Karyotype and chromosome banding in the reed frogHyperolius viridiflavus ommatostictus (Amphibia,Anura, Hyperoliidae)

Summary C-banding and mithramycin staining were used to characterize the karyotypes of 10 specimens of the African reed frogHyperolius viridiflavus ommatostictus from Tanzania. The diploid chromosome number is 2n=24. Although no heteromorphic sex chromosomes were present in the mitotic karyotypes, in many diakineses of male meiosis one or two bivalents exhibited an end-to-end arrangement. In the laboratory 7 out of 24 females changed sex spontaneously. This indicates that an XY/XX system of sex determination operates inH. viridiflavus ommatostictus.This study was supported by the Deutsche Forschungsgemeinschaft (Schm 484/2-4). We thank K. E. Linsenmair and C. M. Richards for helpful comments on an earlier draft.     

Somatic chromosomes of Indian burrowing toad,Uperodon globulosum (Gunther) (Anura; Amphibia)

Summary Somatic chromosome complements of the Indian burrowing toad,Uperodon globulosum, have been described for the first time. The 2n number is 26 (NF=52) in both the sexes. No heteromorphism in relation to sex chromosome pair has been recorded. Deviations from 2n number (2n=10–28) have been noticed in the cells of different specimens. The result has been compared withU. systoma.Acknowledgment. Sincere thanks are due to Prof. P. K. Ghosh, Hooghly Mohsin College and to Dr A. K. Roy of the same college for encouragement. Thanks are due to Mr Bipul Kumar Das for his help during collection of specimen.     

Variation in the specific activity of intestinal DNA in Alytes obstetricians larvae (Amphibia, Anura) treated with thyroxine]

Treatment by thyroxine modified the specific activity of intestianl DNA in premetamorphic Alytes tadpoles. The activity decreased up to the 3rd day, and showed afterwards a peak which culminates on the 9th day. These results have been discussed in comparison with previous radioautographic observations.     

Immunofluorencence localization of secretions related to gonadotropic, corticotropic, melanotropic and somatotropic hormones in hypophysis of Nectophrynoides occidentalis]

In Nectophryno?des occidentalis, ovine anti-LH anti beta (1-24) corticotropin, both anti alpha and anti beta MSH and bovine anti-STH antisera allowed us to identify by immunofluorescence gonadotropic, corticotropic, melanotropic and somatotropic hypophysial cells of a viviparous toad. The identification of these different cell types was confirmed by applying a classical cytologic technique to the same sections.     

Karyotype and chromosome banding in the reed frog Hyperolius viridiflavus ommatostictus (Amphibia, Anura, Hyperoliidae)

C-banding and mithramycin staining were used to characterize the karyotypes of 10 specimens of the African reed frog Hyperolius viridiflavus ommatostictus from Tanzania. The diploid chromosome number is 2n = 24. Although no heteromorphic sex chromosomes were present in the mitotic karyotypes, in many diakineses of male meiosis one or two bivalents exhibited an end-to-end arrangement. In the laboratory 7 out of 24 females changed sex spontaneously. This indicates that an XY/XX system of sex determination operates in H. viridiflavus ommatostictus.     

Consequence of heterospecific cytoplasmic graft on gastrulation of Bufo bufo L. (Amphibia, Anura)]

Bufo bufo nuclei were grafted in virgin and enucleated Bufo calamita eggs. In these conditions embryonnic development was stopped at the early gastrula stage in 92% of the recipient eggs. For accomparative analysis Bufo calamita cytoplasm was injected into fertilized Bufo bufo eggs and produce arrest of development at the early gastrula stage. The progressive enhancement of this development inhibition was related to the increasing of the injected cytoplasm volume.     

The fate of intramitochondrial paracrystalline inclusion bodies in germ line cells of water frogs (Amphibia, Anura)

Numerous intramitochondrial paracrystalline inclusion bodies (ICIB) were observed in the germinal plasm of a mid-blastula, and in primordial germ cells (PGCs) after their migration to the germinal ridges, in Rana ridibunda, R. lessonae and R. esculenta. In oogonia the number of ICIB decreases rapidly. Single ICIB are observed in the germ cells up to the leptotene stage; they have never been observed in pachytene oocytes. In diplotene oocytes that have reached a diameter of about 100 microns ICIB are visible again, and their number increases concomitantly with oocyte growth.     

The fate of intramitochondrial paracrystalline inclusion bodies in germ line cells of water frogs (Amphibia,Anura)

Summary Numerous intramitochondrial pararystalline inclusion bodies (ICIB) were observed in the germinal plasm of a mid-blastula, and in primordial germ cells (PGCs) after their migration to the germinal ridges, inRana ridibunda, R. lessonae andR. esculenta. In oogonia the number of ICIB decreases rapidly. Single ICIB are observed in the germ cells up to the leptotene stage; they have never been observed in pachytene oocytes. In diplotene oocytes that have reached a diameter of about 100 m ICIB are visible again, and their number increases concomitantly with oocyte growth.     

Effect of diet on the mitotic activity and rate of cytolysis of intestinal epithelial cells in tadpoles of the common toad, Bufo bufo (Amphibia, Anura)]

Effects of diet on the mitotic activity and cellular mortality rate of the intestinal epithelium cells have been examined in Toad tadpoles. As yolk is utilized, the composition of diet has little effect on these 2 parameters. As development goes on, the cellular mortality rate increases with dietary carbohydrate, fat or protein supplementation. But only the fats affect the mitotic activity.     

Epitheliophagy: intrauterine cell nourishment in the viviparous alpine salamander, Salamandra atra (Laur.)

The intrauterine nourishment of the viviparous alpine salamander, Salamandra atra, has been demonstrated to consist of two phases: oophagy - after hatching from the jelly membrane, the developing embryo ingests the remaining disintegrated, unfertilized egg mass. Epitheliophagy - a special cranial portion of the uterus wall, the zona trophica, is stimulated by the presence of the embryo. After the yolk mass has been exhausted, the developing embryo is supplied with epithelial cells as nourishment until the end of pregnancy. The epithelial cells of the zona trophica are released into the uterus lumen by partial necrosis of the underlying connective tissue. Regeneration and detachment of the uterine epithelium occur simultaneously in different regions of the zona trophica. A special dentition enables the embryo, according to its position in the uterus, to feed directly on the zona trophica.     

Induction of the mesoderm and primordial germ cells by the endoderm of Pleurodeles waltlii (Amphibia, Urodele): development during gastrulation]

Blastulae ectoderm is combined with dorsal or ventral endoderm from blastulae, gastrulae and early neurulae. In vitro culture reveals the presence of different mesodermal structures whose nature is connected with the endoderm origin site. Primordial germ cells differentiate essentially in the recombinates including ventral endoderm. The inducing capacity of this latter concerning germ cells is maximum at the beginning of gastrulation, then decreases during it and finally disappears at the onset of neurulation.     

Cytotaxonomy of the Seychelles tree frog,Megalixalus seychellensis (Duméril and Bibron) (Amphibia: Hyperoliidae)

Summary The Seychelles tree frog,Megalixalus seychellensis has 2n=24 chromosomes of gradually decreasing length. Pairs 2, 3, and 4 are submetacentric, and the remaining pairs are metacentric. The karyotype affirms hyperoliid assignment of this species, and indicates a link between the Seychellean fauna and the African-Madagascan faunas.Research supported by the National Geographic Society.     

Effect of concanavalin A on the development of blastulae in Pleurodeles waltlii (Amphibia, Urodeles)]

The effect of concanavalin A (con A) on Pleurodeles waltlii blastulae was studied by incubating the eggs in presence of lectin. It was found that the protein exercised an inhibitory effect upon morphogenesis. This inhibition was concentration dependent. In certain cases, the inhibitory effect of con A was attenuated by alpha-D-methyl-mannose (0,05 M).     

Na-pump sites in the oviduct of Salamandra salamandra (L.) (Amphibia, Urodela)

Using 3H-ouabain autoradiography, Na+-K+-ATPase has been localized on the basolateral membranes of ciliated and nonciliated cells in the oviduct (pars recta, p. convoluta I, II, III) of the European fire salamander, Salamandra salamandra. The mucous and seromucous gland cells of the p. convoluta I, II, III, however, do not show any significant labelling. An asymmetrical distribution of ouabain binding sites is a main feature of transporting epithelia.