Penetration of melanocytes from embryonic Japanese quail peritoneum into associated embryonic avian gonads,grown on chicken chorioallantoic membrane

Summary After association on chorioallantoic membrane (CAM) of an embryonic bird testis with pigmented peritoneum from a Japanese quail embryo, numerous melanocytes penetrate in its interstitial tissue. If, instead of a testis, an ovary is transplanted under similar conditions, then the melanocytes may be found in the medulla or between the secondary sex cords at the rim of the ovary.The author is very grateful to Prof.L. Vakaet, R. U. C. A. Antwerp, for his valuable suggestions, and to MissC. Vaniioecke for her technical assistance.     

3H-Thymidine incorporation (DNA synthesis) and radiotoxicity in the ovary of the Japanese quail before and during follicle formation

Summary No evidence was found for ribosomal DNA amplification in the oocytes of the Japanese quail, before or during folliculogenesis. DNA synthesis in the somatic cells, involved in follicle formation, starts at the medullar side of the basement membrane. The localized sterilization of the quail ovary after administration of³H-thymidine (³H-TdR) seems to be due to radiation-induced lesions in the follicle forming somatic cells, rather than to direct radiation damage of the oocyte.The author is very grateful to Prof. Dr L. Vakaet, R.U.C.A.—Antwerpen, for his valuable suggestions and to Mrs D. De Wolf-Van Rompaey for her excellent technical assistance.     

Invasive properties of the ovarian cortex in birds

Summary In quail/chicken ovarian cortex associations, grown on chicken chorioallantoic membrane (CAM), epithelial and/or germ cells from the quail ovary may invade the cortical rim of the chicken ovary. In certain experimental conditions, ovarian cortical cells may leave a transplanted ovary and grow over or invade the mesenchyme of the surrounding CAM. So a germinal epithelium completely free from other ovarian cell groups can be obtained.The author is very grateful to Prof. Dr L. Vakaet, R.U.C.A., Antwerp, for his valuable suggestions and to Mrs S. De Wolf-Van Rompaey, for her excellent technical assistance.     

3H-thymidine incorporation (DNA synthesis) and radiotoxicity in the ovary of the Japanese quail before and during follicle formation

No evidence was found for ribosomal DNA amplification in the oocytes of the Japanese quail, before or during folliculogenesis. DNA synthesis in the somatic cells, involved in follicle formation, starts at the medullar side of the basement membrane. The localized sterilization of the quail ovary after administration of 3H-thymidine (3H-TdR) seems to be due to radiation-induced lesions in the follicle forming somatic cells, rather than to direct radiation damage of the oocyte.     

Bakterien im Ovar aquariengehälterter Meeresfische

Summary In the ovary of the ovoviviparous teleostZoarces viviparus L. kept in aquaria, gram-negative bacteria are found. These penetrate the tissue up to the basement membrane which separates the follicle epithelium from the theca.

---

---

Der Deutschen Forschungsgemeinschaft danke ich für die Förderung der Arbeiten, Herrn Prof. Dr.,P. Giesbrecht, Berlin, für Beratung.     

Ovulation and the role of the ovarian surface epithelium.

Epon sections from all tissue layers of the rabbit ovary, including the often neglected surface or germinal epithelium, were studied to elucidate the mechanism of follicle rupture. Scanning electron microscopy showed cells covering preovulatory follicles increased clearly in size up to 8 hours after human chorionic gonadotropin (HCG) injection. These showed an increasing number of large, intracellular structures with prominent rounded contours. Transmission electron microscopy showed large, electron dense, lysosomelike bodies in some cells 4 hours after HCG. These membrane-surrounded structures increased in size up to 8 hours after HCG, then decreased markedly. These obviously corresponded to the bodies found by light microscopy and scanning electron microscopy. Histochemistry revealed many represent lysosomes. During the last 2 hours before rupture, the dense bodies of the surface epithelium considerably decrease, signs of material emptying into vacuoles is found, and sometimes there is open communication from vacuoles towards the unerlying tunica albuginea. An extracellular edema appeared under the epithelium with degenerated fibroblasts and disintegrated collagen; these changes gradually proceeded inwards. Blood capillaries close to the membrana granulosa gradually showed small pores and close to ovulation the endothelial cells had gaps up to 3 mcm in diameter. The preovulatory follicles grew rapidly and an augmenting edema occupied the whole ovary. In the last hours before ovulation the membrana granulosa gradually dissociated. Whatever the net effect of the prostaglandins, prostaglandin F2alpha appears to be essential for follicle rupture since intrafollicular injections of antiserum blocked ovulation. Prostaglandin E1 promotes vascular permeability and lysosommal enzymes released extracellularly may be coupled to collagen degration. The enzyme synthesis and lysosomal growth in the surface epithelium of preovulatory follicles may be due to the high local concentration of sex steroids.     

Kälte als Auslöser einer Glykogen-Speicherung während der Oogenese vonMusca domestica

Summary InMusca domestica reared under standard conditions (21 °C), glycogen is stored in the oocyte towards the end of egg development. By 1–3 days exposure to lower temperatures (4 °C), a glycogen deposition can be released already in young follicles. This premature glycogen synthesis is not restricted to the ooplasm. Carbohydrates are also found in the nurse cells and the follicle epithelium. Similar results were formerly obtained by inhibition of oogenetic protein synthesis.

---

---

Herrn Prof. Dr. Dr. h.c.Bernhard Rensch zum 70. Geburtstag gewidmet.     

La synthèse de l'ADN prémitotique et préméiotique dans les cellules germinales de l'embryon femelle de la caille japonaise (Coturnix coturnix japonica)

Summary The premeiotic DNA synthesis of the female Japanese quail embryo begins after 9 days incubation. The germ cells in premeiotic S phase present a particular structure different from the structure found in germ cells during premitotic S phase. They are the precursors of the meiocytes in leptotene stage.

---

---

L'auteur remercie vivement le ProfesseurL. Vakaet (R.U.C.A., Anvers) pour ses suggestions très valables.     

Einbau von H3-d-glucose während der Oogenese beiApis mellifica L.

Summary The incorporation of tritiated glucose into the ovary of honey bee queens was studied by autoradiography. During the last stages of oogenesis, the synthesis of respectable amounts of glycogen was found in the reticuloplasm of the developing eggs. The follicle epithelium and also the nurse cells only appeared more lightly and transitory labelled at medium stages. An hypothesis was established concerning an antagonism of protein and polysaccharide formation in the cytoplasm corresponding to the rather late occurrence of glycogen in insect oogenesis.     

La population germinale des gonades chez des embryons chimères obtenus par l'association de fragments de blastodermes de Caille japonaise et de Poulet domestique

Summary The experimental realization of chimerical embryos (Martin's ¹³ technic) permits a quantitative appreciation of the modalities of the colonization of quail gonads by chick germ cells. Results clearly show that nature and origin of the somatic part of the gonad areas settle the characters of the genital ridges populating, and specially the specific index of asymmetry expressed by the percentage of PGC colonizing the right gonad.     

How gill surface ofSaccobranchus fossilis facilitates active gas exchange?

Summary The surface morphology of fish gill has been studied by scanning electron microscopy. The surface of gill epithelium shows a pseudoconcentric arrangement of arborizing ridges and channels. Further, at places on gill filaments the surface shows several infoldings labelled as micropits. The role of these morphological adaptations has been correlated with the gas exchange physiology.The author is deeply indebted to Prof.M. Nishiura, Dr.S. Izumi and Mr.O. Fuse for their kind suggestions and help, and to Prof.H. B. Tewari for encouragement. VKR would like to thank Japan Leprosy Mission for excellent facilities.     

Immunocytochemical demonstration of contractile cells in the human ovarian follicle

Actin- and myosin-like immunoreactivity is found in cells located in the theca externa of the follicle wall of the human ovary, and corresponding to previously observed myoid cells. The immunocytochemical observation provides direct structural evidence that non-vascular contractile cells are also present in the follicle wall in humans. As expected, perifollicular blood vessels showed a positive immunoreaction for actin and myosin in their smooth muscle walls.     

Development and use of shell-less quail chorio-allantoic-membrane cultures to study developing skeletal tissues; a qualitative study

Summary A technique is described for in vitro culture of the quail embryo from the 1st to the 18th day of development. The embryos are cultured in Teflon hammocks, suspended in glass supports and kept in a humidified atmosphere at 36.5°C. The quail CAM is used as support and cell source for developing non-quail cartilage and bone. The quail cells can be identified histologically and easily recognized by Feulgen-staining which is demonstrated in the presence of quail chondro- or osteoclasts in a mouse long bone rudiment cultured on the CAM.     

Localization of wheat germ agglutinin receptor sites on yeast cells by scanning electron microscopy

Summary WGA receptor sites on the surface ofSaccharomyces cerevisiae cells pretreated with an - mannanase were localized by gold granules labelled with WGA. The receptor sites were found on the bud scars, the mother cell-bud junction (chitin) and the bud, but not on the mother cell.Acknowledgment. We thank Prof.C. E. Ballou for supplying theArthrobacter strain GJM-1 and MrsM. Weber for the photographic work.     

Immunocytochemical demonstration of contractile cells in the human ovarian follicle

Summary Actin-and myosin-like immunoreactivity is found in cells located in the theca externa of the follicle wall of the human ovary, and corresponding to previously observed myoid cells. The immunocytochemical observation provides direct structural evidence that non-vascular contractile cells are also present in the follicle wall in humans. As expected, perifollicular blood vessels showed a positive immunoreaction for actin and myosin in their smooth muscle walls.This work was supported by the Swedish Medical Research Council, grant No. 14X-732/5680.     

Development and use of shell-less quail chorio-allantoic-membrane cultures to study developing skeletal tissues; a qualitative study

A technique is described for in vitro culture of the quail embryo from the 1st to the 18th day of development. The embryos are cultured in Teflon hammocks, suspended in glass supports and kept in a humidified atmosphere at 36.5 degrees C. The quail CAM is used as support and cell source for developing non-quail cartilage and bone. The quail cells can be identified histologically and easily recognized by Feulgen-staining which is demonstrated in the presence of quail chondro- or osteoclasts in a mouse long bone rudiment cultured on the CAM.     

On fragmentation and elimination of ovarian oocytes

Summary Examination of numerous fragmented oocytes in the ovary revealed an asynchronous relationship between nuclear and cell divisions. The asynchrony was observed in non-fragmented oocytes as well and was considered to be one of the common processes leading towards oocyte elimination in the ovary. The present study additionally demonstrates the morphology of follicle cell degeneration observed on the surface of fragmented oocytes.The authors are very grateful to Mr T. Horii, Dr K. Takeda, Dr S. Morisawa, Mr K. Takahashi, Mr Y. Matsumoto and Mrs M. Shinohara for their laboratory help.     

Zur Frage des Angriffspunktes des Thiouracil

Summary The mechanism of action of thiouracil and thiourea was investigated on Xenopus tadpoles. Both substances are able to stop metamorphotic changes if administered early enough. Characteristic disturbances occur in the epithelium of the thyroid follicles after only 24 hours. The action of these substances over a period of several weeks may lead to goitre. In the pituitary anterior lobe, on the other hand, the same characteristic changes take place in the basophilic cells as after thyroidectomy. The thyroid structure of hypophysectomised tadpoles corresponds to that of untreated hypophysectomised animals. Thiourea and thiouracil do not inhibit the thyroxine effect on thyroidectomised and hypophysectomised tadpoles. These findings indicate that the point of attack of thiouracil and thiourea lies in the follicular epithelium of the thyroid, and thus supportAstwood's hypothesis.     

Attempt to alter antigenic structure of normal tissues by treatment with dimethyl-triazeno-imidazole-carboxamide in vivo

Summary The antigenic structure of normal skin and spleen cells has been investigated following in vivo treatment with the compound DIC. In experiments involving skin grafting in the normal and sensitized host, cross sensitization with a DIC-antigenic lymphoma and³H-thymidine incorporation by lymphocytes cultured with DIC-treated spleen cells, new antigens on DIC-treated tissues were not demonstrated.Research supported in part by Contract No. 74.00237.04 from C.N.R., Rome.We wish to thank Mr.C. R. Reeder of the Mammalian Genetics and Animal Production Section of NCI, NIH, Bethesda, Maryland, USA, for breeding and providing the animals, and Serpero Foundation, Milan, for support. The proficient technical assistance of Ms.C. Cattoi andD. Peroni is also acknowledged.     

Stérilisation de l'ovaire gauche du Poulet et de la Caille par l'action de la thymidine-3H pendant l'ovogenèse

Summary After successive in ovo³H-thymidine pulses during the period of oogenesis complete sterilization of the left ovary of the female chicken and quail have been obtained at the moment of hatching.