Background: Detecting species at low abundance, including aquatic invasive species (AIS), is critical for making informed management decisions. Environmental DNA (eDNA) methods have become a powerful tool for rare or cryptic species detection; however, many eDNA assays offer limited utility for community-level analyses due to their use of species-specific (presence/absence) 'barcodes'. Metabarcoding methods provide information on entire communities based on sequencing of all taxon-specific barcodes within an eDNA sample.Aims: Evaluate measures of fish species detections, community diversity, and estimates of relative abundance based on eDNA metabarcoding and traditional fisheries sampling approaches in the context of fish community characterization and AIS survellience. Materials and Methods:In 2016, eight limnologically diverse lakes (surface area range: 13 -1,728 ha) in Michigan, USA were sampled using a variety of traditional fisheries gears to characterize fish community composition. Environmental DNAs from surface (33 ± 6, mean ± 1 SD) and benthic (14 ± 2) water samples from each lake were isolated and amplified for two metabarcoding markers (mitochondrial 12S and 16S rDNA loci) using fish-specific primers. Fish species detected within each lake were determined by comparing the sequencing data to a database of sequences from native Michigan fish species and 19 AIS on the Michigan's Watch List.Results: Analysis of species accumulation curves indicated multi-locus eDNA metabarcoding assays can enhance species detection capacities and characterize 95% of a fish community in fewer sampling efforts than traditional gear (range: 2 -62, median: 14). In addition, all AIS detected in traditional gear samples were also detected by eDNA, while some AIS detected by eDNA assays were absent from traditional gear samples. | 369SARD et Al.
We tested the hypothesis that cholinergic stimulation and cyclic stretch regulate inflammatory gene expression in intact airway smooth muscle by measuring mRNA expression in bovine tracheal smooth muscle using limited microarray analysis and RT-PCR. Carbachol (1 microM) induced significant increases in the expression of cyclooxygenase (COX)-1, COX-2, IL-8, and plasminogen activator, urokinase type (PLAU) to levels ranging from 1.3- to 3.1-fold of control. Sinusoidal length oscillation at an amplitude of 10% muscle length and a frequency of 1 Hz induced significant increases in the expression of CCL-2, COX-2, IL-1 beta, and IL-6 to levels ranging from 12- to 206-fold of control. Decreasing the oscillatory amplitude by 50% did not significantly change inflammatory gene expression. In contrast, decreasing the oscillatory frequency by 50% significantly attenuated inflammatory gene expression by 76-93%. Nifedipine (1 microM) had an insignificant effect on carbachol-induced gene expression, but significantly inhibited sinusoidal length oscillation-induced inflammatory gene expression by 40-78%. Correlation analysis revealed two groups of genes with differential responses to sinusoidal length oscillation. The highly responsive group included COX-2, IL-6, and IL-8, which exhibited 45- to 364-fold increases in gene expression in response to sinusoidal length oscillation. The moderately responsive group included CCL2 and PLAU, which exhibited 13- to 19-fold increases in gene expression in response to sinusoidal oscillation. These findings suggest that cyclic stretch regulates inflammatory gene expression in intact airway smooth muscle in an amplitude- and frequency-dependent manner by modulating the activity of L-type voltage-gated calcium channels.
Wild carnivores in zoos, conservation breeding centres, and farms commonly live in relatively small, unstimulating enclosures. Under these captive conditions, in a range of species including giant pandas, black-footed ferrets, and European mink, male reproductive abilities are often poor. Such problems have long been hypothesized to be caused by these animals' housing conditions. We show for the first time that rearing under welfare-improving (i.e., highly valued and stress-reducing) environmental enrichments enhances male carnivores' copulatory performance: in mate choice competitions, enriched male American mink (Neovison vison) mated more often than non-enriched males. We screened for several potential mediators of this effect. First was physiological stress and its impact on reproductive physiology; second, stress-mediated changes in morphology and variables related to immunocompetence that could influence male attractiveness; and third, behavioural changes likely to affect social competence, particularly autistic-like excessive routine and repetition (‘perseveration’) as is reflected in the stereotypies common in captive animals. Consistent with physiological stress, excreted steroid metabolites revealed that non-enriched males had higher cortisol levels and lower androgen levels than enriched conspecifics. Their os penises (bacula) also tended to be less developed. Consistent with reduced attractiveness, non-enriched males were lighter, with comparatively small spleens and a trend to greater fluctuating asymmetry. Consistent with impaired social competence, non-enriched males performed more stereotypic behaviour (e.g., pacing) in their home cages. Of all these effects, the only significant predictor of copulation number was stereotypy (a trend suggesting that low bodyweights may also be influential): highly stereotypic males gained the fewest copulations. The neurophysiological changes underlying stereotypy thus handicap males sexually. We hypothesise that such males are abnormally perseverative when interacting with females. Investigating similar problems in other taxa would be worthwhile, since many vertebrates, wild and domestic, live in conditions that cause stereotypic behaviour and/or impair neurological development.
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