BMC Developmental Biology

official impact factor 2.78

Open Access Highly Access Research article

Control over the morphology and segregation of Zebrafish germ cell granules during embryonic development

Markus J Strasser1, Natalia C Mackenzie1, Karin Dumstrei1, La-Iad Nakkrasae1,2, Jürg Stebler1 and Erez Raz1,3*

Author Affiliations

1 Germ Cell Development, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany

2 Department of Biology, Faculty of Science, Mahidol University, Bangkok, Thailand

3 Institute of Cell Biology, ZMBE, University of Münster, Von-Esmarch-Straße 56, 48149 Münster, Germany

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BMC Developmental Biology 2008, 8:58 doi:10.1186/1471-213X-8-58

Published: 28 May 2008

Abstract

Background

Zebrafish germ cells contain granular-like structures, organized around the cell nucleus. These structures share common features with polar granules in Drosophila, germinal granules in Xenopus and chromatoid bodies in mice germ cells, such as the localization of the zebrafish Vasa, Piwi and Nanos proteins, among others. Little is known about the structure of these granules as well as their segregation in mitosis during early germ-cell development.

Results

Using transgenic fish expressing a fluorescently labeled novel component of Zebrafish germ cell granules termed Granulito, we followed the morphology and distribution of the granules. We show that whereas these granules initially exhibit a wide size variation, by the end of the first day of development they become a homogeneous population of medium size granules. We investigated this resizing event and demonstrated the role of microtubules and the minus-end microtubule dependent motor protein Dynein in the process. Last, we show that the function of the germ cell granule resident protein the Tudor domain containing protein-7 (Tdrd7) is required for determination of granule morphology and number.

Conclusion

Our results suggest that Zebrafish germ cell granules undergo a transformation process, which involves germ cell specific proteins as well as the microtubular network.