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Galligan TM, Helm RF, Case BF, Bodinof Jachowski CM, Frazier CL, Alaasam V, Hopkins WA. Pre-breeding androgen and glucocorticoid profiles in the eastern hellbender salamander (Cryptobranchus alleganiensis alleganiensis). Gen Comp Endocrinol 2021; 313:113899. [PMID: 34499909 DOI: 10.1016/j.ygcen.2021.113899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 08/10/2021] [Accepted: 09/03/2021] [Indexed: 11/28/2022]
Abstract
Seasonally breeding species exhibit cyclical changes in circulating steroid hormone profiles that correspond with changes to their reproductive behavior and ecology. Such information is critical to the conservation of imperiled and data-deficient species, such as the eastern hellbender salamander (Cryptobranchus alleganiensis alleganiensis). We determined changes in plasma testosterone (T), dihydrotestosterone (DHT), 11-ketotestosterone (11-KT), 11-ketoandrostenedione (11-KA), dehydroepiandrosterone (DHEA), cortisol, corticosterone, and progesterone (P4) during a four-month period preceding breeding in adult male and female eastern hellbenders. This pre-breeding period is characterized by increased diel movement and aggression by both sexes, follicular development and yolk production in females, and sperm production, territoriality, and nest site establishment in males. In both males and females, we observed a progressive increase in circulating T and DHT during the pre-reproductive season, both peaking in August (17 days before breeding), but concentrations of both hormones were higher in males. Conversely, 11-KT was higher in females, but did not vary significantly by date. These results suggest that T and DHT are the predominant androgens in eastern hellbenders and are likely important regulators of reproductive processes in both males and females. The detection of significant quantities of DHT and 11-KT in females is particularly interesting, considering that unlike T, neither of these androgens can be converted to estrogens. Therefore, it seems possible that aggression or some aspect of reproduction in the female eastern hellbender may be directly mediated by androgen signaling. Baseline cortisol did not vary throughout the pre-breeding period but was higher in females than males, and also became highly variable in females leading up to breeding. Progesterone, 11-KA, DHEA, and corticosterone were rarely or never detected, and thus, do not appear to be important during the pre-reproductive season. This study provides a physiological framework for future studies of hellbender reproductive biology, which could ultimately be important for their conservation.
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Affiliation(s)
- Thomas M Galligan
- Virginia Tech, Department of Fish and Wildlife Conservation, Blacksburg, VA USA 24060, USA; Environmental Working Group, 1436 U St. NW #100, Washington, DC 20009, USA.
| | - Richard F Helm
- Virginia Tech, Department of Biochemistry, Blacksburg, VA USA 24060, USA
| | - Brian F Case
- Virginia Tech, Department of Fish and Wildlife Conservation, Blacksburg, VA USA 24060, USA
| | - Catherine M Bodinof Jachowski
- Virginia Tech, Department of Fish and Wildlife Conservation, Blacksburg, VA USA 24060, USA; Forestry and Environmental Conservation Department, Clemson University, Clemson, SC 29634, USA
| | - Clara L Frazier
- Virginia Tech, Department of Biochemistry, Blacksburg, VA USA 24060, USA
| | - Valentina Alaasam
- Virginia Tech, Department of Fish and Wildlife Conservation, Blacksburg, VA USA 24060, USA; Ecology, Evolution, and Conservation Biology, University Nevada-Reno, Reno, NV 89557, USA
| | - William A Hopkins
- Virginia Tech, Department of Fish and Wildlife Conservation, Blacksburg, VA USA 24060, USA
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Hincapie Agudelo M, Carbonell Medina BA, Arenas Gómez CM, Delgado JP. Ambystoma mexicanum, a model organism in developmental biology and regeneration: a colombian experience. ACTA BIOLÓGICA COLOMBIANA 2021. [DOI: 10.15446/abc.v27n1.88309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Ambystoma mexicanum is a urodele amphibian endemic to Xochimilco Lake in Mexico, it belongs to the salamander family Ambystomatidae. This species has frequently been used as model organism in developmental biology and regeneration laboratories around the world due to its broad regenerative capacities and adaptability to laboratory conditions. In this review we describe the establishment of the first colony of axolotls in Colombia to study tissue regeneration and our perspectives on the use A. mexicanum as a model organism in Colombia are discussed emphasizing its possible uses in regeneration and developmental biology
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Porras-Gómez TJ, Villagrán-SantaCruz M, Moreno-Mendoza N. Biology of primordial germ cells in vertebrates with emphasis in urodeles amphibians. Mol Reprod Dev 2021; 88:773-792. [PMID: 34532913 DOI: 10.1002/mrd.23533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 08/23/2021] [Accepted: 08/26/2021] [Indexed: 11/08/2022]
Abstract
Primordial germ cells (PGCs) are highly specialized cells that play a relevant role in the maintenance and evolution of the species, since they create new combinations of genetic information between the organisms. Amphibians are a class of amniote vertebrates that are divided into three subclasses, the anurans (frogs and toads), the urodeles (salamanders and newts), and the gymnophiones (caecilians). The study of PGCs in amphibians has been addressed in more detail in anurans while little is known about the biology of this cell lineage in urodeles. Studies in some urodeles species have suggested that PGCs are of mesodermal origin, specifying in the lateral plate mesoderm at the late gastrula stage. With classical experiments it shown that, there is an induction of mesoderm, therefore most likely urodeles PGCs develop from unspecialized mesodermal tissue that responds to extracellular signals. However, some fundamental biological processes of PGCs such as the analysis of their specification, arrival, and colonization to the gonads, and their maintenance and differentiation into mature and fertile gametes remain to be elucidated. Therefore, knowledge about the biology of PGCs is of great importance to ensure the perpetuation of urodeles amphibians, as some species are in danger of becoming extinct.
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Affiliation(s)
- Tania J Porras-Gómez
- Laboratorio de Biología Tisular y Reproductora, Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Maricela Villagrán-SantaCruz
- Laboratorio de Biología Tisular y Reproductora, Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Norma Moreno-Mendoza
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, México
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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.
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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
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Mendoza‐Cruz E, Moreno‐Mendoza N, Zambrano‐González L, Porras‐Gómez TJ, Villagrán‐SantaCruz M. Dimorphic protein expression for
Sox9
and
Foxl2
genes in the testicles and ovaries of the urodele amphibian:
Ambystoma mexicanum. ACTA ZOOL-STOCKHOLM 2020. [DOI: 10.1111/azo.12327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Eva Mendoza‐Cruz
- Laboratorio de Biología Tisular y Reproductora Departamento de Biología Comparada Facultad de Ciencias Universidad Nacional Autónoma de México Ciudad de México México
| | - Norma Moreno‐Mendoza
- Departamento de Biología Celular y Fisiología Instituto de Investigaciones Biomédicas Universidad Nacional Autónoma de México Ciudad de México México
| | - Luis Zambrano‐González
- Laboratorio de Restauración Ecológica Instituto de Biología Universidad Nacional Autónoma de México Ciudad de México México
| | - Tania Janeth Porras‐Gómez
- Laboratorio de Biología Tisular y Reproductora Departamento de Biología Comparada Facultad de Ciencias Universidad Nacional Autónoma de México Ciudad de México México
| | - Maricela Villagrán‐SantaCruz
- Laboratorio de Biología Tisular y Reproductora Departamento de Biología Comparada Facultad de Ciencias Universidad Nacional Autónoma de México Ciudad de México México
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Kakegawa M, Kishi F, Saikawa Y, Hasumi M. Seasonal changes in body shape and mass in a lotic-breeding and externally fertilizing salamander Hynobius kimurae. ZOOL ANZ 2017. [DOI: 10.1016/j.jcz.2017.04.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Uribe MC, Mejía-Roa V. Testicular structure and germ cells morphology in salamanders. SPERMATOGENESIS 2014; 4:e988090. [PMID: 26413406 PMCID: PMC4581064 DOI: 10.4161/21565562.2014.988090] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 11/04/2014] [Accepted: 11/10/2014] [Indexed: 11/19/2022]
Abstract
Testes of salamanders or urodeles are paired elongated organs that are attached to the dorsal wall of the body by a mesorchium. The testes are composed of one or several lobes. Each lobe is morphologically and functionally a similar testicular unit. The lobes of the testis are joined by cords covered by a single peritoneal epithelium and subjacent connective tissue. The cords contain spermatogonia. Spermatogonia associate with Sertoli cells to form spermatocysts or cysts. The spermatogenic cells in a cyst undergo their development through spermatogenesis synchronously. The distribution of cysts displays the cephalo-caudal gradient in respect to the stage of spermatogenesis. The formation of cysts at cephalic end of the testis causes their migration along the lobules to the caudal end. Consequently, the disposition in cephalo-caudal regions of spermatogenesis can be observed in longitudinal sections of the testis. The germ cells are spermatogonia, diploid cells with mitotic activity; primary and second spermatocytes characterized by meiotic divisions that develop haploid spermatids; during spermiogenesis the spermatids differentiate to spermatozoa. During spermiation the cysts open and spermatozoa leave the testicular lobules. After spermiation occurs the development of Leydig cells into glandular tissue. This glandular tissue regressed at the end of the reproductive cycle.
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Affiliation(s)
- Mari Carmen Uribe
- Laboratorio de Biología de la Reproducción; Departamento de Biología Comparada; Facultad de Ciencias; Universidad Nacional Autónoma de México; Ciudad Universitaria; México DF, México
| | - Víctor Mejía-Roa
- Laboratorio de Biología de la Reproducción; Departamento de Biología Comparada; Facultad de Ciencias; Universidad Nacional Autónoma de México; Ciudad Universitaria; México DF, México
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