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Sánchez-Rivera UÁ, Cruz-Cano NB, Medrano A, Álvarez-Rodríguez C, Martínez-Torres M. Sperm Incubation in Biggers-Whitten-Whittingham Medium Induces Capacitation-Related Changes in the Lizard Sceloporus torquatus. Animals (Basel) 2024; 14:1388. [PMID: 38731392 PMCID: PMC11083041 DOI: 10.3390/ani14091388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 05/13/2024] Open
Abstract
Sperm capacitation involves biochemical and physiological changes that enable sperm to fertilize the oocyte. It can be induced in vitro under controlled conditions that simulate the environment of the oviduct. While extensively studied in mammals, its approach in lizards remains absent. Understanding the mechanisms that ensure reproduction is essential for advancing the implementation of assisted reproductive technologies in this group. We aimed to perform a sperm analysis to determine if capacitation-related changes were induced after incubation with capacitating media. Fifteen males of Sceloporus torquatus were collected during the early stage of the reproductive season. The sperm were isolated from the seminal plasma and then diluted up to a volume of 150 μL using BWW medium to incubate with 5% CO2 at 30 °C for a maximum duration of 3 h. A fraction was retrieved hourly for ongoing sperm assessment. The sperm analysis included assessments of its motility, viability, the capacitation status using the chlortetracycline (CTC) assay, and the acrosome integrity with the lectin binding assay to detect changes during incubation. We found that total motility was maintained up to 2 h post incubation, after which it decreased. However, sperm viability remained constant. From that moment on, we observed a transition to a deeper and less symmetrical flagellar bending in many spermatozoa. The CTC assay indicated a reduction in the percentage of sperm showing the full (F) pattern and an increase in those exhibiting the capacitated (B) and reactive (RA) patterns, accompanied by an elevation in the percentage of damaged acrosomes as revealed by the lectin binding assay. In mammals, these changes are often associated with sperm capacitation. Our observations support the notion that this process may also occur in saurian. While sperm analysis is a valuable method for assessing certain functional changes, additional approaches are required to validate this process.
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Affiliation(s)
- Uriel Ángel Sánchez-Rivera
- Laboratorio de Biología de la Reproducción, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Mexico City 54090, Mexico; (N.B.C.-C.)
- Laboratorio de Reproducción, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Mexico City 54714, Mexico;
- Posgrado en Ciencias de la Producción y de la Salud Animal, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Norma Berenice Cruz-Cano
- Laboratorio de Biología de la Reproducción, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Mexico City 54090, Mexico; (N.B.C.-C.)
| | - Alfredo Medrano
- Laboratorio de Reproducción, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Mexico City 54714, Mexico;
| | - Carmen Álvarez-Rodríguez
- Laboratorio de Biología de la Reproducción, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Mexico City 54090, Mexico; (N.B.C.-C.)
| | - Martín Martínez-Torres
- Laboratorio de Biología de la Reproducción, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Mexico City 54090, Mexico; (N.B.C.-C.)
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Sánchez-Rivera UÁ, Medrano A, Cruz-Cano NB, Alcántar-Rodríguez A, Dávila-Govantes R, Castro-Camacho YJ, Martínez-Torres M. Implementation of a method for sperm cryopreservation in sceloporine lizards. CONSERVATION PHYSIOLOGY 2022; 10:coac068. [PMID: 36382339 PMCID: PMC9644977 DOI: 10.1093/conphys/coac068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 10/06/2022] [Accepted: 10/23/2022] [Indexed: 06/16/2023]
Abstract
Actual loss of lizard biodiversity continues, even with the implementation of conventional conservation programs. An approach including assisted reproductive techniques such as sperm cryopreservation may contribute to the management of endangered species. We developed a method for sperm cryopreservation in sceloporine lizards and compared the response among the studied species. Prior to the mating season, we obtained semen from adult males of Sceloporus aeneus (n = 21), Sceloporus grammicus (n = 20) and Sceloporus torquatus (n = 21) via pressure of the genital papilla. Volume and sperm concentration were measured before semen dilution in a Tris-egg yolk (TEY) medium to evaluate progressive motility, sperm viability, morphology, plasma membrane and acrosome integrity. Then, we cooled the remaining volumes to 5°C at a rate of 0.1°C per minute to incorporate glycerol (8% v/v) in two fractions. Immediately afterwards, we placed 40 μl of the mix on solid CO2 to form pellets and immersed them in liquid nitrogen for storage. We thawed the pellets at 29°C for 3 minutes and diluted them 1:1 (v/v) in TEY medium to assess sperm quality. We found a positive relationship between body weight and seminal volume in S. grammicus and S. torquatus and a negative correlation with sperm concentration in S. grammicus (P < 0.05). Moreover, we observed that the freezing-thawing process decreased sperm quality in the three species, mostly affecting motility and viability. However, S. torquatus and S. aeneus showed a higher sperm tolerance than S. grammicus.
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Affiliation(s)
- Uriel Á Sánchez-Rivera
- Laboratorio de Biología de la Reproducción. Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, 54090, México
- Laboratorio de Reproducción Animal. Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, 54714, México
- Posgrado en Ciencias de la Producción y de la Salud Animal, Universidad Nacional Autónoma de México, 04510, México
| | - Alfredo Medrano
- Laboratorio de Reproducción Animal. Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, 54714, México
| | - Norma B Cruz-Cano
- Laboratorio de Biología de la Reproducción. Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, 54090, México
| | - Alicia Alcántar-Rodríguez
- Laboratorio de Reproducción Animal. Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, 54714, México
| | - Rodrigo Dávila-Govantes
- Laboratorio de Biología de la Reproducción. Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, 54090, México
| | - Yabín J Castro-Camacho
- Laboratorio de Biología de la Reproducción. Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, 54090, México
| | - Martín Martínez-Torres
- Laboratorio de Biología de la Reproducción. Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, 54090, México
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Perry SM, Mitchell MA. Reptile assisted reproductive technologies: can ART help conserve 300million years of evolution by preserving extant reptile biodiversity? Reprod Fertil Dev 2021; 34:385-400. [PMID: 34914885 DOI: 10.1071/rd21034] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 11/04/2021] [Indexed: 11/23/2022] Open
Abstract
Biodiversity loss is the greatest environmental problem threatening ecosystem, animal, and human health. Anthropogenic induced changes to climate, habitat, disease, species distributions, poaching, and unsustainable trade have accelerated extinction rates in all vertebrates, including reptiles. Preventing reptile extinctions will require humans to acknowledge these losses and develop ex situ and in situ plans to preserve them. Assisted reproductive technologies (ART) are management tools used to protect numerous vertebrate taxa; however, progress in developing ART for reptiles has lagged. Creating functional and sustainable reptile ART will strengthen our conservation capacity by capturing genetic material from select individuals to overcome natural or manmade boundaries. Utilising short-term gamete storage and genome resource banking, in conjunction with timed artificial insemination (AI) or ex ovo incubation, could lead to profound advances in reptile conservation, mitigating the loss of reptile biodiversity. In this article, we review ART reptile research completed since the 1970s. Topics include AI, hormonal control of reproduction, gamete collection, gamete storage, and genome resource banking. Additionally, we review the potential application of advanced reproductive methodologies, including in vitro/ex ovo fertilisation, intracytoplasmic sperm injection, cloning (somatic cell nuclear transfer), and genetic editing.
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Affiliation(s)
- Sean M Perry
- Department of Veterinary Clinical Sciences, Louisiana State University School of Veterinary Medicine, Skip Bertman Drive, Baton Rouge, LA, USA; and Mississippi Aquarium, 2100 E Beach Boulevard, Gulfport, MS, USA
| | - Mark A Mitchell
- Department of Veterinary Clinical Sciences, Louisiana State University School of Veterinary Medicine, Skip Bertman Drive, Baton Rouge, LA, USA
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Comizzoli P, Holt WV. Recent Progress in Spermatology Contributing to the Knowledge and Conservation of Rare and Endangered Species. Annu Rev Anim Biosci 2021; 10:469-490. [PMID: 34758275 DOI: 10.1146/annurev-animal-020420-040600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
There is a remarkable diversity in the animal kingdom regarding mechanisms underlying the production, maturation, structure, and function of sperm cells. Spermatology studies contribute to the knowledge of species diversity and also provide information about individual or population fitness. Furthermore, this fundamental research is required before collected spermatozoa can be used for conservation breeding, including assisted reproduction and cryobanking. This article aims to (a) review the most recent knowledge on sperm morphology and function in wild animal species, (b) analyze how this knowledge can be used to save species in their natural habitat or ex situ, and (c) propose future scientific directions in wildlife spermatology that could positively impact animal conservation. Variations in sperm structure and performance within and between species have multiple origins and significance. This collective body of knowledge enables the design and implementation of conservation strategies and action plans that integrate several disciplines. Expected final online publication date for the Annual Review of Animal Biosciences, Volume 10 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Pierre Comizzoli
- Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA;
| | - William V Holt
- Academic Unit of Reproductive and Developmental Medicine, University of Sheffield, United Kingdom;
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Hobbs RJ, Upton R, Keogh L, James K, Baxter-Gilbert J, Whiting MJ. Sperm cryopreservation in an Australian skink (Eulamprus quoyii). Reprod Fertil Dev 2021; 34:428-437. [PMID: 34420549 DOI: 10.1071/rd21031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 07/19/2021] [Indexed: 11/23/2022] Open
Abstract
Assisted reproductive technologies for population and genetic management for threatened herpetofauna have grown substantially in the past decade. Here we describe experiments to optimise sperm cryopreservation in a model squamate, the eastern water skink Eulamprus quoyii. Small, concentrated volumes of highly motile spermatozoa were reliably collected from adult male E. quoyii by non-lethal ventral massage. Samples were used to: (1) test whether protein-rich diluents, namely Beltsville poultry semen extender (BPSE) and TES and Tris (TEST) yolk buffer (TYB), improve post-thaw quality metrics compared with Dulbecco's phosphate-buffered saline (DPBS); and (2) compare the efficacy of these diluents in combination with either 1.35M glycerol or 1.35M dimethyl sulfoxide (DMSO) at two freezing rates, fast (approximately -20°C min-1) versus slow (-6°C min-1). Glycerol and DMSO performed equally well in preserving spermatozoa under slow freezing rates. Under these conditions, the use of the complex diluents BPSE and TYB significantly improved post-thaw total motility compared with DPBS. Complex interactions occurred between cryodiluent type, cryoprotectant and freezing rate when testing fast versus slow freezing rates among treatment groups. Under slow freezing rates, DMSO was better at preserving membrane integrity and motility, regardless of diluent type, but successful fast freezing required complex diluents to support motility and membrane integrity, which has implications for implementation in a field setting.
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Affiliation(s)
- Rebecca J Hobbs
- Taronga Institute of Science and Learning, Taronga Conservation Society Australia, Mosman, NSW 2088, Australia; and Corresponding author
| | - Rose Upton
- Conservation Biology Research Group, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308 Australia
| | - Leesa Keogh
- Office of the NSW Chief Scientist and Engineer, MLC Centre, Sydney, NSW 2000, Australia
| | - Karen James
- Taronga Conservation Society Australia, Taronga Western Plains Zoo, Dubbo, NSW 2830, Australia
| | - James Baxter-Gilbert
- Centre for Invasion Biology, Stellenbosch University, Stellenbosch 7600, South Africa
| | - Martin J Whiting
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
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Perry SM, Park T, Mitchell MA. Sex, drugs and rock iguanas: testicular dynamics and plasma testosterone concentrations could predict optimal semen collection times in Cyclura. Reprod Fertil Dev 2021; 34:417-427. [PMID: 34399882 DOI: 10.1071/rd21032] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 07/13/2021] [Indexed: 11/23/2022] Open
Abstract
Iguanas are the most endangered family of reptiles, with 77% categorised as threatened or near threatened. Further, Cyclura is the most endangered reptile genus, with all 12 species considered threatened. Therefore, it is vital that we develop assisted reproductive technologies for Cyclura spp. to enhance their conservation efforts. The goals of this study were to collect semen, and to measure testicle size and testosterone concentrations in Grand Cayman rock iguana hybrids (Cyclura lewisi×nubila (CLN)) and rhinoceros rock iguanas (Cyclura cornuta (CC)). A prospective longitudinal study was performed in 9.0 CLN and 9.0 CC during their reproductive season in southern Florida (February-July). Serial testicle ultrasound measurements and plasma testosterone concentrations were collected monthly. Testicle measurements (length (L), width (W), height (H)) were collected and testicle volume (V) was estimated using the equation V=0.52(LW2). There were significant differences in testicle L, W, H and V for both species. Testicle size peaked for CLN and CC in April and May respectively. Plasma testosterone concentrations increased from baseline during February, March and April in CLN and in March, April and May in CC. Ultrasound testicle measurements could be used to predict when to collect semen in these seasonally monocyclic iguanas.
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Affiliation(s)
- Sean M Perry
- Department of Veterinary Clinical Sciences, Louisiana State University School of Veterinary Medicine, Skip Bertman Drive, Baton Rouge, LA 70803, USA; and Mississippi Aquarium, 2100 E Beach Blvd, Gulfport, MS 39501, USA; and Corresponding author
| | - Ty Park
- Iguanaland, 33900 Bermont Road, Punta Gorda, FL 33982, USA
| | - Mark A Mitchell
- Department of Veterinary Clinical Sciences, Louisiana State University School of Veterinary Medicine, Skip Bertman Drive, Baton Rouge, LA 70803, USA
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