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- Andersson, Björn, et al.
(författare)
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Strain-specific metabarcoding reveals rapid evolution of copper tolerance in populations of the coastal diatom Skeletonema marinoi
- 2023
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Ingår i: Molecular Ecology. - 0962-1083 .- 1365-294X.
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Tidskriftsartikel (refereegranskat)abstract
- Phytoplankton have short generation times, flexible reproduction strategies, large population sizes and high standing genetic diversity, traits that should facilitate rapid evolution under directional selection. We quantified local adaptation of copper tolerance in a population of the diatom Skeletonema marinoi from a mining-exposed inlet in the Baltic Sea and in a non-exposed population 100 km away. We hypothesized that mining pollution has driven evolution of elevated copper tolerance in the impacted population of S. marinoi. Assays of 58 strains originating from sediment resting stages revealed no difference in the average tolerance to copper between the two populations. However, variation within populations was greater at the mining site, with three strains displaying hyper-tolerant phenotypes. In an artificial evolution experiment, we used a novel intraspecific metabarcoding locus to track selection and quantify fitness of all 58 strains during co-cultivation in one control and one toxic copper treatment. As expected, the hyper-tolerant strains enabled rapid evolution of copper tolerance in the mining-exposed population through selection on available strain diversity. Within 42 days, in each experimental replicate a single strain dominated (30%–99% abundance) but different strains dominated the different treatments. The reference population developed tolerance beyond expectations primarily due to slowly developing plastic response in one strain, suggesting that different modes of copper tolerance are present in the two populations. Our findings provide novel empirical evidence that standing genetic diversity of phytoplankton resting stage allows populations to evolve rapidly (20–50 generations) and flexibly on timescales relevant for seasonal bloom progressions.
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| 2. |
- Andersson, Helena M., 1973-, et al.
(författare)
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Active recovery training does not affect the antioxidant response to soccer games in elite female players
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Changes in plasma endogenous and dietary antioxidants and oxidative stress markers were studied following two 90-min elite female soccer games separated by 72 h of either active or passive recovery. The active recovery group (n=8) trained for one hour at 22 and 46 h after the first game (low-intensity cycling and resistance training)while the passive group rested(n=8). Blood samples were taken before, immediately after, 21, 45 and 69 h after the first and immediately after the second game. The oxidative stress markers and antioxidants were not affected by active recovery. The oxidative stress marker oxidized glutathione increased by the same extent after both games, while the lipid peroxidation marker diacrons reactive-oxygen metabolites remained unchanged. The endogenous antioxidants total glutathione, uric acid and ferric reducing/antioxidant power assay increased immediately after both games with the same amplitude, while increases in cysteine, cysteine-glycine and total thiols reached significant levels only after the second game. The changes in dietary antioxidants after the first game were either rapid and persistent (tocopherols, ascorbic acid increased; polyphenols decreased) or delayed (carotenoids). This resulted in high pre-second game levels of tocopherols, ascorbic acid and carotenoids. Polyphenols returned to baseline at 69 h and were not affected by the second game. In conclusion, the soccer-associated dietary but not endogenous antioxidant defence is persistent. Similar acute oxidative stress and endogenous antioxidant responses and dissimilar dietary antioxidant reactions occur during two repeated female soccer games. Finally, the complex antioxidant response to soccer is not affected by active recovery training.
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| 3. |
- Andersson, Helena M., 1973-
(författare)
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The physiological impact of soccer on elite female players and the effects of active recovery training
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Female soccer is becoming more popular and professional in the world. There are, however, limited scientific data available on how elite female players respond to physical stress during soccer games. An effective recovery strategy following a game is important, because there are few recovery days between the games in international tournaments. The present thesis, which was designed to mirror a competitive situation, aimed to investigate changes in several physiological systems occurring in female elite players in response to two soccer games. It also aimed to investigate the effects of active recovery training on the recovery of several physiological systems. METHODS: Two elite female soccer teams played two 90-min games separated by 72 h active or passive recovery. The active recovery training (cycling at 60% HRpeak, resistance training at <50% 1RM) lasted one hour and was performed 22 and 46 h after the first game. Countermovement jump (CMJ), 20-m sprint time and isokinetic knee strength were measured before, immediately, 5, 21, 45, 51, and 69 h after the first game, and immediately after the second game. The physical stress markers (CK, urea), oxidative stress markers (e.g., GSSG, lipid peroxidation), endogenous (e.g., UA, thiols) and dietary antioxidants (e.g., tocopherols, carotenoids) and a large battery of cytokines (e.g., IL-6, TNF-α) were analysed in blood. RESULTS: No significant differences were observed in the performance parameters, oxidative stress and antioxidant levels or inflammatory response between the active and passive recovery groups. Sprint and isokinetic knee strength were reduced by the same extent after both games. CMJ decreased after the first game and remained reduced throughout the study period. Blood physical stress markers, GSSG and endogenous antioxidants increased with similar amplitude after both games together with unchanged lipid peroxidation. The dietary antioxidants showed either a rapid and persistent change (e.g., tocopherols) or a delayed rise (carotenoids) after the first game. A transient increase occurred in several pro- (e.g., IL-12, TNF-a, MCP-1), anti-inflammatory (e.g., IL-4, IL-10, INF-a) and mixed (IL-6) cytokines after the first game. Fewer cytokines increased in response to the second game. CONCLUSION: Two repeated elite female soccer games separated by 72 h induced similar acute changes in several physiological parameters. After the first game, differences in the recovery pattern of the neuromuscular parameters occurred. In particular, the slow recovery of CMJ indicates that special attention should be devoted to the training of explosive force. Furthermore, the recruitment of antioxidants in response to the transient increase in GSSG resulted in the maintenance of the redox-balance in female players. Similarly, a strong and balanced pro- and anti-inflammatory cytokine response occurred after one single female soccer game. The consequences of the dampened cytokine response during repeated soccer games are, however, unknown. In general, the majority of the parameters had recovered prior to the second game and the physiological alterations induced by the first game did not affect the performance of players in the second game. Finally, active recovery training conducted after a soccer game does not accelerate the recovery time for neuromuscular, oxidative stress, antioxidant and inflammatory responses in elite female players.
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