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Fidalgo G, Paiva K, Mendes G, Barcellos R, Colaço G, Sena G, Pickler A, Mota CL, Tromba G, Nogueira LP, Braz D, Silva HR, Colaço MV, Barroso RC. Synchrotron microtomography applied to the volumetric analysis of internal structures of Thoropa miliaris tadpoles. Sci Rep 2020; 10:18934. [PMID: 33144603 PMCID: PMC7641268 DOI: 10.1038/s41598-020-75993-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 10/22/2020] [Indexed: 12/12/2022] Open
Abstract
Amphibians are models for studying applied ecological issues such as habitat loss, pollution, disease, and global climate change due to their sensitivity and vulnerability to changes in the environment. Developmental series of amphibians are informative about their biology, and X-ray based 3D reconstruction holds promise for quantifying morphological changes during growth—some with a direct impact on the possibility of an experimental investigation on several of the ecological topics listed above. However, 3D resolution and discrimination of their soft tissues have been difficult with traditional X-ray computed tomography, without time-consuming contrast staining. Tomographic data were initially performed (pre-processing and reconstruction) using the open-source software tool SYRMEP Tomo Project. Data processing and analysis of the reconstructed tomography volumes were conducted using the segmentation semi-automatic settings of the software Avizo Fire 8, which provide information about each investigated tissues, organs or bone elements. Hence, volumetric analyses were carried out to quantify the development of structures in different tadpole developmental stages. Our work shows that synchrotron X-ray microtomography using phase-contrast mode resolves the edges of the internal tissues (as well as overall tadpole morphology), facilitating the segmentation of the investigated tissues. Reconstruction algorithms and segmentation software played an important role in the qualitative and quantitative analysis of each target structure of the Thoropa miliaris tadpole at different stages of development, providing information on volume, shape and length. The use of the synchrotron X-ray microtomography setup of the SYRMEP beamline of Elettra Synchrotron, in phase-contrast mode, allows access to volumetric data for bone formation, eye development, nervous system and notochordal changes during the development (ontogeny) of tadpoles of a cycloramphid frog Thoropa miliaris. As key elements in the normal development of these and any other frog tadpole, the application of such a comparative ontogenetic study, may hold interest to researchers in experimental and environmental disciplines.
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Affiliation(s)
- G Fidalgo
- Laboratory of Applied Physics to Biomedical Science, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - K Paiva
- Laboratory of Applied Physics to Biomedical Science, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - G Mendes
- Laboratory of Applied Physics to Biomedical Science, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - R Barcellos
- Laboratory of Applied Physics to Biomedical Science, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - G Colaço
- Laboratory of Herpetology, Federal Rural University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - G Sena
- Laboratory of Applied Physics to Biomedical Science, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - A Pickler
- Laboratory of Applied Physics to Biomedical Science, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - C L Mota
- Laboratory of Applied Physics to Biomedical Science, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - G Tromba
- Elettra/Sincrotrone Trieste S.C.P.a., Trieste, Italy
| | - L P Nogueira
- Oral Research Laboratory, Institute of Clinical Dentistry, University of Oslo, Oslo, Norway
| | - D Braz
- Nuclear Engineering Program/COPPE, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - H R Silva
- Laboratory of Herpetology, Federal Rural University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - M V Colaço
- Laboratory of Applied Physics to Biomedical Science, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - R C Barroso
- Laboratory of Applied Physics to Biomedical Science, State University of Rio de Janeiro, Rio de Janeiro, Brazil
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Lesciotto KM, Motch Perrine SM, Kawasaki M, Stecko T, Ryan TM, Kawasaki K, Richtsmeier JT. Phosphotungstic acid-enhanced microCT: Optimized protocols for embryonic and early postnatal mice. Dev Dyn 2019; 249:573-585. [PMID: 31736206 DOI: 10.1002/dvdy.136] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/07/2019] [Accepted: 11/11/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Given the need for descriptive and increasingly mechanistic morphological analyses, contrast-enhanced microcomputed tomography (microCT) represents perhaps the best method for visualizing 3D biological soft tissues in situ. Although staining protocols using phosphotungstic acid (PTA) have been published with beautiful visualizations of soft tissue structures, these protocols are often aimed at highly specific research questions and are applicable to a limited set of model organisms, specimen ages, or tissue types. We provide detailed protocols for micro-level visualization of soft tissue structures in mice at several embryonic and early postnatal ages using PTA-enhanced microCT. RESULTS Our protocols produce microCT scans that enable visualization and quantitative analyses of whole organisms, individual tissues, and organ systems while preserving 3D morphology and relationships with surrounding structures, with minimal soft tissue shrinkage. Of particular note, both internal and external features of the murine heart, lungs, and liver, as well as embryonic cartilage, are captured at high resolution. CONCLUSION These protocols have broad applicability to mouse models for a variety of diseases and conditions. Minor experimentation in the staining duration can expand this protocol to additional age groups, permitting ontogenetic studies of internal organs and soft tissue structures within their 3D in situ position.
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Affiliation(s)
- Kate M Lesciotto
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Susan M Motch Perrine
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Mizuho Kawasaki
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Timothy Stecko
- Center for Quantitative Imaging, Pennsylvania State University, University Park, Pennsylvania
| | - Timothy M Ryan
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Kazuhiko Kawasaki
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Joan T Richtsmeier
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
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