| 1. |
- Dhillon, Sundeep S., et al.
(författare)
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Metabolic profiling of zebrafish embryo development from blastula period to early larval stages
- 2019
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Ingår i: PLOS ONE. - San Francisco : Public Library of Science. - 1932-6203. ; 14:5
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Tidskriftsartikel (refereegranskat)abstract
- The zebrafish embryo is a popular model for drug screening, disease modelling and molecular genetics. In this study, samples were obtained from zebrafish at different developmental stages. The stages that were chosen were 3/4, 4/5, 24, 48, 72 and 96 hours post fertilization (hpf). Each sample included fifty embryos. The samples were analysed using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS). Principle component analysis (PCA) was applied to get an overview of the data and orthogonal projection to latent structure discriminant analysis (OPLS-DA) was utilised to discriminate between the developmental stages. In this way, changes in metabolite profiles during vertebrate development could be identified. Using a GC-TOF-MS metabolomics approach it was found that nucleotides and metabolic fuel (glucose) were elevated at early stages of embryogenesis, whereas at later stages amino acids and intermediates in the Krebs cycle were abundant. This agrees with zebrafish developmental biology, as organs such as the liver and pancreas develop at later stages. Thus, metabolomics of zebrafish embryos offers a unique opportunity to investigate large scale changes in metabolic processes during important developmental stages in vertebrate development. In terms of stability of the metabolic profile and viability of the embryos, it was concluded at 72 hpf was a suitable time point for the use of zebrafish as a model system in numerous scientific applications.
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| 2. |
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| 3. |
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| 4. |
- Torell, Frida, et al.
(författare)
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Metabolic Profiling of Multiorgan Samples : Evaluation of MODY5/RCAD Mutant Mice
- 2018
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 17:7, s. 2293-2306
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, we performed a metabolomics analysis to evaluate a MODY5/RCAD mouse mutant line as a potential model for HNF1B-associated diseases. Gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) of gut, kidney, liver, muscle, pancreas, and plasma samples uncovered the tissue specific metabolite distribution. Orthogonal projections to latent structures discriminant analysis (OPLS-DA) was used to identify the differences between MODY5/RCAD and wild-type mice in each of the tissues. The differences included, for example, increased levels of amino acids in the kidneys and reduced levels of fatty acids in the muscles of the MODY5/RCAD mice. Interestingly, campesterol was found in higher concentrations in the MODY5/RCAD mice, with a four-fold and three-fold increase in kidneys and pancreas, respectively. As expected, the MODY5/RCAD mice displayed signs of impaired renal function in addition to disturbed liver lipid metabolism, with increased lipid and fatty acid accumulation in the liver. From a metabolomics perspective, the MODY5/RCAD model was proven to display a metabolic pattern similar to what would be suspected in HNF1B-associated diseases. These findings were in line with the presumed outcome of the mutation based on the different anatomy and function of the tissues as well as the effect of the mutation on development.
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| 5. |
- Torell, Frida, et al.
(författare)
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The effects of thawing on the plasma metabolome : evaluating differences between thawed plasma and multi-organ samples
- 2017
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Ingår i: Metabolomics. - : Springer. - 1573-3882 .- 1573-3890. ; 13:6
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Post-collection handling, storage and transportation can affect the quality of blood samples. Pre-analytical biases can easily be introduced and can jeopardize accurate profiling of the plasma metabolome. Consequently, a mouse study must be carefully planned in order to avoid any kind of bias that can be introduced, in order not to compromise the outcome of the study. The storage and shipment of the samples should be made in such a way that the freeze–thaw cycles are kept to a minimum. In order to keep the latent effects on the stability of the blood metabolome to a minimum it is essential to study the effect that the post-collection and pre-analytical error have on the metabolome. Objectives: The aim of this study was to investigate the effects of thawing on the metabolic profiles of different sample types. Methods: In the present study, a metabolomics approach was utilized to obtain a thawing profile of plasma samples obtained on three different days of experiment. The plasma samples were collected from the tail on day 1 and 3, while retro-orbital sampling was used on day 5. The samples were analysed using gas chromatography time-of-flight mass spectrometry (GC TOF-MS). Results: The thawed plasma samples were found to be characterized by higher levels of amino acids, fatty acids, glycerol metabolites and purine and pyrimidine metabolites as a result of protein degradation, cell degradation and increased phospholipase activity. The consensus profile was thereafter compared to the previously published study comparing thawing profiles of tissue samples from gut, kidney, liver, muscle and pancreas. Conclusions: The comparison between thawed organ samples and thawed plasma samples indicate that the organ samples are more sensitive to thawing, however thawing still affected all investigated sample types.
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| 6. |
- Dahlbom, Josefin, et al.
(författare)
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Boldness predicts social status in zebrafish (Danio rerio)
- 2011
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:8
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Tidskriftsartikel (refereegranskat)abstract
- This study explored if boldness could be used to predict social status. First, boldness was assessed by monitoring individual zebrafish behaviour in (1) an unfamiliar barren environment with no shelter (open field), (2) the same environment when a roof was introduced as a shelter, and (3) when the roof was removed and an unfamiliar object (Lego® brick) was introduced. Next, after a resting period of minimum one week, social status of the fish was determined in a dyadic contest and dominant/subordinate individuals were determined as the winner/loser of two consecutive contests. Multivariate data analyses showed that males were bolder than females and that the behaviours expressed by the fish during the boldness tests could be used to predict which fish would later become dominant and subordinate in the ensuing dyadic contest. We conclude that bold behaviour is positively correlated to dominance in zebrafish and that boldness is not solely a consequence of social dominance.
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| 8. |
- Lundstedt-Enkel, Katrin, 1959-
(författare)
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QSBMR Quantitative Structure Biomagnification Relationships : Studies Regarding Persistent Environmental Pollutants in the Baltic Sea Biota
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- I have studied persistent environmental pollutants in herring (Clupea harengus), in adult guillemot (Uria aalge) and in guillemot eggs from the Baltic Sea. The studied contaminants were organochlorines (OCs); dichlorodiphenyltrichloroethanes (DDTs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), and brominated flame retardants (BFRs); polybrominated diphenylethers (PBDEs) and hexabromocyclododecane (HBCD). The highest concentration in both species was shown by p,p′DDE with a concentration in guillemot egg (geometric mean (GM) with 95% confidence interval) of 18200 (17000 – 19600) ng/g lipid weight. The BFR with the highest concentration in guillemot egg was HBCD with a GM concentration of 140 (120 – 160) ng/g lw. To extract additional and essential information from the data, not possible to obtain using only univariate or bivariate statistics, I used multivariate data analysis techniques; principal components analysis (PCA), partial least squares regression (PLS), soft independent modelling of class analogy (SIMCA), and PLS discriminant analysis (PLS-DA). I found e.g.; that there are significant negative correlations between egg weight and the concentrations of HCB and p,p'DDE; that concentrations of OCs and BFRs in the organisms co-varied so that concentrations of OCs can be used to calculate concentrations of BFRs; and, that several contaminants (e.g. HBCD) had higher concentration in guillemot egg than in guillemot muscle, that several (e.g. BDE47) showed no concentration difference between muscle and egg and that one contaminant (BDE154) showed higher concentration in the guillemot muscles than in egg. In this thesis I developed a new method, “randomly sampled ratios” (RSR), to calculate biomagnification factors (BMFs) i.e. the ratio between the concentration of a contaminant in an organism and the concentration of the same contaminant in its food. With this new method BMFs are denoted with an estimate of variation. Contaminants that biomagnify are e.g., p,p′DDE, CB118, HCB, βHCH and all of the BFRs. Those that do not biomagnify are e.g., p,p′DDT, αHCH and CB101. Lastly, to investigate which of the contaminants descriptors (physical-chemical/other properties and characteristics) that correlates to the biomagnification of the contaminants, I modeled the contaminants’ respective BMFRSR versus ~100 descriptors and showed that ~20 descriptors in combination were important, either favoring or counteracting biomagnification between herring and guillemot.
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| 9. |
- Morrell, Jane, et al.
(författare)
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Sperm quality variables as indicators of bull fertility may be breed dependent
- 2017
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Ingår i: Animal Reproduction Science. - : ELSEVIER SCIENCE BV. - 0378-4320 .- 1873-2232. ; 185, s. 42-52
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Tidskriftsartikel (refereegranskat)abstract
- A means of discriminating among bulls of high fertility based on sperm quality is needed by breeding centers. The objective of the study was to examine parameters of sperm quality in bulls of known fertility to identify useful indicators of fertility. Frozen semen was available from bulls of known fertility (Viking Genetics, Skara, Sweden): Swedish Red (n = 31), Holstein (n = 25) and Others (one each of Charolais, Limousin, Blonde, SKB). After thawing, the sperm samples were analyzed for motility (computer assisted sperm analysis), plasma membrane integrity, chromatin integrity, acrosome status, mitochondrial activity and reactive oxygen species. A fertility index score based on the adjusted 56-day non-return rate for > 1000 inseminations was available for each bull. Multivariate data analysis (Partial Least Squares Regression and Orthogonal Partial Least Squares Regression) was performed to identify variables related to fertility; Pearson univariate correlations were made on the parameters of interest. Breed of bull affected the relationship of sperm quality variables and fertility index score, as follows: Swedish Red: %DNA Fragmentation Index, r = -0.56, P < 0.01; intact plasma membrane, r = 0.40, P < 0.05; membrane damaged, not acrosome reacted, r = 0.6, P < 0.01; Linearity, r = 0.37, P < 0.05; there was a trend towards significance for Wobble, r = 0.34, P = 0.08. Holstein: Linearity was significant r = 0.46, P < 0.05; there was a trend towards significance for Wobble, r = 0.45, P = 0.08. In conclusion, breed has a greater effect on sperm quality than previously realized; different parameters of sperm quality are needed to indicate potential fertility in different breeds.
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