42 research outputs found
FishResp : R package and GUI application for analysis of aquatic respirometry data
FishResp is a user-friendly tool for calculating oxygen uptake of aquatic organisms. The aim of the software is to improve the quality of metabolic rate estimates based on a straightforward pipeline: background respiration correction, detection of mechanical problems, conduction of QC tests, and filtration based on user-defined criteria. Abstract Intermittent-flow respirometry is widely used to measure oxygen uptake rates and subsequently estimate aerobic metabolic rates of aquatic animals. However, the lack of a standard quality-control software to detect technical problems represents a potential impediment to comparisons across studies in the field of evolutionary and conservation physiology. Here, we introduce FishResp', a versatile R package and its graphical implementation for quality-control and filtering of raw respirometry data. Our goal is to provide a straightforward, cross-platform and free software to help improve the quality and comparability of metabolic rate estimates for reducing methodological fragmentation in the field of aquatic respirometry. FishResp accepts data from various respirometry systems, allows users to detect potential mechanical problems which can occur during oxygen uptake measurements (e.g. chamber leaking, poor water circulation), and offers six options to correct raw data for microbial oxygen consumption. The software performs filtering of raw data based on user criteria, and produces accurate and unbiased estimates of absolute and mass-specific metabolic rates. Using data from three-spined sticklebacks (Gasterosteus aculeatus) and Trinidadian guppies (Poecilia reticulata), we demonstrate the virtues of FishResp, highlighting the importance of detecting mechanical problems and correcting measurements for background respiration.Peer reviewe
The adaptive potential of subtropical rainbowfish in the face of climate change: heritability and heritable plasticity for the expression of candidate genes
Whilst adaptation and phenotypic plasticity might buffer species against habitat degradation associated with global climate change, few studies making such claims also possess the necessary and sufficient data to support them. Doing so requires demonstration of heritable variation in traits affecting fitness under new environmental conditions. We address this issue using an emerging aquatic system to study adaptation to climate change, the crimson-spotted rainbowfish (Melanotaenia duboulayi), a freshwater species from a region of eastern Australia projected to be affected by marked temperature increases. Captive born M. duboulayi of known pedigree were used to assess the long-term effects of contemporary and 2070-projected summer temperatures on the expression of genes previously identified in a climate change transcriptomics (RNA-Seq) experiment. Nearly all genes responded to increasing temperature. Significant additive genetic variance explained a moderate proportion of transcriptional variation for all genes. Most genes also showed broad-sense genetic variation in transcriptional plasticity. Additionally, molecular pathways of candidate genes co-occur with genes inferred to be under climate-mediated selection in wild M. duboulayi populations. Together, these results indicate the presence of existing variation in important physiological traits, and the potential for adaptive responses to a changing thermal environment.R.J. Scott McCairns, Steve Smith, Minami Sasaki, Louis Bernatchez and Luciano B. Beheregara
PENGARUH KOMPETENSI DAN DISIPLIN KERJA TERHADAP KINERJA PEGAWAI PADA DINAS PERIZINAN KOTA YOGYAKARTA
Penelitian ini bertujuan untuk mengetahui: (1) pengaruh kompetensi terhadap kinerja pegawai pada Dinas Perizinan Kota Yogyakarta, (2) pengaruh disiplin kerja terhadap kinerja pegawai pada Dinas Perizinan Kota Yogyakarta, dan (3) pengaruh kompetensi dan disiplin kerja secara simultan terhadap kinerja pegawai pada Dinas Perizinan Kota Yogyakarta.
Penelitian ini termasuk penelitian asosiatif kausal dengan pendekatan kuantitatif. Populasi dari penelitian ini adalah seluruh karyawan Dinas Perizinan Kota Yogyakarta yang berjumlah 125 orang. Data dikumpulkan dengan kuesioner yang telah diuji validitas dan reliabilitasnya. Teknik analisis data yang digunakan adalah regresi berganda.
Hasil penelitian menunjukkan bahwa: (1) terdapat pengaruh positif dan signifikan kompetensi terhadap kinerja pegawai pada Dinas Perizinan Kota Yogyakarta (β = 0,460; p=0,000; ∆R2 = 20,7%); (2) terdapat pengaruh positif dan signifikan disiplin kerja terhadap kinerja pegawai pada Dinas Perizinan Kota Yogyakarta (β = 0,514; p=0,000; ∆R2 = 25,0%); dan (3) terdapat pengaruh kompetensi dan disiplin kerja secara simultan terhadap kinerja pegawai pada Dinas Perizinan Kota Yogyakarta (variabel kompetensi β = 0,353; p=0,000; variabel disiplin kerja β = 0,421; p=0,000; dan ∆R2 = 36,4%)
Regulatory Architecture of Gene Expression Variation in the Threespine Stickleback Gasterosteus aculeatus
Much adaptive evolutionary change is underlain by mutational variation in regions of the genome that regulate gene expression rather than in the coding regions of the genes themselves. An understanding of the role of gene expression variation in facilitating local adaptation will be aided by an understanding of underlying regulatory networks. Here, we characterize the genetic architecture of gene expression variation in the threespine stickleback (Gasterosteus aculeatus), an important model in the study of adaptive evolution. We collected transcriptomic and genomic data from 60 half-sib families using an expression microarray and genotyping-by-sequencing, and located expression quantitative trait loci (eQTL) underlying the variation in gene expression in liver tissue using an interval mapping approach. We identified eQTL for several thousand expression traits. Expression was influenced by polymorphism in both cis- and trans-regulatory regions. Transe-QTL clustered into hotspots. We did not identify master transcriptional regulators in hotspot locations: rather, the presence of hotspots may be driven by complex interactions between multiple transcription factors. One observed hotspot colocated with a QTL recently found to underlie salinity tolerance in the threespine stickleback. However, most other observed hotspots did not colocate with regions of the genome known to be involved in adaptive divergence between marine and freshwater habitats.Peer reviewe
Sticklebacks adapted to divergent osmotic environments show differences in plasticity for kidney morphology and candidate gene expression
Novel physiological challenges in different environments can promote the evolution of divergent phenotypes, either through plastic or genetic changes. Environmental salinity serves as a key barrier to the distribution of nearly all aquatic organisms, and species diversification is likely to be enabled by adaptation to alternative osmotic environments. The threespine stickleback (Gasterosteus aculeatus) is a euryhaline species with populations found both in marine and freshwater environments. It has evolved both highly plastic and locally adapted phenotypes due to salinity-derived selection, but the physiological and genetic basis of adaptation to salinity is not fully understood. We integrated comparative cellular morphology of the kidney, a key organ for osmoregulation, and candidate gene expression to explore the underpinnings of evolved variation in osmotic plasticity within two populations of sticklebacks from distinct salinity zones in the Baltic Sea: the high salinity Kattegat, representative of the ancestral marine habitat; and the low salinity Bay of Bothnia. A common-garden experiment revealed that kidney morphology in the ancestral high-salinity population had a highly plastic response to salinity conditions whereas this plastic response was reduced in the low-salinity population. Candidate gene expression in kidney tissue revealed a similar pattern of population specific differences, with a higher degree of plasticity in the native high-salinity population. Together these results suggest that renal cellular morphology has become canalized to low salinity, and that these structural differences may have functional implications for osmoregulation.Peer reviewe
Eclipse in the Dark Years: Pick-up Flights, Routes of Resistance and the Free French
This article charts the importance of clandestine flights from Britain into occupied France during the Second World War as a route of resistance. These pick-up flights were coordinated from London and were an example of the inter-allied cooperation and Franco-British negotiation that took place between the BCRA, SIS, and SOE. The flights allowed General Charles de Gaulle to hold court with the leaders of resistance networks, smoothing problems on the route to a unified resistance council. Likewise, they allowed him to build bridges between vying factions in France and in London, drawing together the movements under his command and personalising the narrative of resistance. From busy London restaurants and family homes via secret flights to darkened fields in Occupied France, the route of these transfers shaped the character of resistance. This article draws out the personal interactions and connections that underpinned these networks and describes the enduring connections of this route of resistance, starting with the commemoration of Jean Moulin's crash landing at RAF Tangmere, the forward station for many of these flights
Elevated temperatures drive the evolution of armour loss in the threespine stickleback Gasterosteus aculeatus
1. While there is evidence of genetic and phenotypic responses to climate change, few studies have demonstrated change in functional traits with a known genetic basis.
2. Here we present evidence for an evolutionary adaptive response to elevated temperatures in freshwater populations of the threespine stickleback Gasterosteus aculeatus.
3. Using a unique set of historical data and museum specimens, in combination with contemporary samples, we fitted a Bayesian spatial model to identify a population-level decline in the number of lateral bony plates, comprising anti-predator armour, in multiple populations of sticklebacks over the last 91 years in Poland.
4. Armor loss was predicted by elevated temperatures and is proposed to be a correlated response to selection for reduced body size.
5. This study demonstrates a change in a functional trait of known genetic basis in response to elevated temperature, and illustrates the utility of the threespine stickleback as a model for measuring the evolutionary and ecological impacts of environmental change across the northern hemisphere
Protein analysis and gene expression indicate differential vulnerability of Iberian fish species under a climate change scenario
Current knowledge on the biological responses of freshwater fish under projected scenarios of climate change remains limited. Here, we examine differences in the protein configuration of two endemic Iberian freshwater fish species, Squalius carolitertii and the critically endangered S. torgalensis that inhabit in the Atlantic-type northern and in the Mediterranean-type southwestern regions, respectively. We performed protein structure modeling of fourteen genes linked to protein folding, energy metabolism, circadian rhythms and immune responses. Structural differences in proteins between the two species were found for HSC70, FKBP52, HIF1α and GPB1. For S. torgalensis, besides structural differences, we found higher thermostability for two proteins (HSP90 and GBP1), which can be advantageous in a warmer environment. Additionally, we investigated how these species might respond to projected scenarios of 3° climate change warming, acidification (ΔpH = -0.4), and their combined effects. Significant changes in gene expression were observed in response to all treatments, particularly under the combined warming and acidification. While S. carolitertii presented changes in gene expression for multiple proteins related to folding (hsp90aa1, hsc70, fkbp4 and stip1), only one such gene was altered in S. torgalensis (stip1). However, S. torgalensis showed a greater capacity for energy production under both the acidification and combined scenarios by increasing cs gene expression and maintaining ldha gene expression in muscle. Overall, these findings suggest that S. torgalensis is better prepared to cope with projected climate change. Worryingly, under the simulated scenarios, disturbances to circadian rhythm and immune system genes (cry1aa, per1a and gbp1) raise concerns for the persistence of both species, highlighting the need to consider multi-stressor effects when evaluating climate change impacts upon fish. This work also highlights that assessments of the potential of endangered freshwater species to cope with environmental change are crucial to help decision-makers adopt future conservation strategies.info:eu-repo/semantics/publishedVersio
Effects of predator exposure on baseline and stress‐induced glucocorticoid hormone concentrations in pumpkinseed Lepomis gibbosus
We compared baseline and maximal cortisol concentrations between predator exposure and prey blood samples in pumpkinseed Lepomis gibbosus, captured using a standardised fishing event underneath osprey Pandion haliaetus nests and away from osprey nests. We did not detect differences in cortisol or glucose between sites. These findings suggest that predictable sources of predation risk may not confer stress-related costs in teleosts