Seasonal succession of cyanobacterial protease inhibitors and Daphnia magna genotypes in a eutrophic Swedish lake

摘要: Lakes are well known for having a pattern of seasonal succession phytoplankton and zooplankton. The different taxa results in zooplankton taxa, within the genus Daphnia, into genotypes (clones). One cause this Daphnia clones might be production digestive protease inhibitors by cyanobacteria, which usually bloom summer. Here we report changes frequency abundance magna haplotypes eutrophic lake, developed chymotrypsin-inhibitor-producing cyanobacterial May. These were not related to biotic abiotic lake parameters. However, very high content chymotrypsin was observed May (but other months). This assumed have exerted strong punctual selection pressure on population direct targets inhibitors, i.e. chymotrypsins Daphnia. Actually, D. from before during showed activity stained SDS-PAGE comparison month after bloom. no difference tolerance, measured as IC50 values, inhibition natural seston found between Thus, hypothesis that adaptation subpopulations either April/May or June occurred could proven. suggests investigated here is locally adapted inhibitors.