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Ruiz-Fernández MJ, Jiménez S, Fernández-Valle E, García-Real MI, Castejón D, Moreno N, Ardiaca M, Montesinos A, Ariza S, González-Soriano J. Sex Determination in Two Species of Anuran Amphibians by Magnetic Resonance Imaging and Ultrasound Techniques. Animals (Basel) 2020; 10:E2142. [PMID: 33217993 PMCID: PMC7698606 DOI: 10.3390/ani10112142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 11/13/2020] [Accepted: 11/16/2020] [Indexed: 11/22/2022] Open
Abstract
The objective of the present study was to evaluate whether gender determination in two amphibian species (Kaloula pulchra and Xenopus laevis) can be reliably carried out by means of magnetic resonance imaging (benchtop magnetic resonance imaging; BT-MRI) or ultrasound (high-resolution ultrasound; HR-US) techniques. Two species of healthy, sexually mature anurans have been used in the present study. Eight Kaloula (blind study) and six Xenopus were used as controls. Magnetic resonance imaging experiments were carried out on a low-field (1 Tesla) benchtop-MRI (BT-MRI) system. HR-US examination was performed with high-resolution equipment. Low-field BT-MRI images provided a clear and quantifiable identification of all the sexual organs present in both genders and species. The HR-US also allowed the identification of testes and ovaries in both species. Results indicate that BT-MRI allowed a very precise sex identification in both anuran species, although its use is limited by the cost of the equipment and the need for anesthesia. HR-US allowed an accurate identification of ovaries of both species whereas a precise identification of testes is limited by the ultrasonographer experience. The main advantages of this technique are the possibility of performing it without anesthesia and the higher availability of equipment in veterinary and zoo institutions.
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Affiliation(s)
- María José Ruiz-Fernández
- Departamento de Medicina y Cirugía, Facultad de Veterinaria, Universidad Complutense, Avenida Puerta de Hierro s/n, 28040 Madrid, Spain; (M.J.R.-F.); (M.I.G.-R.)
| | - Sara Jiménez
- Departamento de Biología Celular, Facultad de Biología, Universidad Complutense, Avenida José Antonio Novais 12, 28040 Madrid, Spain; (S.J.); (N.M.)
| | - Encarnación Fernández-Valle
- Unidad de RMN—CAI Bioimagen Complutense, Universidad Complutense, Paseo de Juan XXIII 1, 28040 Madrid, Spain; (E.F.-V.); (D.C.)
| | - M. Isabel García-Real
- Departamento de Medicina y Cirugía, Facultad de Veterinaria, Universidad Complutense, Avenida Puerta de Hierro s/n, 28040 Madrid, Spain; (M.J.R.-F.); (M.I.G.-R.)
| | - David Castejón
- Unidad de RMN—CAI Bioimagen Complutense, Universidad Complutense, Paseo de Juan XXIII 1, 28040 Madrid, Spain; (E.F.-V.); (D.C.)
| | - Nerea Moreno
- Departamento de Biología Celular, Facultad de Biología, Universidad Complutense, Avenida José Antonio Novais 12, 28040 Madrid, Spain; (S.J.); (N.M.)
| | - María Ardiaca
- Centro Veterinario Los Sauces, Calle de Santa Engracia 63, 28010 Madrid, Spain; (M.A.); (A.M.); (S.A.)
| | - Andrés Montesinos
- Centro Veterinario Los Sauces, Calle de Santa Engracia 63, 28010 Madrid, Spain; (M.A.); (A.M.); (S.A.)
| | - Salvador Ariza
- Centro Veterinario Los Sauces, Calle de Santa Engracia 63, 28010 Madrid, Spain; (M.A.); (A.M.); (S.A.)
| | - Juncal González-Soriano
- Departamento de Anatomía y Embriología, Sección Departamental de Anatomía y Embriología (Veterinaria), Facultad de Veterinaria, Universidad Complutense, Avenida Puerta de Hierro s/n, 28040 Madrid, Spain
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Calatayud NE, Stoops M, Durrant BS. Ovarian control and monitoring in amphibians. Theriogenology 2017; 109:70-81. [PMID: 29325879 DOI: 10.1016/j.theriogenology.2017.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 12/01/2017] [Indexed: 12/29/2022]
Abstract
Amphibian evolution spans over 350 million years, consequently this taxonomic group displays a wide, complex array of physiological adaptations and their diverse modes of reproduction are a prime example. Reproduction can be affected by taxonomy, geographic and altitudinal distribution, and environmental factors. With some exceptions, amphibians can be categorized into discontinuous (strictly seasonal) and continuous breeders. Temperature and its close association with other proximate and genetic factors control reproduction via a tight relationship with circadian rhythms which drive genetic and hormonal responses to the environment. In recent times, the relationship of proximate factors and reproduction has directly or indirectly lead to the decline of this taxonomic group. Conservationists are tackling the rapid loss of species through a wide range of approaches including captive rescue. However, there is still much to be learned about the mechanisms of reproductive control and its requirements in order to fabricate species-appropriate captive environments that address a variety of reproductive strategies. As with other taxonomic groups, assisted reproductive technologies and other reproductive monitoring tools such as ultrasound, hormone analysis and body condition indices can assist conservationists in optimizing captive husbandry and breeding. In this review we discuss some of the mechanisms of ovarian control and the different tools being used to monitor female reproduction.
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Affiliation(s)
- N E Calatayud
- San Diego Zoo Global, Institute for Conservation Research, 15600 San Pasqual Valley Road, Escondido, CA 92027, United States.
| | - M Stoops
- Cincinnati Zoo & Botanical Garden, Center for Conservation and Research of Endangered Wildlife, 3400 Vine Street, Cincinnati, OH 45220, United States
| | - B S Durrant
- San Diego Zoo Global, Institute for Conservation Research, 15600 San Pasqual Valley Road, Escondido, CA 92027, United States
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