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Méndez-Tepepa M, Morales-Cruz C, García-Nieto E, Anaya-Hernández A. A review of the reproductive system in anuran amphibians. ZOOLOGICAL LETTERS 2023; 9:3. [PMID: 36782341 PMCID: PMC9926845 DOI: 10.1186/s40851-023-00201-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 01/18/2023] [Indexed: 06/18/2023]
Abstract
Reproductive biology is an important topic that is well explored in many vertebrates, but information about frogs' reproductive mechanisms could be improved. Therefore, this review aims to provide organized and specific information on frog reproduction. First, we developed schemes that illustrate the general information regarding reproductive biological mechanisms in frogs in a specific way. Then, we described the physiological, histological, and morphological mechanisms of each organ of the reproductive system of male and female frogs. Finally, this manuscript may contribute to a broader understanding of anuran reproductive biology. Since, understanding frogs' reproductive system permits one to make a comparison with reproduction with other anurans.
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Affiliation(s)
- Maribel Méndez-Tepepa
- Centro de Investigación en Genética y Ambiente, Universidad Autónoma de Tlaxcala, Autopista San Martín-Tlaxcala Km 10.5, Ixtacuixtla, 90120, Tlaxcala, Mexico.
| | - Cuauhtémoc Morales-Cruz
- Centro de Investigación en Genética y Ambiente, Universidad Autónoma de Tlaxcala, Autopista San Martín-Tlaxcala Km 10.5, Ixtacuixtla, 90120, Tlaxcala, Mexico
| | - Edelmira García-Nieto
- Centro de Investigación en Genética y Ambiente, Universidad Autónoma de Tlaxcala, Autopista San Martín-Tlaxcala Km 10.5, Ixtacuixtla, 90120, Tlaxcala, Mexico
| | - Arely Anaya-Hernández
- Centro de Investigación en Genética y Ambiente, Universidad Autónoma de Tlaxcala, Autopista San Martín-Tlaxcala Km 10.5, Ixtacuixtla, 90120, Tlaxcala, Mexico
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Valchi P, Ponssa ML, Farías A, Volonteri MC, Hermida GN. Comparative spermatozoa ultrastructure of neotropical grass frogs (genus Leptodactylus) with comments on anuran reproductive modes and phylogeny. ZOOL ANZ 2022. [DOI: 10.1016/j.jcz.2022.11.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Wang P, Al Azad MAR, Yang X, Martelli PR, Cheung KY, Shi J, Shen Y. Self-adaptive and efficient propulsion of Ray sperms at different viscosities enabled by heterogeneous dual helixes. Proc Natl Acad Sci U S A 2021; 118:e2024329118. [PMID: 34088836 PMCID: PMC8201849 DOI: 10.1073/pnas.2024329118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We disclose a peculiar rotational propulsion mechanism of Ray sperms enabled by its unusual heterogeneous dual helixes with a rigid spiral head and a soft tail, named Heterogeneous Dual Helixes (HDH) model for short. Different from the conventional beating propulsion of sperm, the propulsion of Ray sperms is from both the rotational motion of the soft helical tail and the rigid spiral head. Such heterogeneous dual helical propulsion style provides the Ray sperm with high adaptability in viscous solutions along with advantages in linearity, straightness, and bidirectional motion. This HDH model is further corroborated by a miniature swimming robot actuated via a rigid spiral head and a soft tail, which demonstrates similar superiorities over conventional ones in terms of adaptability and efficiency under the same power input. Such findings expand our knowledge on microorganisms' motion, motivate further studies on natural fertilization, and inspire engineering designs.
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Affiliation(s)
- Panbing Wang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - M A R Al Azad
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Xiong Yang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | | | - Kam Yan Cheung
- Veterinary Department, Ocean Park Corporation, Hong Kong, China
| | - Jiahai Shi
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China;
- Shenzhen Research Institute, City University of Hong Kong, Shen Zhen, China
- Tung Biomedical Sciences Center, City University of Hong Kong, Hong Kong, China
| | - Yajing Shen
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China;
- Shenzhen Research Institute, City University of Hong Kong, Shen Zhen, China
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Landscape and local correlates with two green tree-frogs, Rhacophorus (Amphibia: Rhacophoridae) in different habitats, central Japan. LANDSCAPE AND ECOLOGICAL ENGINEERING 2020. [DOI: 10.1007/s11355-019-00406-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Comparative sperm morphology of Proceratophrys and Odontophrynus (Anura, Odontophrynidae). Micron 2019; 125:102713. [PMID: 31419702 DOI: 10.1016/j.micron.2019.102713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 06/07/2019] [Accepted: 07/07/2019] [Indexed: 11/22/2022]
Abstract
The ultrastructure of the spermatozoa of seven species of Proceratophrys and one of Odontophrynus was analyzed in the present study. The sperm of Odontophrynus juquinha is similar to that of Odontophrynus cultripes, previously described, and to those of Proceratophrys branti, Proceratophrys bigibbosa, Proceratophrys affinis concavitympanum, Proceratophrys huntingtoni, Proceratophrys conformis moratoi, P. moratoi, and Proceratophrys palustris, in relation to the acrosomal vesicle and the subacrosomal cone that covers the anterior region of the nucleus in the sperm head. We observed transverse striations in the midpiece of the Odontophrynus juquinha sperm, a feature not observed in any Proceratophrys species. The sperm tail of all the studied species had a simple flagella and single axoneme associated with auxiliary structures (juxta-axonemal + undulating membrane + axial fiber). However, the juxta-axonemal fiber is thicker and the undulating membrane is shorter in Proceratophrys in comparison with Odontophrynus. In addition to differentiating these two genera, these features represent a possible autapomorphy in Proceratophrys.
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Mattei X, Marchand B, Quilichini Y. A biflagellate spermatozoon in the African bonytongue Heterotis niloticus (Teleostei, Osteoglossidae). JOURNAL OF FISH BIOLOGY 2019; 94:335-338. [PMID: 30565228 DOI: 10.1111/jfb.13894] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 12/17/2018] [Indexed: 06/09/2023]
Abstract
In this transmission electron microscopy study, we describe the ultrastructure of the spermatozoon of Heterotis niloticus (Osteoglossiformes), which is distinguished by having two flagella. Our investigation also highlights the great diversity of sperm cell structures observed across osteoglossiform families, such as aflagellate (Gymnarchidae, Mormyridae), monoflagellate (Notopteridae, Pantodontidae) and biflagellate spermatozoa. As biflagellate spermatozoa are rare in vertebrates, we also summarize the orders and families known to possess this ultrastructural character, most of which are fishes.
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Affiliation(s)
- Xavier Mattei
- Université de Corse, Campus Grimaldi Bât 018, Corte, France
| | - Bernard Marchand
- UMR SPE 6134 CNRS - Université de Corse, Campus Grimaldi Bât 018, Corte, France
| | - Yann Quilichini
- UMR SPE 6134 CNRS - Université de Corse, Campus Grimaldi Bât 018, Corte, France
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Cruz JC, Ferraro DP, Farías A, Santos JS, Recco-Pimentel SM, Faivovich J, Hermida GN. A comparative ultrastructural analysis of spermatozoa in Pleurodema (Anura, Leptodactylidae, Leiuperinae). J Morphol 2016; 277:957-77. [PMID: 27151937 DOI: 10.1002/jmor.20550] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 03/10/2016] [Accepted: 04/05/2016] [Indexed: 11/06/2022]
Abstract
This study describes the spermatozoa of 10 of the 15 species of the Neotropical frog genus Pleurodema through transmission electron microscopy. The diversity of oviposition modes coupled with a recent phylogenetic hypothesis of Pleurodema makes it an interesting group for the study of ultrastructural sperm evolution in relation to fertilization environment and egg-clutch structure. We found that Pleurodema has an unusual variability in sperm morphology. The more variable structures were the acrosomal complex, the midpiece, and the tail. The acrosomal complex has all the structures commonly reported in hyloid frogs but with different degree of development of the subacrosomal cone. Regarding the midpiece, the variability is given by the presence or absence of the mitochondrial collar. Finally, the tail is the most variable structure, ranging from single (only axoneme) to more complex (presence of paraxonemal rod, cytoplasmic sheath, and undulating membrane), with the absence of the typical axial fiber present in hyloid frogs, also shared with some other genera of Leiuperinae. J. Morphol. 277:957-977, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Julio C Cruz
- Laboratorio Biología de Anfibios, Histología Animal, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.,Instituto de Bio y Geociencias (IBIGEO) - CONICET, Universidad de Salta, Salta, Argentina
| | - Daiana P Ferraro
- Instituto Nacional de Limnología (INALI) - CONICET, Santa Fe, Argentina.,División Herpetología, Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" - CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Alejandro Farías
- Laboratorio Biología de Anfibios, Histología Animal, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Julio S Santos
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Brazil
| | - Shirlei M Recco-Pimentel
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Brazil
| | - Julián Faivovich
- División Herpetología, Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" - CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Gladys N Hermida
- Laboratorio Biología de Anfibios, Histología Animal, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
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Muto K, Kubota HY. Ultrastructure and motility of the spermatozoa ofPolypedates leucomystax(Amphibia, Anura, Rhacophoridae). Cytoskeleton (Hoboken) 2012; 70:121-33. [DOI: 10.1002/cm.21092] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 10/22/2012] [Accepted: 10/25/2012] [Indexed: 11/11/2022]
Affiliation(s)
- Kohei Muto
- Department of Zoology, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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Muto K, Kubota HY. Ultrastructural analysis of spermiogenesis in Rhacophorus arboreus (Amphibia, Anura, Rhacophoridae). J Morphol 2011; 272:1422-34. [PMID: 21780156 DOI: 10.1002/jmor.10994] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 05/02/2011] [Accepted: 05/22/2011] [Indexed: 11/08/2022]
Abstract
The spermatozoa of the Japanese green tree frog, Rhacophorus arboreus (Amphibia, Anura, Rhacophoridae), have a characteristic corkscrew-shaped head and a thick tail that extends perpendicular to the longitudinal axis of the head. We examined the process of spermatogenesis in Rh. arboreus, particularly spermiogenesis, using light and transmission electron microscopy. Spermiogenesis was categorized into the early, mid, and late stages based on the spermatid morphology and their location within the cyst. Early spermatids had a round nucleus and two independent flagella that elongated from a pair of parallel centrioles. The centrioles became embedded in centriolar adjunct material and attached to the nucleus. Then, the flagella were covered with a mantle-like cytoplasm that contained many microtubules. An acrosome appeared on the pointed side of the slightly elongated nucleus. Mid spermatids had an elongated rod-like head. As the nucleus elongated, the chromatin fibers became thicker and were arranged parallel to the elongation axis. An elongated acrosome was attached helically along the lateral side of the elongated nucleus. The biflagellate spermatids transformed into monoflagellate spermatids with two axonemes through a process in which the plasma membrane of each flagellum expanded. Late spermatids had a coiled or corkscrew-shaped head. An acrosome was located on the inside of the coiled cone composed of a nucleus. Parallel microtubules were connected in rows, and then became crystallized in the tail. The present report contains the first morphological description of spermatogenesis in Rhacophorus and suggests that spermiogenesis evolved to adapt to the fertilization environment.
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Affiliation(s)
- Kohei Muto
- Department of Zoology, Graduate School of Science, Kyoto University, Kyoto 6068502, Japan
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Muto K, Kubota HY. A novel mechanism of sperm motility in a viscous environment: Corkscrew-shaped spermatozoa cruise by spinning. ACTA ACUST UNITED AC 2009; 66:281-91. [DOI: 10.1002/cm.20358] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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11
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Veiga-Menoncello ACP, Aguiar-Junior O, Lima AP, Recco-Pimentel SM. The biflagellate spermatozoa of Colostethus marchesianus (Melin, 1941) (Anura, Dendrobatidae) from the type locality and of Colostethus sp. (aff. Marchesianus.) from a different locality: A scanning and transmission electron microscopy analysis. ZOOL ANZ 2007. [DOI: 10.1016/j.jcz.2006.12.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Báo SN, Dalton GC, de Oliveira SF. Spermiogenesis in Odontophrynus cultripes (Amphibia, Anura, Leptodactylidae): Ultrastructural and cytochemical studies of proteins using E-PTA. J Morphol 2005; 207:303-314. [PMID: 29865520 DOI: 10.1002/jmor.1052070307] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Spermiogenesis in the South American leptodactylid frog Odontophrynus cultripes was analyzed ultrastructurally. The spermatids undergo morphological modification while still enclosed in microtubule-rich processes of Sertoli cells. Electron-dense plates resembling junctional structures appear in regions at which the spermatids lie in close contact with the surface of Sertoli cell processes. Spermatid differentiation can be divided into five distinct stages based mainly on chromatin condensation. In the late stages, the densely compacted chromatin loses reactivity to ethanolic phosphotungstic acid (E-PTA). Helical arrangements of microtubules appear in the cytoplasm that surrounds the spermatid nucleus after the second stage. The acrosomal vesicle differentiates into a cone-shaped acrosome that caps the anterior region of the nucleus. The connecting piece, located in the flagellum implantation zone, has transverse striations, and is continuous with the axial rod. The tail is formed by a 9 + 2 axoneme, an undulating membrane, and an axial rod that is rich in basic proteins as demonstrated by E-PTA staining.
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Affiliation(s)
- Sônia N Báo
- Department of Genetics and Morphology, and Department of Cell Biology, University of Brasília, 70.919, Brasília, DF., Brazil
| | - Gustavo C Dalton
- Department of Genetics and Morphology, and Department of Cell Biology, University of Brasília, 70.919, Brasília, DF., Brazil
| | - Sergio F de Oliveira
- Department of Genetics and Morphology, and Department of Cell Biology, University of Brasília, 70.919, Brasília, DF., Brazil
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Garda AA, Costa GC, Colli GR, Báo SN. Spermatozoa of Pseudinae (Amphibia, Anura, Hylidae), with a test of the hypothesis that sperm ultrastructure correlates with reproductive modes in anurans. J Morphol 2004; 261:196-205. [PMID: 15216524 DOI: 10.1002/jmor.10238] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We describe, for the first time, the sperm ultrastructure of the two genera of Pseudinae. Based on sperm ultrastructure, the five species herein examined can be separated into three groups: one containing Pseudis paradoxa, P. bolbodactyla, and P. tocantins, the second containing P. minuta, and the third containing Lysapsus laevis. The midpiece is similar in all species and auxiliary fibers and the undulating membrane are absent. In Pseudis a subacrosomal cone and a multilaminar structure (P. minuta) or a granular material (P. paradoxa group) are seen above the nucleus. Lysapsus laevis has only remnants of the subacrosomal cone. All species have peripheral fibers associated with the outer doublets of the axoneme. We tested the hypothesis of correlation between the presence of an undulating membrane and fertilization environments in anurans using a concentrated changes test (CCT) based on the Hay et al. (Mol Biol Evol 1995;12:928-937) hypothesis of phylogenetic relationships among anuran families. Only a subset of the resolved topologies derived from the Hay et al. (1995) cladogram, where Ranoidea is the sister-group of Sooglossidae, produced significant probabilities of the CCT. Therefore, support for the correlation between sperm ultrastructure and fertilization environments in anurans is, at best, equivocal.
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Affiliation(s)
- Adrian A Garda
- Departamento de Biologia Celular, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil
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Aguiar-Jr O, Lima AP, Báo SN, Recco-Pimentel SM. Sperm ultrastructure of the Brazilian Amazon poison frogs Epipedobates trivittatus and Epipedobates hahneli (Anura, Dendrobatidae). ACTA ZOOL-STOCKHOLM 2004. [DOI: 10.1111/j.0001-7272.2004.00154.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Aguiar O, Garda AA, Lima AP, Colli GR, Báo SN, Recco-Pimentel SM. Biflagellate spermatozoon of the poison-dart frogs Epipedobates femoralis and Colostethus sp. (Anura, Dendrobatidae). J Morphol 2003; 255:114-21. [PMID: 12420325 DOI: 10.1002/jmor.10052] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This study describes the spermatozoa of the dendrobatids Epipedobates femoralis and Colostethus sp. using light and transmission electron microscopy. Both species possess a biflagellate spermatozoon, an unusual characteristic only previously reported in two anuran species belonging to the families Leptodactylidae and Racophoridae. The acrosomal complex of both species consists of a conical acrosomal vesicle and a subacrosomal cone, both of which cover the anterior portion of the nucleus, but to differing extents. In the midpiece, the centrioles are disposed parallel to each other and to the cell axis and give rise to two axonemes. Two paraxonemal rods were also seen entering the nuclear fossa. Both flagella are surrounded by a single mitochondrial collar. Each flagellum is formed by an axial fiber connected to the axoneme by an axial sheath; juxta-axonemal fibers are absent. Our data seem to support that Epipedobates femoralis should be placed in a separate clade possibly related to Colosthetus and that these two genera may not be monophyletic.
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Affiliation(s)
- Odair Aguiar
- Departamento de Biologia Celular, Instituto de Biologia, Universidade Estadual de Campinas, (UNICAMP), 13084-971, Campinas, SP, Brasil
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Scheltinga DM, Jamieson BGM, Bickford DP, Garda AA, Báo SN, McDonald KR. Morphology of the spermatozoa of the Microhylidae (Anura, Amphibia). ACTA ZOOL-STOCKHOLM 2002. [DOI: 10.1046/j.1463-6395.2002.00066.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Garda AA, Colli GR, Aguiar-Júnior O, Recco-Pimentel SM, Báo SN. The ultrastructure of the spermatozoa of Epipedobates flavopictus (Amphibia, Anura, Dendrobatidae), with comments on its evolutionary significance. Tissue Cell 2002; 34:356-64. [PMID: 12270262 DOI: 10.1016/s0040816602000368] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We describe, for the first time, the spermatozoon ultrastructure of a dendrobatid frog, Epipedobates flavopictus. Mature spermatozoa of E. flavopictus are filiform, with a moderately curved head and a proportionally short tail. The acrosomal vesicle is a conical structure that covers the nucleus for a considerable distance. A homogeneous subacrosomal cone lies between the acrosome vesicle and the nucleus. The nucleus contains a nuclear space at its anterior end, and electron-lucent spaces and inclusions. No perforatorium is present. In the midpiece, the proximal centriole is housed inside a deep nuclear fossa. Mitochondria are scattered around the posterior end of the nucleus and inside the undulating membrane in the anterior portion of the tail. In transverse section the tail is formed by an U-shaped axial fiber connected to the axoneme through an axial sheath, which supports the undulating membrane. The juxta-axonemal fiber is absent. The spermatozoon of E. flavopictus has several characteristics not observed before in any anurans, such as a curved axial fiber, absence of a juxta-axonemal fiber, and presence of mitochondria in the typical undulating membrane. Our results endorse the view that, in anurans, the conical perforatorium and subacrosomal cone are homologous and that Dendrobatidae should be grouped within Bufonoidea rather than Ranoidea.
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Affiliation(s)
- Adrian A Garda
- Departamento de Biologia Celular, Universidade de Brasília 70919-970, Brasília, DF, Brazil.
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Mizuhira V, Hasegawa H, Notoya M. Fixation and Imaging of Biological Elements: Heavy Metals, Diffusible Substances, Ions, Peptides, and Lipids. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0079-6336(00)80001-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Hasegawa H, Mizuhira V, Notoya M. Microwave-Stimulated Fixation and Histochemical Application to Biological Specimens. Acta Histochem Cytochem 2000. [DOI: 10.1267/ahc.33.319] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
| | - Vinci Mizuhira
- Medical Research Institute, Tokyo Medical and Dental University
| | - Mitsuru Notoya
- Developmental Research Laboratories, Shionogi & Co., Ltd.,
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Abstract
Spermatogenesis appears to be a fairly conserved process throughout the vertebrate series. Thus, spermatogonia develop into spermatocytes that undergo meiosis to produce spermatids which enter spermiogenesis where they undergo a morphological transformation into spermatozoa. There is, however, variation amongst the vertebrates in how germ cell development and maturation is accomplished. This difference can be broadly divided into two distinct patterns, one present in anamniotes (fish, amphibia) and the other in amniotes (reptiles, birds, mammals). For anamniotes, spermatogenesis occurs in spermatocysts (cysts) which for most species develop within seminiferous lobules. Cysts are produced when a Sertoli cell becomes associated with a primary spermatogonium. Mitotic divisions of the primary spermatogonium produce a cohort of secondary spermatogonia that are enclosed by the Sertoli cell which forms the wall of the cyst. With spermatogenic progression a clone of isogeneic spermatozoa is produced which are released, by rupture of the cyst, into the lumen of the seminiferous lobule. Following spermiation, the Sertoli cell degenerates. For anamniotes, therefore, there is no permanent germinal epithelium since spermatocysts have to be replaced during successive breeding seasons. By contrast, spermatogenesis in amniotes does not occur in cysts but in seminiferous tubules that possess a permanent population of Sertoli cells and spermatogonia which act as a germ cell reservoir for succeeding bouts of spermatogenic activity. There is, in general, a greater variation in the organization of the testis and pattern of spermatogenesis in the anamniotes compared to amniotes. This is primarily due to the fact there is more reproductive diversity in anamniotes ranging from a relatively unspecialized condition where gametes are simply released into the aqueous environment to highly specialized strategies involving internal fertilization. These differences are obviously reflected in the mode of spermatogenesis and this is particularly true of the stage of spermiogenesis where the morphology of the species-specific spermatozoon is determined. Moreover, unlike amniotes, many anamniotes display a spermatogenic wave manifest, depending upon the species, either at the level of the cyst or seminiferous lobule. This variation in the organization of the testis makes certain anamniotes perfect models for investigating germ cell development and maturation. For instance, the presence of a spermatogenic wave provides an opportunity to manually isolate discrete germ cell stages for analysis of specific Sertoli/germ cell interactions. Furthermore, for many anamniotes, germ cells mature in association with a morphologically poorly developed Sertoli cell. This seeming independence of Sertoli cell regulation allows the in vitro culture of isolated germ cells of some species of anamniotes through several developmental stages. Thus, due either to the anatomical organization of the testis, or structural simplicity of the germinal units, nonmammalian vertebrates can provide excellent experimental animal models for investigating many basic problems of male reproduction.
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Affiliation(s)
- J Pudney
- Fearing Research Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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LEE MICHAELSY, JAMIESON BARRIEGM. The ultrastructure of the spermatozoa of bufonid and hylid frogs (Anura, Amphibia): implications for phylogeny and fertilization biology. ZOOL SCR 1993. [DOI: 10.1111/j.1463-6409.1993.tb00361.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Lee MSY, Jamieson BGM. The Ultrastructure of the Spermatozoa of Three Species of Myobatrachid Frogs (Anura, Amphibia) with Phylogenetic Considerations. ACTA ZOOL-STOCKHOLM 1992. [DOI: 10.1111/j.1463-6395.1992.tb01085.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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