Chromatoid body (CB) is a typical cytoplasmic organelle of germ cells, and it seems to be involved in RNA/protein accumulation for later germ-cell differentiation. Despite most of the events in mammals spermatogenesis had been widely described in the past decades and the increase in the studies related to the CB molecular composition and physiology, the origins and functions of this important structure of male germ cells are still unclear. The aims of this study were to describe the nucleolar cycle and also to find some relationship between the nucleolar organization and the CB assembling during the spermatogenesis in mammals. Cytochemical and cytogenetics analysis showed nucleolar fragmentation in post-pachytene spermatocytes and nucleolar reorganization in post-meiotic spermatids. Significant difference in the number and in the size of nucleoli between spermatogonia and round spermatids, as well as differences in the nucleolar position within the nucleus were also observed. Ultrastructural analysis showed the CB assembling in the cytoplasm of primary spermatocytes and the nucleolar fragmentation occurring at the same time. In conclusion our results suggest that the CB may play important roles during the spermatogenesis process in mammals and that its origin may be related to the nucleolar cycle during the meiotic cell cycle. 1. Introduction Spermatogenesis is the biological process of gradual transformation of germ cells into spermatozoon over an extended period of time within the boundaries of the seminiferous tubules of the testis. This process involves cellular proliferation by repeated mitotic divisions, duplication of chromosomes, genetic recombination through crossover, reduction division by meiotic cell division to produce haploid spermatids, and terminal differentiation of the spermatids into spermatozoon [1]. This important biological process has been extensively studied and described, and currently there are appropriate biological terminologies to describe every step of the spermatozoon formation [2]. However, there are some recent important aspects of the spermatogenesis, as, for example, the assembling and the function of the chromatoid body (CB), which is not so clearly understood. The CB is a typical cytoplasmic organelle of haploid germ cells and is involved in RNA and protein accumulation for later germ-cell differentiation [3, 4]. Many studies have been carried out intending to clarify the origins and functions of this intriguing cytoplasmic structure of male germ cells. Recent efforts to elucidate the functions of the CB have been
References
[1]
R. A. Hess, “Spermatogenesis, overview,” in Encyclopedia of Reproduction, vol. 4, Academic Press, New York, NY, USA, 1999.
[2]
Y. Clermont, “Kinetics of spermatogenesis in mammals: seminiferous epithelium cycle and spermatogonial renewal,” Physiological Reviews, vol. 52, no. 1, pp. 198–236, 1972.
[3]
K. O. Soderstrom and M. Parvinen, “Transport of material between the nucleus, the chromatoid body and the Golgi complex in the early spermatids of the rat,” Cell and Tissue Research, vol. 168, no. 3, pp. 335–342, 1976.
[4]
P. T. K. Saunders, M. R. Millar, S. M. Maguire, and R. M. Sharpe, “Stage-specific expression of rat transition protein 2 mRNA and possible localization to the chromatoid body of step 7 spermatids by in situ hybridization using a nonradioactive riboprobe,” Molecular Reproduction and Development, vol. 33, no. 4, pp. 385–391, 1992.
[5]
E. Raz, “The function and regulation of vasa-like genes in germ-cell development,” Genome Biology, vol. 1, no. 3, pp. 1–6, 2000.
[6]
T. Noce, S. Okamoto-Ito, and N. Tsunekawa, “Vasa homolog genes in mammalian germ cell development,” Cell Structure and Function, vol. 26, no. 3, pp. 131–136, 2001.
[7]
N. Kotaja, S. N. Bhattacharyya, L. Jaskiewicz et al., “The chromatoid body of male germ cells: similarity with processing bodies and presence of Dicer and microRNA pathway components,” Proceedings of the National Academy of Sciences of the United States of America, vol. 103, no. 8, pp. 2647–2652, 2006.
[8]
N. Kotaja, H. Lin, M. Parvinen, and P. Sassone-Corsi, “Interplay of PIWI/Argonaute protein MIWI and kinesin KIF17b in chromatoid bodies of male germ cells,” Journal of Cell Science, vol. 119, no. 13, pp. 2819–2825, 2006.
[9]
Y. Costa, R. M. Speed, P. Gautier et al., “Mouse MAELSTROM: the link between meiotic silencing of unsynapsed chromatin and microRNA pathway?” Human Molecular Genetics, vol. 15, no. 15, pp. 2324–2334, 2006.
[10]
M. Parvinen and L. M. Parvinen, “Active movements of the chromatoid body. A possible transport mechanism for haploid gene products,” Journal of Cell Biology, vol. 80, no. 3, pp. 621–628, 1979.
[11]
M. Parvinen, J. Salo, M. Toivonen, O. Nevalainen, E. Soini, and L. J. Pelliniemi, “Computer analysis of living cells: movements of the chromatoid body in early spermatids compared with its ultrastructure in snap-frozen preparations,” Histochemistry and Cell Biology, vol. 108, no. 1, pp. 77–81, 1997.
[12]
D. W. Fawcett, E. M. Eddy, and D. M. Phillips, “Observations on the fine structure and relationships of the chromatoid body in mammalian spermatogenesis,” Biology of Reproduction, vol. 2, no. 1, pp. 129–153, 1970.
[13]
A. Reunov, V. Isaeva, D. Au, and R. Wu, “Nuage constituents arising from mitochondria: is it possible?” Development Growth and Differentiation, vol. 42, no. 2, pp. 139–143, 2000.
[14]
D. E. Comings and T. A. Okada, “The chromatoid body in mouse spermatogenesis: evidence that it may be formed by the extrusion of nucleolar components,” Journal of Ultrasructure Research, vol. 39, no. 1-2, pp. 15–23, 1972.
[15]
K. Andersen, “Fine structure of spermatogonia and spermatocytes in the blue fox (Alopex lagopus),” Acta Veterinaria Scandinavica, vol. 19, pp. 229–242, 1978.
[16]
M. Andonov, “Further study of the chromatoid body in rat spermatocytes and spermadits,” Zeitschrift fur Mikroskopisch-Anatomische Forschung—Abteilung 2, vol. 104, no. 1, pp. 46–54, 1990.
[17]
R. L. Peruquetti, I. M. Assis, S. R. Taboga, and M. T. V. de Azeredo-Oliveira, “Meiotic nucleolar cycle and chromatoid body formation during the rat (Rattus novergicus) and mouse (Mus musculus) spermiogenesis,” Micron, vol. 39, no. 4, pp. 419–425, 2008.
[18]
R. L. Peruquetti, S. R. Taboga, and M. T. V. de Azeredo-Oliveira, “Characterization of Mongolian gerbil chromatoid bodies and their correlation with nucleolar cycle during spermatogenesis,” Reproduction in Domestic Animals, vol. 45, no. 3, pp. 399–406, 2010.
[19]
D. Hernandez-Verdun, “The nucleolus today,” Journal of Cell Science, vol. 99, no. 3, pp. 465–471, 1991.
[20]
S. A. Gerbi, A. V. Borovjagin, and T. S. Lange, “The nucleolus: a site of ribonucleoprotein maturation,” Current Opinion in Cell Biology, vol. 15, no. 3, pp. 318–325, 2003.
[21]
F. M. Boisvert, S. Van Koningsbruggen, J. Navascués, and A. I. Lamond, “The multifunctional nucleolus,” Nature Reviews Molecular Cell Biology, vol. 8, no. 7, pp. 574–585, 2007.
[22]
V. Sirri, S. Urcuqui-Inchima, P. Roussel, and D. Hernandez-Verdun, “Nucleolus: the fascinating nuclear body,” Histochemistry and Cell Biology, vol. 129, no. 1, pp. 13–31, 2008.
[23]
T. Pederson, “Proteomics of the nucleolus: more proteins, more functions?” Trends in Biochemical Sciences, vol. 27, no. 3, pp. 111–112, 2002.
[24]
W. Shou, J. H. Seol, A. Shevchenko et al., “Exit from mitosis is triggered by Tem1-dependent release of the protein phosphatase Cdc14 from nucleolar RENT complex,” Cell, vol. 97, no. 2, pp. 233–244, 1999.
[25]
A. F. Straight, W. Shou, G. J. Dowd et al., “Net1, a Sir2-associated nucleolar protein required for rDNA silencing and nucleolar integrity,” Cell, vol. 97, no. 2, pp. 245–256, 1999.
[26]
R. Visintin, E. S. Hwang, and A. Amon, “Cfi 1 prevents premature exit from mitosis by anchoring Cdc14 phosphatase in the nucleolus,” Nature, vol. 398, no. 6730, pp. 818–823, 1999.
[27]
S. N. Garcia and L. Pillus, “Net results of nucleolar dynamics,” Cell, vol. 97, no. 7, pp. 825–828, 1999.
[28]
M. Carmo-Fonseca, L. Mendes-Soares, and I. Campos, “To be or not to be in the nucleolus,” Nature Cell Biology, vol. 2, no. 6, pp. E107–E112, 2000.
[29]
L. Montanaro, D. Treré, and M. Derenzini, “Nucleolus, ribosomes, and cancer,” The American Journal of Pathology, vol. 173, pp. 301–310, 2007.
[30]
P. A. San-Segundo and G. Shirleen Roeder, “Pch2 links chromatin silencing to meiotic checkpoint control,” Cell, vol. 97, no. 3, pp. 313–324, 1999.
[31]
M. G. Ribeiro and S. R. Lima, Inicia？？o às Técnicas de Prepara？？o de Material Para Estudo e Pesquisa em Morfologia, SEGRAC Editora e Gráfica Limitada, Belo Horizonte, Brazil, 2000.
[32]
M. L. S. Mello, “Cytochemistry of DNA, RNA and nuclear proteins,” Brazilian Journal of Genetics, vol. 20, no. 2, pp. 257–264, 1997.
[33]
W. M. Howell and D. A. Black, “Controlled silver-staining of nucleolus organizer regions with a protective colloidal developer: a 1-step method,” Experientia, vol. 36, no. 8, pp. 1014–1015, 1980.
[34]
M. L. S. Mello and B. C. Vidal, Práticas de Biologia Celular, FUNCAMP Editora Edgard Blücher LTDA, Campinas, Brazil, 1980.
[35]
R. R. Ha and J. C. Ha, Integrative Statistics for Behavioral Science, Pearson Custom Publishing, Boston, Mass, USA, 2007.
[36]
J. H. Zar, Biostatiscical Analysis, Prentice Hall, New Jersey, NJ, USA, 1999.
[37]
A. D. Kligerman and S. E. Bloom, “Distribuition of F-bodies, heterocromatin and nuclear organizers in the genome of the central mudminnow,” Cytogenetics and Cell Genetics, vol. 18, pp. 182–196, 1977.
[38]
L. A. C. Bertollo and C. A. Mestriner, “The X1X2Y sex chromosome system in the fish Hoplias malabaricus. II. Meiotic analyses,” Chromosome Research, vol. 6, no. 2, pp. 141–147, 1998.
[39]
G. Cotta Pereira, F. Guerra Rodrigo, and J. F. David Ferreira, “The use of tannic acid glutaraldehyde in the study of elastic and elastic related fibers,” Stain Technology, vol. 51, no. 1, pp. 7–11, 1976.
[40]
M. L. Watson, “Staining of tissue sections for electron microscopy with heavy metals. II. Application of solutions containing lead and barium,” The Journal of Biophysical and Biochemical Cytology, vol. 4, no. 6, pp. 727–730, 1958.
[41]
J. H. Venable and R. A. Coggeshall, “A simplified lead citrate stain for use in electron microscopy,” The Journal of Cell Biology, vol. 25, pp. 407–408, 1965.
[42]
C. P. Leblond and Y. Clermont, “Spermiogenesis of rat, mouse, hamster and guinea pig as revealed by the periodic acid-fuchsin sulfurous acid technique,” The American Journal of Anatomy, vol. 90, no. 2, pp. 167–215, 1952.
[43]
R. Korstanjea, P. C. M. O'Brienc, F. Yangc, et al., “Complete homology maps of the rabbit (Oryctolagus cuniculus) and human by reciprocal chromosome painting,” Cytogenetics and Cell Genetics, vol. 86, pp. 317–322, 1999.
[44]
M. Parvinen, “The chromatoid body in spermatogenesis,” International Journal of Andrology, vol. 28, no. 4, pp. 189–201, 2005.
[45]
N. Kotaja and P. Sassone-Corsi, “The chromatoid body: a germ-cell-specific RNA-processing centre,” Nature Reviews Molecular Cell Biology, vol. 8, no. 1, pp. 85–90, 2007.
[46]
J. R. Head and C. K. Kresge, “Reaction of the chromatoid body with a monoclonal antibody to a rat histocompatibility antigen,” Biology of Reproduction, vol. 33, no. 4, pp. 1001–1008, 1985.
[47]
S. Chuma, M. Hosokawa, K. Kitamura et al., “Tdrd1/Mtr-1, a tudor-related gene, is essential for male germ-cell differentiation and nuage/germinal granule formation in mice,” Proceedings of the National Academy of Sciences of the United States of America, vol. 103, no. 43, pp. 15894–15899, 2006.
[48]
C. S. Pikaard, “Transcription and tyranny in the nucleolus: the organization, activation, dominance and repression of ribosomal RNA genes,” in The Arabidopsis Book, C. R. Somerville and E. M. Meyerowits, Eds., American Society of Plant Biologists, Rockville, Md, USA, 2002.
[49]
M. Teruel, J. Cabrero, F. Perfectti, and J. P. M. Camacho, “Nucleolus size variation during meiosis and NOR activity of a B chromosome in the grasshopper Eyprepocnemis plorans,” Chromosome Research, vol. 15, no. 6, pp. 755–765, 2007.
[50]
O. Meikar, M. Da Ros, H. Korhonen, and N. Kotaja, “Chromatoid bodyand small RNAs in male germ cells,” Reproduction, vol. 142, no. 2, pp. 195–209, 2011.
[51]
I. K. Takeuchi and Y. K. Takeuchi, “Ethanol-phosphotungstic acid and bismuth staining of spermatid nucleoli in mouse spermiogenesis,” Journal of Structural Biology, vol. 103, no. 2, pp. 104–112, 1990.
[52]
R. L. Peruquetti, S. R. Taboga, and M. T. V. De Azeredo-Oliveira, “Nucleolar cycle and its correlation with chromatoid bodies in the Tilapia rendalli (Teleostei, Cichlidae) spermatogenesis,” Anatomical Record, vol. 293, no. 5, pp. 900–910, 2010.
[53]
R. L. Peruquetti, S. R. Taboga, L. R. D. S. Santos, C. de Oliveira, and M. T. V. de Azeredo-Oliveira, “Nucleolar cycle and chromatoid body formation: is there a relationship between these two processes during spermatogenesis of Dendropsophus minutus (Amphibia, Anura)?” Micron, vol. 42, no. 1, pp. 87–96, 2011.
[54]
M. Biggiogera, S. H. Kaufmann, J. H. Shaper, N. Gas, F. Amalric, and S. Fakan, “Distribution of nucleolar proteins B23 and nucleolin during mouse spematogenesis,” Chromosoma, vol. 100, no. 3, pp. 162–172, 1991.
[55]
M. Schmid, C. Loser, J. Schmidtke, and W. Engel, “Evolutionary conservation of a common pattern of activity of nucleolus organizers during spermatogenesis in vertebrates,” Chromosoma, vol. 86, no. 2, pp. 149–179, 1982.
[56]
F. Wachtler and A. Stahl, “The nucleolus: a structural and functional interpretation,” Micron, vol. 24, no. 5, pp. 473–505, 1993.
[57]
B. Lefèvre, “The nucleolus of the maternal gamete is essential for life,” BioEssays, vol. 30, pp. 613–616, 2008.
[58]
S. Berríos, R. Fernández-Donoso, J. Pincheira, J. Page, M. Manterola, and M. Cristina Cerda, “Number and nuclear localisation of nucleoli in mammalian spermatocytes,” Genetica, vol. 121, no. 3, pp. 219–228, 2004.
[59]
M. Guo, D. Davis, and J. A. Birchler, “Dosage effects on gene expression in a maize ploidy series,” Genetics, vol. 142, no. 4, pp. 1349–1355, 1996.
[60]
T. Caspersson, Cell Growth and Cell Function, A Cytochemical Study, WW Norton, New York, NY, USA, 1950.
[61]
I. Schubert and G. Kunzel, “Position-dependent NOR activity in barley,” Chromosoma, vol. 99, no. 5, pp. 352–359, 1990.
[62]
K. Nakamoto, A. Ito, K. Watabe et al., “Increased expression of a nucleolar Nop5/Sik family member in metastatic melanoma cells: evidence for its role in nucleolar sizing and function,” American Journal of Pathology, vol. 159, no. 4, pp. 1363–1374, 2001.
[63]
W. Mosgoeller, “Nucleolar ultrastructure in vertebrates,” in The Nucleolus, M. O. J. Olson, Ed., Kluwer, New York, NY, USA, 2004.
[64]
E. ünal, B. Kinde, and A. Amon, “Gametogenesis eliminates age-induced cellular damage and resets life span in yeast,” Science, vol. 332, pp. 1554–1557, 2011.
[65]
R. Paniaguea, M. Nistal, P. Amat, and M. C. Rodriguez, “Ultrastructural observations on nucleoli and related structures during human spermatogenesis,” Anatomy and Embryology, vol. 174, no. 3, pp. 301–306, 1986.
[66]
R. A. Hess, L. A. Miller, J. D. Kirby, E. Margoliash, and E. Goldberg, “Immunoelectron microscopic localization of testicular and somatic cytochromes c in the seminiferous epithelium of the rat,” Biology of Reproduction, vol. 48, no. 6, pp. 1299–1308, 1993.
[67]
C. M. Haraguchi, T. Mabuchi, S. Hirata et al., “Chromatoid bodies: aggresome-like characteristics and degradation sites for organelles of spermiogenic cells,” Journal of Histochemistry and Cytochemistry, vol. 53, no. 4, pp. 455–465, 2005.
[68]
J. T. Soley, “Centriole development and formation of the flagellum during spermiogenesis in the ostrich (Struthio camelus),” Journal of Anatomy, vol. 185, no. 2, pp. 301–313, 1994.
[69]
X. M. Tang, M. F. Lalli, and Y. Clermont, “A cytochemical study of the Golgi apparatus of the spermatid during spermiogenesis in the rat,” American Journal of Anatomy, vol. 163, no. 4, pp. 283–294, 1982.
[70]
H. Walt and B. L. Armbruster, “Actin and RNA are components of the chromatoid bodies in spermatids of the rat,” Cell and Tissue Research, vol. 236, no. 2, pp. 487–490, 1984.
[71]
G. Aumuller and J. Seitz, “Immunocytolchemical localization of actin and tubulin in rat testis and spermatozoa,” Histochemistry, vol. 89, no. 3, pp. 261–267, 1988.
[72]
M. D. Andonov and G. N. Chaldakov, “Morphological evidence for calcium storage in the chromatoid body of rat spermatids,” Experientia, vol. 45, no. 4, pp. 377–378, 1989.
[73]
B. Sud, “Morphological and histochemical studies of the chromatoid body and related elements in the spermatogenesis of rat,” Quarterly Journal of Microscopical Science, vol. 102, pp. 273–292, 1961.
[74]
S. Yokota, “Historical survey on chromatoid body research,” Acta Histochemica et Cytochemica, vol. 41, no. 4, pp. 65–82, 2008.
