1
|
Arregui L, Bosch J. Gamete Collection, Artificial Fertilization and Captive-Rearing of Eggs in a Terrestrial-Breeding Anuran with Parental Care: Alytes obstetricans. Animals (Basel) 2023; 13:2802. [PMID: 37685066 PMCID: PMC10487003 DOI: 10.3390/ani13172802] [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: 07/31/2023] [Revised: 08/28/2023] [Accepted: 08/31/2023] [Indexed: 09/10/2023] Open
Abstract
The genus Alytes consists of six primitive terrestrial-breeding species (five of them endangered or present in restricted distributions) with unique male parental care. Alytes obstetricans was used as a model for the development of assisted reproductive technologies for gamete collection, artificial fertilization and captive-rearing of embryos. Sperm collection was achieved with human chorionic gonadotropin (hCG), but only 17 to 50% of males responded to the hormone. In addition, an effect of captivity on sperm quality was observed. A combination of gonadotropin-releasing hormone agonist (GnRHa) and hCG was tested for induction of ovulation, and 100% of females responded to the treatment. Recently collected sperm was used in artificial fertilization, and 10% of eggs showed complete embryo development. To design a method for captive-rearing of embryos, natural clutches (n = 13) were removed from males and divided into two sub-clutches. One was kept with all eggs together and in the other, the egg string was cut and eggs were split individually. All sub-clutches with eggs kept separated presented embryo survival (ranging from 27 to 61%) that hatched normally, while only one sub-clutch with embryos maintained together had some embryo survival (36%). These results may contribute to the management of this and related species.
Collapse
Affiliation(s)
- Lucía Arregui
- Centro de Investigación, Seguimiento y Evaluación, Parque Nacional de la Sierra de Guadarrama, Ctra. M-604, Km 27.6, Rascafria, 28740 Madrid, Spain;
| | - Jaime Bosch
- Centro de Investigación, Seguimiento y Evaluación, Parque Nacional de la Sierra de Guadarrama, Ctra. M-604, Km 27.6, Rascafria, 28740 Madrid, Spain;
- IMIB-Biodiversity Research Institute, University of Oviedo-CSIC-Principality of Asturias, C/Gonzalo Gutiérrez Quirón S/N, Mieres, 33600 Asturias, Spain
| |
Collapse
|
2
|
Silla AJ, Hobbs RJ, Gilbert DJ, Goodall D, Parrott ML, Lee A, O'Brien JK, Byrne PG. Application of Reproductive Technologies to the Critically Endangered Baw Baw Frog, Philoria frosti. Animals (Basel) 2023; 13:2232. [PMID: 37444030 DOI: 10.3390/ani13132232] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 07/01/2023] [Accepted: 07/03/2023] [Indexed: 07/15/2023] Open
Abstract
Reproductive technologies (RTs) can assist integrated conservation breeding programs to attain propagation targets and manage genetic diversity more effectively. While the application of RTs to enhance the conservation management of threatened amphibians has lagged behind that of other taxonomic groups, a recent surge in research is narrowing the divide. The present study reports on the first application of RTs (hormone-induced spawning, hormone-induced sperm-release, and sperm cryopreservation) to the critically endangered Baw Baw frog, Philoria frosti. To determine the effect of hormone therapy on spawning success, male-female pairs were administered either 0 μg/g gonadotropin-releasing hormone agonist (GnRHa), 0.5 μg/g GnRHa, or 0.5 μg/g GnRHa + 10 μg/g metoclopramide (MET) (n = 6-7 pairs/treatment), and the number of pairs ovipositing, total eggs, and percent fertilisation success were quantified. To determine the effect of hormone therapy on sperm-release and to establish the peak time to collect sperm post-hormone administration, males were administered 0 IU/g (n = 4), or 20 IU/g hCG (n = 16). Total sperm, sperm concentration, and percent viability were quantified at 0, 2, 4, 6, 8, 10, and 12 h post-hormone administration. Overall, the percentage of pairs ovipositing was highest in the GnRHa + MET treatment, with 71% of pairs ovipositing, compared to 57% and 33% of pairs in the GnRHa and control treatments, respectively. The quantity of sperm released from males in response to hCG peaked at 4 h post-hormone administration, though it remained high up to 12 h. The percent sperm viability also peaked at 4 h post-administration (94.5%), exhibiting a steady decline thereafter, though viability remained above 77% throughout the 12 h collection period. The remaining sperm samples (n = 22) were cryopreserved using established protocols and biobanked for long-term storage and future conservation applications. The mean post-thaw sperm viability was 59%, and the percent total motility was 17%. The results from this preliminary study will direct further applications of RTs to the critically endangered Baw Baw frog to assist with species recovery.
Collapse
Affiliation(s)
- Aimee J Silla
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Rebecca J Hobbs
- Taronga Institute of Science and Learning, Taronga Conservation Society Australia, Mosman, NSW 2088, Australia
| | - Deon J Gilbert
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
- Wildlife Conservation and Science, Zoos Victoria, Elliott Avenue, Parkville, VIC 3052, Australia
| | - Damian Goodall
- Wildlife Conservation and Science, Zoos Victoria, Elliott Avenue, Parkville, VIC 3052, Australia
| | - Marissa L Parrott
- Wildlife Conservation and Science, Zoos Victoria, Elliott Avenue, Parkville, VIC 3052, Australia
| | - Adam Lee
- Wildlife Conservation and Science, Zoos Victoria, Elliott Avenue, Parkville, VIC 3052, Australia
| | - Justine K O'Brien
- Taronga Institute of Science and Learning, Taronga Conservation Society Australia, Mosman, NSW 2088, Australia
| | - Phillip G Byrne
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
| |
Collapse
|
3
|
Browne RK, Kaurova SA, Vasudevan K, McGinnity D, Venu G, Gonzalez M, Uteshev VK, Marcec-Greaves R. Reproduction technologies for the sustainable management of Caudata (salamander) and Gymnophiona (caecilian) biodiversity. Reprod Fertil Dev 2022; 34:479-497. [PMID: 35157827 DOI: 10.1071/rd21356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 12/30/2021] [Indexed: 11/23/2022] Open
Abstract
We review the use of reproduction technologies (RTs) to support the sustainable management of threatened Caudata (salamanders) and Gymnophiona (caecilian) biodiversity in conservation breeding programs (CBPs) or through biobanking alone. The Caudata include ∼760 species with ∼55% threatened, the Gymnophiona include ∼215 species with an undetermined but substantial number threatened, with 80% of Caudata and 65% of Gymnophiona habitat unprotected. Reproduction technologies include: (1) the exogenous hormonal induction of spermatozoa, eggs, or mating, (2) in vitro fertilisation, (3) intracytoplasmic sperm injection (ICSI), (4) the refrigerated storage of spermatozoa, (5) the cryopreservation of sperm, cell or tissues, (6) cloning, and (7) gonadal tissue or cell transplantation into living amphibians to eventually produce gametes and then individuals. Exogenous hormone regimens have been applied to 11 Caudata species to stimulate mating and to 14 species to enable the collection of spermatozoa or eggs. In vitro fertilisation has been successful in eight species, spermatozoa have been cryopreserved in seven species, and in two species in vitro fertilisation with cryopreserved spermatozoa has resulted in mature reproductive adults. However, the application of RTs to Caudata needs research and development over a broader range of species. Reproduction technologies are only now being developed for Gymnophiona, with many discoveries and pioneering achievement to be made. Species with the potential for repopulation are the focus of the few currently available amphibian CBPs. As Caudata and Gymnophiona eggs or larvae cannot be cryopreserved, and the capacity of CBPs is limited, the perpetuation of the biodiversity of an increasing number of species depends on the development of RTs to recover female individuals from cryopreserved and biobanked cells or tissues.
Collapse
Affiliation(s)
- Robert K Browne
- Sustainability America, La Isla Road, Sarteneja, Corozal District, Belize
| | - Svetlana A Kaurova
- Institute of Cell Biophysics of the Russian Academy of Sciences, PSCBR RAS, Pushchino, Moscow Region 142290, Russia
| | - Karthikeyan Vasudevan
- Laboratory for the Conservation of Endangered Species, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Telangana 500048, India
| | - Dale McGinnity
- Ectotherm Department, Nashville Zoo at Grassmere, Nashville, TN 37211, USA
| | - Govindappa Venu
- Department of Zoology, Centre for Applied Genetics, Bangalore University, Jnana Bharathi Campus, Bengaluru, Karnataka 560056, India
| | - Manuel Gonzalez
- Departamento de Produccion Animal, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
| | - Victor K Uteshev
- Institute of Cell Biophysics of the Russian Academy of Sciences, PSCBR RAS, Pushchino, Moscow Region 142290, Russia
| | - Ruth Marcec-Greaves
- National Amphibian Conservation Center Detroit Zoological Society, Detroit, MI, USA. Honduras Amphibian Rescue and Conservation Center, Oak Grove Missouri 64075
| |
Collapse
|
4
|
Glass Campbell L, Anderson KA, Marcec‐Greaves R. Topical application of hormone gonadotropin‐releasing hormone (
GnRH‐A
) stimulates reproduction in the endangered Texas blind salamander (
Eurycea rathbuni
). CONSERVATION SCIENCE AND PRACTICE 2021. [DOI: 10.1111/csp2.609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
| | - Kelsey A. Anderson
- US Fish and Wildlife Service San Marcos Aquatic Resources Center San Marcos Texas USA
| | | |
Collapse
|
5
|
Silla AJ, Calatayud NE, Trudeau VL. Amphibian reproductive technologies: approaches and welfare considerations. CONSERVATION PHYSIOLOGY 2021; 9:coab011. [PMID: 33763231 PMCID: PMC7976225 DOI: 10.1093/conphys/coab011] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 01/29/2021] [Accepted: 02/07/2021] [Indexed: 06/12/2023]
Abstract
Captive breeding and reintroduction programs have been established for several threatened amphibian species globally, but with varied success. This reflects our relatively poor understanding of the hormonal control of amphibian reproduction and the stimuli required to initiate and complete reproductive events. While the amphibian hypothalamo-pituitary-gonadal (HPG) axis shares fundamental similarities with both teleosts and tetrapods, there are more species differences than previously assumed. As a result, many amphibian captive breeding programs fail to reliably initiate breeding behaviour, achieve high rates of fertilization or generate large numbers of healthy, genetically diverse offspring. Reproductive technologies have the potential to overcome these challenges but should be used in concert with traditional methods that manipulate environmental conditions (including temperature, nutrition and social environment). Species-dependent methods for handling, restraint and hormone administration (including route and frequency) are discussed to ensure optimal welfare of captive breeding stock. We summarize advances in hormone therapies and discuss two case studies that illustrate some of the challenges and successes with amphibian reproductive technologies: the mountain yellow-legged frog (Rana muscosa; USA) and the northern corroboree frog (Pseudophryne pengilleyi; Australia). Further research is required to develop hormone therapies for a greater number of species to boost global conservation efforts.
Collapse
Affiliation(s)
- Aimee J Silla
- Corresponding author: School of Earth, Atmospheric and Life Sciences, University of Wollongong, Northfields Ave, Wollongong, New South Wales 2522, Australia.
| | - Natalie E Calatayud
- Taronga Institute of Science and Learning, Taronga Conservation Society Australia, Taronga, Western Plains Zoo, Obley Rd, Dubbo, New South Wales 2830, Australia
- San Diego Zoo Global-Beckman Center for Conservation Research, San Pasqual Valley Rd, Escondido, CA 92027, USA
| | - Vance L Trudeau
- Department of Biology, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| |
Collapse
|