enhancers

(2025)

Regulatory elements (enhancers) are major drivers of gene expression in mammals and harbor many genetic variants associated with human diseases. Here, we present an updated VISTA Enhancer Browser (https://enhancer.lbl.gov), a database of transgenic enhancer assays conducted in developing mouse embryos in vivo. Since the original publication in 2007, the database grew nearly 20-fold from 250 to over 4500 experiments and currently harbors over 23 500 images. The updated database provides structured information on experiments conducted at different stages of embryonic development, including enhancer activities of human pathogenic and synthetic variants and sequences derived from a variety of species. In addition to manually curated results of thousands of individual experiments, the new database also features hundreds of manually curated comparisons between alleles. The VISTA Enhancer Browser provides a crucial resource for study of human genetic variation, gene regulation and developmental biology.

Cover page of Genomes OnLine Database (GOLD) v.10: new features and updates

Genomes OnLine Database (GOLD) v.10: new features and updates

(2025)

The Genomes OnLine Database (GOLD; https://gold.jgi.doe.gov/) at the Department of Energy Joint Genome Institute is a comprehensive online metadata repository designed to catalog and manage information related to (meta)genomic sequence projects. GOLD provides a centralized platform where researchers can access a wide array of metadata from its four organization levels namely Study, Organism/Biosample, Sequencing Project and Analysis Project. GOLD continues to serve as a valuable resource and has seen significant growth and expansion since its inception in 1997. With its expanded role as a collaborative platform, it not only actively imports data from other primary repositories like National Center for Biotechnology Information but also supports contributions from researchers worldwide. This collaborative approach has enriched the database with diverse datasets, creating a more integrated resource to enhance scientific insights. As genomic research becomes increasingly integral to various scientific disciplines, more researchers and institutions are turning to GOLD for their metadata needs. To meet this growing demand, GOLD has expanded by adding diverse metadata fields, intuitive features, advanced search capabilities and enhanced data visualization tools, making it easier for users to find and interpret relevant information. This manuscript provides an update and highlights the new features introduced over the last 2 years.

Cover page of [PSI]-CIC: A Deep-Learning Pipeline for the Annotation of Sectored Saccharomyces cerevisiae Colonies

[PSI]-CIC: A Deep-Learning Pipeline for the Annotation of Sectored Saccharomyces cerevisiae Colonies

(2025)

The [PSI+] prion phenotype in yeast manifests as a white, pink, or red color pigment. Experimental manipulations destabilize prion phenotypes, and allow colonies to exhibit [psi-] (red) sectored phenotypes within otherwise completely white colonies. Further investigation of the size and frequency of sectors that emerge as a result of experimental manipulation is capable of providing critical information on mechanisms of prion curing, but we lack a way to reliably extract this information. Images of experimental colonies exhibiting sectored phenotypes offer an abundance of data to help uncover molecular mechanisms of sectoring, yet the structure of sectored colonies is ignored in traditional biological pipelines. In this study, we present [PSI]-CIC, the first computational pipeline designed to identify and characterize features of sectored yeast colonies. To overcome the barrier of a lack of manually annotated data of colonies, we develop a neural network architecture that we train on synthetic images of colonies and apply to real images of [PSI+] , [psi-] , and sectored colonies. In hand-annotated experimental images, our pipeline correctly predicts the state of approximately 95% of colonies detected and frequency of sectors in approximately 89.5% of colonies detected. The scope of our pipeline could be extended to categorizing colonies grown under different experimental conditions, allowing for more meaningful and detailed comparisons between experiments. Our approach streamlines the analysis of sectored yeast colonies providing a rich set of quantitative metrics and provides insight into mechanisms driving the curing of prion phenotypes.

Cover page of Genetic Variation in the Atlantic Bobtail Squid-Vibrio Symbiosis From the Galician Rías.

Genetic Variation in the Atlantic Bobtail Squid-Vibrio Symbiosis From the Galician Rías.

(2025)

Symbiotic marine bacteria that are transmitted through the environment are susceptible to abiotic factors (salinity, temperature, physical barriers) that can influence their ability to colonize their specific hosts. Given that many symbioses are driven by host specificity, environmentally transmitted symbionts are more susceptible to extrinsic factors depending on conditions over space and time. In order to determine whether the population structure of environmentally transmitted symbionts reflects host specificity or biogeography, we analysed the genetic structure of Sepiola atlantica (Cephalopoda: Sepiolidae) and their Vibrio symbionts (V. fischeri and V. logei) in four Galician Rías (Spain). This geographical location is characterized by a jagged coastline with a deep-sea entrance into the land, ideal for testing whether such population barriers exist due to genetic isolation. We used haplotype estimates combined with nested clade analysis to determine the genetic relatedness for both S. atlantica and Vibrio bacteria. Analyses of molecular variance (AMOVA) were used to estimate variation within and between populations for both host and symbiont genetic data. Our analyses reveal a low percentage of variation among and between host populations, suggesting that these populations are panmictic. In contrast, Vibrio symbiont populations show certain degree of genetic structure, demonstrating that the hydrology of the rías is driving bacterial distribution (and not host specificity). Thus, for environmentally transmitted symbioses such as the sepiolid squid-Vibrio association, abiotic factors can be a major selective force for determining population structure for one of the partners.

Cover page of Perceived barriers and facilitators to HPV vaccination: Insights from focus groups with unvaccinated mid-adults in a U.S. medically underserved area.

Perceived barriers and facilitators to HPV vaccination: Insights from focus groups with unvaccinated mid-adults in a U.S. medically underserved area.

(2024)

Shared clinical decision-making (SCDM) about HPV vaccination has been recommended for U.S. mid-adults aged 27-45 since 2019. To explore barriers and facilitators to HPV vaccination in this population, we conducted 14 virtual focus groups with 86 unvaccinated mid-adults (34 men and 52 women) in Californias medically underserved Inland Empire between September 2020 and January 2021. We systematically analyzed the focus group data using the rigorous and accelerated data reduction (RADaR) technique to identify key themes. Identified barriers included: lack of awareness, vaccine hesitancy, and perceived unaffordability (cited in 14 groups); lack of healthcare provider communication and insufficient time (13 groups); fear of moral judgment (12 groups); lack of motivation and information needs (10 groups); and lack of reliable transportation and foregone care during the COVID-19 pandemic (3 groups). Proposed facilitators included: tailored HPV vaccine information for mid-adults, cost mitigation, and improved vaccine accessibility (12 groups); healthcare provider-initiated conversations (6 groups); and vaccine reminders (4 groups). These findings highlight challenges to HPV vaccination among U.S. mid-adults eligible for SCDM and point to actionable strategies for improvement. Specifically, tailored educational interventions, decision-making tools for pharmacists, and integrating HPV vaccination into other healthcare encounters may enhance vaccination efforts in areas with limited primary care resources.

Cover page of Evaluation of outbreak persistence caused by multidrug-resistant and echinocandin-resistant Candida parapsilosis using multidimensional experimental and epidemiological approaches

Evaluation of outbreak persistence caused by multidrug-resistant and echinocandin-resistant Candida parapsilosis using multidimensional experimental and epidemiological approaches

(2024)

Candida parapsilosis is known to cause severe and persistent outbreaks in clinical settings. Patients infected with multidrug-resistant C. parapsilosis (MDR Cp) isolates were identified in a large Turkish hospital from 2017-2020. We subsequently identified three additional patients infected with MDR Cp isolates in 2022 from the same hospital and two echinocandin-resistant (ECR) isolates from a single patient in another hospital. The increasing number of MDR and ECR isolates contradicts the general principle that the severe fitness cost associated with these phenotypes could prevent their dominance in clinical settings. Here, we employed a multidimensional approach to systematically assess the fitness costs of MDR and ECR C. parapsilosis isolates. Whole-genome sequencing revealed a novel MDR genotype infecting two patients in 2022. Despite severe in vitro defects, the levels and tolerances of the biofilms of our ECR and MDR isolates were generally comparable to those of susceptible wild-type isolates. Surprisingly, the MDR and ECR isolates showed major alterations in their cell wall components, and some of the MDR isolates consistently displayed increased tolerance to the fungicidal activities of primary human neutrophils and were more immunoevasive during exposure to primary human macrophages. Our systemic infection mouse model showed that MDR and ECR C. parapsilosis isolates had comparable fungal burden in most organs relative to susceptible isolates. Overall, we observed a notable increase in the genotypic diversity and frequency of MDR isolates and identified MDR and ECR isolates potentially capable of causing persistent outbreaks in the future.