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.     

A new chromosome number forBombina (Anura,Discoglossidae)

Summary The karyotype of a primitive discoglossid anuran,Bombina maxima, native to southwestern China, has 2n=28 chromosomes with 6 large and 8 small bi-armed homologous pairs. This is a higher chromosome number than described for otherBombina species, all of which have 2n=24.     

Karyotype and chromosome banding in the Turkish desert woodlouseDesertellio elongatus (Crustacea,Isopoda, Oniscidea)

The karyotype ofD. elongatus was investigated by means of C-banding, silver staining, and mithramycin-and quinacrine fluorescent staining. The diploid chromosome number is 2n=50. C-banding shows pericentromerically localized constitutive heterochromatin in every chromosome. Two of the chromosome pairs carry two telomeric nucleolus organizer regions each. No heteromorphic sex chromosomes were found.     

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.     

Seasonal variations in the fertilizing capacity ofBufo arenarum (Amphibia Anura) spermatozoa

Resumen La capacidad fecundante de los espermatozoides deBufo arenarum decae más rápidamente en verano que en invierno. Ello probablemente sea debido a la presencia, durante el invierno, de factores testiculares de protección.

---

---

This work was supported by a grant from the Consejo Nacional de Investigaciones Cientificas y Técnicas de la República Argentina and by the Population Council grant No. 71.68 awarded to the Consejo Nacional de Investigaciones Cientificas y Técnicas to be administered by the Instituto de Biología, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán.

---

The author is most grateful to Dr.F. D. Barbieri for his kind discussion and helpful advice in the course of the present study.     

New chromosome numbers in Australian Leptodactylidae (Amphibia,Salientia)

Summary Fra i Leptodactylidi Australiani,Cyclorana alboguttatus ha 2n=26 come le forme più generalizzate della famiglia, mentre alcune specie diLimnodynastes hanno 2n=22; specie di altri 5 generi hanno 2n=24. Fra questi ultimi, il problematicoRheobatrachus, completamente acquatico, possiede alcuni microcromosomi come i membri più primitivi dell'ordine.     

Presence of intrachromatidic bands in mitotic chromosomes ofTriturus marmoratus (Amphibia: Caudata)

Summary The C-banding technique has revealed the existence of single and double intrachromatidic bands in mitotic chromosomes ofTriturus marmoratus. The presence of the bands is discussed on the basis of the helical coil model versus the radial loop model, which assumes a different packing of the DNA fiber.We are very indebted to Prof. C. García de la Vega for his indispensable help, to Prof. Dr J. Martín for his comments and to M. Herrero for his support.     

The chromosome banding patterns of the aardvarkOrycteropus afer (Tubulidentata,Orycteropidae)

Summary C- and G-banding patterns ofOrycteropus afer are described on the basis of fibroblast cultures obtained from a female individual.This work was supported in part by a research grant DEB 76-10580 from the National Science Foundation.     

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.     

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.     

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 karyotype,C-bands and AgNO3-bands of a lungless salamander from Korea:Onychodactylus fischeri (Boulenger) (Amphibia,Urodela)

The karyotype of a lungless salamander,Onychodactylus fischeri, from Korea was analyzed and compared with that of the Japanese congeneric species,O. japonicus. In both species the diploid karyotype consists of78 chromosomes, including 6 pairs of large chromosomes, 6 pairs of medium-sized ones, and the remaining 27 pairs of microchromosomes. The chromosome number ofO. fischeri, 2n=78, is, like that ofO. japonicus, the largest so far reported in the order Urodela. C-banding showed that constitutive heterochromatin inO. fischeri was mainly in the centromeric regions and near the secondary constrictions of the large chromosomes. AgNO₃-bands were located in the secondary constrictions associated with C-band heterochromatin.     

Effect of bromocriptine on the "prolactin-like cell" of Nectophrynoides occidentalis (Amphibia, viviparous Anura): optical and electronic microscopical studies]

Bromocriptin has an effect on prolactin-like cells of Nectophryno?des occidentalis. 16 days after delivery, these cells are fully active in normal animals. Retention of secretory granules and myelinic formations have been observed in the prolactin-like cells of females treated by CB 154.     

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

Summary Using³H-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.     

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.     

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.     

Invariability of the H-Y antigen expression in the heterogametic sex of some amphbians and evidence for sexual dimophrism of the antigen expression in Pelodytes punctatus D (Amphibia, Anura)]

The H-Y antigen is studied in some Amphibians whose sexual genetic constitution is known. Thus, in Pelurodeles waltlii, Ambystoma mexicanum, Xenopus laevis and Rana ridibunda, the invariability of the H-Y antigen expression in the heterogametic, sex is confirmed. In Pelodytes punctatus the genetic sex is unknown but the existence of the H-Y antigen in phenotypic males leads to the conclusion of a male heterogamety of the XY type.