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Effects of Cadmium Exposure on Leydig Cells and Blood Vessels in Mouse Testis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19042416. [PMID: 35206604 PMCID: PMC8878469 DOI: 10.3390/ijerph19042416] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 02/17/2022] [Accepted: 02/17/2022] [Indexed: 11/17/2022]
Abstract
Environmental exposure to cadmium (Cd) contributes to a decline in the quality of human semen. Although the testis is sensitive to Cd exposure, the mechanism underlying how cadmium affects the testis remains to be defined. In this study, male mice were treated with intraperitoneal injections of 0, 0.5, 1.5 and 2.5 mg CdCl2/kg/day for 10 days, respectively. Both the testicular weight and the 3β-HSD activity of Leydig cells were significantly reduced with the administration of 2.5 mg CdCl2/kg/day. The height of endothelial cells in the interstitial blood vessels significantly increased with the use of 2.5 mg CdCl2/kg/day compared with the control. Western blot data showed that the protein levels of CD31, αSMA, caveolin and Ng2 increased with cadmium exposure, and this increase was particularly significant with the administration of 2.5 mg CdCl2/kg/day. CD31, αSMA, caveolin and Ng2 are related to angiogenesis. Based on our data, cadmium exposure may stimulate the proliferation of the mural cells and endothelial cells of blood vessels, which may lead to abnormal function of the testis.
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Viana IKS, S. GMF, Pantoja JCD, Oliveira RS, Mendes YA, Nunes JLG, Ferreira MAP, Rocha RM. Subfamily hypostominae: similarities and differences in testicular structure of amazonian fish. BMC ZOOL 2022; 7:3. [PMID: 37170306 PMCID: PMC10127008 DOI: 10.1186/s40850-021-00106-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 12/21/2021] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Hypostominae is a subfamily of the family Loricariidae that has a great diversity of species. Accordingly, testicular studies in fish can contribute to the phylogeny and taxonomy of species and to the comparison of reproductive aspects between species. Thus, this work aimed to characterize the testicular morphology and spermatogenesis of the Hypostominae species Baryancistrus xanthellus, Peckoltia oligospila and Hypancistrus zebra.
Results
B. xanthellus, P. oligospila and H. zebra had an anastomosed tubular type of testis. The germinal epithelium was continuous with unrestricted spermatogonia, and the proliferative, meiotic and spermiogenic phases were defined in all species. In the spermiogenic phase, spermatids were classified as initial, intermediate and final. Only in B. xanthellus in the final phase was there nuclear rotation. The sperm for the three species had a head with an oval shape and a single flagellum composed of the short midpiece, principal piece and end piece. B. xanthellus and P. oligospila showed a cylindrical flagellum and H. zebra showed projections that produced a flattened appearance.
Conclusions
On the basis testicular structure and ultrastructural characteristics of the germ cells, there was a greater relationship between B. xanthelus and P. oligospila, while H. zebra had particular characteristics. These aspects show that despite belonging to the same subfamily, the species have distinct biological characteristics.
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de Siqueira-Silva DH, da Silva Rodrigues M, Nóbrega RH. Testis structure, spermatogonial niche and Sertoli cell efficiency in Neotropical fish. Gen Comp Endocrinol 2019; 273:218-226. [PMID: 30195025 DOI: 10.1016/j.ygcen.2018.09.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 07/23/2018] [Accepted: 09/04/2018] [Indexed: 11/23/2022]
Abstract
Neotropical icthyofauna represents one of the most diverse and extreme ecosystems in the world. Likewise, reproduction showed enormous diversity with different reproductive systems, modes and behavior. On the other hand, information on Neotropical fish species, in particular on male reproductive physiology is restricted to few species. This mini-review aimed to compile the existing information on spermatogenesis of Neotropical teleosts focusing on testis structure, spermatogonial niche and Sertoli cell efficiency. The first topic covers the histological analysis of the testicular structure, showing a conserved testicular pattern in relation to the phylogenetic position: basal species present anastomosing tubular testis (e.g. Astyanax altiparanae, Conorhynchos conirostris, Pimelodus maculatus, Lophiosilurus alexandri, Rhinelepis aspera, among others), while derived teleosts showed lobular testis (e.g. Cichlasoma dimerus, Cichla kelberi, Odontesthes bonariensis, Synbranchus marmoratus and others). Next to testicular structure, existing data showed that type A undifferentiated spermatogonia (Aund) is differentially distributed among the Neotropical species. Aund can be restricted at the blind-end of the germinal compartment (O. bonariensis), or spread along the germinal epithelium (A. altiparanae), or even distributed along the germinal epithelium but concentrated at the blind-end (C. kelberi and C. intermedia). Moreover, recent studies in A. altiparanae have demonstrated that within the germinal compartment, Aund have a preferential distribution in areas neighboring the interstitial compartment - the spermatogonial niche. The proximity with the interstitium suggests that interstitial cells, such as Leydig cells, are important for Aund maintenance in the testis. Finally, this mini-review highlighted Sertoli cell efficiency, showing that a single Sertoli cell can support a higher number of germ cells (80-140 spermatids) in Neotropical species evaluated at the moment (e.g. A. altiparanae, Hoplias malabaricus, Poecilia reticulata, Serrasalmus spilopleura, C. intermedia). Overall, this review provided basic and functional information on spermatogenesis of Neotropical species. More studies in this field are necessary since Neotropical region is considered one of the hotspot regions to discovery new species providing, therefore, new opportunities to investigate spermatogenesis in fish.
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Affiliation(s)
- Diógenes Henrique de Siqueira-Silva
- Group of Studies on the Reproduction of Amazon fish (GERPA/LANEC), PPG in Biodiversity and Biotechnology (BIONORTE), University of South and Southern of Pará (Unifesspa), Marabá, Pará, Brazil.
| | - Maira da Silva Rodrigues
- Reproductive and Molecular Biology Group, Department of Morphology, Institute of Biosciences, São Paulo State University (UNESP) - Botucatu Campus, Botucatu, Brazil; Aquaculture Center of São Paulo State University (CAUNESP), São Paulo State University (UNESP) - Jaboticabal Campus, Jaboticabal, Brazil
| | - Rafael Henrique Nóbrega
- Reproductive and Molecular Biology Group, Department of Morphology, Institute of Biosciences, São Paulo State University (UNESP) - Botucatu Campus, Botucatu, Brazil.
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Action of the Metalloproteinases in Gonadal Remodeling during Sex Reversal in the Sequential Hermaphroditism of the Teleostei Fish Synbranchus marmoratus (Synbranchiformes: Synbranchidae). Cells 2018; 7:cells7050034. [PMID: 29695033 PMCID: PMC5981258 DOI: 10.3390/cells7050034] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/14/2018] [Accepted: 04/19/2018] [Indexed: 12/26/2022] Open
Abstract
Teleostei present great plasticity regarding sex change. During sex reversal, the whole gonad including the germinal epithelium undergoes significant changes, remodeling, and neoformation. However, there is no information on the changes that occur within the interstitial compartment. Considering the lack of information, especially on the role played by metalloproteinases (MMPs) in fish gonadal remodeling, the aim of this study was to evaluate the action of MMPs on gonads of sex reversed females of Synbranchus marmoratus, a fresh water protogynic diandric fish. Gonads were processed for light microscopy and blood samples were used for the determination of plasma sex steroid levels. During sex reversal, degeneration of the ovaries occurred and were gradually replaced by the germinal tissue of the male. The action of the MMPs induces significant changes in the interstitial compartment, allowing the reorganization of germinal epithelium. Leydig cells also showed an important role in female to male reversion. The gonadal transition coincides with changes in circulating sex steroid levels throughout sex reversion. The action of the MMPs, in the gonadal remodeling, especially on the basement membrane, is essential for the establishment of a new functional germinal epithelium.
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Nóbrega RH, de Jesus LWO, Honji RM, Borella MI. Characterization of gonadotropic cells during continuous and seasonal spermatogenesis of two freshwater fish species: a histochemical and immunohistochemical study. FISH PHYSIOLOGY AND BIOCHEMISTRY 2017; 43:51-63. [PMID: 27492246 DOI: 10.1007/s10695-016-0267-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Accepted: 08/01/2016] [Indexed: 06/06/2023]
Abstract
This work describes gonadotropic (GtH) cells and their morphological and immunohistochemical changes during the spermatogenic cycle of Serrasalmus maculatus (continuous spermatogenesis) and Pimelodus maculatus (seasonal spermatogenesis). GtH cells, widely distributed in the proximal pars distalis of the adenohypophysis, were characterized as round-shaped cells with eccentric nucleus, and cytoplasm with basophilic secretory granules and a variable number of vacuoles for both species. Immunohistochemistry against β-follicle-stimulating hormone (Fsh) and β-luteinizing hormone (Lh) in adjacent sections showed two separated GtH-producing cell populations, and a third population where both GtHs are expressed in the same cell for both species. In the seasonal spermatogenesis of P. maculatus, GtH cells seemed to be more abundant during developing and spawning capable phases. In contrast, no cyclic changes were detected in the continuous spermatogenesis of S. maculatus, except for the strong immunoreaction for Fsh and Lh in males with intense spermiogenesis. We conclude that changes reported here might reflect the type of spermatogenic cycle (seasonal or continuous) which are under different regulatory mechanisms (environmental and internal cues) controlling the reproduction in these species.
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Affiliation(s)
- Rafael Henrique Nóbrega
- Department of Morphology, Institute of Biosciences, São Paulo State University, UNESP, Botucatu, Brazil
| | - Lázaro Wender Oliveira de Jesus
- Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, USP, São Paulo, Brazil
| | - Renato Massaaki Honji
- Department of Physiology, Institute of Biosciences, University of São Paulo, USP, São Paulo, Brazil
| | - Maria Inês Borella
- Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, USP, São Paulo, Brazil.
- Departamento de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Professor Lineu Prestes 1524, São Paulo, SP, 05508-000, Brazil.
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Faccioli CK, Chedid RA, Mori RH, Amaral ACD, Franceschini-Vicentini IB, Vicentini CA. Acid and alkaline phosphatase localization in the digestive tract mucosa of the Hemisorubim platyrhynchos. Acta Histochem 2016; 118:722-728. [PMID: 27510428 DOI: 10.1016/j.acthis.2016.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 07/14/2016] [Accepted: 08/03/2016] [Indexed: 10/21/2022]
Abstract
This cytochemical study investigated the acid and alkaline phosphatase of the digestive tract of Hemisorubim platyrhynchos. Acid phosphatase was detected in the lining epithelium throughout the digestive tract, whereas alkaline phosphatase was only observed in the intestine. In the esophagus, an acid phosphatase reaction occurred in the apical cytoplasm of the epithelial cells and was related to epithelial protection and freeing of superficial cells for sloughing. Similar results were also observed in epithelial cells of gastric epithelium. In the gastric glands, acid phosphatase occurred in lysosomes of the oxynticopeptic cells acting in the macromolecule degradation for use as an energy source, whereas in the vesiculotubular system, its presence could be related to secretion processes. Furthermore, acid phosphatase in the intestine occurred in microvilli and lysosomes of the enterocytes and was correlated to absorption and intracellular digestion. However, no difference was reported among the regions of the intestine. However, alkaline phosphatase reaction revealed a large number of reaction dots in the anterior intestine, with the number decreasing toward the posterior intestine. This enzyme has been related to several functions, highlighting its role in the nutrient absorption primarily in the anterior intestine but also being essential in pH regulation because this is a carnivorous species with many gastric glands with secretions that could damage the intestine.
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Meneguelli De Souza LC, Retamal CA, Rocha GM, Lopez ML. Morphological evidence for a permeability barrier in the testis and spermatic duct of Gymnotus carapo (Teleostei: Gymnotidae). Mol Reprod Dev 2015; 82:663-78. [PMID: 26073744 DOI: 10.1002/mrd.22503] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 05/07/2015] [Indexed: 11/10/2022]
Abstract
Cell-cell interactions play essential roles in the regulation of gametogenesis. The involvement of junctional complexes in permeability barriers, for example, provides structural and physiological support for male germ-cell development. This study describes morphological characteristics of the reproductive system of Gymnotus carapo, a neo-tropical freshwater fish widely distributed in South and Central America, focusing on the detection of permeability barriers using morphological and biochemical approaches. Ultrastructural analysis of testes treated with the lanthanum nitrate exclusion technique showed that the tracer penetrated the interstitial compartment of the testis, surrounding and appearing within cysts containing spermatogonia and spermatocytes in early stages of meiosis, but was not detected in the spermatid cysts or inside the lumen of spermatogenic tubules. These results suggest the presence of a permeability barrier that is stabilized after meiosis is completed and serves to protect the haploid cells from the vascular system. In the spermatic-duct region, the tracer was obstructed near the lumen of the duct. Junctional complexes and focal tight junctions between adjacent cells were observed in the testis and spermatic duct. Freeze-fracture methods indeed confirmed the presence of tight junctions, which were visualized as parallel rows of individual particles between adjacent cells. More evidence supporting the existence of a permeability barrier was gathered from differences observed in the electrophoretic protein profiles of testis and spermatic-duct fluids compared to blood plasma. Together, these observations demonstrate the existence of a permeability barrier formed by tight junctions in the testis and spermatic duct of G. carapo.
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Affiliation(s)
- Lara C Meneguelli De Souza
- Setor Biologia da Reprodução, Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, Brazil
| | | | - Gustavo M Rocha
- Instituto Nacional de Metrologia, Padronização e Qualidade Industrial, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Maria Luisa Lopez
- Setor Biologia da Reprodução, Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, Brazil
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Siqueira-Silva DHD, Vicentini CA, Ninhaus-Silveira A, Veríssimo-Silveira R. Reproductive cycle of the Neotropical cichlid yellow peacock bass Cichla kelberi: A novel pattern of testicular development. NEOTROPICAL ICHTHYOLOGY 2013. [DOI: 10.1590/s1679-62252013000300012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study describes the testicular maturation phases (associating the germ cells development and the morphological changes suffered by the germinal epithelium along the whole year), and the testicular morphology in the yellow peacock bass Cichla kelberi, relating it to other species. For this purpose, 78 specimens were studied according conventional techniques of light microscope. The testes in C. kelberi were classified as unrestricted spermatogonial lobular, an apomorphic characteristic in the recent groups of Teleost. Furthermore, were defined five testicular maturation phases: Preparatory phase; Early Germinal Epithelium Development; Mid Germinal Epithelium Development; Late Germinal Epithelium Development and; Regression. Similar classifications were described to other species indicating that the testicular classifications based on this propose, can be applied to lots of fishes. However, besides it similarity, the testicular reproductive cycle of C. kelberifollows a different pattern in the Regression phase, on which the gonadal restructuration and the spermatogonial proliferation gathers at the same time. So, the testes in C. kelberi never return to the Preparatory phase to start a new reproductive cycle, being this one present only at the first reproductive cycle in this species. This fact also explains the absence of individuals totally spent after their first reproductive cycle.
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Kang HW, Chung EY, Chung JS, Lee KY. Ultrastructural studies of spermatogenesis and the functions of Leydig cells and Sertoli cells associated with spermatogenesis inLarimichthys polyactis(Teleostei, Perciformes, Sciaenidae). Anim Cells Syst (Seoul) 2013. [DOI: 10.1080/19768354.2013.829783] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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Ahmed YA, Samei NAA, Zayed AZ. Morphological and histomorphological structure of testes of the catfish "Clarias gariepinus" from Egypt. Pak J Biol Sci 2013; 16:624-9. [PMID: 24505985 DOI: 10.3923/pjbs.2013.624.629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Knowledge of the normal reproductive biology of catfish is of a great importance not only for better understanding of the theory of fish development, but also to be used as a baseline for understanding the pathological changes results form exposure to harmful toxicants. Thus, the aim of the current study was to elucidate the gross anatomical and light microscopic features of the testes of the catfish "Clarias gariepinus" from Egypt. The present study was carried out on 36 mature male catfish (Clarias gariepinus) collected monthly during the spawning period (April-September) throughout the Nile River, crossing Sohag city in Egypt, in the year 2011. Samples were processed for light and electron microscopy. Each testis consisted of two regions, a fringed outer lateral region and a smooth sagittal-medial region. Histological examination revealed that the testis was covered with a highly vascular connective tissue capsule sending septa dividing the testis into seminiferous lobules separated by interstitial connective tissue containing steroid secreting Leydig cells. Seminiferous lobules were made up of spermatogenic cells and Sertoli cells; the spermatogenic cells located within cysts formed by the cytoplasmic projections of the Sertoli cells. According to the maturation stages, the seminiferous lobules were classified into three types. Spermatogenic seminiferous lobules were lined with different spermatogenic cells but had few or no spermatozoa. Pubertal seminiferous lobules were packed with spermatozoa with few spermatogenic cells. Spent seminiferous lobules contained remnants of spermatozoa and spermatogenic cells. In conclusion, the testis of catfish Clarias gariepinus from Egypt was similar in structure to other catfish and teleost species.
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Affiliation(s)
- Yasser A Ahmed
- Faculty of Veterinary Medicine, South Valley University, Egypt
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Pfennig F, Kurth T, Meißner S, Standke A, Hoppe M, Zieschang F, Reitmayer C, Göbel A, Kretzschmar G, Gutzeit HO. The social status of the male Nile tilapia (Oreochromis niloticus) influences testis structure and gene expression. Reproduction 2012; 143:71-84. [DOI: 10.1530/rep-11-0292] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Dominant and territorial behaviour are known social phenomena in cichlids and social stress influences reproduction and growth. The gonadotropic hormones trigger spermatogenesis and subordinate males have typically lower levels of gonadotropins than dominant males. In this study, we compared testis morphology and gene expression of dominant and subordinate Nile tilapia males (d- and s-males) in socially stable communities. The d-males had the highest gonadosomatic index but they were not the largest animals in the majority of studied cases. Long-term d-males showed large groups of Leydig cells and hyperplasia of the tunica albuginea due to numerous cytochrome-P450-11β-hydroxylase (Cyp11b) expressing myoid cells. Increased Cyp11b expression in d-males was reflected by elevated 11-ketotestosterone plasma values. However, immunofluorescence microscopy and expression analysis of selected genes revealed that most s-males conserved their capability for spermatogenesis and are, therefore, ready for reproduction when the social environment changes. Moreover, in s-males gene expression analysis by quantitative RT-PCR showed increased transcript levels for germ line-specific genes (vasa,sox2anddmc1) and Sertoli-specific genes (amh,amhrIIanddmrt1) whereas gene expression of key factors for steroid production (sf1andcyp11b) were reduced. The Nile tilapia is a promising model to study social cues and gonadotropic signals on testis development in vertebrates.
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Franco A, Kellner K, Goux D, Mathieu M, Heude Berthelin C. Intragonadal Somatic Cells (ISCs) in the male oyster Crassostrea gigas: Morphology and contribution in germinal epithelium structure. Micron 2011; 42:718-25. [DOI: 10.1016/j.micron.2011.04.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 04/11/2011] [Accepted: 04/12/2011] [Indexed: 01/06/2023]
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13
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Martins YS, De Moura DF, Santos GB, Rizzo E, Bazzoli N. Comparative folliculogenesis and spermatogenesis of four teleost fish from a Reservoir in south-eastern Brazil. ACTA ZOOL-STOCKHOLM 2010. [DOI: 10.1111/j.1463-6395.2009.00437.x] [Citation(s) in RCA: 13] [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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14
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Nóbrega RH, Batlouni SR, França LR. An overview of functional and stereological evaluation of spermatogenesis and germ cell transplantation in fish. FISH PHYSIOLOGY AND BIOCHEMISTRY 2009; 35:197-206. [PMID: 18716890 DOI: 10.1007/s10695-008-9252-z] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2008] [Accepted: 07/22/2008] [Indexed: 05/26/2023]
Abstract
Although there are almost thirty-thousand species of fish living in a great variety of habitats and utilizing vast reproductive strategies, our knowledge of morphofunctional and quantitative aspects of testis structure and spermatogenesis is still incipient for this group of vertebrates. In this review, we discuss aspects that are important to better understanding of testis structure and function, and of the development of germ cells (GC) during spermatogenesis. To achieve this, we have recently completed a number of studies presenting morphometric and functional data related to the numbers of GC and Sertoli cells (SC) per each type of spermatogenic cyst, the number of spermatogonial generations, the SC efficiency, and the magnitude of GC loss that normally occurs during spermatogenesis. We also investigated SC proliferation and the relationship of this important event to early spermatogenic cysts. The available data strongly suggest that SC proliferation in sexually mature tilapia is the primary factor responsible for the increase in testis size and for determination of the magnitude of sperm production. The influence of temperature on the duration of spermatogenesis in tilapia was also evaluated and we have used this knowledge to deplete endogenous spermatogenesis in this teleost, in order to develop an experimental system for GC transplantation. This exciting technique results in new possibilities for investigation of spermatogenesis and spermatogonial stem cell biology, creating also an entirely new and promising scenario in biotechnology-transgenic animal production and the preservation of the genetic stocks of valuable animals or endangered species.
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Affiliation(s)
- R H Nóbrega
- Department of Morphology, Laboratory of Cellular Biology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
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