A study of some factors involved in the adaptation to temperature in the freshwater crayfish austropotamobius pallipes (lereboullet)

The phenomena of resistance compensation to temperature and heat death in the freshwater crayfish Austropotamobius pallipes has been studied, with particular regard to muscle membranes. The lipid composition of whole muscle was analysed by conventional chromatographic techniques. The principle phospholipids present were choline phosphoglycerides (50%), ethanolamine phosphoglycerides (25%) and serine/inositol phosphoglycerides (10%). Temperature acclimation had no effect on the phospholipid composition. The fatty acid composition of various phospholipid classes were also analysed by GLC and were found to be highly unsaturated. Total phospholipid extracts from animals acclimated to 4 C (18 hr light photoperiod) contained as lightly greater proportion of unsaturated fatty acids, compared to extracts from 25 C acclimated crayfish. The acidic phospholipids showed the greatest changes. Acclimation to 4 C with 8 hr light photoperiod conditions caused incorporation of a still greater proportion of unsaturated fatty acids into membrane phospholipids. This daylength effect, however, was not associated with a change in the thermal resistance of the whole animal. The overall activity of the Ca(^2+) stimulated ATPase of crayfish sarcoplasmic reticulum was unaffected by thermal acclimation, although warm-acclimated crayfish yielded significantly more microsomal protein per gram muscle weight. The kinetics characteristics of enzyme activity were independent of temperature up to 28 C. Incubation at 35 C (a lethal temperature) caused a decline in enzyme-substrate affinity. Thermal acclimation had no effect upon these characteristics. Arrhenius plots of enzyme activity for preparations isolated from both acclimated groups were linear. The activation energy for the enzyme from each acclimation group was similar (approximately 15 Kcals. Mole(^-1) ; 62,8 KJ. Mole(^-1)).The process of inactivation of the Ca(^2+)-stimulated ATPase at lethal temperature was also studied. High KC1 media protected the enzyme from inactivation, although dilution, and addition of BSA and calcium had no effect. Inactivation in low KC1 media, was a first order process. Acclimation had no significant effect upon the rate of inactivation. The proposed role of membranes in the phenomenon of resistance compensation has been discussed in the light of this and other data. An ultrastructural and histological study of a Microsporidian parasite of crayfish muscle is also presented

ExprAlign - the identification of ESTs in non-model species by alignment of cDNA microarray expression profiles

<p>Abstract</p> <p>Background</p> <p>Sequence identification of ESTs from non-model species offers distinct challenges particularly when these species have duplicated genomes and when they are phylogenetically distant from sequenced model organisms. For the common carp, an environmental model of aquacultural interest, large numbers of ESTs remained unidentified using BLAST sequence alignment. We have used the expression profiles from large-scale microarray experiments to suggest gene identities.</p> <p>Results</p> <p>Expression profiles from ~700 cDNA microarrays describing responses of 7 major tissues to multiple environmental stressors were used to define a co-expression landscape. This was based on the Pearsons correlation coefficient relating each gene with all other genes, from which a network description provided clusters of highly correlated genes as 'mountains'. We show that these contain genes with known identities and genes with unknown identities, and that the correlation constitutes evidence of identity in the latter. This procedure has suggested identities to 522 of 2701 unknown carp ESTs sequences. We also discriminate several common carp genes and gene isoforms that were not discriminated by BLAST sequence alignment alone. Precision in identification was substantially improved by use of data from multiple tissues and treatments.</p> <p>Conclusion</p> <p>The detailed analysis of co-expression landscapes is a sensitive technique for suggesting an identity for the large number of BLAST unidentified cDNAs generated in EST projects. It is capable of detecting even subtle changes in expression profiles, and thereby of distinguishing genes with a common BLAST identity into different identities. It benefits from the use of multiple treatments or contrasts, and from the large-scale microarray data.</p

Novel Candidate Genes Identified in the Brain during Nociception in Common Carp (Cyprinus carpio) and Rainbow Trout (Oncorhynchus mykiss)

Recent studies have demonstrated that teleost fish possess nociceptors that detect potentially painful stimuli and that the physiological properties of these fibres are markedly similar to those found in mammals. This finding led to suggestions of possible pain perception in fish, contrary to the view that the sensory response in these animals is limited to the spinal cord and hindbrain and as such is reflexive. Therefore, the aim of this study was to determine if the brain is active at the molecular level by using a microarray analysis of gene expression in the forebrain, midbrain and hindbrain of two fish species. A comparison between the two species at different time points showed that many genes were differentially regulated in response to a noxious stimulus compared with controls. A number of genes that are involved in mammalian nociception, such as brain-derived neurotrophic factor (BDNF) and the cannabinoid CB1 receptor were regulated in the fish brain after a nociceptive event. Novel candidates that showed significant regulation in both species were also identified. In particular, the Van Gogh-like 2 gene, was regulated in both carp and trout and should be pursued to establish its precise role in nociception

Behavioural Analysis of a Nociceptive Event in Fish: Comparisons Between Three Species Demonstrate Specific Responses

Nociception is the sensory mechanism by which potentially harmful stimuli are detected in animals and humans. The behavioural responses to noxious stimulation have been studied in two fish species thus far. However, since species-specific differences are seen in mammals, more species need to be examined to determine whether nociceptive responses are generic in fish. The present study investigated the behavioural and respiratory response to an acute noxious or potentially painful stimulus in common carp (Cyprinus carpio), zebrafish (Danio rerio) and rainbow trout (Oncorhynchus mykiss). Behavioural parameters such as frequency of swimming, use of cover and any anomalous behaviour were measured along with ventilation rate before and after noxious stimulation in the carp and zebrafish. Although no differences in behavioural or ventilation rate response were observed between noxiously stimulated carp and control fish, anomalous behaviours of rocking from side to side and rubbing of lips against the tank walls were observed in two of the five fish. In contrast, zebrafish displayed a significant reduction in frequency of swimming and an increase in ventilation rate, which was similar to the results obtained from rainbow trout. Zebrafish did not display any anomalous behaviour. These dissimilarities in response to potentially painful stimulation demonstrate that there are species-specific behavioural and physiological responses to a nociceptive event in fish

Experimental sexual selection reveals rapid evolutionary divergence in sex-specific transcriptomes and their interactions following mating

Work was supported by the Natural Environment Research Council (NE/I014632/1 to M.G.R., A.R.C., and R.R.S), the Natural Environment Research Council Biomolecular Analysis Facility (NBAF654 to M.G.R), and the Swedish Research Council (Vetenskapsrådet; 2018-04598 to R.R.S).Postcopulatory interactions between the sexes in internally fertilizing species elicits both sexual conflict and sexual selection. Macroevolutionary and comparative studies have linked these processes to rapid transcriptomic evolution in sex-specific tissues and substantial transcriptomic postmating responses in females, patterns of which are altered when mating between reproductively isolated species. Here we test multiple predictions arising from sexual selection and conflict theory about the evolution of sex-specific and tissue-specific gene expression and the postmating response at the microevolutionary level. Following over 150 generations of experimental evolution under either reduced (enforced monogamy) or elevated (polyandry) sexual selection in Drosophila pseudoobscura, we found a substantial effect of sexual selection treatment on transcriptomic divergence in virgin male and female reproductive tissues (testes, male accessory glands, the female reproductive tract and ovaries). Sexual selection treatment also had a dominant effect on the postmating response, particularly in the female reproductive tract ? the main arena for sexual conflict - compared to ovaries. This effect was asymmetric with monandry females typically showing more postmating responses than polyandry females, with enriched gene functions varying across treatments. The evolutionary history of the male partner had a larger effect on the postmating response of monandry females, but females from both sexual selection treatments showed unique patterns of gene expression and gene function when mating with males from the alternate treatment. Our microevolutionary results mostly confirm comparative macroevolutionary predictions on the role of sexual selection on transcriptomic divergence and altered gene regulation arising from divergent coevolutionary trajectories between sexual selection treatments.Publisher PDFPeer reviewe

Investigation of Van Gogh-like 2 mRNA Regulation and Localisation in Response to Nociception in the Brain of Adult Common Carp (Cyprinus carpio)

The Van Gogh-like 2 (vangl2) gene is typically associated with planar cell polarity pathways, which is essential for correct orientation of epithelial cells during development. The encoded protein of this gene is a transmembrane protein and is highly conserved through evolution. Van Gogh-like 2 was selected for further study on the basis of consistent regulation after a nociceptive stimulus in adult common carp and rainbow trout in a microarray study. An in situ hybridisation was conducted in the brain of mature common carp (Cyprinus carpio), 1.5 and 3 h after a nociceptive stimulus comprising of an acetic acid injection to the lips of the fish and compared with a saline-injected control. The vangl2 gene was expressed in all brain regions, and particularly intensely in neurons of the telencephalon and in ependymal cells. In the cerebellum, a greater number (P = 0.018) of Purkinje cells expressed vangl2 after nociception (n=7) compared with controls (n = 5). This regulation opens the possibility that vangl2 is involved in nociceptive processing in the adult fish brain and may be a novel target for central nociception in vertebrates

3D-Modeling for the Analysis of Range Data

In this paper a new method of modeling 30-objects for the interpretation of range images is described.In range data it is possible to detect surface patches, edges and 30- vertices by local and therefore fast operations. Recognition of an object is done by associating these structures with one element of a set of possible objects. For that it is necessary to use an adequate description of objects which supports fast matching. In this paper a model is presented, which represents an object by surfaces, edges, vertices and neighborhood relationships. The representation of the objects is restricted on those surfaces, which are easy to detect by the used range sensor.A further requirement is a fast and easy interactive construction of object models which assists human demands and thus reduces the costs of providing and maintenance of the object database

Welfare Challenges Influence the Complexity of Movement: Fractal Analysis of Behaviour in Zebrafish

The ability to assess welfare is an important refinement that will ensure the good condition of animals used in experimentation. The present study investigated the impact of invasive procedures on the patterns of movement of zebrafish (Danio rerio). Recordings were made before and after fin clipping, PIT tagging and a standard pain test and these were compared with control and sham handled zebrafish. The fractal dimension (FD) from the 3D trajectories was calculated to determine the effect of these treatments on the complexity of movement patterns. While the FD of zebrafish trajectories did not differ over time in either the control or sham group, the FDs of the treatment groups reduced in complexity. The FD of fish injected with different strengths of acetic acid declined in a dose-dependent manner allowing us to develop an arbitrary scale of severity of the treatments. The 3D trajectory plots from some groups indicated the presence of repetitive swimming patterns akin to stereotypical movements. When administered with lidocaine, which has analgesic properties, the movement complexity of fin clipped fish reverted to a pattern that resembled that of control fish. Fractal analysis of zebrafish locomotion could potentially be adopted as a tool for fish welfare assessment

Defining Global Neuroendocrine Gene Expression Patterns Associated with Reproductive Seasonality in Fish

Many vertebrates, including the goldfish, exhibit seasonal reproductive rhythms, which are a result of interactions between external environmental stimuli and internal endocrine systems in the hypothalamo-pituitary-gonadal axis. While it is long believed that differential expression of neuroendocrine genes contributes to establishing seasonal reproductive rhythms, no systems-level investigation has yet been conducted. gamma2 receptor, calmodulin, and aromatase b by independent samplings of goldfish brains from six seasonal time points and real-time PCR assays.Using both theoretical and experimental strategies, we report for the first time global gene expression patterns throughout a breeding season which may account for dynamic neuroendocrine regulation of seasonal reproductive development

Automated monitoring of behaviour in zebrafish after invasive procedures

Fish are used in a variety of experimental contexts often in high numbers. To maintain their welfare and ensure valid results during invasive procedures it is vital that we can detect subtle changes in behaviour that may allow us to intervene to provide pain-relief. Therefore, an automated method, the Fish Behaviour Index (FBI), was devised and used for testing the impact of laboratory procedures and efficacy of analgesic drugs in the model species, the zebrafish. Cameras with tracking software were used to visually track and quantify female zebrafish behaviour in real time after a number of laboratory procedures including fin clipping, PIT tagging, and nociceptor excitation via injection of acetic acid subcutaneously. The FBI was derived from activity and distance swum measured before and after these procedures compared with control and sham groups. Further, the efficacy of a range of drugs with analgesic properties to identify efficacy of these agents was explored. Lidocaine (5 mg/L), flunixin (8 mg/L) and morphine (48 mg/L) prevented the associated reduction in activity and distance swum after fin clipping. From an ethical perspective, the FBI represents a significant refinement in the use of zebrafish and could be adopted across a wide range of biological disciplines