{"title":"[Changes in Elemental and Isotopic Composition Accompanying Larval Growth and Metamorphosis of the Moor Frog].","authors":"Yu K Doronin, A V Tiunov, E N Kalistratova","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>A variety of early ontogenetic events of anuran species (growth, structural and biochemical diversification,\nmetamorphosis) offers a unique opportunity to evaluate the effectiveness and application limits of\nmass spectrometry method for the analysis of metabolic and transformation events in developing organisms.\nThe dynamics of relative carbon and nitrogen contents and stable isotopes of these elements during larval\ndevelopment in the period of metamorphosis climax and after its conclusion in moor frog specimens developing\nin their natural habitat and in vitro on a referent diet are traced. A decrease in C/N ratio and enrichment\nof the tissues with heavy stable isotopes of carbon and nitrogen during embryonal and larval development\n(prior to the beginning of independent feeding) indicates the increase in the portion and variety of proteins,\naccompanied by consumption of yolk lipids. The relative nitrogen content increase and C/N ratio decreases\nwith the growth and development of independently feeding tadpoles, which indicates surpassing increase of\nthe portion of proteins in tissues. In growing tadpoles, the rates of tissue renewal in general and rates of protein\nmetabolism in particular affect the kinetics of changes of tissue isotope composition, which approaches isotope\ncomposition of the consumed food. A decrease in С/N ratio in the bodies of metamorphs during mass\ntissue decomposition is indicative of continuing reconstruction of larval organs and growth of anlage of definitive\norgans. Significant increase of C/N ratio and depletion of liver samples by heavy carbon isotopes are\nassociated with intensive synthesis and reservation of lipids within the organ. Strong enrichment of metamorphs’\ntissues with heavy nitrogen isotope indicates the substitution of ammoniotelic type of nitrogen\nmetabolism by urotelic type. Decrease in C/N ratio and enrichment of tissues by heavy carbon isotope may\nbe connected to intensive oxidation of lipids, which supports the growing energy costs of terrestrial underyearlings.\nRelative contents of heavy nitrogen isotope in the tissues of underyearlings does not change compared\nto the tissues of metamorphs.</p>","PeriodicalId":19673,"journal":{"name":"Ontogenez","volume":"48 1","pages":"46-54"},"PeriodicalIF":0.0000,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ontogenez","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
A variety of early ontogenetic events of anuran species (growth, structural and biochemical diversification,
metamorphosis) offers a unique opportunity to evaluate the effectiveness and application limits of
mass spectrometry method for the analysis of metabolic and transformation events in developing organisms.
The dynamics of relative carbon and nitrogen contents and stable isotopes of these elements during larval
development in the period of metamorphosis climax and after its conclusion in moor frog specimens developing
in their natural habitat and in vitro on a referent diet are traced. A decrease in C/N ratio and enrichment
of the tissues with heavy stable isotopes of carbon and nitrogen during embryonal and larval development
(prior to the beginning of independent feeding) indicates the increase in the portion and variety of proteins,
accompanied by consumption of yolk lipids. The relative nitrogen content increase and C/N ratio decreases
with the growth and development of independently feeding tadpoles, which indicates surpassing increase of
the portion of proteins in tissues. In growing tadpoles, the rates of tissue renewal in general and rates of protein
metabolism in particular affect the kinetics of changes of tissue isotope composition, which approaches isotope
composition of the consumed food. A decrease in С/N ratio in the bodies of metamorphs during mass
tissue decomposition is indicative of continuing reconstruction of larval organs and growth of anlage of definitive
organs. Significant increase of C/N ratio and depletion of liver samples by heavy carbon isotopes are
associated with intensive synthesis and reservation of lipids within the organ. Strong enrichment of metamorphs’
tissues with heavy nitrogen isotope indicates the substitution of ammoniotelic type of nitrogen
metabolism by urotelic type. Decrease in C/N ratio and enrichment of tissues by heavy carbon isotope may
be connected to intensive oxidation of lipids, which supports the growing energy costs of terrestrial underyearlings.
Relative contents of heavy nitrogen isotope in the tissues of underyearlings does not change compared
to the tissues of metamorphs.