Acta histochem. Bd. 60, S. 247-252 (1977)
Departamento de Bio-Morfologia do Instituto de Ciencias do. Saude do. Universidade Federal do. Bahia, Bahia (Brasil)
The Rete ovarii and follicle formation in marmosets ( Callithrix jacchu8 and Callithrix penicillata)l) By
MARIA
LUCIA
COSTA GUEDES
and
TULIO MIRAGLIA
With 7 figures (Received April 18, 1977)
Summary The Rete ovarii in young marmosets shows a strong reactivity for a certain number of enzymes (LDH; NADH2 -TR; NADPH 2 -TR; G-6-PDH; 6-PGDH; (X-GPDH; ,B-OHBDH and nonspecific esterase). The granulosa cells of the cortical innermost placed follicles have the same enzymatic reactivity. The germinal epithelium results negative to the mentioned group of enzymes at this phase of the development. The Rete ovarii must play an important role in the granulosa cells differentiation.
Introduction Although the origin of the ovarian follicular cells from the surface epithelium of the gonad (germinal epithelium) has obtained the most elder general consensus, GROPP and OHNO (1966) concluded that this epithelium is not envolved in the differentiation of the sex cords in cattle. Indeed, these authors using the alkaline phosphatase activity as a label noted that the follicular cells (alkaline phosphatase positives) take place in situ within a central blastema which is also alkaline phosphatase positive and not from the germinal epithelium that results negative to that enzyme. On the other hand PETERS and PEDERSEN (1967) injecting tritiated thymidine into newborn mice and preparing autoradiographs 1 h, 3 and 7 days after the injection, observed that at the day of the mice birth the oocytes are not accompanied by follicle cells while labeled stroma cells can be seen 1 h after the injection. Only in the 7-dayold mice PETERS and PEDERSEN (1967) saw follicles with 2 to 3 rows of labeled follicle cells surrounding some of the oocytes. Thus, they concluded that the follicle cells originate from the stroma cells that were still present in the newborn mouse ovary. v. KOELLIKER (1898) reported a continuity between the Rete ovarii cells and the follicular cells in dog ovary. BYSKOV and RASMUSSEN (1973) referred to those resemblance between the ultrastructure of Rete ovarii cells and that of the follicular cells. In another paper BYSKOV and LINTERN-MoORE (1973) studying the development of the Rete ovarii in the mouse concluded that it can be divided into 3 portions: 1) Supported by Conselho Nacional de Desenvolvimento Cientifico e Tecnol6gico.
248
M. L. COSTA GUEDES and T. MIRAGLIA
1. the extraovarian rete coming from the mesonephric duct and lying in the periovarian tissue; 2. the intraovarian rete found within the ovary and 3. the connecting rete that joins the extraovarian to the intraovarian rete. Moreover BYSKOV and LINTERN·MoORE (1973) noted that at birth the oocytes are found within the intraovarian cords of the Rete ovarii. At the first week of life it occurs the isolation of follicles through the movement of both the stromal fibroblasts and the basement membrane into the rete cords. At the 7th day the centre of the ovary contains the growing follicles. However, the main mitotic activity is not found within these follicles but in the extraovarian rete cells. According to BYSKOV and LINTERN -MoORE (1973) a possible explanation for that fact is that cells arising in the extraovarian rete move into the ovary promoting the follicle formation primare ly around the centrally located oocytes. BYSKOV (1974) studied experimentally the development of the cranial part of mice ovaries with the adhe~ent extraovarian rete tubules and the development of the caudal part of the same gonadal tissue without extraovarian r et e tubules. From that study BYSKOV (1974) concluded that the Rete ovarii is not only essential for the transformation of the oogonia to oocytes but also responsible for the further differentiation of the ovarian follicles (granulosa cells).
As studying some histochemical aspects of young marmosets we observed the persistence of several strands of Rete ovarii in the inner part of their ovaries. These cellular cords showed continuity with the granulosa cells and the same enzymatic reactivity. For that reason we decided to present our results with the aim of to give another contribution to the concept that ascribes to the Rete ovarii an important roll for the development of the ovarian follicles .
Material and methods The ovaries of 3 young marmo sets (2 Callithrix jacchu8 and 1 Callithrix penicillata) weighing b et ween 125 and 132 g were quickly frozen in liquid nitrogen (-196 °C).and cut in a cryostat (- 20°C) at 8 [tm. Some of these sections were stained with hematoxylin and eosin (H. E.) whereas other ones were investigated for the following enzymes: 1. lactate dehydrogenase (LDH) a ccord ing to N ACHLAS et 801. (1958); 2. N ADH2 -tetrazoliumreductase (NADH2 - TR) andNADPH 2 -tetrazolium reductase (NADPH 2 TR) according to SCARPELLI et al. (1958); 3. glucose-6-phosphate dehydrogenase (G-6-PDH) and 6-phosphogluconate dehydrogenase (6-PGDH) according to WEGMANN and GERZELI (1961); 4. nonspecific esterase searched by the technique of DAVIS (1959); 5. (X-glycerophosphate d ehydrogenase «(X-GPDH) and p-hydroxybutyrate dehydrogenase (1'1OHBDH) according to WEGMANN et 801. (1964).
Results The prepuberal marmoset ovaries are enveloped by cuboidal epithelial cells with basophilic cytoplasm containing round nuclei of dense chromatin (fig. 1). The oocyte;; are distributed throughout the cortical zone as voluminous cells with a cytoplasm of moderate basophilia and a round nucleus frequently disposed in an excentric position. The peripheral oocytes result smaller and more concentrated than the innermost placed ones. Only the last oocytes are surrounded by 2 or more rows of follicular cells (fig. 1). The ovary medulla contains a certain number of cellular cords (intraovarian rete) that run almost parallel in the central part of the organ but are interwined near the cortical portion (fig. 2, il). Some of the cellular cords are in continuity with the
The Rete ovm'ii and follicle formation in marmosets
249
Fig. 1. Prepuberal ovary of C. jacchus. Note the continuity between the medullary cords of the Rete ovarii and the granulosa cells of the larger follicles (H. E.). X 120.
Fig. 2-3. The cells of the Rete ovarii and granulosa of the innermost placed follicles are NADPH 2 TR positives. The cytoplasm of the oocytes is also reactive while the germinal epithelium is negative. X 42. (3) Detail of the precedent figure. X 120. 17
Acta histochem. Bd. 60
250
M.
L.
COSTA GUEDES
and T.
MLHAGLIA
Fig. 4. Note the NADH2-TR reactivity of the medullary cords, granulosa cells and cytoplasm of the oocytes. The germinal epithelium results negative. X 120.
·Fig. 5. The medullary cords and the granulosa cells of the innermost placed follicles show a 6· PGDH reactivity. X 42.
The Rete ovar'ii and follicle formation in marmosets
251
Fig. 6-7. The granulosa cells of the larger follicles show a nonspecific esterase reactivity while the cytoplasm of the oocytes is negative (6). The Rete ovarii cells also result nonspecific esterase reactives (7). X 120.
granulosa cells of the deeper follicles and react to the following enzymes: LDH; (XGPDH; /1-0HBDH; NADPH 2-TR (fig. 2 and 3); NADH2-TR (fig. 4); G-6-PDH; 6-PGDH (fig. 5) and non- specific esterase (fig. 6, 7). This reactivity is stronger in some medullary cords and follicular cells than in other ones. The cells of the germinal epithelium resulted negatives to the same group of enzymes (fig. 2, 4, 6). The cytoplasm of the oocytes although reactive to diaphorase (fig. 2,4) and NAD and NADP dependent enzymes is negative to the nonspecific esterase (fig. 6, 7).
Discussion Our results agree with those of BYSKOV (1974) showing that the Rete ovarii contribute for the differentiation of the granulosa cells of the ovarian follicles. According to ARCHIBALD et al. (1971) the Rete ovarii in heifers produce a holocrine type of secretion composed of mucoproteins, glycoproteins or very weak proteins. This secretion is restricted to dioestrous phase of the oestrus cycle and thus indicative of some endocrine influence. Although SHEHATA (1964, 1974) believes that the Rete ovarii cell~ must be considered not as simple embryological vestiges but as possessing an endocrine function, our results, at the present phase of this research, permited us only conclude that these cells have an enzymatic reactivity that must be important for the ovarian follicles development. 17*
252
M. L. COSTA GUEDES and T. MIRAGLIA, The Rete ovarii and follicle formation in marmosets
Literature ARCHIBALD, L. F., SCHULTZ, R. H., FAHNING, M. L., KURTZ, H. J., and ZEMJ"ANIS, R., Rete ovarii in heifers: a preliminary study. J. Reprod. Fert. 26, 413-414 (1971). BYSKOV, A. G. S., Does the rete ovarii act as a trigger for the onset of the meiosis? Nature (Lon· don) 252, 396-397 (1974). and LINTERN.MoORE, S., Follicle formation in the immature mouse ovary: the role of the Rete ovarii. J. Anat. 116, 207-217 (1973). and RASMUSSEN, G., Ultrastructural studies of the developing follicle. In the development and maturation of the ovary and its function." Excerpta Medica Internat. Congress Series 267,55-62 (1973). DAVIS, B. J., Histochemical demonstration of erythrocyte esterase. Proc. Soc. expo BioI. Med. 101, 90-93 (1959). GROPP, A., and' OHNO, S., The presence of a common embryonic blastema for ovarian and testi· cular parenchymal (follicular, interstitial and tubular) cells in cattle, B08 taurU8. Z. Zellforsch. 74, 505 - 528 (1966). KOELLIKER, A. VON, Uber die Markkanale und Markstrange in den Eierstiicken junger Hiindinnen. Verh. Anat. Ges. 12, 151 (1898). NACHLAS, M. M., WALKER, D. G., and SELIGMAN, A. M., A histochemical method for the demonstration of diphosphopyridine nucleotide diaphorase. J. Biophys. Biochem. Cytol. 4, 29 to 38 (1958). PETERS, H., and PEDERSEN, T., Origin of follicle cells in the infant mouse ovary. Fert. Steril. 18, 309-313 (1967). SCARPELLI, D. G., HESS, R., and PEARSE, A. G. E., The cytochemical localization of oxidative enzymes. 1. Diphosphopyridine nucleotide diaphorase and triphosphopyridine nucleotide dia· phorase. J. Byophys. Biochem. Cytol. 4, 747-760 (1958). SHEHATA, R., Medullary tubes in the ovary of the camel and other mammals. Vet. Rec. 76, 750 to 753 (1964). - Mesonephric remnants in the female genital system of the domestic cat. Acta anat. 87, 301 to 310 (1974). WEG)iANN, R., CORCOS, V., ALBANO, 0., et JULIEN, C., Histoenzymologie tumorale et gastrique d'une maladie de Zollinger. Ellison. Sem. Hop. 40, 1737 -1747 (1964). et GERZELI, G., La glucose·6.phosphate deshydrogenase et ses correlations avec des substrats voisins du glucose·6·phosphate. Role de l'hexokinase. Ann. Histochim. 6, 111-124 (1961). Address: Dr. MARIA L. COSTA GUEDES and Prof. Dr. TULlO MIRAGLIA, Departamento de BioMorfologia, Instituto de Ciencias da Saude Universidade Federal da Bahia, Bahia, Brasil.
Departamento de Bio-Morfologia do Instituto de Ciencias do. Saude do. Universidade Federal do. Bahia, Bahia (Brasil)
The Rete ovarii and follicle formation in marmosets ( Callithrix jacchu8 and Callithrix penicillata)l) By
MARIA
LUCIA
COSTA GUEDES
and
TULIO MIRAGLIA
With 7 figures (Received April 18, 1977)
Summary The Rete ovarii in young marmosets shows a strong reactivity for a certain number of enzymes (LDH; NADH2 -TR; NADPH 2 -TR; G-6-PDH; 6-PGDH; (X-GPDH; ,B-OHBDH and nonspecific esterase). The granulosa cells of the cortical innermost placed follicles have the same enzymatic reactivity. The germinal epithelium results negative to the mentioned group of enzymes at this phase of the development. The Rete ovarii must play an important role in the granulosa cells differentiation.
Introduction Although the origin of the ovarian follicular cells from the surface epithelium of the gonad (germinal epithelium) has obtained the most elder general consensus, GROPP and OHNO (1966) concluded that this epithelium is not envolved in the differentiation of the sex cords in cattle. Indeed, these authors using the alkaline phosphatase activity as a label noted that the follicular cells (alkaline phosphatase positives) take place in situ within a central blastema which is also alkaline phosphatase positive and not from the germinal epithelium that results negative to that enzyme. On the other hand PETERS and PEDERSEN (1967) injecting tritiated thymidine into newborn mice and preparing autoradiographs 1 h, 3 and 7 days after the injection, observed that at the day of the mice birth the oocytes are not accompanied by follicle cells while labeled stroma cells can be seen 1 h after the injection. Only in the 7-dayold mice PETERS and PEDERSEN (1967) saw follicles with 2 to 3 rows of labeled follicle cells surrounding some of the oocytes. Thus, they concluded that the follicle cells originate from the stroma cells that were still present in the newborn mouse ovary. v. KOELLIKER (1898) reported a continuity between the Rete ovarii cells and the follicular cells in dog ovary. BYSKOV and RASMUSSEN (1973) referred to those resemblance between the ultrastructure of Rete ovarii cells and that of the follicular cells. In another paper BYSKOV and LINTERN-MoORE (1973) studying the development of the Rete ovarii in the mouse concluded that it can be divided into 3 portions: 1) Supported by Conselho Nacional de Desenvolvimento Cientifico e Tecnol6gico.
248
M. L. COSTA GUEDES and T. MIRAGLIA
1. the extraovarian rete coming from the mesonephric duct and lying in the periovarian tissue; 2. the intraovarian rete found within the ovary and 3. the connecting rete that joins the extraovarian to the intraovarian rete. Moreover BYSKOV and LINTERN·MoORE (1973) noted that at birth the oocytes are found within the intraovarian cords of the Rete ovarii. At the first week of life it occurs the isolation of follicles through the movement of both the stromal fibroblasts and the basement membrane into the rete cords. At the 7th day the centre of the ovary contains the growing follicles. However, the main mitotic activity is not found within these follicles but in the extraovarian rete cells. According to BYSKOV and LINTERN -MoORE (1973) a possible explanation for that fact is that cells arising in the extraovarian rete move into the ovary promoting the follicle formation primare ly around the centrally located oocytes. BYSKOV (1974) studied experimentally the development of the cranial part of mice ovaries with the adhe~ent extraovarian rete tubules and the development of the caudal part of the same gonadal tissue without extraovarian r et e tubules. From that study BYSKOV (1974) concluded that the Rete ovarii is not only essential for the transformation of the oogonia to oocytes but also responsible for the further differentiation of the ovarian follicles (granulosa cells).
As studying some histochemical aspects of young marmosets we observed the persistence of several strands of Rete ovarii in the inner part of their ovaries. These cellular cords showed continuity with the granulosa cells and the same enzymatic reactivity. For that reason we decided to present our results with the aim of to give another contribution to the concept that ascribes to the Rete ovarii an important roll for the development of the ovarian follicles .
Material and methods The ovaries of 3 young marmo sets (2 Callithrix jacchu8 and 1 Callithrix penicillata) weighing b et ween 125 and 132 g were quickly frozen in liquid nitrogen (-196 °C).and cut in a cryostat (- 20°C) at 8 [tm. Some of these sections were stained with hematoxylin and eosin (H. E.) whereas other ones were investigated for the following enzymes: 1. lactate dehydrogenase (LDH) a ccord ing to N ACHLAS et 801. (1958); 2. N ADH2 -tetrazoliumreductase (NADH2 - TR) andNADPH 2 -tetrazolium reductase (NADPH 2 TR) according to SCARPELLI et al. (1958); 3. glucose-6-phosphate dehydrogenase (G-6-PDH) and 6-phosphogluconate dehydrogenase (6-PGDH) according to WEGMANN and GERZELI (1961); 4. nonspecific esterase searched by the technique of DAVIS (1959); 5. (X-glycerophosphate d ehydrogenase «(X-GPDH) and p-hydroxybutyrate dehydrogenase (1'1OHBDH) according to WEGMANN et 801. (1964).
Results The prepuberal marmoset ovaries are enveloped by cuboidal epithelial cells with basophilic cytoplasm containing round nuclei of dense chromatin (fig. 1). The oocyte;; are distributed throughout the cortical zone as voluminous cells with a cytoplasm of moderate basophilia and a round nucleus frequently disposed in an excentric position. The peripheral oocytes result smaller and more concentrated than the innermost placed ones. Only the last oocytes are surrounded by 2 or more rows of follicular cells (fig. 1). The ovary medulla contains a certain number of cellular cords (intraovarian rete) that run almost parallel in the central part of the organ but are interwined near the cortical portion (fig. 2, il). Some of the cellular cords are in continuity with the
The Rete ovm'ii and follicle formation in marmosets
249
Fig. 1. Prepuberal ovary of C. jacchus. Note the continuity between the medullary cords of the Rete ovarii and the granulosa cells of the larger follicles (H. E.). X 120.
Fig. 2-3. The cells of the Rete ovarii and granulosa of the innermost placed follicles are NADPH 2 TR positives. The cytoplasm of the oocytes is also reactive while the germinal epithelium is negative. X 42. (3) Detail of the precedent figure. X 120. 17
Acta histochem. Bd. 60
250
M.
L.
COSTA GUEDES
and T.
MLHAGLIA
Fig. 4. Note the NADH2-TR reactivity of the medullary cords, granulosa cells and cytoplasm of the oocytes. The germinal epithelium results negative. X 120.
·Fig. 5. The medullary cords and the granulosa cells of the innermost placed follicles show a 6· PGDH reactivity. X 42.
The Rete ovar'ii and follicle formation in marmosets
251
Fig. 6-7. The granulosa cells of the larger follicles show a nonspecific esterase reactivity while the cytoplasm of the oocytes is negative (6). The Rete ovarii cells also result nonspecific esterase reactives (7). X 120.
granulosa cells of the deeper follicles and react to the following enzymes: LDH; (XGPDH; /1-0HBDH; NADPH 2-TR (fig. 2 and 3); NADH2-TR (fig. 4); G-6-PDH; 6-PGDH (fig. 5) and non- specific esterase (fig. 6, 7). This reactivity is stronger in some medullary cords and follicular cells than in other ones. The cells of the germinal epithelium resulted negatives to the same group of enzymes (fig. 2, 4, 6). The cytoplasm of the oocytes although reactive to diaphorase (fig. 2,4) and NAD and NADP dependent enzymes is negative to the nonspecific esterase (fig. 6, 7).
Discussion Our results agree with those of BYSKOV (1974) showing that the Rete ovarii contribute for the differentiation of the granulosa cells of the ovarian follicles. According to ARCHIBALD et al. (1971) the Rete ovarii in heifers produce a holocrine type of secretion composed of mucoproteins, glycoproteins or very weak proteins. This secretion is restricted to dioestrous phase of the oestrus cycle and thus indicative of some endocrine influence. Although SHEHATA (1964, 1974) believes that the Rete ovarii cell~ must be considered not as simple embryological vestiges but as possessing an endocrine function, our results, at the present phase of this research, permited us only conclude that these cells have an enzymatic reactivity that must be important for the ovarian follicles development. 17*
252
M. L. COSTA GUEDES and T. MIRAGLIA, The Rete ovarii and follicle formation in marmosets
Literature ARCHIBALD, L. F., SCHULTZ, R. H., FAHNING, M. L., KURTZ, H. J., and ZEMJ"ANIS, R., Rete ovarii in heifers: a preliminary study. J. Reprod. Fert. 26, 413-414 (1971). BYSKOV, A. G. S., Does the rete ovarii act as a trigger for the onset of the meiosis? Nature (Lon· don) 252, 396-397 (1974). and LINTERN.MoORE, S., Follicle formation in the immature mouse ovary: the role of the Rete ovarii. J. Anat. 116, 207-217 (1973). and RASMUSSEN, G., Ultrastructural studies of the developing follicle. In the development and maturation of the ovary and its function." Excerpta Medica Internat. Congress Series 267,55-62 (1973). DAVIS, B. J., Histochemical demonstration of erythrocyte esterase. Proc. Soc. expo BioI. Med. 101, 90-93 (1959). GROPP, A., and' OHNO, S., The presence of a common embryonic blastema for ovarian and testi· cular parenchymal (follicular, interstitial and tubular) cells in cattle, B08 taurU8. Z. Zellforsch. 74, 505 - 528 (1966). KOELLIKER, A. VON, Uber die Markkanale und Markstrange in den Eierstiicken junger Hiindinnen. Verh. Anat. Ges. 12, 151 (1898). NACHLAS, M. M., WALKER, D. G., and SELIGMAN, A. M., A histochemical method for the demonstration of diphosphopyridine nucleotide diaphorase. J. Biophys. Biochem. Cytol. 4, 29 to 38 (1958). PETERS, H., and PEDERSEN, T., Origin of follicle cells in the infant mouse ovary. Fert. Steril. 18, 309-313 (1967). SCARPELLI, D. G., HESS, R., and PEARSE, A. G. E., The cytochemical localization of oxidative enzymes. 1. Diphosphopyridine nucleotide diaphorase and triphosphopyridine nucleotide dia· phorase. J. Byophys. Biochem. Cytol. 4, 747-760 (1958). SHEHATA, R., Medullary tubes in the ovary of the camel and other mammals. Vet. Rec. 76, 750 to 753 (1964). - Mesonephric remnants in the female genital system of the domestic cat. Acta anat. 87, 301 to 310 (1974). WEG)iANN, R., CORCOS, V., ALBANO, 0., et JULIEN, C., Histoenzymologie tumorale et gastrique d'une maladie de Zollinger. Ellison. Sem. Hop. 40, 1737 -1747 (1964). et GERZELI, G., La glucose·6.phosphate deshydrogenase et ses correlations avec des substrats voisins du glucose·6·phosphate. Role de l'hexokinase. Ann. Histochim. 6, 111-124 (1961). Address: Dr. MARIA L. COSTA GUEDES and Prof. Dr. TULlO MIRAGLIA, Departamento de BioMorfologia, Instituto de Ciencias da Saude Universidade Federal da Bahia, Bahia, Brasil.
