Impacts of nanomaterials synthesized by greener methods on aquatic vertebrates

Regenerative capacity of the brain is a variable trait within animals. Aquatic vertebrates such as zebrafish have widespread ability to renew their brains upon damage, while mammals have—if not none—very limited overall regenerative competence. Underlying cause of such a disparity is not fully evident; however, one of the reasons could be activation of peculiar molecular programs, which might have specific roles after injury or damage, by the organisms that regenerate. If this hypothesis is correct, then there must be genes and pathways that (a) are expressed only after injury or damage in tissues, (b) are biologically and functionally relevant to restoration of neural tissue, and (c) are not detected in regenerating organisms. Presence of such programs might circumvent the initial detrimental effects of the damage and subsequently set up the stage for tissue redevelopment to take place by modulating the plasticity of the neural stem/progenitor cells. Additionally, if transferable, those “molecular mechanisms of regeneration” could open up new avenues for regenerative therapies of humans in clinical settings. This review focuses on the recent studies addressing injury/damage-induced molecular programs in zebrafish brain, underscoring the possibility of the presence of genes that could be used as biomarkers of neural plasticity and regeneration.

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Polychaetes as Intermediate Hosts of Helminth Parasites of Vertebrates: A Review

Journal of the Fisheries Research Board of Canada ◽

10.1139/f71-216 ◽

1971 ◽

Vol 28 (10) ◽

pp. 1385-1392 ◽

Cited By ~ 17

Author(s):

L. Margolis

Keyword(s):

Helminth Parasites ◽

Intermediate Hosts ◽

Larval Stages ◽

Aquatic Vertebrates

The role of polychaetes as intermediate hosts of helminth parasites of aquatic vertebrates is reviewed. Some 18–20 species of trematodes and three or four each of cestodes and nematodes are known to have larval stages in these annelids. There are no records of acanthocephalan larvae from polychaetes. Trematoda use polychaetes as first (three species) or second intermediate hosts. The polychaete hosts are found among various genera of Errantia, Sedentaria, and Myzostomida. Definitive hosts are mainly fishes, with a few species of trematodes and one of cestodes developing in birds, and apparently one genus of nematodes (two species) maturing in the lungs of seals. A list of polychaetes and their larval helminth parasites is given.

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An aquatic vertebrate can use amino acids from environmental water

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2016.0996 ◽

2016 ◽

Vol 283 (1839) ◽

pp. 20160996 ◽

Cited By ~ 2

Author(s):

Noboru Katayama ◽

Kobayashi Makoto ◽

Osamu Kishida

Keyword(s):

Amino Acids ◽

Organic Matter ◽

Amino Acid ◽

Dissolved Organic Matter ◽

Larval Growth ◽

Environmental Water ◽

Acid Solutions ◽

Aquatic Vertebrates ◽

Amino Acid Solutions ◽

Salamander Larvae

Conventional food-web theory assumes that nutrients from dissolved organic matter are transferred to aquatic vertebrates via long nutrient pathways involving multiple eukaryotic species as intermediary nutrient transporters. Here, using larvae of the salamander Hynobius retardatus as a model system, we provide experimental evidence of a shortcut nutrient pathway by showing that H. retardatus larvae can use dissolved amino acids for their growth without eukaryotic mediation. First, to explore which amino acids can promote larval growth, we kept individual salamander larvae in one of eight different high-concentration amino acid solutions, or in control water from which all other eukaryotic organisms had been removed. We thus identified five amino acids (lysine, threonine, serine, phenylalanine, and tyrosine) as having the potential to promote larval growth. Next, using 15 N-labelled amino acid solutions, we demonstrated that nitrogen from dissolved amino acids was found in larval tissues. These results suggest that salamander larvae can take up dissolved amino acids from environmental water to use as an energy source or a growth-promoting factor. Thus, aquatic vertebrates as well as aquatic invertebrates may be able to use dissolved organic matter as a nutrient source.

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