Cytogenetic studies of Hynobiidae (Urodela). IX. Karyological characteristics ofHynobius abei Sato by means of R-and C-banding

Summary Chromosomal characteristics of the salamander speciesHynobius abei, from Ohimya (Kyoto) were revealed by the techniques of R-and C-banding. The karyotype ofH. abei was characterized by the shortness of an R-negative (C-positive) band in the terminal region of the long arm of chromosome 2 and a band encompassing the whole short arm of chromosome 10. These two bands inH. abei were the shortest among those of the variousHynobius species that have been examined. Otherwise no differences could be detected betweenH. abei and seven other pond-type species ofHynobius (2n=56) in terms of the banding patterns of 18 specifically identifiable pairs of their chromosomes.     

Fluorescence replication banding of frog chromosomes

To identify individual chromosomes of a frog karyotype by their fluorescence banding patterns, chromosomes were stained with actinomycin D and 4,6-diamidino-2-phenylindole (DAPI) after incorporation of BrdU during the late S-phase. The chromosomes of three Rana species which were selected for this study (R. ridibunda, R. lessonae and R. japonica) showed well-defined late replication bands. The fluorescence patterns obtained were the reverse of those produced by a 4Na-EDTA Giemsa-staining technique. Fluorescence patterns of the two water frog species (R. ridibunda and R. lessonae) were similar to each other, except for the different fluorescence of the centromeric heterochromatin, which gave extremely bright signals in R. ridibunda but no signal in R. lessonae. Experiments also showed differences between the fluorescence patterns of R. lessonae chromosome 13 in the Italian and Luxembourgian populations. These results sho w that the fluorescence replication banding using actinomycin D and DAPI is very effective in identifying individual frog chromosomes and detecting their structural changes. Received 7 June 1996; received after revision 23 July 1996; accepted 21 August 1996     

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.     

Cytogenetic studies of Hynobiidae (Urodela). XIV. Analysis of the chromosome of a Chinese salamander, Batrachuperus pinchonii (David)

The chromosome number of a Chinese salamander, Batrachuperus pinchonii, was re-examined. Adults and embryonic specimens had a diploid number of 66, with 33 bivalents during meiosis, in contrast to previous reported results. Furthermore, when C-banding analysis was performed with embryos, chromosomes with banding patterns homoeologous to those of Salamandrella keyserlingii and Hynobius species were found. It appears, therefore, that Batrachuperus, Salamandrella and Hynobius might be derived from a common ancestral species in eastern Asia. Received 22 August 1997; received after revision 14 October 1997; accepted 20 November 1997     

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.     

Karyotypes of two species of insectivora from Taiwan (Insectivora,Soricidae)

Summary The karyotypes of two Insectivora species from Taiwan are described here for the first time.Soriculus caudatus fumidas has 2n=40 chromosomes, FN=52 andAnourosorex squamipes yamashinai has 2n=50 chromosomes, FN=96. ForA. s. yamashinai the G- and C-banding pattern are presented.Acknowledgment. The authors are grateful to Dr P. T. Tseng, and Mr H. M. Lin of Taiwan Provincial Institute of Infectious Diseases and to Prof. I. Sawada of Nara University of Education for their help during the collection of the material and their encouragement.     

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.     

New contribution to the study of chromosomes of the European Cryptocephalinae (Coleoptera,Chrysomelidae)

Summary The chromosomes of three species ofPachybrachis and nine ofCryptocephalus chrysomelids were analyzed. The male meiotic bivalent formula ofP. azureus Suffr.,P. catalonicus Burl. andP. petitpierrei Daccordi is 7^II+Xy_r.Cryptocephalus sexmaculatus Ol. andC. vittula Suffr. have 13^II+Xy_p,C. bipunctatus L. 14^II+Xy_r,C. ochroleucus Steph. andC. ocellatus Drap. 14^II+Xy_p,C. crassus 01. 15^II+Xy_r,C. sulphureus 01. 15^II+Xy_p, the same number as inC. fulvus Goeze with 2n=32 chromosomes, whileC. primarius Har. has 19^II+Xy_p. The modal chromosome number inCryptocephalus is 2n=30 (about 60% of spp.), and most species are characterized their small chromosomes. The low variation found in the karyotypes of Cryptocephalinae along with their possible interrelationships with allied chrysomelid subfamilies are also discussed.     

Feulgen-DNA amounts and karyotype lengths of three planarian species of the genusDugesia

Summary Genome sizes of the planariansD. lugubris (2n=8),D. polychroa (2n=8) andD. benazzii (2n=16) were evaluated on metaphase plates by measuring both the Feulgen-DNA contents and the karyotype lengths. In the three species, genome sizes are significantly different; this finding rules out the possibility of a karyotype evolution through simple chromosome rearrangements betweenD. lugubris andD. polychroa. A different Feulgen-DNA content per unit length of karyotype in the three species studied was also found, which suggests that DNA could be differently packed along metaphase chromosomes.     

Karyotypes of several frogs from Korea,Taiwan and the Philippines

Summary Rana amurensis coreana, R. plancyi chosenica, R. latouchii, R. narina andOoeidozyga laevis have 2n=26 chromosomes,R. kuhlii has 2n=22, andKaloula picta has 2n=28. Males ofR. narina have a conspicuous heteromorphic pair, No. 8, which might play a rôle in sex-determination.Supported in part by a grant from the Japan-American Scholarship Foundation.I wish to thank Dr H.K. Kim, Dr Y.-S. Liang, Dr V. Samson-Carino, Mr C.-S. Wang, Mr P.S. Lin and Mr B. Durusan for their aid in every aspect during the collecting trips.     

Cytotaxonomy of the myobatrachid frogs of the genusLimnodynastes

Summary 4 of the 5 species ofLimnodynastes of theperoni group show 2n=24. Onlysalmini has 2n=22, thus resembling the species ofPlatyplectron (thedorsalis andornatus complexes) which all show 22 chromosomes. This 2nd group also includes species (ornatus) with very low DNA amounts. From a karyological point of view, the species of thePlatyplectron (plus eventuallysalmini) group appear more differentiated than the species of theperoni group, from which they have probably arisen.Research partly supported by a contribution from C.N.R., Rome.     

Trends of karyological evolution in Pelobatoid frogs

Summary The Pelobatids have a basal karyotype of 26 chromosomes, with 6 pairs of large and 7 of small chromosomes (6+7). From this karyotype, shown byLeptobrachium, Pelobates andScaphiopus, those ofMegophrys andSpea (5+8) may be derived, as well as that ofL. pelodytoides, with only 24 chromosomes.Pelodytes has 24 chromosomes and a karyotype 7+5 differing from that of typical Pelobatids under several respects.Research supported by a contribution from the Italian C. N. R.     

Germ cell chromosomes in two species of terrestrial isopods from India

Summary In 2 species of terrestrial isopods, namelyPorcellio assamensis andP. laevis, the diploid and haploid numbers of chromosomes have been established to be 48 and 24 respectively for the former species and 50 and 25 respectively for the latter species. Female heterogamety of the ZW type has been found to exist inP. laevis.The authors express their sincere thanks to Prof. G.P. Sharma, and to Prof. S. Khera, Department of Zoology, Panjab University, Chandigarh, for the necessary laboratory facilities.     

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.     

Karyological relationships between the Cryptobranchid salamanders

Summary The 3 living Cryptobranchids (Andrias japonicus, A. davidianus andCryptobranchus alleganiensis) show 2n=60 and nuclear DNA amounts of respectively 92.9, 100.1 and 112.5 pg. Karyologically, the 2 genera differ in the morphology of 2 chromosome pairs. The hypotheses are advanced that either theCryptobranchus karyotype is derived from that ofAndrias through an unequal translocation, or the karyotypes of both genera are derived from that of a common (perhaps hynobiid) ancestor with at least 62 chromosomes.Research supported by a contribution from the Italian C.N.R.     

Constitutive heterochromatin and nucleolus organizer region in the knifefish,Apteronotus albifrons (Pisces,Apteronotidae)

Summary The C-banding and silver staining of the chromosomes of the knifefishApteronotus albifrons (2n=24), demonstrated the presence of constitutive heterochromatin in the centromeric region of every chromosome, except pair 4, where the entire long arm was darkly stained, the silver stain positive nucleolus organizer region (NOR) being embedded in it.The authors are grateful to Dr Sen Pathak (University of Texas System Cancer Center at Houston, Texas, USA) and Dr Yatiyo Yassuda (Universidade de São Paulo, São Paulo, Brasil) for their suggestions. This study was supported in part by grants of the Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq).     

Karyological pattern of two Chilean lizards species of the genusLiolaemus (sauria; iguanidae)

Summary The karyotypes of Chilean lizardsLiolaemus pictusandLiolaemus cyanogaster is described for the first time. Both species possess 34 chromosomes; 6 pairs of macrochromosomes and 11 pairs of microchromosomes. Karyologically it is possible to differenciate this species because the pair No. 2 is metacentric (m) inL. pictusand submetacentric (sm) inL. cyanogaster. It is shortly discussed the signification of formule 2n=34 for the species ofLiolaemus analized karyologically and its possible mechanism of acquisition.     

The karyotypes of the Corsican and Sardinian mountain salamanders,Euproctus montanus andE. platycephalus (Urodela: Salamandridae)

Summary The chromosomes ofEuproctus montanus andE. platycephalus were studied by means of the C-banding method and the AS-SAT technique which are useful for identifying the single pairs of the complement and for recognizing nucleolar organizer regions. According to the morpho-structural characteristics shown by the specific karyotypes, it has been possible to draw some cytotaxonomic deductions concerning the karyological evolution within the insular group.This work was supported by grant CT 76.01271.04/115.3822 from C.N.R., Rome.     

Cytologie comparée des Muridae. L'origine des Ellobii

Summary (1) The present paper deals with the chromosomial cytology of 11 species and underspecies ofMuridae. (2) The diploïd number being the same (2N=42), there are striking differences between two species ofBandicota, B. indica showing about 20 big metacentric chromosomes which are lackingB. bengalensis. (3)Meriones blackleri is characterized by 72 chromosomes, the species previously described possessing either 44 or 60 elements. (4) The study ofPhenacomys ungava confirms the view that 56 (54) is the primitive number in theMicroti. There is an interesting parallelism between the morphological and the cytological data. (5) A missing link betweenMicroti andEllobii has been found inMicrotus oregoni which possesses 17 chromosomes, its digamety belonging to the typeX-O, X-X. (6) Owing to the fact thatM. oregoni is more fossorial than the otherMicrotus, it is a morphological intermediate betweenMicroti andEllobii. (7) The genusChilotus (Baird) is also fully valid.     

Remarks on the karyotype of the polypteriformes. The chromosomes ofPolypterus delhezi,P. endlicheri congicus andP. palmas

Summary The chromosomes of 3 species of bikirs (Polypterus delhezi, P. endlicheri congicus andP. palmas) were studied in somatic metaphases. The diploid number was found to be 2 n=36 in all the species and a basic morphological identity of the karyotype emerges from karyogram comparison not only in the 3 species described herein, but also in the other Polypteriformes already studied.