Understanding transmission dynamics of SARS-CoV-2 in institutions of higher education (IHEs) is important because these settings have potential for rapid viral spread. Here, we used genomic ...surveillance to retrospectively investigate transmission dynamics throughout the 2020-2021 academic year for the University of Idaho ("University"), a mid-sized IHE in a small rural town. We generated genome assemblies for 1168 SARS-CoV-2 samples collected during the academic year, representing 46.8% of positive samples collected from the University population and 49.8% of positive samples collected from the surrounding community ("Community") at the local hospital during this time. Transmission dynamics differed for the University when compared to the Community, with more infection waves that lasted shorter lengths of time, potentially resulting from high-transmission congregate settings along with mitigation efforts implemented by the University to combat outbreaks. We found evidence for low transmission rates between the University and Community, with approximately 8% of transmissions into the Community originating from the University, and approximately 6% of transmissions into the University originating from the Community. Potential transmission risk factors identified for the University included congregate settings such as sorority and fraternity events and residences, holiday travel, and high caseloads in the surrounding community. Knowledge of these risk factors can help the University and other IHEs develop effective mitigation measures for SARS-CoV-2 and similar pathogens.
Conditions during fetal development influence health and disease in adulthood, especially during critical windows of organogenesis. Fetal exposure to the endocrine disrupting chemical, bisphenol A ...(BPA) affects the development of multiple organ systems in rodents and monkeys. However, effects of BPA exposure on cardiac development have not been assessed. With evidence that maternal BPA is transplacentally delivered to the developing fetus, it becomes imperative to examine the physiological consequences of gestational exposure during primate development. Herein, we evaluate the effects of daily, oral BPA exposure of pregnant rhesus monkeys (Macaca mulatta) on the fetal heart transcriptome. Pregnant monkeys were given daily oral doses (400 µg/kg body weight) of BPA during early (50-100 ± 2 days post conception, dpc) or late (100 ± 2 dpc--term), gestation. At the end of treatment, fetal heart tissues were collected and chamber specific transcriptome expression was assessed using genome-wide microarray. Quantitative real-time PCR was conducted on select genes and ventricular tissue glycogen content was quantified. Our results show that BPA exposure alters transcription of genes that are recognized for their role in cardiac pathophysiologies. Importantly, myosin heavy chain, cardiac isoform alpha (Myh6) was down-regulated in the left ventricle, and 'A Disintegrin and Metalloprotease 12', long isoform (Adam12-l) was up-regulated in both ventricles, and the right atrium of the heart in BPA exposed fetuses. BPA induced alteration of these genes supports the hypothesis that exposure to BPA during fetal development may impact cardiovascular fitness. Our results intensify concerns about the role of BPA in the genesis of human metabolic and cardiovascular diseases.
In studies of consistent individual differences (personality) along the bold-shy continuum, a pattern of behavioral correlations frequently emerges: individuals towards the bold end of the continuum ...are more likely to utilize risky habitat, approach potential predators, and feed under risky conditions. Here, we address the hypothesis that observed phenotypic correlations among component behaviors of the bold-shy continuum are a result of underlying genetic correlations (quantitative genetic architecture). We used a replicated three-generation pedigree of zebrafish (Danio rerio) to study three putative components of the bold-shy continuum: horizontal position, swim level, and feeding latency. We detected significant narrow-sense heritabilities as well as significant genetic and phenotypic correlations among all three behaviors, such that fish selected for swimming at the front of the tank swam closer to the observer, swam higher in the water column, and fed more quickly than fish selected for swimming at the back of the tank. Further, the lines varied in their initial open field behavior (swim level and activity level). The quantitative genetic architecture of the bold-shy continuum indicates that the multivariate behavioral phenotype characteristic of a "bold" personality type may be a result of correlated evolution via underlying genetic correlations.
Domesticated animal populations often show profound reductions in predator avoidance and fear-related behavior compared to wild populations. These reductions are remarkably consistent and have been ...observed in a diverse array of taxa including fish, birds, and mammals. Experiments conducted in common environments indicate that these behavioral differences have a genetic basis. In this study, we quantified differences in fear-related behavior between wild and domesticated zebrafish strains and used microarray analysis to identify genes that may be associated with this variation.
Compared to wild zebrafish, domesticated zebrafish spent more time near the water surface and were more likely to occupy the front of the aquarium nearest a human observer. Microarray analysis of the brain transcriptome identified high levels of population variation in gene expression, with 1,749 genes significantly differentially expressed among populations. Genes that varied among populations belonged to functional categories that included DNA repair, DNA photolyase activity, response to light stimulus, neuron development and axon guidance, cell death, iron-binding, chromatin reorganization, and homeobox genes. Comparatively fewer genes (112) differed between domesticated and wild strains with notable genes including gpr177 (wntless), selenoprotein P1a, synaptophysin and synaptoporin, and acyl-CoA binding domain containing proteins (acbd3 and acbd4).
Microarray analysis identified a large number of genes that differed among zebrafish populations and may underlie behavioral domestication. Comparisons with similar microarray studies of domestication in rainbow trout and canids identified sixteen evolutionarily or functionally related genes that may represent components of shared molecular mechanisms underlying convergent behavioral evolution during vertebrate domestication. However, this conclusion must be tempered by limitations associated with comparisons among microarray studies and the low level of population-level replication inherent to these studies.
Studies of “behavioral syndromes” in different populations and species of animals can be used to shed light on the underlying mechanisms of evolution. For example, some personality syndromes suggest ...the existence of an underlying hormonal link, whereas other relationships between boldness and aggression appear to be the result of similar selective pressures. Here, we used 1 wild-derived and 2 laboratory strains of zebrafish (Danio rerio) to examine relationships among 5 behavioral measures: shoaling, activity level, predator approaches, latency to feed after a disturbance, and biting to a mirror stimulus. We found evidence of an activity syndrome, as if underlying metabolic costs influence variation in multiple forms of behavior. Evidence for a relationship between boldness and aggression was also apparent but depended both on strain and which specific behavior patterns were identified as measures of “boldness.” Although some comparisons of laboratory and wild-derived strains were consistent with a domestication syndrome, others were not. Most observed relationships were relatively weak and occasionally inconsistent, arguing against strong underlying genetic linkages or pleiotropic effects relating any of the behavioral measures. Instead, it may be more important to study the details of selective context or the long-term impact of linkages between some, but not all, of a large set of genes influencing complex behavioral traits. We found profound differences among strains in most behavior patterns, but few sex differences. One strain (TM1) was consistently different from the others (SH and Nadia) being more social, more likely to approach predators, and taking less time to recover from disturbance than were the other 2 strains.
By characterizing the trajectories of antibiotic resistance gene transfer in bacterial communities such as the gut microbiome, we will better understand the factors that influence this spread of ...resistance. Our aim was to investigate the host network of a multidrug resistance broad-host-range plasmid in the culturable gut microbiome of zebrafish. This was done through
and
conjugation experiments with
as the donor of the plasmid pB10::
When this donor was mixed with the extracted gut microbiome, only transconjugants of
were detected. In separate matings between the same donor and four prominent isolates from the gut microbiome, the plasmid transferred to two of these four isolates,
and
, but not to
and
When these
and
transconjugants were the donors in matings with the same four isolates, the plasmid now also transferred from
to
was unable to donate the plasmid, and
was unable to acquire it. Finally, when the
donor was added
to zebrafish through their food, plasmid transfer was observed in the gut, but only to
, a rare member of the gut microbiome. This work shows that the success of plasmid-mediated antibiotic resistance spread in a gut microbiome depends on the donor-recipient species combinations and therefore their spatial arrangement. It also suggests that rare gut microbiome members should not be ignored as potential reservoirs of multidrug resistance plasmids from food.
To understand how antibiotic resistance plasmids end up in human pathogens, it is crucial to learn how, where, and when they are transferred and maintained in members of bacterial communities such as the gut microbiome. To gain insight into the network of plasmid-mediated antibiotic resistance sharing in the gut microbiome, we investigated the transferability and maintenance of a multidrug resistance plasmid among the culturable bacteria of the zebrafish gut. We show that the success of plasmid-mediated antibiotic resistance spread in a gut microbiome can depend on which species are involved, as some are important nodes in the plasmid-host network and others are dead ends. Our findings also suggest that rare gut microbiome members should not be ignored as potential reservoirs of multidrug resistance plasmids from food.
Zebrafish (Danio rerio) have emerged as a popular model for studying the pharmacology and behavior of anxiety. While there have been numerous studies documenting the anxiolytic and anxiogenic effects ...of common drugs in zebrafish, many do not report or test for behavioral differences between the sexes. Previous studies have indicated that males and females differ in their baseline level of anxiety. In this study, we test for a sex interaction with fluoxetine and nicotine. We exposed fish to system water (control), 10 mg/L fluoxetine, or 1 mg/L nicotine for three minutes prior to being subjected to four minutes in an open-field drop test. Video recordings were tracked using ProAnalyst. Fish from both drug treatments reduced swimming speed, increased vertical position, and increased use of the top half of the open field when compared with the control, though fluoxetine had a larger effect on depth related behaviors while nicotine mostly affected swimming speed. A significant sex effect was observed where females swam at a slower and more constant speed than males, however neither drug produced a sex-dependent response.
We used microarray and quantitative real-time PCR (qRT-PCR) analyses in adult female zebrafish (Danio rerio) to identify metabolic pathways regulated by starvation in the liver and brain. The ...transcriptome of whole zebrafish brain showed little response to 21 days of starvation. Only agouti-related protein 1 (agrp1) significantly responded, with increased expression in brains of starved fish. In contrast, a 21-day period of starvation significantly downregulated 466 and upregulated 108 transcripts in the liver, indicating an overall decrease in metabolic activity, reduced lipid metabolism, protein biosynthesis, proteolysis, and cellular respiration, and increased gluconeogenesis. Starvation also regulated expression of many components of the unfolded protein response, the first such report in a species other than yeast (Saccharomyces cerevisiae) and mice (Mus musculus). The response of the zebrafish hepatic transcriptome to starvation was strikingly similar to that of rainbow trout (Oncorhynchus mykiss) and less similar to mouse, while the response of common carp (Cyprinus carpio) differed considerably from the other three species.
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