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Non-invasive age estimation based on fecal DNA using methylation-sensitive high-resolution melting for Indo-Pacific bottlenose dolphins
  • +5
  • Genfu Yagi,
  • Huiyuan Qi,
  • Kana Arai,
  • Yuki F. Kita,
  • Kazunobu Kogi,
  • Tadamichi Morisaka,
  • Motoi Yoshioka,
  • Miho Inoue-Murayama
Genfu Yagi
Mie University
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Huiyuan Qi
Kyoto University
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Kana Arai
Kyoto University
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Yuki F. Kita
Tokai University
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Kazunobu Kogi
Mikurashima Tourism Association
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Tadamichi Morisaka
Mie University
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Motoi Yoshioka
Mie University
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Miho Inoue-Murayama
Kyoto University

Corresponding Author:[email protected]

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Age is necessary information for the study of life history of wild animals. A general method to estimate the age of odontocetes is counting dental growth layer groups (GLGs). However, this method is highly invasive as it requires the capture and handling of individuals to collect their teeth. Recently, the development of DNA-based age estimation methods has been actively studied as an alternative to such invasive methods, of which many have used biopsy samples. However, if DNA-based age estimation can be developed from fecal samples, age estimation can be performed without touching or disrupting individuals, thus establishing an entirely non-invasive method. We developed an age estimation model using the methylation rate of two gene regions, GRIA2 and CDKN2A, measured through methylation-sensitive high-resolution melting (MS-HRM) from fecal samples of wild Indo-Pacific bottlenose dolphins (Tursiops aduncus). The age of individuals was known through conducting longitudinal individual identification surveys underwater. Methylation rates were quantified from 36 samples. Both gene regions showed a significant correlation between age and methylation rate. The age estimation model was constructed based on the methylation rates of both genes which achieved sufficient accuracy (after LOOCV: MAE = 5.08, R2 = 0.34) for the ecological studies of the Indo-Pacific bottlenose dolphins, with a lifespan of 40-50 years. This is the first study to report the use of non-invasive fecal samples to estimate the age of marine mammals.
07 Jul 2023Submitted to Molecular Ecology Resources
10 Jul 2023Submission Checks Completed
10 Jul 2023Assigned to Editor
10 Jul 2023Review(s) Completed, Editorial Evaluation Pending
16 Jul 2023Reviewer(s) Assigned
11 Sep 2023Editorial Decision: Revise Minor
10 Oct 20231st Revision Received
30 Oct 2023Review(s) Completed, Editorial Evaluation Pending
31 Oct 2023Editorial Decision: Revise Minor
15 Nov 20232nd Revision Received
15 Nov 2023Submission Checks Completed
15 Nov 2023Assigned to Editor
15 Nov 2023Review(s) Completed, Editorial Evaluation Pending
17 Nov 2023Editorial Decision: Accept