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1.
A. Morescalchi 《Cellular and molecular life sciences : CMLS》1967,23(12):1071-1072
Riassunto Il cariotipo diCeratophrys calcarata (Leptodactylidae oCeratophrydae) consta di 26 cromosomi, 12 grandi e 14 più piccoli; il settimo paio mostra zone eterocromatiche. Il genoma diCeratophrys presenta una stretta somiglianza con quello diPelobates cultripes (Pelobatidae); l'A ritiene che questo fatto possa fornire utili indicazioni sulle relazioni tassonomiche deiCeratophrydae.
Research carried out by means of a contribution from the C.N.R. (Genetics Enterprise). 相似文献
Research carried out by means of a contribution from the C.N.R. (Genetics Enterprise). 相似文献
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J. R. Formas 《Cellular and molecular life sciences : CMLS》1978,34(4):446-446
Summary 3 different karyotypes are described in the Chilean frog,Eupsophus roseus, which could be an unnatural assemblage of species. The3 karyological forms are considered as full species.Supported by Proyecto S-77-47, Dirección de Investigación, Universidad Austral de Chile.The technical assistence of Sonia Lacrampe is acknowledged with appreciation. 相似文献
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J. R. Formas 《Cellular and molecular life sciences : CMLS》1980,36(10):1163-1164
Summary The karyotype of the Chilean frogEupsophus calcaratus is described for the first time. The evolutionary karyological trends of this genus are presented.Supported by Proyecto S-79-3, Dirección de Investigación, Universidad Austral de Chile.The technical assistence of Sonia Lacrampe is acknowledged with appreciation. 相似文献
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M. O. Cabada 《Cellular and molecular life sciences : CMLS》1975,31(2):174-175
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. 相似文献
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. 相似文献
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S. Chakrabarti 《Cellular and molecular life sciences : CMLS》1979,35(6):743-744
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. 相似文献
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C. G. de Almeida T. U. Grafe M. Guttenbach M. Schmid 《Cellular and molecular life sciences : CMLS》1990,46(5):509-511
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. 相似文献
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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. 相似文献
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M Ogielska 《Experientia》1990,46(1):98-101
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. 相似文献
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M. Ogielska 《Cellular and molecular life sciences : CMLS》1990,46(1):98-101
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. 相似文献
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M Dau?a J Hourdry 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1978,286(12):973-975
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. 相似文献
13.
M Delarue 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1977,285(4):397-400
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. 相似文献
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M Zuber-Vogeli 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1978,286(19):1379-1381
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. 相似文献
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Resumen Se estudiaron los cariotipos de 23 especies de la familia sudamericana Leptodactylidae (anfibios anuros), no hallándose cromosomas sexuales citológicamente diferenciados. 相似文献
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Summary Electrophoretic investigations of the serum protein patterns of natterjacks (Bufo calamita Laur.) from the Iberian Peninsula and from Western and Central Europe, and of green toads (Bufo viridis Laur.) from Central Europa, Asia Minor and North Africa show that the two species differ disctinctly in the position of their albumin fractions. The identification of problematic specimens can result from the production of mixed serum with specimens of both species. As the albumin fraction of hybrids is doubled according to this method, it is also suitable for demonstrating the existence of such hybrids in natural populations. 相似文献
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A. Morescalchi 《Cellular and molecular life sciences : CMLS》1968,24(1):81-82
Summary The karyotype of the African PipidHymenochirus boettgeri (2n=24, all meta- or submetacentric chromosomes) is different from the one of the African PipidXenopus laevis (2n=36). The karyotype of the American PipidPipa (Protopipa)parva (2n=30, all acrocentric chromosomes) is very primitive and different from the karyotypes of the African Pipids and from that ofPipa pipa; the male meiotic chromosomes ofP. parva, usually with 1 procentric chiasma, show a clear difference from the male bivalents of the other Pipids, all with 2 terminal chiasmata. 相似文献
18.
We investigated the sound communication associated with mating inNezara viridula (L.) to clarify conflicting reports on the medium through which acoustic signals are borne. Recordings made from virgin pairs ofN. viridula during precopulatory and compulatory behaviour have revealed that signals transmitted as vibrations through the substrate are a more likely means of communication than signals transmitted by a radiation of sound pressure waves through the air (at least in Australian populations). We present evidence (additional to that already in the literature) that air-borne acoustics are an unlikely mechanism of sexual communication in this species. Specifically, the recorded pulse train patterns showed no consistency or repeatability in relation to different stages of mating behaviour. In contrast, frequency spectrograms of substrate-borne signals reveal repeatable patterns that do correspond with the stage of mating behaviour. 相似文献
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Resumen Se estudiaron los cariotipos de ocho especies de Bufonidae sudamericanos:B. arenarum, B. ictericus ictericus, B. paracnemis, B. marinus, B. crucifer, B. granulosus d'orbignyi, B. granulosus fernandezae andB. spinulosus. En todas las especies se encontraron 2n = 22 chromosomas. No se encontró en el macho, ningun par heteromórfico, ni bivalente con caracteristicas y comportamiento que indicara la presencia de cromosomas sexuales. 相似文献