{"title":"海洋哺乳动物牙本质生长层群稳定同位素分析的检验假设","authors":"Kelly R. Bowen, Carolyn M. Kurle","doi":"10.1002/rcm.9997","DOIUrl":null,"url":null,"abstract":"<div>\n \n \n <section>\n \n <h3> Rationale</h3>\n \n <p>Stable isotope analysis of growth layer groups (GLGs) in mammal dentin is an increasingly prevalent and noninvasive approach to study animal foraging ecology. However, empirical evidence to support assumed proper methodologies for sampling GLGs is lacking. Here, we examine the effects of intratooth and intertooth variations with respect to targeted GLGs, as well as the effects of common pretreatments (e.g., formic acid and graphite) to enhance GLG visibility, on stable isotope values (<i>δ</i><sup>13</sup>C and <i>δ</i><sup>15</sup>N) from dentin.</p>\n </section>\n \n <section>\n \n <h3> Methods</h3>\n \n <p>We measured the <i>δ</i><sup>13</sup>C and <i>δ</i><sup>15</sup>N values of killer whale (<i>Orcinus orca</i>) dentin. We used dentin from 37 teeth to compare stable carbon (<i>δ</i><sup>13</sup>C) and nitrogen (<i>δ</i><sup>15</sup>N) isotope values from multiple locations within a GLG (intratooth variation), from corresponding GLGs among teeth of an individual (intertooth variation), and from treated and untreated teeth.</p>\n </section>\n \n <section>\n \n <h3> Results</h3>\n \n <p>We observed no significant differences in the <i>δ</i><sup>13</sup>C or <i>δ</i><sup>15</sup>N values when sampling a single GLG from multiple locations (intratooth variation) or when comparing the same GLG across duplicate teeth of individuals (intertooth variation). One tooth in a triplicate set showed a significantly different but likely biologically inconsequential <i>δ</i><sup>13</sup>C value. Lastly, formic acid and graphite highlighting to accentuate GLGs did not significantly influence measured stable isotope values.</p>\n </section>\n \n <section>\n \n <h3> Conclusions</h3>\n \n <p>We validate several previous assumptions in this field of study. First, dentin samples for stable isotope analysis can be sampled from different locations across a GLG. Second, researchers can compare stable isotope values from the same GLGs of different teeth collected from the same individual in most cases, as the <i>δ</i><sup>13</sup>C and <i>δ</i><sup>15</sup>N values did not vary with the sampled tooth. Third, a common protocol of formic acid and graphite treatment to enhance GLG visibility does not bias the <i>δ</i><sup>13</sup>C and <i>δ</i><sup>15</sup>N values from dentin. We also describe factors to consider and cautions associated with these conclusions.</p>\n </section>\n </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 9","pages":""},"PeriodicalIF":1.8000,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.9997","citationCount":"0","resultStr":"{\"title\":\"Testing Assumptions for Stable Isotope Analysis of Marine Mammal Dentin Growth Layer Groups\",\"authors\":\"Kelly R. Bowen, Carolyn M. Kurle\",\"doi\":\"10.1002/rcm.9997\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div>\\n \\n \\n <section>\\n \\n <h3> Rationale</h3>\\n \\n <p>Stable isotope analysis of growth layer groups (GLGs) in mammal dentin is an increasingly prevalent and noninvasive approach to study animal foraging ecology. However, empirical evidence to support assumed proper methodologies for sampling GLGs is lacking. Here, we examine the effects of intratooth and intertooth variations with respect to targeted GLGs, as well as the effects of common pretreatments (e.g., formic acid and graphite) to enhance GLG visibility, on stable isotope values (<i>δ</i><sup>13</sup>C and <i>δ</i><sup>15</sup>N) from dentin.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Methods</h3>\\n \\n <p>We measured the <i>δ</i><sup>13</sup>C and <i>δ</i><sup>15</sup>N values of killer whale (<i>Orcinus orca</i>) dentin. We used dentin from 37 teeth to compare stable carbon (<i>δ</i><sup>13</sup>C) and nitrogen (<i>δ</i><sup>15</sup>N) isotope values from multiple locations within a GLG (intratooth variation), from corresponding GLGs among teeth of an individual (intertooth variation), and from treated and untreated teeth.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Results</h3>\\n \\n <p>We observed no significant differences in the <i>δ</i><sup>13</sup>C or <i>δ</i><sup>15</sup>N values when sampling a single GLG from multiple locations (intratooth variation) or when comparing the same GLG across duplicate teeth of individuals (intertooth variation). One tooth in a triplicate set showed a significantly different but likely biologically inconsequential <i>δ</i><sup>13</sup>C value. Lastly, formic acid and graphite highlighting to accentuate GLGs did not significantly influence measured stable isotope values.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Conclusions</h3>\\n \\n <p>We validate several previous assumptions in this field of study. First, dentin samples for stable isotope analysis can be sampled from different locations across a GLG. Second, researchers can compare stable isotope values from the same GLGs of different teeth collected from the same individual in most cases, as the <i>δ</i><sup>13</sup>C and <i>δ</i><sup>15</sup>N values did not vary with the sampled tooth. Third, a common protocol of formic acid and graphite treatment to enhance GLG visibility does not bias the <i>δ</i><sup>13</sup>C and <i>δ</i><sup>15</sup>N values from dentin. We also describe factors to consider and cautions associated with these conclusions.</p>\\n </section>\\n </div>\",\"PeriodicalId\":225,\"journal\":{\"name\":\"Rapid Communications in Mass Spectrometry\",\"volume\":\"39 9\",\"pages\":\"\"},\"PeriodicalIF\":1.8000,\"publicationDate\":\"2025-02-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.9997\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Rapid Communications in Mass Spectrometry\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/rcm.9997\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"BIOCHEMICAL RESEARCH METHODS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Rapid Communications in Mass Spectrometry","FirstCategoryId":"92","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/rcm.9997","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"BIOCHEMICAL RESEARCH METHODS","Score":null,"Total":0}
Testing Assumptions for Stable Isotope Analysis of Marine Mammal Dentin Growth Layer Groups
Rationale
Stable isotope analysis of growth layer groups (GLGs) in mammal dentin is an increasingly prevalent and noninvasive approach to study animal foraging ecology. However, empirical evidence to support assumed proper methodologies for sampling GLGs is lacking. Here, we examine the effects of intratooth and intertooth variations with respect to targeted GLGs, as well as the effects of common pretreatments (e.g., formic acid and graphite) to enhance GLG visibility, on stable isotope values (δ13C and δ15N) from dentin.
Methods
We measured the δ13C and δ15N values of killer whale (Orcinus orca) dentin. We used dentin from 37 teeth to compare stable carbon (δ13C) and nitrogen (δ15N) isotope values from multiple locations within a GLG (intratooth variation), from corresponding GLGs among teeth of an individual (intertooth variation), and from treated and untreated teeth.
Results
We observed no significant differences in the δ13C or δ15N values when sampling a single GLG from multiple locations (intratooth variation) or when comparing the same GLG across duplicate teeth of individuals (intertooth variation). One tooth in a triplicate set showed a significantly different but likely biologically inconsequential δ13C value. Lastly, formic acid and graphite highlighting to accentuate GLGs did not significantly influence measured stable isotope values.
Conclusions
We validate several previous assumptions in this field of study. First, dentin samples for stable isotope analysis can be sampled from different locations across a GLG. Second, researchers can compare stable isotope values from the same GLGs of different teeth collected from the same individual in most cases, as the δ13C and δ15N values did not vary with the sampled tooth. Third, a common protocol of formic acid and graphite treatment to enhance GLG visibility does not bias the δ13C and δ15N values from dentin. We also describe factors to consider and cautions associated with these conclusions.
期刊介绍：
Rapid Communications in Mass Spectrometry is a journal whose aim is the rapid publication of original research results and ideas on all aspects of the science of gas-phase ions; it covers all the associated scientific disciplines. There is no formal limit on paper length ("rapid" is not synonymous with "brief"), but papers should be of a length that is commensurate with the importance and complexity of the results being reported. Contributions may be theoretical or practical in nature; they may deal with methods, techniques and applications, or with the interpretation of results; they may cover any area in science that depends directly on measurements made upon gaseous ions or that is associated with such measurements.
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