TY - JOUR
T1 - Optimizing hormone extraction protocols for whale baleen
T2 - Tackling questions of solvent:sample ratio and variation
AU - Fernández Ajó, Alejandro
AU - Hunt, Kathleen E.
AU - Dillon, Danielle
AU - Uhart, Marcela
AU - Sironi, Mariano
AU - Rowntree, Victoria
AU - Loren Buck, C.
N1 - Funding Information:
Funding for the hormone assays was provided by the Arizona Board of Regents Technology Research Initiative Fund, and by Northern Arizona University to Dr. CLB. This work was possible thanks to a Fulbright-Ministerio de Educación y Deportes de Argentina scholarship granted to AFA.
Funding Information:
We are grateful to the many researchers, collaborators, and volunteers of the Southern Right Whale Health Monitoring Program (SRWHMP) in Argentina that assisted with the collection of SRW baleen samples: Matias Di Martino, Luciano La Sala, Luciana Melina Pozzi, Luciana Musmeci, Nadia Mohamed, Juan Emilio Sala, Julian Andrejuk, Andrea Chirife, Lucas Bandieri, Marcelo Franco, Lucas Beltramino, Lucía Alzugaray, Pablo de Diego, Maria Virginia Rago, Marcos Ricciardi, Diego Taboada, Roxana Schteinbarg, Luciano Valenzuela and the many volunteers who made the field work possible. The SRWHMP is run by Instituto de Conservación de Ballenas, the University of Utah, the University of California-Davis, Wildlife Conservation Society, Ocean Alliance and Fundación Patagonia Natural, with funding from a number of sources. We also acknowledge contributions from the government of Chubut province, Armada Argentina, Prefectura Naval Argentina, Aluar, and Aeroclub Puerto Madryn. Research permits for the SRWHMP work were issued annually by the Dirección de Fauna y Flora Silvestre and the Subsecretaría de Turismo y Áreas Protegidas of Chubut Province, Argentina. We also thank Carolina Giese for statistical consultations.
Funding Information:
We are grateful to the many researchers, collaborators, and volunteers of the Southern Right Whale Health Monitoring Program (SRWHMP) in Argentina that assisted with the collection of SRW baleen samples: Matias Di Martino, Luciano La Sala, Luciana Melina Pozzi, Luciana Musmeci, Nadia Mohamed, Juan Emilio Sala, Julian Andrejuk, Andrea Chirife, Lucas Bandieri, Marcelo Franco, Lucas Beltramino, Luc?a Alzugaray, Pablo de Diego, Maria Virginia Rago, Marcos Ricciardi, Diego Taboada, Roxana Schteinbarg, Luciano Valenzuela and the many volunteers who made the field work possible. The SRWHMP is run by Instituto de Conservaci?n de Ballenas, the University of Utah, the University of California-Davis, Wildlife Conservation Society, Ocean Alliance and Fundaci?n Patagonia Natural, with funding from a number of sources. We also acknowledge contributions from the government of Chubut province, Armada Argentina, Prefectura Naval Argentina, Aluar, and Aeroclub Puerto Madryn. Research permits for the SRWHMP work were issued annually by the Direcci?n de Fauna y Flora Silvestre and the Subsecretar?a de Turismo y ?reas Protegidas of Chubut Province, Argentina. We also thank Carolina Giese for statistical consultations. Funding for the hormone assays was provided by the Arizona Board of Regents Technology Research Initiative Fund, and by Northern Arizona University to Dr. CLB. This work was possible thanks to a Fulbright-Ministerio de Educaci?n y Deportes de Argentina scholarship granted to AFA.
Publisher Copyright:
© 2021 Elsevier Inc.
PY - 2022/1/1
Y1 - 2022/1/1
N2 - Obtaining endocrine data from alternative sample types such as baleen and other keratinized tissues has proven a valuable tool to investigate reproductive and stress physiology via steroid hormone quantification, and metabolic stress via thyroid hormone quantification in whales and other vertebrates. These alternative sample types provide an integrated measure of plasma levels over the period that the structure was growing, thus capturing months or even years of an individual's endocrine history. Additionally, their robust and stable keratin matrix allows such samples to be stored for years to decades, enabling the analysis and comparison of endocrine patterns from past and modern populations. However, the extraction and analysis of hormones from baleen and other keratinized tissues remains novel and requires both biological and analytical validations to ensure the method fulfills the requirements for its intended use. We utilized baleen recovered at necropsy from southern right whales (Eubalaena australis) that died at Península Valdés, Argentina, using a commercially available progesterone enzyme immunoassay (EIA) to address two methodological questions: 1) what is the minimum sample mass required to reliably quantify hormone content of baleen samples analyzed with commercially available EIAs, and 2) what is the optimal ratio of solvent volume to sample mass, i.e., the ratio that yields the maximum amount of hormone with high accuracy and low variability between replicates. We concluded that masses of at least 20 mg should be used whenever possible, and extraction is best performed using an 80:1 ratio of solvent to sample (volume of solvent to sample mass; μl:mg). These results can help researchers to make informed methodological decisions when using a destructive extraction method with rare or unique specimens.
AB - Obtaining endocrine data from alternative sample types such as baleen and other keratinized tissues has proven a valuable tool to investigate reproductive and stress physiology via steroid hormone quantification, and metabolic stress via thyroid hormone quantification in whales and other vertebrates. These alternative sample types provide an integrated measure of plasma levels over the period that the structure was growing, thus capturing months or even years of an individual's endocrine history. Additionally, their robust and stable keratin matrix allows such samples to be stored for years to decades, enabling the analysis and comparison of endocrine patterns from past and modern populations. However, the extraction and analysis of hormones from baleen and other keratinized tissues remains novel and requires both biological and analytical validations to ensure the method fulfills the requirements for its intended use. We utilized baleen recovered at necropsy from southern right whales (Eubalaena australis) that died at Península Valdés, Argentina, using a commercially available progesterone enzyme immunoassay (EIA) to address two methodological questions: 1) what is the minimum sample mass required to reliably quantify hormone content of baleen samples analyzed with commercially available EIAs, and 2) what is the optimal ratio of solvent volume to sample mass, i.e., the ratio that yields the maximum amount of hormone with high accuracy and low variability between replicates. We concluded that masses of at least 20 mg should be used whenever possible, and extraction is best performed using an 80:1 ratio of solvent to sample (volume of solvent to sample mass; μl:mg). These results can help researchers to make informed methodological decisions when using a destructive extraction method with rare or unique specimens.
KW - Baleen hormone
KW - Conservation physiology
KW - Extraction efficiency
KW - Progesterone
KW - Small sample effect
KW - Steroids
KW - Validation
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UR - http://www.scopus.com/inward/citedby.url?scp=85107646007&partnerID=8YFLogxK
U2 - 10.1016/j.ygcen.2021.113828
DO - 10.1016/j.ygcen.2021.113828
M3 - Article
C2 - 34058189
AN - SCOPUS:85107646007
SN - 0016-6480
VL - 315
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
M1 - 113828
ER -