Although biomass variations in Microcystis and microcystin have been widely reported,few studies have addressed whether different trophic states of natural lake water affect the spatial-temporal variations in abundanc...Although biomass variations in Microcystis and microcystin have been widely reported,few studies have addressed whether different trophic states of natural lake water affect the spatial-temporal variations in abundances of microcystin-producing Microcystis in a given bloom.In this study,we used a harmful algal bloom in Chaohu Lake,eastern China,as an example to investigate the mutual relationship between different nutrient states and environmental factors,and the impact on Microcystis.Overall,cyanobacteria and Microcystis were more abundant in the middle and western parts of the lake under high nutrients levels,while in the eastern part,nutrient concentrations were low enough to limit biomass,and their fluctuations affected the contents of toxic Microcystis.Moreover,microcystin concentration was correlated positively to nutrient levels and Microcystis biomass during bloom developing in 2013 from June to August.Temporally,the cellular content of total microcystin was lowest when the bloom peaked in intensity.Our results suggest that lake eutrophication not only results in cyanobacterial blooms,but may also increase the proportion of toxic Microcystis species and their cell-bound MCs contents(i.e.microcystin cell quotas) under mild eutrophication.The present investigation provided molecular evidence for the selection of MC-producing and non-MC-producing genotypes.The current study provides new evidence advocating the monitoring of partitions of large lakes when studying cyanobacteria and toxin-contaminated freshwaters,which will be beneficial for both water agencies and water researchers.展开更多
The fundamental unit of rapid, physiological color change in vertebrates is the dermal chromato- phore unit. This unit, comprised of cellular associations between different chromatophore types, is relatively conserved...The fundamental unit of rapid, physiological color change in vertebrates is the dermal chromato- phore unit. This unit, comprised of cellular associations between different chromatophore types, is relatively conserved across the fish, amphibian, and reptilian species capable of physiological color change and numerous attempts have been made to understand the nature of the four major chro- matophore types （melanophores, erythrophores, xanthophores, and iridophores） and their bio- chemical regulation. In this review, we attempt to describe the current state of knowledge regard- ing what classifies a pigment cell as a dynamic chromatophore, the unique characteristics of each chromatophore type, and how different hormones, neurotransmitters, or other signals direct pig- ment reorganization in a variety of vertebrate taxa.展开更多
基金Supported by the Major Science and Technology Program for Water Pollution Control and Treatment(Nos.2012ZX07103-004-02,2015ZX07204002)the Henan Institute of Engineering Innovation Team Building Program(No.CXTD2014005)+2 种基金the Henan Province Science Projects for Colleges and Universities(No.15A610011)the City Science and Technology Project(No.20140659)the Fund Project for Doctor(No.D2014009)
文摘Although biomass variations in Microcystis and microcystin have been widely reported,few studies have addressed whether different trophic states of natural lake water affect the spatial-temporal variations in abundances of microcystin-producing Microcystis in a given bloom.In this study,we used a harmful algal bloom in Chaohu Lake,eastern China,as an example to investigate the mutual relationship between different nutrient states and environmental factors,and the impact on Microcystis.Overall,cyanobacteria and Microcystis were more abundant in the middle and western parts of the lake under high nutrients levels,while in the eastern part,nutrient concentrations were low enough to limit biomass,and their fluctuations affected the contents of toxic Microcystis.Moreover,microcystin concentration was correlated positively to nutrient levels and Microcystis biomass during bloom developing in 2013 from June to August.Temporally,the cellular content of total microcystin was lowest when the bloom peaked in intensity.Our results suggest that lake eutrophication not only results in cyanobacterial blooms,but may also increase the proportion of toxic Microcystis species and their cell-bound MCs contents(i.e.microcystin cell quotas) under mild eutrophication.The present investigation provided molecular evidence for the selection of MC-producing and non-MC-producing genotypes.The current study provides new evidence advocating the monitoring of partitions of large lakes when studying cyanobacteria and toxin-contaminated freshwaters,which will be beneficial for both water agencies and water researchers.
文摘The fundamental unit of rapid, physiological color change in vertebrates is the dermal chromato- phore unit. This unit, comprised of cellular associations between different chromatophore types, is relatively conserved across the fish, amphibian, and reptilian species capable of physiological color change and numerous attempts have been made to understand the nature of the four major chro- matophore types （melanophores, erythrophores, xanthophores, and iridophores） and their bio- chemical regulation. In this review, we attempt to describe the current state of knowledge regard- ing what classifies a pigment cell as a dynamic chromatophore, the unique characteristics of each chromatophore type, and how different hormones, neurotransmitters, or other signals direct pig- ment reorganization in a variety of vertebrate taxa.
