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Melica V, Thornton SJ. Killer whale fecal samples: How to get the most out of a single extraction. Gen Comp Endocrinol 2024; 354:114544. [PMID: 38705419 DOI: 10.1016/j.ygcen.2024.114544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 04/19/2024] [Accepted: 04/30/2024] [Indexed: 05/07/2024]
Abstract
Fecal samples are a non-invasive and relatively accessible matrix for investigating physiological processes in resident killer whale (Orcinus orca) populations. The high lipid content of the diet (primarily salmonids) leads to lower density fecal material and slower dispersion, facilitating sample collection. As fecal discharge is relatively infrequent and the volume of sample is variable, maximizing analytical options is an important consideration. Here we present an extraction methodology to measure hormones and lipid content from the same fecal aliquot. Lipid extractions are commonly conducted using chloroform and methanol from Folch or Bligh and Dyer (B&D), while alcohol is the primary solvent for hormone extraction. We evaluated the possibility of using the methanol layer from lipid extractions to assess fecal steroid hormone levels. Folch and B&D methanol residues were assayed form metabolites of progesterone (PMs) and corticosterone (GCs), and results were compared to aliquots extracted in 70 % ethanol. Hormone concentrations measured in the methanol layer from Folch and B&D extractions were 55 % to 79 % lower than concentrations in 70 % ethanol. We developed mathematical corrections, using linear regression models fitted to Folch or B&D methanol vs 70 % ethanol hormone concentrations (p < 0.01). Fecal concentrations of PMs and GCs from methanol extractions were biologically validated and are significantly higher in confirmed pregnant females compared to non-pregnant individuals (p < 0.05). This study demonstrates that lipid extraction protocols may be used for the analysis of multiple biomarkers, maximizing the use of small-volume samples.
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Affiliation(s)
- V Melica
- Marine Mammal Conservation Physiology Program, Fisheries and Oceans Canada, 4160 Marine Drive, West Vancouver, BC, Canada
| | - S J Thornton
- Marine Mammal Conservation Physiology Program, Fisheries and Oceans Canada, 4160 Marine Drive, West Vancouver, BC, Canada.
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Pratt EAL, Beheregaray LB, Fruet P, Tezanos-Pinto G, Bilgmann K, Zanardo N, Diaz-Aguirre F, Secchi ER, Freitas TRO, Möller LM. Genomic Divergence and the Evolution of Ecotypes in Bottlenose Dolphins (Genus Tursiops). Genome Biol Evol 2023; 15:evad199. [PMID: 37935115 PMCID: PMC10655200 DOI: 10.1093/gbe/evad199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 10/03/2023] [Accepted: 10/14/2023] [Indexed: 11/09/2023] Open
Abstract
Climatic changes have caused major environmental restructuring throughout the world's oceans. Marine organisms have responded to novel conditions through various biological systems, including genomic adaptation. Growing accessibility of next-generation DNA sequencing methods to study nonmodel species has recently allowed genomic changes underlying environmental adaptations to be investigated. This study used double-digest restriction-site associated DNA (ddRAD) sequence data to investigate the genomic basis of ecotype formation across currently recognized species and subspecies of bottlenose dolphins (genus Tursiops) in the Southern Hemisphere. Subspecies-level genomic divergence was confirmed between the offshore common bottlenose dolphin (T. truncatus truncatus) and the inshore Lahille's bottlenose dolphin (T. t. gephyreus) from the southwestern Atlantic Ocean (SWAO). Similarly, subspecies-level divergence is suggested between inshore (eastern Australia) Indo-Pacific bottlenose dolphin (T. aduncus) and the proposed Burrunan dolphin (T. australis) from southern Australia. Inshore bottlenose dolphin lineages generally had lower genomic diversity than offshore lineages, a pattern particularly evident for T. t. gephyreus, which showed exceptionally low diversity. Genomic regions associated with cardiovascular, musculoskeletal, and energy production systems appear to have undergone repeated adaptive evolution in inshore lineages across the Southern Hemisphere. We hypothesize that comparable selective pressures in the inshore environment drove similar adaptive responses in each lineage, supporting parallel evolution of inshore bottlenose dolphins. With climate change altering marine ecosystems worldwide, it is crucial to gain an understanding of the adaptive capacity of local species and populations. Our study provides insights into key adaptive pathways that may be important for the long-term survival of cetaceans and other organisms in a changing marine environment.
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Affiliation(s)
- Eleanor A L Pratt
- Molecular Ecology Laboratory, College of Science and Engineering, Flinders University, Bedford Park, South Australia, Australia
- Cetacean Ecology, Behaviour and Evolution Laboratory, College of Science and Engineering, Flinders University, Bedford Park, South Australia, Australia
| | - Luciano B Beheregaray
- Molecular Ecology Laboratory, College of Science and Engineering, Flinders University, Bedford Park, South Australia, Australia
| | - Pedro Fruet
- Laboratório de Ecologia e Conservação da Megafauna Marinha (ECOMEGA), Universidade Federal do Rio Grande-FURG, Rio Grande, Brazil
- Museu Oceanográfico Prof. Eliézer de C. Rios, Universidade Federal do Rio Grande-FURG, Rio Grande, Brazil
- Kaosa, Rio Grande, Brazil
| | | | - Kerstin Bilgmann
- Department of Biological Sciences, Macquarie University, North Ryde, New South Wales, Australia
| | - Nikki Zanardo
- Molecular Ecology Laboratory, College of Science and Engineering, Flinders University, Bedford Park, South Australia, Australia
- Cetacean Ecology, Behaviour and Evolution Laboratory, College of Science and Engineering, Flinders University, Bedford Park, South Australia, Australia
- Department of Environment and Water, Adelaide, South Australia, Australia
| | - Fernando Diaz-Aguirre
- Molecular Ecology Laboratory, College of Science and Engineering, Flinders University, Bedford Park, South Australia, Australia
- Cetacean Ecology, Behaviour and Evolution Laboratory, College of Science and Engineering, Flinders University, Bedford Park, South Australia, Australia
| | - Eduardo R Secchi
- Laboratório de Ecologia e Conservação da Megafauna Marinha (ECOMEGA), Universidade Federal do Rio Grande-FURG, Rio Grande, Brazil
- Museu Oceanográfico Prof. Eliézer de C. Rios, Universidade Federal do Rio Grande-FURG, Rio Grande, Brazil
| | - Thales R O Freitas
- Laboratório de Citogenética e Evolução, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Luciana M Möller
- Molecular Ecology Laboratory, College of Science and Engineering, Flinders University, Bedford Park, South Australia, Australia
- Cetacean Ecology, Behaviour and Evolution Laboratory, College of Science and Engineering, Flinders University, Bedford Park, South Australia, Australia
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de Oliveira-Ferreira N, Santos-Neto EB, Manhães BMR, Domit C, Secchi ER, Botta S, Cunha HA, Azevedo AF, Bisi TL, Lailson-Brito J. An additional threat to populations predicted to collapse: Organobromine compounds of natural and anthropogenic sources in rough-toothed dolphins from the Southwestern Atlantic Ocean. CHEMOSPHERE 2023; 323:138237. [PMID: 36863632 DOI: 10.1016/j.chemosphere.2023.138237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 02/14/2023] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
Organic contaminants with toxic effects, like the conventional brominated flame retardants (BFRs) and BFRs of emergent concern, and their synergistic effects with other micropollutants, can be an additional threat to delphinids. Rough-toothed dolphins (Steno bredanensis) populations strongly associated with coastal environments already face a potential risk of decline due to high exposure to organochlorine pollutants. Moreover, natural organobromine compounds are important indicators of the environment's health. Polybrominated diphenyl ethers (PBDEs), pentabromoethylbenzene (PBEB), hexabromobenzene (HBB) and the methoxylated PBDEs (MeO-BDEs) were determined in the blubber of rough-toothed dolphins from three ecological populations from the Southwestern Atlantic Ocean (Southeastern, Southern and Outer Continental Shelf/Southern populations, SE, S, and OCS/S, respectively). The profile was dominated by the naturally produced MeO-BDEs (mainly 2'-MeO-BDE 68 and 6-MeO-BDE 47), followed by the anthropogenic BFRs PBDEs (mainly BDE 47). Median ΣMeO-BDE concentrations varied between 705.4 and 3346.0 ng g-1 lw among populations and ΣPBDE from 89.4 until 538.0 ng g-1 lw. Concentrations of anthropogenic organobromine compounds (ΣPBDE, BDE 99 and BDE 100) were higher in SE population than in OCS/S, indicating a coast - ocean gradient of contamination. Negative correlations were found between the concentration of the natural compounds and age, suggesting their metabolization and/or biodilution and maternal transference. Conversely, positive correlations were found between the concentrations of BDE 153 and BDE 154 and age, indicating low biotransformation capability of these heavy congeners. The levels of PBDEs found are concerning, particularly for SE population, because they are similar to concentrations known for the onset of endocrine disruption in other marine mammals and may be an additional threat to a population in a hotspot for chemical pollution.
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Affiliation(s)
- Nara de Oliveira-Ferreira
- Laboratório de Mamíferos Aquáticos e Bioindicadores (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (UERJ), Rua São Francisco Xavier, 524, Postal Code: 20550-013, Rio de Janeiro, Brazil; Programa de Pós-Graduação em Ciências Biológicas - Biofísica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), Avenida Carlos Chagas Filho, 373, Postal Code: 21941-590; Rio de Janeiro, Brazil.
| | - Elitieri B Santos-Neto
- Laboratório de Mamíferos Aquáticos e Bioindicadores (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (UERJ), Rua São Francisco Xavier, 524, Postal Code: 20550-013, Rio de Janeiro, Brazil
| | - Bárbara M R Manhães
- Laboratório de Mamíferos Aquáticos e Bioindicadores (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (UERJ), Rua São Francisco Xavier, 524, Postal Code: 20550-013, Rio de Janeiro, Brazil
| | - Camila Domit
- Laboratório de Ecologia e Conservação (LEC), Centro de Estudos do Mar (CEM), Universidade Federal do Paraná (UFPR), Avenida Beira Mar s/n, Postal Code: 83255-000, Pontal do Paraná, Paraná, Brazil
| | - Eduardo R Secchi
- Laboratório de Ecologia e Conservação da Megafauna Marinha (ECOMEGA), Instituto de Oceanografia, Universidade Federal do Rio Grande (FURG), Avenida Itália, km 8, Postal Code: 96203-900, Rio Grande, Rio Grande do Sul, Brazil
| | - Silvina Botta
- Laboratório de Ecologia e Conservação da Megafauna Marinha (ECOMEGA), Instituto de Oceanografia, Universidade Federal do Rio Grande (FURG), Avenida Itália, km 8, Postal Code: 96203-900, Rio Grande, Rio Grande do Sul, Brazil
| | - Haydée A Cunha
- Laboratório de Mamíferos Aquáticos e Bioindicadores (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (UERJ), Rua São Francisco Xavier, 524, Postal Code: 20550-013, Rio de Janeiro, Brazil; Departamento de Genética, Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro (UERJ), Rua São Francisco Xavier, 524, Postal Code: 20550-013, Rio de Janeiro, Brazil
| | - Alexandre F Azevedo
- Laboratório de Mamíferos Aquáticos e Bioindicadores (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (UERJ), Rua São Francisco Xavier, 524, Postal Code: 20550-013, Rio de Janeiro, Brazil
| | - Tatiana L Bisi
- Laboratório de Mamíferos Aquáticos e Bioindicadores (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (UERJ), Rua São Francisco Xavier, 524, Postal Code: 20550-013, Rio de Janeiro, Brazil
| | - José Lailson-Brito
- Laboratório de Mamíferos Aquáticos e Bioindicadores (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (UERJ), Rua São Francisco Xavier, 524, Postal Code: 20550-013, Rio de Janeiro, Brazil; Programa de Pós-Graduação em Ciências Biológicas - Biofísica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), Avenida Carlos Chagas Filho, 373, Postal Code: 21941-590; Rio de Janeiro, Brazil
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Yun HY, Larsen T, Choi B, Won E, Shin K. Amino acid nitrogen and carbon isotope data: Potential and implications for ecological studies. Ecol Evol 2022; 12:e8929. [PMID: 35784034 PMCID: PMC9163675 DOI: 10.1002/ece3.8929] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 04/18/2022] [Accepted: 04/25/2022] [Indexed: 12/17/2022] Open
Abstract
Explaining food web dynamics, stability, and functioning depend substantially on understanding of feeding relations within a community. Bulk stable isotope ratios (SIRs) in natural abundance are well‐established tools to express direct and indirect feeding relations as continuous variables across time and space. Along with bulk SIRs, the SIRs of individual amino acids (AAs) are now emerging as a promising and complementary method to characterize the flow and transformation of resources across a diversity of organisms, from microbial domains to macroscopic consumers. This significant AA‐SIR capacity is based on empirical evidence that a consumer's SIR, specific to an individual AA, reflects its diet SIR coupled with a certain degree of isotopic differences between the consumer and its diet. However, many empirical ecologists are still unfamiliar with the scope of applicability and the interpretative power of AA‐SIR. To fill these knowledge gaps, we here describe a comprehensive approach to both carbon and nitrogen AA‐SIR assessment focusing on two key topics: pattern in AA‐isotope composition across spatial and temporal scales, and a certain variability of AA‐specific isotope differences between the diet and the consumer. On this basis we review the versatile applicability of AA‐SIR to improve our understanding of physiological processes as well as food web functioning, allowing us to reconstruct dominant basal dietary sources and trace their trophic transfers at the specimen and community levels. Given the insightful and opportunities of AA‐SIR, we suggest future applications for the dual use of carbon and nitrogen AA‐SIR to study more realistic food web structures and robust consumer niches, which are often very difficult to explain in nature.
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Affiliation(s)
- Hee Young Yun
- Deparment of Marine Science and Convergent Technology Hanyang University Ansan Korea
| | - Thomas Larsen
- Department of Archaeology Max Planck Institute for the Science of Human History Jena Germany
| | - Bohyung Choi
- Deparment of Marine Science and Convergent Technology Hanyang University Ansan Korea
- Inland Fisheries Research Institute National Institute of Fisheries Science Geumsan‐gun Korea
| | - Eun‐Ji Won
- Deparment of Marine Science and Convergent Technology Hanyang University Ansan Korea
| | - Kyung‐Hoon Shin
- Deparment of Marine Science and Convergent Technology Hanyang University Ansan Korea
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