Multi-Tissue Methylation Clocks for Age and Sex Estimation in the Common Bottlenose Dolphin

Accurate identification of individual ages within wild bottlenose dolphins (Tursiops truncatus) is critical for determining population health and the development of population management strategies. As such, we analyzed DNA methylation (DNAm) patterns by applying a custom methylation array (HorvathMammalMethyl40) to both blood (n = 140) and skin samples (n = 87) from known age or approximate age (0–57 years) bottlenose dolphins. We present three bottlenose dolphin specific age estimation clocks using combined blood and skin [48 CpGs, R = 0.93, median absolute error (MAE) = 2.13 years], blood only (64 CpGs, R = 0.97, error = 1.46 years) and skin only (39 CpGs, R = 0.95, error = 2.53). We characterized individual cytosines that correlate with sex and age in dolphins and developed a sex estimator based on 71 CpGs that predicts the sex of any odontocete species with 99.5% accuracy. The presented epigenetic clocks are expected to be useful for conservation efforts and for determining if anthropogenic events affect aging rates in wild populations.

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Multi-tissue methylation clocks for age estimation in the common bottlenose dolphin

10.1101/2021.05.03.442523 ◽

2021 ◽

Author(s):

Todd R Robeck ◽

Zhe Fei ◽

Amin Haghani ◽

Joseph Alan Zoller ◽

Caesar Z Li ◽

...

Keyword(s):

Age Estimation ◽

Bottlenose Dolphin ◽

Bottlenose Dolphins ◽

Management Strategies ◽

Absolute Error ◽

Accurate Identification ◽

Methylation Array ◽

Common Bottlenose Dolphin ◽

The Common ◽

Methylation Patterns

Accurate identification of individual ages within wild bottlenose dolphins (Tursiops truncatus) is critical for determining population health and the development of population management strategies. As such, we analyzed DNA methylation patterns by applying a custom methylation array (HorvathMammalMethyl40) to both blood (n = 140) and skin samples (n = 87) from known age or approximate age (0 to 57 years) bottlenose dolphins. We present three bottlenose dolphin specific age estimation clocks using combined blood and skin (48 CpGs, R = 0.93, median absolute error = 2.13 years), blood only (64 CpGs, R = 0.97, error= 1.46 years) and skin only (39 CpGs, R = 0.95, error= 2.53). Our sex estimator based on 71 CpGs predicts the sex of any odontocete species with 99.5% accuracy. We characterize individual cytosines that correlate with sex and age in dolphins. The presented epigenetic clocks are expected to be useful for conservation efforts and for studying anthropogenic events.

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Taxonomy and distribution of bottlenose dolphins (genus Tursiops) in Australian waters: an osteological clarification

Canadian Journal of Zoology ◽

10.1139/cjz-2018-0270 ◽

2020 ◽

Vol 98 (7) ◽

pp. 461-479 ◽

Cited By ~ 1

Author(s):

M. Jedensjö ◽

C.M. Kemper ◽

M. Milella ◽

E.P. Willems ◽

M. Krützen

Keyword(s):

Bottlenose Dolphin ◽

Bottlenose Dolphins ◽

Three Dimensional ◽

Large Sample Size ◽

Type Specimens ◽

Tursiops Aduncus ◽

Common Bottlenose Dolphin ◽

Intermediate Size ◽

The Common ◽

Taxonomic Studies

Species relationships in the bottlenose dolphin (genus Tursiops Gervais, 1855) are controversial. We carried out a comprehensive osteological study of 264 skulls, including type specimens, and 90 postcranial skeletons of Tursiops spp. to address taxonomic uncertainties in Australia using two-dimensional (2D) measurements, and three-dimensional geometric morphometrics (3DGM), tooth and vertebral counts, and categorical data. Analyses provided support for the presence of two forms, aligned to the Indo-Pacific bottlenose dolphin (Tursiops aduncus (Ehrenberg, 1832)) and the common bottlenose dolphin (Tursiops truncatus (Montagu, 1821)), including type specimens. The Burrunan dolphin (Tursiops australis Charlton-Robb, Gershwin, Thompson, Austin, Owen and McKechnie, 2011) fell well within T. truncatus for both 2D and 3DGM methods. Thirteen Tursiops spp. specimens, no T. australis specimens, were of intermediate size (2D) and could not be assigned to either species. For 3DGM data, there was a strong allometric influence and few non-allometric differences between species. Length and width of the cranium and rostrum were important discriminating variables. Tursiops aduncus was smaller, had more teeth, fewer vertebrae, and more erosion on the pterygoids and frontals than T. truncatus. Overall cranium shape was round in T. aduncus and angular in T. truncatus. Skull length of T. aduncus was smaller in low than in high latitudes. This study highlights the importance of large sample size, multiple analytical methods, and extensive geographical coverage when undertaking taxonomic studies.

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Development and Validation of Monoclonal and Polyclonal Antibodies for the Detection of Immunoglobulin G of Bottlenose Dolphins (Tursiops Truncatus)

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063870701900502 ◽

2007 ◽

Vol 19 (5) ◽

pp. 465-470 ◽

Cited By ~ 12

Author(s):

Hendrik H. Nollens ◽

Linda G. Green ◽

Diane Duke ◽

Michael T. Walsh ◽

Beth Chittick ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Polyclonal Antibody ◽

Immunoglobulin G ◽

Bottlenose Dolphin ◽

Tursiops Truncatus ◽

Bottlenose Dolphins ◽

Enzyme Linked Immunosorbent Assay ◽

Common Bottlenose Dolphin ◽

Circulating Antibodies ◽

The Common

Antibodies directed against species-specific immunoglobulin G (IgG) have a broad range of applications in serologic and immunologic research and in the development of clinical assays. Validated anti-IgG antibodies for marine mammal species are in short supply. The objective of this study was to produce and validate antibodies with specificity for IgG of the common bottlenose dolphin ( Tursiops truncatus). Bottlenose dolphin IgG was purified using protein G. Two mouse monoclonal antibodies and a rabbit polyclonal antibody were developed from mice and rabbits immunized with bottlenose dolphin IgG. The specificity of the monoclonal antibodies and the polyclonal antibody for bottlenose dolphin IgG was first verified by Western blot analysis and enzyme-linked immunosorbent assay (ELISA). For further validation, both monoclonal antibodies and the polyclonal antibody were incorporated in an indirect ELISA for the detection of the immune response of bottlenose dolphins to a vaccine antigen. Three bottlenose dolphins were immunized with a commercial Erysipelothrix rhusiopathiae vaccine, and serial blood samples were collected from all dolphins for measurement of levels of circulating antibodies. Seroconversion was observed in all 3 dolphins by use of both monoclonal antibodies and the polyclonal antibody. Circulating antibodies were detectable as early as 6 days after immunization in 1 dolphin. Peak antibody levels were detected 14 days after the immunization. The ability to detect seroconversion in all 3 immunized bottlenose dolphins firmly establishes the specificity of the monoclonal antibodies and the polyclonal antibody for IgG of the common bottlenose dolphin.

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Genetic divergence and fine scale population structure of the common bottlenose dolphin (Tursiops truncatus, Montagu) found in the Gulf of Guayaquil, Ecuador

PeerJ ◽

10.7717/peerj.4589 ◽

2018 ◽

Vol 6 ◽

pp. e4589 ◽

Cited By ~ 6

Author(s):

Rosa de los Ángeles Bayas-Rea ◽

Fernando Félix ◽

Rommel Montufar

Keyword(s):

Population Structure ◽

Bottlenose Dolphin ◽

Tursiops Truncatus ◽

Bottlenose Dolphins ◽

Western Coast ◽

Common Bottlenose Dolphin ◽

Dolphin Population ◽

The Common ◽

Gulf Of Guayaquil ◽

Outer Estuary

The common bottlenose dolphin, Tursiops truncatus, is widely distributed along the western coast of South America. In Ecuador, a resident population of bottlenose dolphins inhabits the inner estuarine area of the Gulf of Guayaquil located in the southwestern part of the country and is under threat from different human activities in the area. Only one genetic study on South American common bottlenose dolphins has been carried out to date, and understanding genetic variation of wildlife populations, especially species that are identified as threatened, is crucial for defining conservation units and developing appropriate conservation strategies. In order to evaluate the evolutionary link of this population, we assessed the phylogenetic relationships, phylogeographic patterns, and population structure using mitochondrial DNA (mtDNA). The sampling comprised: (i) 31 skin samples collected from free-ranging dolphins at three locations in the Gulf of Guayaquil inner estuary, (ii) 38 samples from stranded dolphins available at the collection of the “Museo de Ballenas de Salinas,” (iii) 549 mtDNA control region (mtDNA CR) sequences from GenBank, and (iv) 66 concatenated sequences from 7-mtDNA regions (12S rRNA, 16S rRNA, NADH dehydrogenase subunit I–II, cytochrome oxidase I and II, cytochrome b, and CR) obtained from mitogenomes available in GenBank. Our analyses indicated population structure between both inner and outer estuary dolphin populations as well as with distinct populations of T. truncatus using mtDNA CR. Moreover, the inner estuary bottlenose dolphin (estuarine bottlenose dolphin) population exhibited lower levels of genetic diversity than the outer estuary dolphin population according to the mtDNA CR. Finally, the estuarine bottlenose dolphin population was genetically distinct from other T. truncatus populations based on mtDNA CR and 7-mtDNA regions. From these results, we suggest that the estuarine bottlenose dolphin population should be considered a distinct lineage. This dolphin population faces a variety of anthropogenic threats in this area; thus, we highlight its fragility and urge authorities to issue prompt management and conservation measures.

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Bone mineral density of the common bottlenose dolphin radius: A primary skeletal site for clinical bone densitometry and preliminary descriptive data set using archival specimens

Marine Mammal Science ◽

10.1111/mms.12769 ◽

2020 ◽

Author(s):

James W. B. Powell ◽

Deborah A. Duffield ◽

Jonathan J. Kaufman ◽

Gangming Luo ◽

Gretchen N. Lovewell ◽

...

Keyword(s):

Bone Mineral Density ◽

Bone Densitometry ◽

Bottlenose Dolphin ◽

Mineral Density ◽

Descriptive Data ◽

Data Set ◽

Common Bottlenose Dolphin ◽

Skeletal Site ◽

The Common ◽

Archival Specimens

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The influence of fish farm activity on the social structure of the common bottlenose dolphin in Sardinia (Italy)

PeerJ ◽

10.7717/peerj.10960 ◽

2021 ◽

Vol 9 ◽

pp. e10960

Author(s):

Serena Frau ◽

Fabio Ronchetti ◽

Francesco Perretti ◽

Alberto Addis ◽

Giulia Ceccherelli ◽

...

Keyword(s):

Social Structure ◽

Bottlenose Dolphin ◽

Foraging Strategy ◽

Important Change ◽

Fish Farm ◽

Photo Identification ◽

Common Bottlenose Dolphin ◽

The Social ◽

Dolphin Population ◽

The Common

In a wide variety of habitats, including some heavily urbanised areas, the adaptability of populations of common bottlenose dolphin (Tursiops truncatus) may depend on the social structure dynamics. Nonetheless, the way in which these adaptations take place is still poorly understood. In the present study we applied photo-identification techniques to investigate the social structure of the common bottlenose dolphin population inhabiting the Gulf of Alghero (Sardinia, Italy), analysing data recorded from 2008 to 2019. The social structure analysis showed a division of the entire population into five different communities and the presence of non-random associations, while there was no evidence of segregation between sexes. Furthermore, results highlighted an important change in social structure through time, likely due to a reduction in fish farm activity since 2015. The division of the population into different communities, the presence of segregation based on the foraging strategy (inside or outside the fish farm area) and the social network measures were evaluated by analysing independently the two datasets: the intense and low farm activity periods: 2008–2014 and 2015–2020, respectively. Segregation among individuals belonging to the same foraging strategy class was found only in the earlier period, and the composition of the four communities was consistent with this result. Our study improves the knowledge about bottlenose dolphin adaptation, as a lower complexity in social structure was linked to a reduction in anthropogenic food availability.

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