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Structural and ultrastructural characteristics of the yolk syncytial layer in Prochilodus lineatus (Valenciennes, 1836) (Teleostei; Prochilodontidae)

Published online by Cambridge University Press:  01 August 2007

A. Ninhaus-Silveira*
Affiliation:
Universidade Estadual Paulista (UNESP) – Depto. de Biologia e Zootecnia–Ilha Solteira–SP.
F. Foresti
Affiliation:
Universidade Estadual Paulista (UNESP) – Depto. de Morfologia–Botucatu–SP.
A. de Azevedo
Affiliation:
Universidade Estadual Paulista (UNESP) – Depto. de Morfologia–Botucatu–SP.
C.A. Agostinho
Affiliation:
Universidade Estadual Paulista (UNESP) – Depto. de Produção e Exploração Animal–Botucatu–SP.
R. Veríssimo-Silveira
Affiliation:
Universidade Estadual Paulista (UNESP) – Depto. de Morfologia–Botucatu–SP.
*
All correspondence to: A. Ninhaus-Silveira, Departamento de Biologia e Zootecnia - Universidade Estadual Paulista/Ilha Solteira, Av. Brasil, 56 – Centro Postal Box 31, CEP: 15385–000 Ilha Solteira, São Paulo, Brasil. Tel: +55 02118 37431285. Fax: +55 02118 37431186. e-mail: ninhaus@bio.feis.unesp.br

Summary

The yolk syncytial layer (YSL) has been regarded as one of the main obstacles for a successful cryopreservation of fish embryos. The purpose of this study was to identify and characterize the YSL in Prochilodus lineatus, a fish species found in southeastern Brazil and considered a very important fishery resource. Embryos were obtained through artificial breeding by hormonal induction. After fertilization, the eggs were incubated in vertical incubators with a controlled temperature (28 °C). Embryos were collected in several periods of development up to hatching and then fixed with 2% glutaraldehyde and 4% paraformaldehyde in 0.1 M sodium phosphate buffer (pH 7.3). Morphological analyses were carried out under either light, transmission or scanning electron microscopy. The formation of the YSL in P. lineatus embryos starts at the end of the cleavage stage (morula), mainly at the margin of the blastoderm, and develops along the embryo finally covering the entire yolk mass (late gastrula) and producing a distinct intermediate zone between the yolk and the endodermal cells. The YSL was characterized by the presence of microvilli on the contact region with the yolk endoderm. A cytoplasmic mass, full of mitochondria, vacuoles, ribosomes, endomembrane nets and euchromatic nuclei, indicated a high metabolic activity. This layer is shown as an interface between the yolk and the embryo cells that, besides sustaining and separating the yolk, acts as a structure that makes it available for the embryo. The structural analyses identified no possible barriers to cryoprotectant penetration.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2007

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References

Betchaku, T. & Trinkaus, J.P. (1986). Programmed endocytosis during epiboly in Fundulus heteroclitus. Am. Zool. 26, 193–9.CrossRefGoogle Scholar
Corrêa e Castro, R.M. (1990). Revisão taxonômica da família Prochilodontidae (Ostariophysi: Characiformes). [Thesis]. São Paulo, Instituto de Biociências, Universidade de São Paulo.Google Scholar
Devillers, C. (1961). Structural and dynamics aspects of the development of the teleostean egg. Adv. Morphol. 1, 379428.CrossRefGoogle Scholar
Fowler, H.W. (1954). Os peixes de água doce do Brasil. Arq. Zool. 2, 1400.Google Scholar
Hagedorn, M., Hsu, E.W., Pilatus, U., Wildt, D.E., Rall, W.F. & Blackband, S.J. (1996). Magnetic resonance microscopy and spectroscopy reveal kinetics of cryoprotectant permeation in a multicompartimental biological system. Proc. Natl. Acad. Sci. USA 93, 7454–9.CrossRefGoogle Scholar
Hagedorn, M., Kleinhans, E.W., Wildt, D.E. & Rall, W.E. (1997). Chill sensitivity and cryoprotectant permeability of dechorionated zebrafish embryos, Brachydanio rerio. Cryobiology 34, 251–63.CrossRefGoogle ScholarPubMed
Hagedorn, M., Kleinhans, E.W., Artemov, D. & Pilatus, U. (1998). Characterization of a major permeability barrier in the zebrafish embryo. Biol. Reprod. 59, 1240–50.CrossRefGoogle Scholar
Kimmel, C.B. & Law, R.D. (1985). Cell lineage of zebrafish blastomeres. I. Cleavage pattern and cytoplasmic bridges between cells. Dev. Biol. 108, 7885.CrossRefGoogle ScholarPubMed
Kimmel, C.B., Ballard, W.W., Kimmel, S.R. & Ullmann, B. (1995). Stages of embryonic development of zebrafish. Dev. Dyn. 203, 253–10.CrossRefGoogle Scholar
Lentz, T.L. & Trinkaus, J.P. (1967). A fine structural study of cytodifferentiation during cleavage, blastula and gastrula stages of Fundulus heteroclitus. J. Cell. Biol. 32, 121–38.CrossRefGoogle ScholarPubMed
Rawson, D.M., Zhang, T., Kalicharan, D. & Jongebloed, W. L. (2000). Field emission scanning electron microscopy and transmission electron microscopy studies of the chorion, plasma membrane and syncytial layers of the gastrula stage embryo of the zebra fish. Brachydanio rerio: a consideration of the aspect structural and functional relationships with respect to cryoprotectant penetration. Aquac. Res. 31, 325–36.CrossRefGoogle Scholar
Reynolds, E.S. (1963). The use of lead citrate at light pH an electron-opaque stain for electron microscopy. J. Cell. Biol. 17, 208–15.CrossRefGoogle Scholar
Trinkaus, J.P. (1951). A study of mechanism of epiboly in the egg of Fundulus heteroclitus. J. Exp. Zool. 118, 269320.CrossRefGoogle Scholar
Trinkaus, J.P. (1984 a). Cells into Organs: the Forces that Shape the Embryo, 2nd edn, Prentice-Hall, Englewood Cliffs, NJ.Google Scholar
Trinkaus, J.P. (1984 b). Mechanism of Fundulus epiboly – a current review. Am. Zool. 24, 673–88.CrossRefGoogle Scholar
Trinkaus, J.P. (1993). The yolk syncytial layer of Fundulus heteroclitus: origin and history and its significance for early embryogenesis. J. Exp. Zool. 265, 258–84.CrossRefGoogle Scholar
Walzer, C. & Schönenberger, N. (1979). Ultrastructure and cytochemistry study of the yolk syncytial layer in the alevin of trout (Salmo fario trutta1.) after hatching. Cell Tissue Res. 196, 5973.Google ScholarPubMed
Watson, M.L. (1958). Staining of tissue sections for electron microscopy with heavy metals. J. Biophys. Biochem. Cytol. 4, 58.CrossRefGoogle ScholarPubMed
Zhang, T.T. & Rawson, D.M. (1996). Permeability of the vilelline membrane of zebrafish (Brachydanio rerio) embryos to methanol and propane-1,2-diol. Cryo. Lett. 17, 273–80.Google Scholar
Zhang, T.T. & Rawson, D.M. (1998). Permeability of the vitelline membrane of 1-cell and 6-somite stage zebrafish (Brachydanio rerio) embryos to water and methanol. Cryobiology 37, 1321.CrossRefGoogle Scholar